BACKGROUND

Field of the invention

The present disclosure generally relates to a tube perforating machine for perforating a curved portion of a tube.

Description of the Related Art

Tube perforating machines are commonly used to perforate hollow tubes, such as tubes used in mufflers for vehicles. Known tube perforating machines comprise a tube guide for receiving and guiding a tube into the machine. An annular die mounted to a straight mandrel cooperates with the tube guide to punch holes through the tube from an exterior surface of the tube and through to its interior surface. The tube guide and annular die are typically located at one end of the machine so that the tube is inserted horizontally. Although such machines are useful for perforating straight tubes, the machines cannot be used to perforate a curved portion of a tube.

There is therefore a need to provide a machine configured to perforate a curved portion of tube or that at least provides a useful alternative to known tube perforating machines.

In this specification where reference has been made to patent specifications, other external documents, or other sources of information, this is generally to provide a context for discussing features of the invention. Unless specifically stated otherwise, reference to such external documents or sources of information is not to be construed as an admission that such documents or such sources of information, in any jurisdiction, are prior art or form part of the common general knowledge in the art.

SUMMARY OF THE INVENTION

In a first aspect, the invention provides a programmable tube perforating machine for perforating a curved portion of a hollow tube. The machine comprises a drive system and a punch head comprising an annulus for receiving a portion of the tube therein. The machine further comprises a plurality of punch housings, each punch housing configured to house a punch and a punch actuator operated by the drive system, wherein each punch housing comprises a punch aperture extending into the punch annulus and configured to receive a distal end portion of the punch; a mandrel located in the punch head annulus, wherein the mandrel comprises a curved portion having a radius of curvature that generally corresponds to that of the curved portion of the tube; and a die located on the mandrel, wherein the mandrel and die are dimensioned to be fit within the hollow of the tube.

In some forms, the mandrel and die are located concentrically within the punch head annulus. Optionally, the mandrel is removable.

Optionally, the die is removably attached to the mandrel.

In some forms, the die is slidably attached to the mandrel.

In some forms, the mandrel is attached to the punch head via a positioning system that provides adjustable positioning of the mandrel and die within the punch head.

Optionally, the positioning system comprises a clamp that attaches the mandrel to a shaft attached to a positioning member and wherein the positioning member is adjustably attached to the punch head.

In some forms, the mandrel is elongate and comprises a circular outer peripheral surface.

Optionally, the die comprises a circular peripheral surface defined by first and second sides of the die and wherein the circular peripheral surface comprises chamfered edges.

In some forms, the diameter of the die is about 0.25mm less than an internal diameter of the tube.

In some forms, the die comprises a plurality of punch receiving apertures, each being configured to receive a distal end portion of a respective punch.

In some forms, the number of punch receiving apertures of the die corresponds to the number of punches within the punch head.

Optionally, the machine further comprises a robotic arm programmed to grip and manipulate the position of the tube within the punch head.

In some forms, the machine further comprises a tube jig configured to hold the tube in a desired position for retrieval by the robotic arm. Optionally, the robotic arm is programmed to retrieve the tube from the tube jig and locate the tube concentrically within the punch head annulus.

In some forms, the machine comprises a programmable control system to control actuation of the punch actuators and movement of the robotic arm.

In some forms, the machine comprises one or more position sensors that sense the orientation or location of the tube, or both, within the punch head and send sensed signal data to the control system to control movement of the robotic arm.

In some forms, the punch actuators comprise hydraulically powered rams.

In some forms, the punch actuators comprise pneumatically powered rams.

In some forms, the punch actuators comprise electro-mechanically powered rams.

In some forms, the control system is programmed to activate the rams to cause the punches to perforate the tube when the sensor(s) signal that the tube is in a correct position for perforation.

In some forms, the control system is programmed to cause the robotic arm to insert the tube further within the punch head annulus; at least partially retract the tube from the punch head annulus; or to rotate the tube within the head annulus. In some forms, each punch is held by a punch holder.

In some forms, a proximal end portion of each punch is held by the respective punch holder and wherein the punch holder is engageable by the respective punch actuator to move the punch between an engaged position, in which a distal end portion of the punch projects into the punch annulus to punch through a side wall of the tube, and a disengaged position, in which the distal end portion of the punch retracts from the tube by at least partially retracting within the punch housing.

Optionally, the punch housings are spaced equidistant around the punch head annulus.

In some forms, the punch head comprises 12 punch housings radiating from the punch head annulus, each housing comprising a punch, a punch holder, and a punch actuator.

In some forms, the punch head comprises an annular tube guide comprising an inner wall that defines the punch head annulus and wherein the punch apertures extend through the tube guide.

Optionally, the punch head is interchangeable with a punch head comprising a different number of punches.

In a second aspect, the invention comprises a mandrel comprising a curved portion for use with a tube perforating machine according to the first aspect of the invention.

In a third aspect, the invention provides a method of perforating a hollow tube comprising a curved portion. The method comprises the steps of: providing a programmable tube perforating machine comprising a punch head comprising a punch head annulus in which a mandrel comprising a die is concentrically located; inserting the tube within the punch head annulus to locate the die and the mandrel within the hollow of the tube; causing punches within punch housings of the punch head to project through punch apertures in the punch head annulus and punch through a side wall of the hollow tube in an engaged position; and then causing the punches to retract from the side wall of the hollow tube and to at least partially retract within the punch housings in a disengaged position.

In some forms, the punches are moved between the engaged and disengaged positions by actuating rams located within the punch housings.

In some forms, the actuating rams are hydraulically powered rams.

In some forms, the machine comprises a robotic arm and a tube jig and wherein the machine is programmed to cause the robotic arm to retrieve the tube from the tube jig and to then insert the tube concentrically within the punch head annulus.

Optionally, the machine is programmed to cause the robotic arm to locate at least a portion of the tube concentrically over the curved mandrel and die.

In some forms, the machine is programmed to cause the robotic arm to rotate the tube and/or to move the tube along the curved mandrel without touching the tube to the mandrel when the punches are in the disengaged position. In some forms, the machine is programmed to operate according to a predetermined specification for the tube that specifies at least the locations and shape of punch holes to be made on the tube, and wherein the machine is programmed to cause the robotic arm to remove the tube from the punch head when all specified punch holes have been made.

This invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations of any two or more said parts, elements or features. Where specific integers are mentioned herein which have known equivalents in the art to which this invention relates, such known equivalents are deemed to be incorporated herein as if individually described.

The term 'comprising' as used in this specification and claims means 'consisting at least in part of'. When interpreting statements in this specification and claims that include the term 'comprising', other features besides those prefaced by this term can also be present. Related terms such as 'comprise' and 'comprised' are to be interpreted in a similar manner.

As used herein the term '(s)' following a noun means the plural and/or singular form of that noun. As used herein the term 'and/or' means 'and' or 'or', or where the context allows, both.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will now be described by way of example only and with reference to the accompanying drawings in which:

Figure 1 is an isometric view showing one form of tube perforating machine according to the invention, in which the cover of the machine has been removed;

Figure 2 is an isometric view of one form of tube jig for use with a tube perforating machine of the invention;

Figure 3 is an isometric view of one form of robotic arm that may be used with the tube perforating machine of the invention;

Figure 4 is a side view of one form of tube comprising a curved portion that has been perforated by a tube perforating machine of the invention;

Figure 5 is a cutaway perspective view of one form of punch head that may be used with the tube perforating machine of the invention;

Figure 6 is a cross-sectional view of the punch head of Figure 5, in which the punch housings and components within the punch housings are visible;

Figure 6A is an enlarged view of area A of Figure 6, in which the punch actuators are in a disengaged position;

Figure 6B is an enlarged view of an area similar to area A of Figure 6, but in which the punch actuators are in an engaged position; Figure 6c is an enlarged view of an area similar to area A of Figure 6, but in which he punch holders and punches of alternating punch housings have been replaced with clamping members;

Figure 7 is an illustrative cross-sectional view of the form of tube perforating machine of Figure 1, showing a tube placed over a mandrel of the machine;

Figure 7A is an enlarged view of area B of Figure 7, showing an internal die mounted on the mandrel and positioned within the tube to be perforated;

Figure 7B is an illustrative view of the perforation system of the machine from below, through line A-A of Figure 7, showing one form of mounting system for the mandrel;

Figure 8 is a front view of one form of tube to be perforated, the tube being held in a first position;

Figure 8A is a partial cutaway side view of the tube of Figure 8;

Figure 9 is a front view of one form of tube to be perforated, the tube being held in an intermediate position;

Figure 9A is a partial cutaway side view of the tube of Figure 9;

Figure 10 is a front view of one form of tube to be perforated, the tube being held in a final position;

Figure 10A is a partial cutaway side view of the tube of Figure 10;

Figure 11 is an isometric view of one form of mandrel mounting components and one form of die in an exploded state;

Figure 11A is a detail view of Figure 11, showing the die and an end of the mandrel;

Figure 12 is a side view of one form of die;

Figure 13 is an isometric view of one form of curved tube comprising perforations punched in a straight pattern;

Figure 14 is an isometric view of another form of tube comprising perforations punched in a staggered pattern;

Figure 15 is an isometric view of another form of tube comprising perforations punched in a spiral pattern;

Figure 16 is a cross-sectional view of another form of punch head for a tube perforating machine that comprises a pneumatic actuation system to move punches in the punch head between engaged and disengaged positions; and

Figure 17 is a partial cutaway view showing one form of punch head for a tube perforating machine that comprises an electro-mechanical actuation system to move punches in the punch head between engaged and disengaged positions.

DETAILED DESCRIPTION

The tube perforating machine of the invention is configured to perforate a curved portion of a hollow tube. For example, the machine may be utilised to perforate a hollow metal tube for use in a muffler that includes a curved portion. The machine comprises a selectively positionable mandrel comprising a curved region, and a die mounted on the mandrel. The mandrel and die may be removable and replaceable with another mandrel and die to suit the specification of the tube to be perforated.

