The present invention relates to a laser tube cutting machine, where the term "tubes" is to be understood to refer generally to elongated semi-finished products having a hollow section of any shape.

More specifically, the present invention relates to a laser tube cutting machine equipped with an apparatus for cleaning the tubes being worked, that is, an apparatus suitable for collecting the debris produced during the cutting of the tubes by means of a laser beam.

A known example of a tube cleaning apparatus intended to be installed on a laser tube cutting machine is shown in FIGS. 1 and 2 of the accompanying drawings.

With reference initially to FIG. 1, a tube cleaning apparatus according to the prior art is indicated as a whole at 10. The tube being processed is indicated at T, while 12 indicates a working head suitable for performing cutting operations on the tube T by means of a laser beam.

The apparatus 10 comprises first a rod 14, extending in a longitudinal direction x parallel to the longitudinal axis of the tube T, and a collecting head 16 mounted at an end of the rod 14 facing towards the tube T. The collecting head 16 is typically made of a material other than that of the rod 14, for example copper. The collecting head 16 is formed as a hollow body, preferably with a cylindrical shape, and has an opening 18 through which the debris produced during the cutting of the tube T may penetrate inside the collecting head 16 to be collected therein.

The rod 14, and the collecting head 16 therewith, are both movable in the longitudinal direction x and in a transverse direction z perpendicular to the longitudinal direction x. Typically, the longitudinal direction x is oriented horizontally, while the transverse direction z is oriented vertically. In this regard, the rod 14 is held by a support body 20, which is in turn held by a support structure 22 (hereinafter referred to as "first support structure") and is movable relative to this structure in the longitudinal direction x under the control of a first motorized driving unit (comprising for example a brushless electric motor). Furthermore, the first support structure 22, and with it the support body 20 and the rod 14 held thereby, is movable relative to the base structure of the machine in the transverse direction z under the control of a second motorized driving unit (comprising for example a brushless electric motor).

While the tube T is being cut, the rod 14 is appropriately moved by the aforesaid first and second driving units so as to position the collecting head 16 inside the tube T near the wall portion of the tube T on which the laser beam is focused by the working head 12. In this way, the debris (molten material) produced during the process of cutting the tube T is projected inside the collecting head 16 passing through the opening 18.

Once the cutting operation is complete, the cut piece of tube is separated from the remaining part of the tube T and deposited on the rod 14. The rod 14 is capable of simultaneously accommodating several pieces of tube, the number of which naturally depends on the length of the rod and the length of the pieces of tube deposited thereon.

With reference to FIG. 2, the apparatus 10 further comprises an abutment member 24 adapted to cooperate with the rod 14 to allow the removal of the pieces of tube from the rod 14. The abutment member 24 comprises a bush 26 (advantageously made from, or at least coated with, material with a low friction coefficient, such as bronze, brass, Teflon, etc.) through which the rod 14, controlled by the aforesaid first driving unit, may slide relative to the abutment member 24 in the longitudinal direction x. The abutment member 24 is mounted on a support structure 28 (hereinafter referred to as "second support structure"), which in turn is attached to the first support structure 22. The second support structure 28 may be displaced manually by an operator in the longitudinal direction x relative to the first support structure 22 so as to position the abutment member 24 at a given distance from the cutting plane, i.e. from the plane in which the T tube is cut by the laser beam focused by the working head 12.

Such a known solution entails the disadvantage that the operation of changing the position of the abutment member, which as said is performed manually by an operator, entails the need to stop the machine in order to ensure operator safety. Furthermore, the manual positioning of the abutment member requires particular skill on the part of the operator to be performed correctly.

To overcome these drawbacks, the use of a further motorized driving unit is known, in addition to the aforesaid first motorized driving unit, to move the second support structure in the longitudinal direction relative to the first support structure. However, such a solution is particularly expensive on the one hand and rather complicated on the other, due to the limited space available.

The object of the present invention is therefore to overcome the drawbacks of the prior art discussed above, by making available an apparatus for cleaning the tubes in a laser tube cutting machine that allows the abutment member to be positioned in the longitudinal direction without requiring manual intervention by an operator which is at the same time less expensive and less complicated to implement than the known solution of using an additional motorized driving unit.

This and other objects are fully achieved according to the present invention by an apparatus for cleaning tubes having the features specified in the independent claim 1.