Each tube to be perforated includes a specification that determines various characteristics of the tube, such as the shape of the tube, including the location and radius of curvature of the curved portion(s) of the tube, and that also determines the location, pattern, and size of the area of perforations/holes on the tube and the size and shape of the perforation holes. Different specifications may therefore be provided for different shaped tubes and to produce different perforation patterns and locations.

The tube perforating machine of the invention may be configured to perforate a tube having a curved portion with a curve angle of above 0° and below or including 90°. For example, the tube may have a 45° or 90° curved portion. The curved portions may be located at different distances from the end of the tube. In some forms, a tube may have multiple curved portions. The tubes to be perforated may also have different diameters. Furthermore, the tubes to be perforated may have different perforation specifications. For example, the number of rows of perforated holes, the spacing of the holes, the location of the holes, and the diameter of the holes may vary between tube specifications. The tube perforating machine of the invention is configured to perforate a wide variety of tubes having different tube specifications, by programming the control system with the required tube specifications and by selecting certain components to meet the tube specifications, as will be described herein.

In some forms, the curved tube may comprise a straight portion and the machine may be configured to perforate at least a portion of the straight portion of the tube.

The tube perforating machine may optionally use an electronically controlled arm, such as a robotic arm, to grip a tube comprising a curved portion and to then locate the tube within the machine to enable the machine to perforate the tube. The electronically controlled arm may be programmed to manipulate the position of the tube. For example. The arm may be configured to rotate the tube, feed the tube into a punch head of the machine, or at least partially retract the tube from the punch head to achieve the desired arrangement of holes/perforations and the desired location of holes/perforations on the tube.

Various embodiments and methods of use will now be described with reference to Figures 1 to 17.

Figure 1 shows one form of tube perforating machine 100 according to the invention. The machine 100 comprises a perforation system, and a drive system comprising an actuation system and a control system, each of which comprise component parts that are supported by a frame 1. The machine may optionally comprise a positioning system and/or a coolant system and/or a slug extraction system. The machine 100 typically also comprises a cover (not shown) comprising isolating switches to conform to international safety specifications. The frame 1 of the tube perforating machine 100 may comprise a bedplate lOlthat provides a support for at least some components of the perforation system, the actuation system, and the positioning system. The bedplate 101 may be located at or near the top of the machine. In some forms, the bed plate 101 comprises a generally horizontal panel. In another form, the bedplate comprises a generally vertical panel.

In one form, the machine 100 comprises a programmable multi-axis robotic arm 300 configured to grip a tube 900 to be perforated and to manipulate the tube 900 within the machine 100. The robotic arm 300 may be integrated with the machine 100 by being mounted on a support structure. For example, the arm 300 may be located on the bedplate 101, which forms a support structure for the arm 300. In other forms, the robotic arm support structure may be a side panel or other panel or structure of the machine that is configured to mount the robotic arm thereon. Alternatively, the arm 300 may be mounted separately to the machine 100. Regardless of whether the robotic arm 300 is integrated with the tube perforating machine 100 or is separate to the machine, the robotic arm 300 comprises or communicates with a programmable control system that is programmed to cause the robotic arm to grip and manoeuvre a tube 900 to be perforated according to instructions from the control system, which will take into account the specification of the tube to be perforated.

The robotic arm 300 forms part of an optional positioning system of the machine 100. The positioning system may also comprise a tube rest/tube jig 102. In this form, the bedplate

101 and tube jig 102 form a bedplate assembly. The tube jig 102 may be configured to locate the tube 900 to be perforated in a specific position on the bedplate 101. Each tube jig 102 is removable and replaceable by another tube jig that may be selected from a set of tube jigs to be used with the machine 100, so that a specific tube jig 102 can be selected to satisfy the specifications of the tube 900 to be perforated. In other words, each tube jig 102 may be specifically selected according to the specification requirements of each individual tube 900 to be perforated. The tube jig 102 mounted on the bedplate 101 at any one time is configured to locate the specific shape of tube 900 within the jig 102 appropriately so that the tube jig

102 accurately aligns the tube 900 for the robotic arm 300 to ensure that the tube 900 is perforated to a given tolerance and specification.

The tube jig 102 will be located within reach of the robotic arm 300 and may be at a location where minimal travel is required by the robotic arm 300 to collect the tube 900 from the tube jig 102. The location of the tube 900 within the tube jig 102 may be programmed into the robotic arm control system so that the robotic arm 300 can readily find, grip and remove the tube 900 from the tube jig 102.

The perforation system of the tube perforating machine 100 comprises a punch head 200, in which punches and punch actuators are held. The punch head 200 is configured to punch holes in the hollow tube. The punch head may be supported by the bed plate 101. In one form, the bed plate 101 comprises a punch head aperture through which a tube may be located to access the punch head 200. The punch head 200 comprises an annulus 210 that forms an opening to the punch head 200. In some forms, the annulus 210 is located generally centrally on the punch head 200. In one form, the punch head annulus 210 is located within the punch aperture of the bedplate 101, which may lie in a generally horizontal plane, as shown in Figures 1, 7 and 7A. In this form, the punch head 200 is secured to the bedplate 101. In other forms, the punch head 200 and punch head annulus 210 may be located on a bedplate 101 that lies in a generally vertical plane. For example, the punch head 200 and punch head annulus 210 may be located on a bedplate comprising a side panel or other vertical punch head support structure of the machine 100 and may be secured to the side panel or structure.

In one form, the punch head annulus 210 is defined by an annular mounting element 212 that forms part of the punch head 200. In one form, the mounting element 212 may comprise two parts: a mounting ring 212a, and a optionally a tube guide retainer 212b, which are removably coupled together. Both the mounting ring 212a and the tube guide retainer 212b comprise a central aperture that forms a portion of the punch head annulus 210. The mounting ring 212a is attached to the bedplate 101, such as via fasteners, which may include bolts, screws, rivets, welds, adhesive or any other suitable fasteners. The mounting ring 212a forms a central hub of the punch head and provides a central support for at least some of the other components of the punch head 200, which may be directly or indirectly attached to the mounting ring 212a. In one form, the mounting element 212 is removably attached to the bedplate 101 and is replaceable with a mounting element 212 having a central aperture of a different desired diameter to satisfy the diameter of the given tube 900 to be perforated.

The punch head 200 also comprises an annular tube guide 220 that may be located generally centrally within the punch head 200. The tube guide 220 is typically attached to the mounting ring 212a. The tube guide 220 comprises a tube receiving aperture that forms part of the punch head annulus 210. In this way, the tube guide 220 also defines a portion of the central annulus 210 of the punch head 200. In some forms, the tube guide 220 comprises a cylindrical shape having a circular outer wall 221, a circular inner wall 222 and a central aperture generally corresponding to the central aperture of each of the mounting ring 212a and tube guide retainer 212b to form a continuous central annulus 210 through the punch head 200. The inner wall of the central annulus 210 and the inner wall 222 of the tube guide 220 together form a cylindrical inner wall of the punch head 200. The tube guide may be removably attached to the mounting ring 212a so that a tube guide having a tube receiving aperture of the desired shape and size may be selected.

In one form, as shown in Figure 5, the tube guide 220 may comprise first and second parts 224, 225 that are removably coupled together to form the tube guide 220. In some forms, the tube guide retainer 212b is configured to attach to both the first and second parts 224, 225 to couple the first and second parts of the tube guide 220 together. In these forms, the first part 224 of the tube guide is located between the tube guide retainer 212b and the second part 225 of the tube guide. The second part 225 is attached to the mounting ring 212a via removable fasteners, such as bolts, screws or the like to allow the tube guide 220 to be removed from the mounting ring 212a and replaced with a different sized tube guide 220. Where the tube guide is located in a punch head 200 that is mounted on a horizontal bedplate 101, the first part 224 of the tube guide lies above the second part 225. Therefore, the first part 224 forms an upper part of the tube guide and the second part 225 forms a lower part of the tube guide in this arrangement.

The tube guide 220 is configured to receive and guide a tube 900 into position within the annulus 210 of the punch head 200, so that the tube 900 is located within the tube receiving aperture of the tube guide 220.

The tube guide 220 may be configured to support a plurality of punches 231 within the punch head 200 and to allow a distal end portion of each punch to project into the annulus 210 and punch holes 905 through a side wall of a tube 900 located within the punch head 200.

Multiple punches 231, each driven by an actuator 235, are provided in the punch head 200 for punching perforation holes in the tube 900. The punch head 200 comprises a plurality of punch set housings 230, each of which is configured to house a punch set comprising a punch 231, a punch holder 232, and a punch actuator 235. The punch set housings 230 may be spaced equidistant around the tube guide 220 and may be defined, at least in part, by the mounting ring 212a, tube guide retainer 212b, and tube guide 220, as shown in Figure 5. In some forms, the punch set housings are arranged to radiate from the punch head annulus 210.

In some forms, the actuators comprise rams, such as hydraulic, pneumatic or electrically powered rams. In these forms, each punch set housing 230 may comprise a head portion 230a, a shaft portion 230b and a punch bore 230c. The head portion 230a may be configured to house a head of the respective ram 235. Where the ram is hydraulically or pneumatically operated, the head portion 230a also houses hydraulic fluid or gas for pneumatic rams, as the case may be, that drives movement of the hydraulic ram within the housing 230. The shaft portion 230b may be configured to house the shaft of the ram and the punch bore 230c may be configured to house the respective punch 231.

In some forms, the head portion 230a, shaft portion 230b, and punch bore 230c each have a circular lateral cross-section. Typically, the shaft portion 230b has a smaller diameter than the head portion 230a and a larger diameter than the punch bore 230c.

The punch head 200 may comprise any number of punch set housings 230 and punches 231 according to the invention. In some forms, the punch head 200 comprises at least two opposing punch set housings 230, and punch sets. For example, the punch head 200 may comprise an even number of punch set housings 230 and punch sets or an odd number of punch set housings 230 and punch sets. In some forms, the punch head 200 comprises between 1 and 16 punch set housings 230 and punch sets.

In some forms, the punch head is interchangeable with another punch head that comprises a different number of punches. For example, the machine may be provided with a variety of removable and replaceable punch heads, each punch head having a different number of punch set housings and punch sets, so that a user can select a punch head with the appropriate number of punch set housings and punch sets to meet the requirements of a particular tube specification. For example, a punch head may comprise 6, 8, or 10 punch set housings and punch sets to respectively punch 6, 8 or 10 holes in a tube simultaneously.

Each punch set housing 230 comprises or is in communication with a punch aperture located in the inner wall of the tube guide 220 and forming an opening to the respective punch bore 230c. In one form, the punch apertures 234 are evenly spaced around the inner wall of the tube guide 220 so that the punch bores 230c radiate from the punch head annulus 210. In some forms, the punch set housings 230 are also spaced equidistant around the inner wall of the tube guide and therefore around the annulus 210 of the punch head 200. Because each punch bore 230c forms a portion of a punch set housing 230, the tube guide 220 defines a portion of the punch set housings 230. In some forms, the mounting ring 212a provides a mount for the punch actuators/rams. The mounting ring 212a may therefore also define a portion of each punch set housing 230.

Where the tube guide 220 comprises a two piece assembly, comprising a first part 224 and a second part 225, the first part 224 may comprise semi-circular channels along a first edge and the second part 225 may comprise semi-circular channels along a first edge, so that when the first and second parts 224, 225 are placed together to meet along the first edges of each part 224, 225, the channels may align to form punch apertures 234 opening into punch bores 230c of the punch set housings 230. The first and second parts 224, 225 of the tube guide 220 may be selectively replaced with other parts 224, 225 that have larger and/or differently shaped channels to accommodate larger and/or differently shaped punches 231, and the overall form, while still remaining generally circular and with a central aperture, may be differently shaped to accommodate the specification of a particular tube. For example, some forms of tube guide 220 may comprise bevelled or curved edges.

Typically, each punch aperture 234 is sized and shaped to accommodate the size and shape of at least the distal end portion of a punch 231 to allow the punch to move freely in and out of the punch aperture 234. For example, each punch aperture 234 should have a diameter that is equal to or larger than the diameter of the distal end portion of the punch 231 that is configured to project through the punch aperture 234. Typically, each punch bore 230c is sized and shaped to accommodate the size and shape of the punch 231 to allow the punch to move longitudinally back and forth along the length of the bore 230c. For example, each punch bore 230c should have a diameter or width that is equal to or larger than the diameter or width of the punch 231 that is located within the bore 230c. In some forms, the punch 231 is generally cylindrical, the punch bore 230c is generally cylindrical and the punch aperture 234 is generally circular. For example, each punch 231 may comprise a cylindrical distal end portion to form circular holes in the tube 900. However, punches 231 of other shapes may also be used with the tube perforating machine 100 of the invention. For example, the machine 100 may be used with punches 231 that comprise a distal end portion having any regular or irregular shape, including but not limited to a square shape, an oval shape, semi-circular shape, and a star shape.

The punches 231 may be removed from the punch head 200 to be replaced with new punches, when the existing punches are worn, or to be replaced with punches of a different shape or size.

Where the tube guide 220 is formed in two parts 224, 225, one or both of the two parts (such as the uppermost part) may be removed to access the punch set housings 230 and to replace the punches 231 with new punches 231 when the existing punches are worn. In this embodiment, access to the first part 224 of the tube guide is achieved by removing the tube guide retainer 212b from the mounting ring 212a to uncouple the tube guide from the mounting ring. The first 224 part of the tube guide 220 may then be uncoupled from the tube guide retainer to provide access to at least the punch bores 230c of the punch set housings 230. For example, the punches 231 and punch holders 232 may be removed from the punch head 200 by separating the first part 224 from the second part 225 of the tube guide 220 to access and remove the punches 231 and punch holders 232 from within selected punch set housings 230. The removed worn punches 231 may be replaced with new punches 231. Alternatively, if the specification of the next tube to be perforated requires few hole perforations in each row of perforations then not as many punches will be needed so the punch set housings 230 from which the punches 231 and punch holders 232 have been removed may remain substantially empty, albeit a punch actuator 235 may remain in those punch housings 230.

Where the tube guide 220 is formed in two parts 224 and 225, and the existing punches 231 are to be replaced with punches of a different shape or diameter, it may be necessary to replace the first and second parts 224, 225 of the tube guide also. The tube guide parts 224, 225 should be selected so that the punch apertures 234 and punch bores 230c defined by the tube guide 220 are of an appropriate size and shape to satisfy the specification of the next tube to be perforated.

Each punch 231 is configured to move between an engaged/punch position and a disengaged/release position by moving longitudinally within the respective punch aperture 234 and punch bore 230c. In the engaged position, the distal end portion comprising the cutting end of the punch 231 projects from the punch aperture 234 of the tube guide 220 to punch into a sidewall of the tube 900. In the disengaged position, the distal end portion of the punch 231 retracts from the tube 900 by at least partially retracting within the punch bore 230c and tube guide 220.

A single movement of a perforating set between a disengaged position to an engaged position and back to the disengaged position is referred to in this specification as a punch stroke. Each punch stroke creates a single row/set of punch holes 905 on the tube 900 being perforated.

Each punch 231 may be held by a punch holder 232. For example, each punch 231 may comprise a proximal end portion, which may be held by a punch holder 232 to locate the punch 231 generally concentrically within the punch set housing 230, punch bore 230c, and punch aperture 234. The punch 231 and the punch holder 232 are both configured to move longitudinally within the punch aperture 234 and punch bore 230c between the engaged and disengaged positions.

In some forms, the punch holder 232 is removably attached to the punch actuator 235 and is also removably attached to a proximal end of the punch 231. For example, the punch actuator 235 may comprise a ram having a distal end comprising an opening configured to receive a portion of a punch holder therein. The punch holder may be removably attached to the ram 235 by any suitable form of attachment, such as a friction fit, mechanical connection, or fasteners. For example, the distal end of the ram 235 may comprise a T-shaped opening, the punch holder 232 may comprise a generally cylindrical member having a punch receiving aperture and the punch 231 may comprise a generally cylindrical shaft. The punch holder 232 is located within the top-most portion of the T-shaped opening (that is, the punch holder is located in the portion that corresponds to the lateral extension of the T-shape). The punch receiving aperture is located generally centrally within the punch holder to align with the leg- portion (the longitudinal portion) of the T-shaped opening. The punch 231 may comprise an enlarged proximal end that is larger than at least a portion of the diameter of the punch receiving aperture of the punch holder 232. For example, the punch receiving aperture may be between 3mm and 5mm in diameter and the proximal end of the punch 231 may be slightly larger. In one form, the punch receiving aperture may taper toward the punch aperture 234. The punch 231 may be slid within the punch receiving aperture of the punch holder 232 so that the enlarged proximal end of the punch 231 is located between the punch holder 232 and the ram 235. The enlarged proximal end prevents the punch 231 from pulling out through the punch receiving aperture of the punch holder 232 so that the punch 231 is held in place within the punch holder 232.

In another form, the punch 231 and punch holder 232 may be screwed together. In another form, the ram 235 may comprise a distal end that is configured as a punch holder 232 to hold a proximal end of a punch 231. In this form, the punch is directly engaged with the ram. The punches are a wear part, which become worn down through use. By allowing access to the punches 231 and allowing the punches to be removable in this arrangement, it is possible to replace the punches without interfering with the punch actuators. The use of punch holders means that when a punch wears out, only the punch needs to be replaced, and not the holder also.

It is envisaged that the total number of punches 231 in the head 200 may be of any suitable number to suit the tube 900 being perforated. In one form, the punch head 200 comprises 12 punch set housings 230 for housing 12 punches 231, and their respective punch actuators 235. However, depending on the specification for the tube 900 to be perforated, a fewer number of punches 231 than punch set housings 230 may be required. In some forms, it may be possible to remove punches 231 from selected punch set housings 230 to vary the spacing between perforated holes in the same row. Typically, punches 231 and punch holders 232 will be removed from selected punch set housings 230 so that the remaining punches are evenly spaced around the inner wall of the tube guide 220.

In some forms, as shown in Figure 6c, it may be possible to substitute punches 231 in at least some of the punch set housings 230 with clamping members 240. The clamping members 240 are configured to clamp against the side wall of a tube 900 to be perforated to help hold the tube 900 in position within the tube guide 220 as the tube is being punched. The clamping members 240 may each comprise a distal end portion that is configured to project from the respective punch aperture 234 in order to contact and press against the side wall of the tube 900, when engaged by a punch actuator 235. The clamping members 240 may provide additional positional support to the tube 900 as it is being perforated.

In one form, two or more opposing punch housings 230 may each comprise a clamping member 240 instead of a punch 231, or they may replace both the punch 231 and punch holder 232. For example, a punch head 200 comprising 12 punch housings may comprise six punches 231 and six clamping members 240, alternating around the punch head 200, as shown in Figure 6C, or any other suitable number of combination and arrangement of punches

231 and clamping members 240. Where the tube guide 220 is formed in two parts 224, 225, the first part 224 may be removed to access the punch set housings 230 and replace one or more (optionally two or more) of the punches 231, or to replace the punches 231 and punch holders 232, with clamping members 240. For example, the punches 231 and punch holders

232 may be easily removed from the punch head 200 by separating the first and second parts 224, 225 of the tube guide 220 to access and remove the punches 231 and punch holders 232 from within the punch set housings 230 and to insert a clamping member 240 within each punch set housing 230 that is devoid of punches 231. Optionally, a clamping member 240 may be placed within all of the punch set housings 230 that are devoid of punches 231 or within only some of the punch set housings 230 that are devoid of punches 231. In one form, the punch head 200 may be configured so that one or more of the punch set housings 230 are each configured to house a punch actuator 235, punch holder 232 and punch 231, and other punch set housings 230 may be configured to house punch actuators 235 and clamping members 240. In such forms, the punch set housings for housing punches may have a different shape and/or configuration to the punch set housings for housing clamping members. For example, the punch set housings for housing punches may each comprise a punch aperture 234 and punch bore 230c that is of a smaller width or diameter than that of the punch aperture 234 and bore 230c of the punch set housings for the clamping members 240. In one form, the punch aperture 234 and bore 230c of the punch set housings for punches have a diameter of about 3.5mm and the punch aperture 234 and bore 230c of the punch set housings for clamping members have a diameter of about 6mm,

In these forms where the punch head 200 comprises clamping members 240, the punch head 200 is configured so that during a punch stroke, the punches 231 make contact with the tube 900 first. As the punches 231 contact with and meet the resistance of the tube 900, the movement of the punches stops as the punches are pressed firmly against the tube 900. The force applied by the punches to the tube builds before the punches overcome the tube resistance and punch through the tube before stopping at an end point and then being retracted from the tube 900. While the punches 231 are momentarily stopped and pressing against the side of the tube 900, the clamping members 240 continue to move forward toward the tube 900. The clamping members contact the tube and press against the tube to hold the tube in position. The machine is typically configured so that the clamping members 240 are already holding the tube 900 before the punches 231 punch through the tube. Clamping members may be necessary in both embodiments of the machine 100 that do or do not include a robotic arm 300 to hold a tube 900 to be perforated. In other forms, clamping members are not used and the tube is simply held in place by the robotic arm 300.