Advantageous embodiments of the invention are defined in the dependent claims, the content of which is to be understood as an integral part of the description that follows. In short, the invention is based on the idea of providing an apparatus for cleaning the tubes of the type indicated above, wherein the second support structure is mounted slidably in the longitudinal direction relative to the first support structure, and wherein the apparatus further comprises first locking means joined to the abutment member and switchable between a disengaged position, wherein they allow the abutment member to move relative to the rod in the longitudinal direction, and an engaged position, wherein they integrally connect the abutment member with the rod in translation in the longitudinal direction, as well as second locking means joined to the second support structure and switchable between a disengaged position, wherein they allow the second support structure to move relative to the first support structure in the longitudinal direction, and an engaged position, wherein they lock the second support structure longitudinally relative to the first support structure.

Due to such a configuration, the longitudinal displacement of the second support structure, and the abutment member therewith, may be controlled by integrally connecting the abutment member with the rod in translation in the longitudinal direction by means of the aforesaid first locking means and moving the assembly formed of the rod, the abutment member and the second support structure in the longitudinal direction by means of the aforesaid first motorized driving unit. The longitudinal displacement of the second support structure, and the abutment member therewith, may therefore be carried out using the first motorized driving unit provided for the movement of the rod in the longitudinal direction, and thus without the need for manual intervention by an operator and without the need for a further motorized driving unit specifically for the second support structure. Once the abutment member has been brought into the desired longitudinal position, it may be locked in this position by activating the aforesaid second locking means, i.e. by switching from the disengaged position to the engaged position.

According to one embodiment, the abutment member is supported by the second support structure rotatably about an axis of rotation perpendicular to the longitudinal direction, and the aforesaid first locking means comprise an actuator which is interposed between the abutment member and the second support structure and is controllable to rotate the abutment member relative to the second support structure, and thus relative to the rod, about the aforesaid axis of rotation. In this case, the disengaged position of the aforesaid first locking means corresponds to a position of substantial alignment between the bush of the abutment member and the rod, i.e. the position wherein the axis of the bush is positioned substantially in the longitudinal direction, while the engaged position of the aforesaid first locking means is obtained by rotating the abutment member about the aforesaid axis of rotation until the bush of the abutment member is in interference with the rod.

Further features and advantages of the present invention will become clear from the detailed description that follows, given purely by way of non-limiting example with reference to the accompanying drawings, wherein:

FIG. 1 is a side view partially showing a laser tube cutting machine equipped with an apparatus for cleaning tubes according to the prior art;

FIG. 2 is a perspective view of the apparatus for cleaning tubes of FIG. 1;

FIG. 3 and 4 are perspective views of an apparatus for cleaning tubes for a laser tube cutting machine according to an embodiment of the present invention; and

FIGS. 5 and 6 are top views, partially in section, showing the apparatus of FIGS. 3 and 4 with the abutment member respectively in the disengaged and engaged position relative to the rod.

With reference to FIGS. 3 and 4, wherein parts and elements that are identical or corresponding to those of FIGS. 1 and 2 (prior art) are marked with the same reference numbers, an apparatus for cleaning tubes (hereinafter indicated simply as "apparatus") according to an embodiment of the present invention is indicated as a whole at 10. The apparatus 10 is intended to be mounted on a laser tube cutting machine (not shown) comprising, in a manner known per se, a working head suitable to focus a laser beam on the tube being worked (also not shown). The apparatus 10 comprises a rod 14, extending in a longitudinal direction x parallel to the longitudinal axis of the tube being worked, and a collecting head 16 mounted at one end of the rod 14 which, in use, is facing the tube being worked. The collecting head 16 is preferably made of a different material than that of the rod 14, for example copper. The collecting head 16 is formed as a hollow body, preferably of a cylindrical shape, and has an opening 18 through which the debris produced during the tube cutting process may penetrate inside the collecting head 16 to be collected therein.

The rod 14 is held by a support body 20, which in turn is held by a first support structure 22 and is movable relative to this structure in the longitudinal direction x under the control of a first motorized driving unit (not shown, but in any case of a type known per se), comprising, for example, a brushless electric motor. The first support structure 22, and with it the support body 20 and the rod 14 held by the support body 20, is in turn movable relative to a base structure of the machine in a transverse direction z, perpendicular to the longitudinal direction x, under the control of a second motorized driving unit (not shown, but in any case of a type known per se), also comprising, for example, a brushless electric motor. Advantageously, as in the example embodiment shown here, the longitudinal direction x is oriented horizontally, while the transverse direction z is oriented vertically.