The punches 231, punch holders, 232 and clamping members 240 (if present, are each moved between engaged and disengaged positions by punch actuators 235.

In one form, as shown in Figures 5 and 7b, the punch actuator 235 comprises a ram that is configured to push against a proximal surface of the punch holder 232 (or clamping member as the case may be), thereby pushing the punch holder 232 (or clamping member 240) toward the punch aperture 234. As the punch holder 232 is pushed toward the punch aperture 234, the punch holder 232 pushes against the punch 231, causing the punch 231 to push through the punch aperture 234 so as to project from the inner wall of the punch head 230 and through the side wall of a tube 900 within the punch head 200 in the engaged position. The ram may also be configured to move backward toward a proximal end of the punch set housing 230 to allow the punches (or clamping members 240) to retract to a disengaged position in which the punches are at least partially or fully retracted through respective punch apertures 234. In some forms, the punch ram 235 is a hydraulically powered ram connected to the hydraulic fluid reservoir by hydraulic hoses. In another form, the punch ram 235 is a pneumatically operated ram connected to a gas source of by pneumatic hoses. In yet another form, the punch ram 235 is an electro-mechanically operated ram driven by a motor. For example, the punch actuator 235 may comprise an electronically controlled rotating cam member configured to rotate about the punch head and contact and push against the proximal end of each punch holder 232 simultaneously to push the respective punch 231 into the engaged position, and to release contact with the punch holder 232 to allow the punch 231 to return to the disengaged position as the cam member rotates and moves to the next punch 231 and punch holder 232 along its rotating path.

Regardless of whether the rams 235 in the punch head 200 are hydraulically powered, pneumatically powered or electro-mechanically powered, each punch ram 235 acts as a piston within the punch set housing 230 so that when powered, the punch ram 235 pushes forward against the proximal end portion of the punch holder 232 with a force sufficient to push the punch 231 through the punch aperture 234 and through the side wall of the tube 900 to be perforated.

In a disengaged position, the head 235a of each ram may be located at or near the rear wall of the housing 230. When the ram 235 is in the disengaged position, the punch 231 is also in the disengaged position. When the ram 235 is in the engaged position, the head 235a of the ram 235 is pushed away from the rear wall of the housing 230 and the ram shaft 235b is pushed toward the punch 231 and punch aperture 234. When the ram 235 is in the engaged position, the punch 231 is also in the engaged position.

In some forms, each punch set housing 230 comprises a hydraulically or pneumatically operated punch ram 235, which comprises a body having a head 235a (located farthest from the punch 231) comprising a proximal end portion and located within the head portion 230a of the punch set housing 230. The head portion 230a of the housing 230 is also configured to receive hydraulic fluid or compressed gas to move the ram between disengaged and engaged positions and vice versa. The ram head is shorter than the length of the length of the head portion 230a of the housing 230 so that the ram head is able to move longitudinally within the head portion 230a to allow the ram to move between the disengaged and engaged positions. The ram body also comprises a shaft 235b comprising a distal end portion for engaging with and pushing against the punch holder 232. The shaft 235b may be integrally formed with the ram head 235a or the head 235a and shaft 235b may be separately formed and attached together, such as by screwing the two parts 235a, 235b together along threaded regions provided on each part 235a, 235b. The shaft 235b is located within the shaft portion 230b of the punch set housing 230. In some forms, the shaft portion 230b of the punch set housing 230 is a generally cylindrical bore that extends between the head portion 230a and the tube guide 220. The shaft 235b of the ram 235 is shorter than the length of the shaft portion 230b of the housing 230 so that the shaft 235b can move longitudinally within the shaft portion 230b.

Where the rams are hydraulically or pneumatically powered, each ram 235 may be positioned within the housing 230 so that a portion of the peripheral surface of the ram body forms a seal with internal walls of the housing 230. In one form, the shaft portion 230b of the housing 230 may comprise an internal wall that seals with a shaft portion 235b of the ram. In one form, a portion of the peripheral surface of the ram body supports a sealing member 280, which creates a seal with at least one internal walls of the housing 230. In one form, the sealing member 280 is held within a channel formed on the peripheral surface of the ram shaft 235b. The sealing member 280 may be located in the approximate centre of the ram shaft 235b to separate a high pressure side of the housing 230 from a low pressure side. Figure 6a shows the rams in a position where high pressure fluid/gas 230a is at the distal end of the head portion 230a of the housing between the ram and a front wall of the head portion 230a. Figure 6b shows the rams in a position where the high pressure fluid/gas is at the proximal end of the head portion 230a, between the ram and the rear wall of the head portion 230a and housing 230.

In one form, a guide or gland 236 supports one or more seals to seal between the ram 235 and the housing 230 to retain hydraulic fluid or gas in the head portion 230a of the housing 230. The guide/gland 236 may be attached to the ram or the housing 230, or may be integrally formed with the ram 235 or housing 230. In one form, each guide/gland 236 comprises a second seal 282 between the guide/gland 236 and the housing 230. Each guide/gland 236 may also comprise a third seal 281 between the shaft of the ram 235, the mounting ring 212a and the guide/gland 236. The guide/gland 236 may be configured to guide the ram shaft 235b within the housing 230 and may act as an end stop for the ram 235 to prevent the ram abutting a front wall of the housing 230. The guide/gland 236 may be configured to help distribute hydraulic fluid or gas evenly through the head portion of the housing 230.

The guide/gland and seal arrangements described above are just some forms of arrangements that may be used with the machine of the invention. It is envisaged that other sealing and fluid or gas distributions arrangements may instead be used without departing from the scope of the invention, as will be understood by those skilled in the art.

To activate hydraulically powered rams, pressurised hydraulic fluid flows from a hydraulic fluid reservoir and along a first dispensing channel 237a and through an opening 237 in the head portion 230a of each punch set housing simultaneously. The pressurised fluid forces the punch ram 235 to move forward towards the punch aperture 234 until the ram abuts the guide/gland 236, thereby moving the punches 231 toward and through the tube in the engaged position. For the rams to retract, the pressurised fluid is redirected through a second opening 238 in the head portion 230a of each punch set housing 230 simultaneously and through a second dispensing channel 238a to allow the fluid to flow back toward the fluid reservoir. The pressurised fluid forces the punch ram 235 to move backwards away from the punch aperture 234 until the ram contacts or nears the rear inner wall of the ram housing 230, thereby retracting the punch rams 235 and punches 231 to a disengaged position.

In some forms, the drive system may comprise a hydraulic solenoid valve, or cetop valve, to direct hydraulic fluid into either channel 237a or 238a to engage or disengage the punches 231. The direction of the valve may be controlled by the control system, which is programmed according to the tube specification.

To activate pneumatically powered rams, as shown in Figure 16, pressurised gas flows from a compressed gas support and along a first dispensing channel 237a and through an opening 237 in the head portion 230a of each punch set housing simultaneously. The pressurised gas forces the punch ram 235 to move forward towards the punch aperture 234 until the ram abuts the guide/gland 236, thereby moving the punches 231 toward and through the tube in the engaged position. For the rams to retract, the pressurised gas is redirected through a second opening 238 in the head portion 230a of each punch set housing 230 simultaneously and through a second dispensing channel 238a to allow the gas to flow back toward the compressed gas supply. The pressurised gas forces the punch ram 235 to move backwards away from the punch aperture 234 until the ram contacts or nears the rear inner wall of the ram housing 230, thereby retracting the punch rams 235 and punches 231 to a disengaged position.

In some forms, the drive system may comprise a solenoid valve to direct compressed gas into either channel 237a or 238a to engage or disengage the punches 231. The direction of the valve may be controlled by the control system, which is programmed according to the tube specification.

In one form, as shown in Figure 17, the machine 100 comprises electro-mechanically powered rams. In this form, each punch set housing 230 comprises a punch set comprising a punch actuator 235, punch 231 and punch holder 232, as described above, and also comprises a clamping member 240 and a clamp actuator 241. The punch head 200 comprises a rotating portion having a cam assembly that is configured to engage and then disengage with each punch ram to simultaneously move each punch set between the engaged and disengaged positions. Each punch set housing 230 also comprises a first opening defining the punch aperture 234, and a second opening at the proximal end of the housing that allows the cam assembly to engage with the punch actuator 235 and clamp actuator 241 within the housing 230. The cam assembly is driven by a motor 600, which may include a gear box. The cam assembly comprises a drive gear 610, driven by the motor and connected to a ring gear 290 and a drive belt 291. The cam assembly also comprises a paired roller arrangement 292 engaged with the ring gear, and an actuating roller 293 driven by the paired roller arrangement 292. In this arrangement, the punch set housing are located in an actuator hub of the punch head. The actuator hub comprises a central annulus defining the punch head annulus 210 and tube guide 220.

A punch actuator 235, comprising a ram, is located in the clamp actuator 241, which is held within the punch set housing 230. The punch actuator 235 includes an angled proximal end (farthest from the respective punch 231) that at least partially projects beyond the second aperture of the housing 230 when the punch 231 is in a retracted position. The distal end of the punch actuator 235, which is located opposite its proximal end, is configured to operatively engage with the respective punch 231. In one form, the distal end of the punch actuator 235 engages with a punch holder 232, which is attached to or is configured to engage with a respective punch 231. The punch holder 231 may be any suitable holder, such as a threaded aperture located in the proximal end of the punch actuator 235 and with which a threaded distal end of the punch 231 may be engaged.

Each punch holder 231 is preferably held in a T-slot formed in a distal end portion of the respective punch actuator/ram 235 and is centred within the respective clamp actuator 241. The punch actuator 235, and therefore also the punch holder 232 and the punch 231, is able to move longitudinally between the punch aperture 234 and the second aperture of the punch set housing 230 so as to move between an engaged position, when the punch actuator has moved toward the punch aperture 234 to its maximum extent, and a disengaged position, when the punch actuator has moved toward and through the second aperture to its maximum extent.

The clamp actuator has a proximal end that projects through the second aperture of the punch set housing 230 when in a disengaged position. The clamp actuator 241 also comprises a distal end that is configured to engage with a clamping member 240 located within the housing 230. In one form, the clamp actuator 241 may be attached to the clamping member 240 or may be integrally formed with the clamping member. In another form, the clamp actuator 241 may configured to press against the clamping member 240 to hold the clamping member 240 in an engaged/clamping position, and to release contact with the clamping member when the clamping member and clamp actuator are in a disengaged position. In the engaged position, the clamp actuator 241 causes the clamping member 240 to press/clamp against the outer surface of the tube 900 held within the tube guide 220 in order to hold the tube in a fixed position. In the disengaged position, the clamp actuator 241 causes the clamping member 240 to release contact with the tube 900 so that the tube can be moved within the tube guide 220.

In one form, the clamp actuator 241 comprises a bore that extends between the proximal and distal ends of the clamp actuator and within which the punch actuator 235 is concentrically located. The distal end of the clamp actuator 241 comprises a first contact surface configured to press against the associated clamping member 240 to clamp the tube clamp against the tube to be perforated.

At least a portion of each punch 231 projects through the bore opening at the proximal end of the respective clamp actuator 241 and is concentrically located within a bore of the respective clamping member 240. The punch 231 is configured to move between an engaged/punch position and a disengaged/ release position by moving longitudinally between the first and second openings of the punch set housing 230 and within the bore of the clamp actuator 241 and the bore of the clamping member 240. In the engaged position, the proximal, cutting end of the punch 231 projects from the bore of the clamping member 240 to punch into the tube that the clamping member 240 is holding in position. In the disengaged position, the cutting end of the punch 231 retracts at least partially through the punch aperture 234 and into the clamping member 240 to pull away from the tube 900.

The actuator hub provides a curved, generally smooth and uninterrupted outer surface between adjacent punch set housings 230, that each form a 'disengaged' zone. The disengaged zones and the rotating cam assembly of the punch head cooperate to allow the punches 231, punch actuators 235, clamping members 240 and clamp actuators 241 to return to and remain in a disengaged position for a period of time. In effect, the arrangement provides a pause between punch strokes so that the tube may be moved longitudinally within the tube guide 220 and/or may be rotated within the tube guide before the next punch stroke occurs.

The rotating cam assembly comprises front and rear plates and a roller assembly comprising a plurality of paired rollers 292 that may be connected to the front plate and the rear plate. Each pair of rollers comprises a first roller and a second roller. The travel rollers 293 are held between the paired rollers 292 and the actuator hub and are configured to rotate freely about the actuator hub. Where the punch head comprises eight perforating sets, the rotating cam assembly comprises eight paired rollers 292 (16 total rollers) and eight travel rollers 293. The travel rollers are configured to rotate and travel around the peripheral surface of the stationary actuator hub, which is attached to the frame of the machine, such as to a front plate at the front of the machine 100. Typically, the travel rollers 293 are configured to rotate and travel in a clockwise direction. The punch actuator 235 has an angled proximal end and is orientated within the housing 230 so that its angled proximal end is inclined in the same direction as the direction of travel of the travel rollers. Therefore, if the travel rollers move in a clockwise direction, the angled proximal end of the punch actuator 235 is configured to be inclined in a clockwise direction.

The rotating cam assembly of the punch head further comprises a ring gear 290. The sleeve/ring gear comprises an outer surface that defines both the outer peripheral surface of the rotating cam assembly of the punch head body and the outer peripheral surface of the punch head in its entirety. The outer surface of the ring gear is configured to engage with the drive belt 291, driven by the drive gear 610, which is powered by the motor. The ring gear is also attached to the front and rear plates of the punch head 200 and comprises an inner surface configured to engage with the paired rollers 292 of the rotating cam assembly of the punch head. In this configuration, the motor causes the drive gear 610 to rotate, which in turn causes the drive belt 291 to rotate. The rotating drive belt causes the ring gear 290 to rotate, which causes the front and back plates of the punch head to rotate. As the front and back plates rotate, the paired rollers 292 and travel rollers 293 begin to rotate and move around the peripheral surface of the actuator hub of the punch head.

At least one of each of the rollers in each of the paired rollers 292 presses against or otherwise engages with the associated travel roller 293, causing the travel roller to rotate. Typically, the drive gear 610, drive belt 291 and ring gear 290 will rotate in a clockwise direction, causing the travel rollers 293 to rotate in a clockwise direction and begin to travel in a clockwise direction around the periphery of the actuator hub. Similarly, the front and rear plates of the punch head begin to rotate simultaneously and in the same direction as the ring gear.

The rotating cam assembly of the punch head 200 is configured to rotate about the actuator hub so that the travel rollers 293 engage with the clamp actuators 241 and the punch actuators 235 to cause the clamping members 240 to clamp the tube in position within the tube guide 220 and to then cause the punches 231 to punch holes in the tube 900.

As each travel roller 293 approaches a housing 230, the travel roller 293 (trapped between the paired rollers and the peripheral surface of the actuator hub) is forced to press down on the proximal end of the clamp actuator 241 to cause the clamp actuator to move toward the punch aperture 234 and therefore the annulus 210 of the punch head 200 and tube guide 220. The distal end of the clamp actuator 241 presses against the associated clamping member 240, causing at least a portion of the clamping member to project from the punch aperture 234 of the punch set housing and press against the outer surface of the tube held within the tube guide, as the die supports the tube from the inside.

As each travel roller 293 continues to move in the direction of travel, it begins to press against the proximal end of the punch actuator 235 that is projecting from the second opening of the housing 230. The proximal end of the punch actuator 235 is inclined in the direction of travel of the travel rollers 293, so that as each travel roller moves further across the inclined end of the respective punch actuator, the punch actuator 235 is pushed further and further into the housing 230. The movement of the punch actuator toward the punch aperture 234 of the housing 230 causes the punch 231 to move in the same direction and to project from the bore of the clamping member 240 and through the punch aperture 234. The punch 231 presses against the outer surface of the tube 900. Pressure on the punch steadily increases as a result of the travel roller 293 moving along and pressing against the inclined proximal end of the punch actuator 235. The increased pressure on the punch 231 causes the punch to increase its pressure on the tube until the pressure is such that the punch punches through the tube to create a hole in the tube.

As the travel roller 293 passes the proximal end of the punch actuator 235, the pressure on the punch actuator is released, allowing the punch actuator to return to its disengaged position in which its proximal end projects from the second aperture of the housing 230. Consequently, the punch 231 is simultaneously retracted from the tube 900. The clamping actuator 241 and therefore the clamping member 240 continue to be held in the clamping position until the travel roller 293 travels past and releases contact with the proximal end of the clamp actuator 241. Once the travel roller 293 passes the clamp actuator 241, the clamp actuator returns to its disengaged position in which its proximal end projects from the second aperture of the punch set housing 230. The clamping member 240 simultaneously moves toward the second aperture of the actuator housing 230 to release contact with the tube. The tube is now able to be moved rotatably and linearly within the tube guide 220.

The perforation system of the tube perforating machine 100 also comprises an internal die 250, which may be removably mounted on a mandrel 260. The die 250 and mandrel 260 are generally concentrically located within the tube guide 220 so that the die 250 is positioned between opposing punch apertures 234 and a space is provided between the punch apertures 234 and the peripheral circular outer surface of the die. In other words, the internal die 250 is located on the mandrel 260 so as to sit within the tube guide 220 in opposing relationship to the punches 231 within the tube guide 220. The space allows a tube 900 to be located between the punch apertures 234 and the die 234, whilst also providing clearance between an inner surface of the tube and the peripheral outer circular surface of the die 250.

A tube 900 to be perforated is placed within the tube guide 220 so that the die 250 is concentrically located within the hollow interior of the tube 900 and the tube is concentrically located within the central aperture of the tube guide 220. The tube 900 has an internal diameter D1 and the die 250 has an external diameter D2 that is smaller than the internal diameter of the tube 900 (D1 >D2The external diameter of the die 250 is smaller than the internal diameter of the tube 900 so that the tube can be easily positioned over the die 250 without touching the die. The curve radius of the tube 900 may guide selection of a die having a desired outer diameter D2, so that at any point along the curved portion of the tube, the die does not come into contact with the internal wall of the tube, maintaining a given clearance between the die and tube at all times. In some forms, the clearance between the tube 900 and die 250 may be between 0.1 to 1mm. In some forms, the clearance may be 0.25mm.