During the tube cutting process, the rod 14 is suitably moved by the first and second motorized driving units so as to position the collecting head 16 inside the tube near the wall portion of the tube on which the laser beam is focused. In this way, the debris (molten material) produced during the tube cutting process is projected inside the collecting head 16 by passing through the opening 18.

The apparatus 10 further comprises an abutment member 24 suitable to cooperate with the rod 14 to allow the tube pieces deposited on the rod 14 to be removed from the same rod once they are cut. With reference also to FIGS. 5 and 6, the abutment member 24 comprises a bush 26 (advantageously made from, or at least coated with, a material with a low friction coefficient, such as bronze, brass, Teflon, etc.) through which the rod 14 may slide, controlled by the first motorized driving unit, relative to the abutment member 24 in the longitudinal direction x.

The abutment member 24 is mounted on a second support structure 28, which in turn is mounted on the first support structure 22 so as to be able to slide relative to the latter in the longitudinal direction x. A locking device (not shown) is joined to the second support structure 28 which is controllable (for example pneumatically, hydraulically or electrically) between a disengaged position and an engaged position, wherein it allows and respectively prevents the relative movement of the second support structure 28 relative to the first support structure 22 in the longitudinal direction x. Preferably, force adjustment means are joined to the locking device suitable to allow the clamping force exerted by the locking device on the second support structure 28 to be adjusted to lock the latter relative to the first support structure 22. The possibility of adjusting the clamping force with which the second support structure 28 is locked allows damage to the support structure itself and to the abutment member 24 it holds to be avoided.

The abutment member 24 is integral in translation with the second support structure 28 in the longitudinal direction x, but is rotatable relative to the second support structure 28, and thus relative to the rod 14, about an axis of rotation r perpendicular to the longitudinal direction x. In the present case, the axis of rotation r is oriented in the transverse direction z; however this orientation is not essential for the purposes of the invention.

In particular, the abutment member 24 is capable of assuming a first position (FIG. 5) wherein the bush 26 is aligned with the rod 14, and thus the rod 14 is free to slide inside the bush 26 to be moved in the longitudinal direction x relative to the abutment member 24, and a second position (FIG. 6) wherein the bush 26 is rotated relative to the rod 14 so as to be locked by interference with the same. In this second position, therefore, the bush 26, and the abutment member 24 therewith, is integral with the rod 14 in movement in the longitudinal direction x relative to the first support structure 22.

An actuator 30, for example a pneumatic, hydraulic or electric actuator, is joined to the abutment member 24, suitable to control the rotary movement of the abutment member 24 relative to the second support structure 28 about the axis of rotation r between the first and second positions mentioned above.

The positioning of the abutment member 24 in the desired position in the longitudinal direction x is therefore carried out in the following way.

With the locking device in the disengaged position, the abutment member 24 is made integral in translation with the rod 14, under the control of the actuator 30, by rotation about the axis of rotation r from the first to the second position mentioned above. At this point, the abutment member 24 may be moved together with the rod 14 in the longitudinal direction x by the first motorized driving unit. Once positioned in the desired longitudinal position, the abutment member 24 is returned by the actuator 30 to the aforesaid first position, so as to allow the rod 14 to move relative to the abutment member 24 in the longitudinal direction x, and the second support structure 28 is secured longitudinally to the first support structure 22 by switching the locking device from the disengaged position to the engaged position, so as to ensure the abutment member 24, which as said is integral in translation with the second support structure 28 in the longitudinal direction x, is maintained in the longitudinal position thus reached.

As is clear from the above description, the apparatus for cleaning tubes that is the subject matter of the present invention allows the abutment member to move longitudinally in an automated way, thus without requiring the manual intervention of an operator, and thus without requiring the machine to be stopped, using the same motorized driving unit already normally provided for the movement of the rod in the longitudinal direction, thereby reducing the costs and complexity of the equipment relative to a solution that provides for an additional longitudinal driving unit dedicated to the movement of the second support structure, and the abutment member therewith. Naturally, without prejudice to the principle of the invention, the embodiments and details of construction may vary widely relative to that which has been described and illustrated purely by way of non-limiting example, without thereby departing from the scope of the invention as defined in the accompanying claims.