The die 250 supports the inner wall of the tube 900 as it is perforated to help reduce buckling or disfiguring of the tube 900, and to ensure that the perforations created conform to the specification of the tube. The die 250 comprises a plurality of punch receiving openings 252. The die may be generally cylindrical in shape and comprises a generally circular peripheral surface on which the punch receiving openings 252 are located. The punch receiving openings 252 may be spaced equidistant around the peripheral surface of the die. Each punch receiving opening 252 is sized to receive the distal end portion of a corresponding punch 231 and the punched out material of the tube 900 as the punch 231 punches through the tube 900. Each punch receiving opening 252 is configured to generally align with a punch aperture 234 of the tube guide so that the distal end portion of a punch 231 projecting from a respective punch aperture 234 and through the side wall of the tube 900 can be received within a corresponding punch receiving opening 252 of the die 250. The punch receiving openings 252 may be sized according to the diameter and shape of the punches 231 used in the punch head 200 and the wall thickness of the tube 900 to be perforated. In one form, the die comprises punch receiving openings 252 comprising circular apertures in which the diameter of each opening 252 generally corresponds to or is slightly larger than the diameter of the respective punch 231 and the thickness of the material of the tube 900. Therefore, if a punch 231 comprises a cylindrical distal end having a diameter of 5mm, the corresponding punch receiving opening 251 may be a circular opening or recess of a larger diameter, such as a diameter of 5.2mm or larger. The punch receiving openings 252 enable an accurately sized perforation to be punched cleanly.

The number of punch receiving openings 252 of the die 250 typically equals the number of punch set housings 230 (and therefore the maximum number of punches 231) of the punch head 200. For example, if the punch head 200 comprises 12 punch set housings 230 for housing 12 punches 231 and 12 punch holders 232, the die 250 should also comprise 12 receiving openings 252. Similarly, if the punch head 200 comprises 7 punch set housings 230, the die 250 should comprise 7 punch receiving openings 252. In another form, a die 250 may be selected in which the number of punch receiving openings 252 corresponds to the number of punches 231 in the punch head 200.

The peripheral surface of the die 250 is generally shaped and sized in such a way that it allows the tube 900 to pass over the die 250 freely while also remaining close enough to the inner wall of the tube 900 to sufficiently support the tube 900. For example, the die 250 may be sized to maintain a minimum clearance, such as 0.15 to 0.50 clearance, and optionally 0.25mm clearance, between the inner wall of the tube 900 and the outer surface of the die 250.

As the tube is located within the tube guide 220, the inside of the tube 900 is supported by the die 250, which may be a solid or a 'split die' type comprising punch receiving openings 252 provided within die buttons

In one form, as shown in Figures 11a and 12, the die 250 may comprise a single row of punch receiving openings 252. In another form, multiple rows of punch receiving openings 252 may be formed on the outer curved peripheral surface of the die 250 to increase the tool life of the die 250. In this arrangement, as one row of punch receiving openings 251 wears down, the next row of punch receiving openings 251 can be used without needing to replace the die 250.

In some forms, the die 250 is removably attached to the mandrel 260, which also forms part of the perforation system. In some forms, the die 250 is slidably and removably attached to the mandrel 260 to adjust the position of the die on the mandrel. By allowing the die to be removable, it is possible to select a die 250 that meets the specification (especially the size and/or shape) of the tube 900 to be perforated.

In one form, as shown in Figures 11 and 11a, the die may be configured to be slid along the mandrel to the desired position and then secured in position by any suitable attachment system. For example, the die may be held in the desired position with fasteners. In one form, the die 250 and mandrel 260 may each comprise threaded regions by which the die and mandrel can be screwed together to detachably attach the die and mandrel together.

In another form, one of the die 250 and mandrel 260 may comprise a keyway and the other of the die and mandrel may comprise a locking member 251 configured to engage with and disengage from the keyway to detachably attach the die and mandrel together. It should be appreciated that any other suitable system for detachably attaching the die 250 and mandrel 260 together may be used without departing from the scope of the present invention.

The mandrel 260 is typically an elongate member that is removable from the tube perforating machine 100 so that each mandrel 260 can be replaced with another mandrel 260 selected according to the size and shape of the tube 900 to be perforated. The mandrel 260 may comprise an attachment portion for mounting to the machine frame or to another structure or component of the machine 100. The mandrel 260 may also comprise a tube receiving portion over which a portion of the tube is located while the tube is being perforated. The tube receiving portion may comprise a curved portion. The die 250 is located on the tube receiving portion of the mandrel. Each mandrel 260 is selected to allow the tube 900 to pass over the mandrel 260, preferably without abutting side surfaces of the mandrel. For example, the mandrel 260 may comprise a curved portion that generally follows the radius of curvature of the tube 900 to be perforated. In other words, different mandrels 260 may have curved portions comprising a different radius of curvature. Different mandrels 260 may comprise a curved portion at a different location on the mandrel 260, so that the curve profile/shape of the selected mandrel 260 placed within the machine 100 generally conforms to the curve profile/shape of the given tube 900 to be perforated. The mandrel 260 comprises a width or diameter that is smaller than the diameter of the internal hollow of the tube 900 to provide clearance between the tube 900 and mandrel 260. In some forms, the tube receiving portion of the mandrel 260 has a generally circular lateral cross-section with a diameter of between 20 to 40mm. In some forms, the tube receiving portion has a diameter of about 24 mm or about 28mm. The mandrel may be attached to any suitably supporting structure or component of the tube perforating machine 100. For example, the mandrel 260 may be attached to the frame 1, the bed plate 101 or the punch head 200. The mandrel 260 may be attached by an attachment member or system that engages both the attachment portion of the mandrel and the supporting structure of the machine. The attachment member or system is typically located offset from a centre-line passing through the centre of the punch head annulus 210. The mandrel 260 may be mounted to the machine by any suitable arrangement that allows the mandrel to be removed and replaced. Preferably, the attachment arrangement also allows the height or the position of the curved portion of the mandrel to be adjusted relative to the punch head annulus. In some forms, the mandrel attachment portion may comprise a generally straight shaft and the tube receiving portion may comprise a curved portion located at or near the other end of the mandrel 260, as shown in Figures 7, 7A, 7B, 8A, 9A, and 10A. The attachment portion may extend adjacent to the bed plate 101. Where the bed plate is horizontal, the attachment portion of the mandrel 260 may extend beneath the bed plate 101, preferably generally parallel to the bed plate 101. The curved portion of the mandrel 260 is preferably located within and/or beneath the central annulus of the tube guide 220.

In one form, as shown in Figure 7A, the mandrel 260 is connected to the bed plate 101 by an adjustable positioning system that allows selectively adjustable positioning of the mandrel 260 and die 250 relative to the punch head 200. In one form, the positioning system comprises a mandrel holder or clamp 261, a shaft 262, and a positioning member 263. Fasteners or any other suitable attachment system may be used to hold the mandrel 260 in position on the shaft 262. The shaft may be attached to the positioning member 263 by any suitable attachment system. In one form, the shaft is attached to the positioning member with fasteners 262a. In one form, the positioning member is attached to the bed plate 101 by any suitable attachment system, such as fasteners 263a.

In one form, the mandrel is held by the mandrel holder/clamp 261, which is attached to or otherwise mounted on the shaft 262. The mandrel clamp 261 comprises a clamping system, comprising an opening and opposing moveable clamping members configured to be moved toward each other to clamp against an outer surface of the mandrel 260 to hold the mandrel in position within the opening. The clamping system can also be released to move the clamping members away from each other to allow the mandrel to slide within the clamp opening to adopt another position, or to be rotated within the clamp opening, or to be removed from the clamp 261 and replaced with a different mandrel 260 designed for different tube specifications. The mandrel clamp 261 may also be configured to slide along the shaft 262. The shaft 262 is connected to the bed plate 101 via positioning member 263. The positioning member 263 is removably fastened to connection apertures within the bed plate 101, such as via one or more fasteners such as screws or the like that project through one or more adjustment apertures in the positioning member 263. In one form, the positioning member 263 comprises an adjustment aperture 264 comprising an elongate slot through which one or more fasteners may be located. By tightening the fasteners, the positioning member 263, and therefore the shaft 262, mandrel clamp 261 and mandrel 260 are held in position in relation to the punch head 200. By loosening and sliding the fasteners along the slot 264, it is possible to adjust the position of the positioning member 263 with respect to the punch head 200, thereby adjusting the position of the mandrel 260. In another form, the punch head may comprise an elongate slot for engagement with one or more adjustment apertures of the positioning member 263, that comprise holes, via one or more fasteners 263a. In yet another form, the positioning member 263 and punch head 200 may each comprise a series of separate adjustment apertures, each comprising a hole configured to receive a fastener 263a. In this form, the positioning member 263 is located in the desired position. A fastener 263a is then located through aligned adjustment apertures of the positioning member 263 and punch head 200 and tightened to hold the positioning member 263, and therefore the mandrel 260, in the desired position. In some forms, the elongate slot 264 or adjustment aperture holes may follow a curve to allow the positioning member 263 and therefore the mandrel 260 to be selectively located about the punch head annulus 210.

The arrangement of the mandrel clamp, mandrel shaft and positioning member 263 allow for various shaped mandrels 260 to be used to meet the curve profile of the tube 900 to be perforated. In effect, the mandrel clamp 261, shaft 262 and positioning member 263 allow the mandrel 260 to be adjusted according to the shape and profile of the tube 900 to be perforated.

In some forms, the die 250 may be located on the mandrel 260 and the mandrel may be positioned to align the punch receiving openings 252 of the die 250 with the punch apertures 234 of the tube guide 220 using an alignment tool. Once the die 250 and mandrel

260 are correctly located, the mandrel 260 may be secured in position by the mandrel clamp

261 and positioning member 263.

The die 250, mandrel 260, and tube guide 220 (such as the first and second parts 224, 225 of the tube guide 220) may be removable and selectively replaceable with suitably sized and shaped equivalent components to accommodate the specification of the given tube 900 being perforated.

The actuation system of the tube perforation machine 100 comprises the punch set housing 230 and the punch actuator/ram 235 of the punch head 200 and also comprises a connection system to connect the housing 230 and/or actuator 235 to a drive source of the machine 100. The drive source may be any component or arrangement that is used to drive movement of the punch actuators. For example, where the machine is hydraulically powered, the drive source may comprise a hydraulic fluid reservoir. Where the machine is pneumatically powered, the drive source may comprise a compressed gas supply. Where the machine is electrically powered or electro-mechanically powered, the drive source may comprise a power supply.

In some forms, as described above, the punch head 200 is hydraulically powered. In this form, the punch set housings 230 are each connected to a drive source comprising a hydraulic fluid reservoir via one or more hydraulic hoses, pumps and/or valves. The hydraulic fluid reservoir provides hydraulic pressure to the hydraulic hoses and therefore to the punch set housings 230 in the punch head 200. In one form, the hydraulic fluid is plumbed through a transfer member 205 of the punch head 200 and into a dispensing element 206, which comprises dispensing channels 237a and 238a for dispensing hydraulic fluid to the punch set housings 230. In some forms, the transfer member 205 is a lower plate and the dispensing element 206 is a hydraulic fluid plate. In one form, where the punch head 200 is located on the bedplate 101 of the tube perforating machine 100, the lower/transfer member 205 of the punch head 200 forms a base and the hydraulic flow plate/dispensing element 206 forms an upper cover that lies adjacent the transfer member/base 205 so that hydraulic fluid is held in dispensing channels 237a and 238a of the dispensing element 206 and between the transfer member 205 and dispensing element 206. The channels 237a and 238b within the dispensing element 206 are in fluid communication with the punch set housing 230 within which the ram 235 is located. The same or a similar arrangement may be used where the punch head 200 is pneumatically powered.

The drive system may be located in whole or in part within the machine 100 frame or the drive system may be located in whole or in part externally to the machine frame and may be connected to the actuation system of the machine 100. For example, the drive system may comprise an air compressor to drive pneumatically powered rams 235 and the air compressor may be located externally to the machine frame but may be connected to the punch set housings 230 via hoses or the like. The drive system comprises a motor. The tube perforating machine may be operated by a single drive motor that operates a pump for hydraulically or pneumatically controlled punch rams 235 or that operates a rotating drive for an electro-mechanically controlled punch rams 235.

In one form, where the rams 235 are hydraulically powered, the motor drives a hydraulic pump connected to a hydraulic fluid reservoir. The pump collects hydraulic fluid from the reservoir and pumps it out of the reservoir and into the punch head 200, which creates pressure in the closed fluid flow paths through the machine. The pressurised fluid may be directed to an electronically controlled hydraulic solenoid, or 'cetop' valve, which directs hydraulic fluid to a chosen dispensing channel 237a, 238a to engage or disengage the rams 235 or to hold pressure, such as while the rams are disengaged and the robotic arm 300 is repositioning the tube 900.

Similarly, where the rams 235 are pneumatically powered, the motor drives a pneumatic pump connected to a compressed gas supply. The pump pumps pressurised gas from the compressed gas supply and pumps it into the punch head 200, which creates pressure in the closed gas flow paths through the machine. The pressurised gas may be directed to an electronically controlled solenoid, which directs pressurised gas to a chosen dispensing channel 237a, 238a to engage or disengage the rams 235 or to hold pressure, such as while the rams are disengaged and the robotic arm 300 is repositioning the tube 900.

By activating the actuation system, high pressure hydraulic fluid or gas is forced into and through the dispensing element 206 and into the fluid receiving space within the head portion 230a of each punch housing 230. The fluid or gas pushes against the proximal end of the respective ram 235, causing the ram to push toward the punch aperture 234 to an engaged position. As the ram 235 moves forward, it pushes against the respective punch holder 232 which in turn pushes the distal end portion of the respective punch 231 through the punch aperture 234, into the punch head annulus 210 and through the side wall of a tube 900 held within the punch head annulus 210.

By changing the direction of flow of pressurised hydraulic fluid or gas from dispensing channel 237a to channel 238a, such as by using a solenoid or cetop valve, the punch ram 235 is forced to move backwards within the housing 230, to return to the original disengaged position, allowing the respective punch holder and punch to at least partially or fully retract within the punch housing 230, thereby disengaging the punches 231 from the tube 900. After retracting the punches 231 from the tube 900, the tube is able to be removed moved to a new position within the punch head 200 in anticipation of the next punch stroke, or removed from the punch head entirely to be replaced with a new tube.

It is envisaged that the operator may selectively activate or deactivate individual rams 235 as necessary for the tube 900 being perforated. This may be achieved by way of physical shutoff valves connected to each punch set housing 230, or via an electronic interface (e.g. button, computer or similar) connected to solenoids which can isolate each ram 235 individually. For example, an operator may choose to shut off/deactivate one or more of the rams 235 to achieve the desired pattern of perforations on the tube 900.

The drive system of the tube perforating machine 100 is connected to the control system 800, the actuation system and the perforation system. Where the machine 100 comprises a positioning system with a robotic arm 300, the control system 800 is also connected to the robotic arm. The control system 800 may be programmed to control actuation of the punch actuators/ rams and, optionally, movement of the robotic arm 300. In some forms, the robotic arm 300 may comprise a second control system (a robotic arm control system) that is connected to the machine control system of the tube perforating machine 100.

The tube perforating machine control system 800 may be programmable to configure the machine 100 to perforate a tube 900 according to the specifications provided for that tube 900. The control system 800 may comprise a user interface 810 through which a user may programme and control the control system according to the specification of the tube to be perforated. The control system may comprise a memory configured to hold multiple tube specification programmes. The control system may be programmed to control the timing and movement of the punch actuators 235 and the punches 231 and to control the timing and movement of the robotic arm. In some forms, the user interface may comprise a control panel located on the machine 100 and through which the control system may be programmed and controlled. In other forms, the user interface may comprise a remote interface, such as a personal computer or handheld device that is configured to communicate with the control system 800 and through which the control system 800 may be programmed and controlled. In one form, the control system may be pre-programmed to include different operating programmes, each operating programme being associated with a particular tube specification. The pre-programming may be carried out via the user interface, which may be located on the machine 100 or may be a remote user interface. In this arrangement, the machine user interface may comprise one or more inputs through which a user may select the programme that matches the tube specification for the tube to be perforated, before the perforation process begins. For example, if the tube has been allocated specification number 101, the control system may be programmed to operate the machine according to this specification when a user inputs Ί0 into the user interface. In this arrangement, it is possible to programme the control system of the machine to operate the machine according to many different tube specifications and for a user to use the user inputs to easily modify the machine to operate according to a different tube specification.

The control system 800 may be configured to receive signals from one or more proximity/position sensors that sense the orientation and/or location of the tube 900 within the punch head 200 and send sensed signal data to the control system to control movement of the robotic arm 300. The sensed data may be provided as feedback to the control system by one or more signals from the sensor(s). For example, the machine 100 may optionally comprise at least one tube position sensor to activate the rams 235 when the tube 900 is in the desired perforation position within the tube guide 220. For example, each tube sensor may sense the location of the distal end of the tube within the punch head 200 and provide signal data to the machine control system. The machine control system compares that signal data with the tube specification programmed into the control system to identify whether the tube is in the correct location to begin the next punch set. If the control system identifies that the tube is in the correct location to be perforated, the machine control system will activate the punch actuators/ rams 235 to begin the next punch set. In another form, the robotic arm may be programmed to move to a start position, given a 'pause' period where it will hold its position while a punch stroke takes place, then move to a second position, pause while a second punch stroke takes place, move to the next programmed position, pause, and so on until the tube 900 has been perforated according to its specification. The programmable machine control system may comprise a communication system to communicate send and receive signals from the robotic arm. For example, the robotic can may be configured to send a signal to the perforating machine controller when the arm is in a 'pause' position and holding the tube still. From there, a punch cycle will take place, and when receiving a disengaged signal from a ram position sensor, the perforating machine controller may signal the robotic arm to cause the arm to move the tube to the next position. This communication between the control system and robotic arm may take place for every punch stroke and arm movement.

The machine may additionally or alternatively comprise at least one position sensor to signal to the control system whether the punches are in the disengaged or engaged position. For example, each position sensor may be configured to sense whether the punches 231 have been extracted from the tube 900 and are therefore in the disengaged position in which it is safe to move the tube 900 within the punch head 200. Each punch position sensor sends a signal to the control system that identifies whether the punches 231 are in the disengaged position. Upon receiving a signal that identifies that the punches 231 are disengaged, the machine control system may cause the robotic arm 300 to manipulate the tube 900 to the desired position for the next punch set, according to the specification for the given tube, or to remove the tube from the punch head 200 if the perforations are complete. Where the robotic arm 300 comprises a second control system, the machine control system may signal to the second control system that the robotic arm 300 is free to manipulate the position of the tube according to the tube specification. In another form, the position sensor senses the position of the ram 235 within the housing 230, rather than sensing the punch itself. The position sensor may be located in the punch set housing 230.

In one form, the machine 100 may comprise a punch sensor configured to sense the location of one or more punches 231, or to sense movement of the punch(es) 231, or both, and the control system 800 may be configured to stop movement of the robotic arm 300 and to optionally generate an alarm if the control system identifies that one or more punches 231 are moving at the same time as the robotic arm 300 is moving and/or if one or more punches 231 have not retracted through the respective punch aperture(s) 234 and at the same time, the robotic arm 300 is moving.

In one form, the tube perforating machine 100 comprises a coolant system that provides coolant to the tube 900 and tooling to ensure reliable operation of the machine 100. In some forms, coolant is provided to at least the tube 900 and punches 231. The coolant system comprises a coolant tank 510, a pump, and tubing. The pump may be any suitable pump, such as an electrically powered pump. The tubing may or may not include one or more valves along its length. The coolant system enables coolant to be pumped from the coolant tank 510 to the punch head 200 and tube 900 via the tubing. In one form, the tubing may be in fluid communication with channels formed in the mounting element 212, such as within the tube retaining ring 212b. The channels distribute the coolant to the punch head annulus 210, so that the coolant can flow down the inner wall of the punch head annulus 210 to cool and lubricate the tube 900 within the punch head 200 and to cool and lubricate the tooling in the punch head 200, especially the punches 231. It is envisaged that the coolant may alternatively or additionally be expressed through openings of one or more flexible hoses or other fluid conduits located at or near the central annulus 210 of the punch head 200 to cool and lubricate the punches 231 and tube 900.

The tube perforating machine 100 may also comprises a slug extraction system. The slug extraction system is configured to extract slugs from the punch head 200. The slugs comprise punched out material from each tube 900. The slug extraction system may be integral with the coolant system or separate from the coolant system. In one form, the sl ug extraction system comprises a slug receiving container 720 and the mandrel 260 is connected to the container 720 via a flexible hose 270, to allow waste slugs to fall clear of the punch head 200 and die 250 and into the container 710. The container 720 may be removable to empty the slugs from the container. The slug extraction system may be gravity fed or vacuum assisted. The machine shown in Figure 1, comprises a vacuum assisted slug extraction system, comprising a vacuum generator 710.

To operate the machine 100, a hollow tube 900 to be perforated is selected. Typically, the tube is a metal tube 900. A user will follow a predetermined specification that has been set for the tube 900. The specification will specify the desired number of holes to be punched into the tube at each punch stroke, the pattern of the holes between sets/rows (for example, whether the holes should be staggered, spiral or aligned in columns and rows), the distance between holes in each set/row, and the start and end points of the area of the tube that is to be perforated. Based on the tube specification, a user will select the appropriate tube jig 102, tube guide 220 (such as the first and second parts 224, 225 of the tube guide), die 250 and mandrel 260.

To begin perforating a tube 900, the un-perforated or partially perforated tube is placed in the tube jig 102. Placement of the tube in the tube jig 102 may be carried out by a human operator or an industrial robot. Once the tube 900 is seated correctly in the tube jig 102, the machine 100 may begin its perforation cycle. The signal to start the perforation cycle may be given manually at the beginning of each perforation cycle by an operator, or it may be triggered automatically. In one form, placement of a tube within the tube jig 102 may automatically trigger the beginning of a perforation cycle. Optionally, at least one sensor is associated with the tube jig 102 and is configured to send signal data to the control system when a tube is placed correctly in the jig 102. The control system may be programmed to automatically and immediately start the perforation cycle after receiving data from the jig sensor(s) or the control system may comprise a timer that is programmed to delay the start of the perforation cycle after receiving the jig sensor data. The perforation cycle may be delayed by a matter of seconds or minutes. In another form, if an operator is manually placing tubes into the tube jig 102, the perforation cycle may begin once the operator is in a safe zone, which may be an area outside of the operating zone of the machine 100. In this form, the safe zone may comprise one or more sensors, such as light curtains or laser sensors for example, that signal to the control system of the machine 100 that the operator is in the safe zone so that the machine can begin the perforation cycle. In another form, the control system timer may be programmed so that the perforation cycle is triggered automatically at programmed time intervals. For example, if the machine is set up so that a second industrial robot places tubes into the tube jig 102 and this step takes about 10 seconds and a perforation cycle takes about 30 seconds then the control system may be configured to automatically start the perforation cycle every minute or at any other time interval that is greater than the time taken to load the tube jig and complete the perforation cycle. The control system may be programmed to being the perforation cycle according to the user's needs.

At the beginning of the perforation cycle, in which a single tube is perforated according to its tube specification, the robotic arm 300 will move to a position where it can retrieve the tube 900 from the tube jig 102 by clamping the tube 900 between opposing grippers/claws 310, such as a V style clamp, of the robotic arm. The claws 310 may be hydraulically, pneumatically or electrically powered.

The robotic arm 300 is programmed specifically for each tube specification. Because the tube 900 to be perforated is seated in the tube jig 102, the robotic arm 300 can retrieve the unperforated tube 900 from the same position each time and grip each tube at the same location along the length of the tube, so that the tube 900 is accurately perforated within the allowable tolerances of the tube specification.

Once the tube 900 is gripped by the robotic arm 300, the arm 300 will move the tube 900 towards the punch head 200. The robotic arm 300 will then guide the tube 900 through the annulus 210 of the punch head 200 and over an internal die 250, following the internal bend radius/radii of the tube 900 to be perforated to ensure that the tube remains concentric with the die 250 and punch head annulus 210.

The robotic arm 300 is configured to temporarily hold the tube 900 in a fixed, non rotating position within the punch head 200 and tube guide 220. The robotic arm 300 aligns the desired location of a single row/set of perforations with the punch apertures 234 of the tube guide 220 in order to perforate the tube 900. The tube 900 is held by the robotic arm 300 concentrically within the punch head annulus 210, the tube guide 220 being selected to be of a size such that the robotic arm 300 can place the tube 900 within the punch head annulus 210 without the tube 900 touching the inner wall of the annulus 210 and therefore without touching the inner walls of the mounting element 212 and tube guide 220. Depending on the specification of the tube being perforated, the path of the robotic arm 300 will vary to accommodate the curved portion and size of the tube 900.

During each punch stroke (in which each punch punches a single hole in the tube), the tube 900 must remain stationary within the tube guide 220. The robotic arm 300 continues to grip the tube 900 as it is being punched within the punch head 200 and also between punch sets. The robotic arm 300 may be programmed to move the tube within the punch head 200 between punch sets linearly and/or rotationally. For example, the robotic arm 300 may be programmed to rotate the tube 900 about the die 250 between punch sets, in order to achieve different perforation patterns along the length of the tube, such as an aligned punched hole pattern, a staggered punched hole pattern, spiral punched hole pattern. In one form, the robotic arm 300 may rotate the tube 900 and/or move the tube linearly, such as by pushing the tube further within the punch head 200 and/or retracting the tube partially from the punch head between punch strokes, so that the next set of holes are punched at the desired location according to the tube specification. After moving the tube according to the pre-programmed tube specification, the robotic arm 300 will pause at pre-programmed location points within the punch head 200 to allow the punches 231 to punch holes 905 in the tube 900 and to then retract before the next punch set. Movement of the arm 300 may be controlled by the control system depending on signal data from one or more ram position sensors and/or tube position sensors. For example, one or more position sensors may send a verification signal to the control system 800 when the rams 235, and therefore also the punches 231, have retracted through the punch aperture 234. The control system 800 may be programmed to then send a verification signal to the robotic arm 300 to cause the arm 300 to manipulate the tube 900 to the next punch position or to retract the tube 900 from the punch head 200 if the tube perforation is complete.

The robotic arm 300 may be programmed to operate according to the user's needs and the tube specification. For example, the path that tube robotic arm 300 guides the tube 900 will be programmed to suit the particular tube being perforated. Generally, where a tube is curved, the robotic arm 300 will follow the bend /curvature 901 of the tube, pivoting about the virtual centre 901a of the radius of the curve so that at any given point along the curve 901, the tube 900 is held concentrically with the die 250 and punch head annulus 210 so that a central axis 904 of the tube generally corresponds with a central axis of the annulus 210 and die 250.

The angle 902 at which the tube 900 will be pivoted within the punch head 200 is determined by the shape of the tube being perforated, and may be up to 90°. The angle between perforations 903, is determined by the tube specification. For example, in the embodiment shown in Figure 4, the angle 902 is approximately 3.6°, so the robotic arm 300 will be programmed to pivot the tube 900 about the virtual radius centre 901a by 3.6°. At this point, the robotic arm 300 will pause and hold the tube 900 in position within the tube guide 220 while a punch stroke takes place. If the specification of the tube requires it, the robotic arm 300 may rotate the tube 900 about the central axis of the die 250 to provide additional perforations around the tube, or so that the pattern of perforations along the length of tube 900 forms a staggered or spiral perforation pattern, as shown in Figures 14 and 15. In one form, before the first perforation, the robotic arm 300 may insert the tube to the furthest point along the tube necessary for a punch set to meet the tube specification (for example, by inserting the tube into the punch head 200 until the location of the uppermost row of specified perforations is aligned with the punch apertures 234). After completing the first punch set, the robotic arm 300 may then extract the tube 900 along the programmed path, with pauses in movement of the tube 900 where perforations are required. The robotic arm 300 gradually retracts the tube 900 from the punch head 200 between punch sets until the last row of holes is punched closest to the proximal end of the tube. By manipulating the position of the tube 900 to follow this perforation path, any burrs which may form along the inner surface of the tube 900 as a result of the perforation process are less likely to interfere with the die 250.

Alternatively, the robotic arm 300 may be programmed to place the tube 900 within the punch head 200 so that the location of the first line of holes to be perforated aligns with the punch apertures 234. The robotic arm 300 continues to push the tube further into the punch head 200 between punch sets until the last row of holes is punched, after which the robotic arm 300 retracts the tube 900 from the punch head 200.

Once perforation of the tube 900 is completed according to the tube specification, the tube 900 may optionally be placed in an area for completed parts by the robotic arm 300 or by a human operator. In one form, the robotic arm 300 may be programmed to extract the tube 900 from the punch head annulus 210, again following any internal curve radii of the tube 900 to ensure clearance of the tube with the internal die 250 and the inner wall of the punch head 200. After extracting the tube 900 from the machine 100, the robotic arm 300 may then deposit the tube 900 to a desired location near the machine 100. This may be for example into a box, onto a conveyor belt, or to another machine. The placement location of the perforated tube 900 may be programmed into the control system for the robotic arm 300 according to the user's needs. In another form, the robotic arm 300 may be programmed to extract the tube 900 from the punch head annulus 210 and replace the tube within the tube jig 102 for collection by a person or possibly by another robot.

Some embodiments of the invention have been described by way of example only and modifications may be made thereto without departing from the scope of the invention.

The embodiments described in this specification include a robotic arm mounted on the machine 100. However, it should be appreciated that the robotic arm would operate in the same manner if mounted separately from the machine. Such embodiments are included within the scope of the present invention. It is also envisaged that the perforation machine of the invention may be used without a robotic arm. Instead, a tube to be perforated may be manually manipulated in the machine. However, for safety reasons and accuracy, some embodiments of the invention include a programmable robotic arm to manipulate the tube.