Description Field of the art

The present invention refers to a machine that can be used both by at artisan (plumber, etc.) and at industrial level, for bending metal pipes.

Prior art and the disadvantages thereof

Known machines comprise an external casing/body which houses and protects a series of reduction gears. The drive motor, installed within the external casing or body of the machine initially has an angular speed of the output shaft thereof which is generally in the order of 1400 revolutions per minute. This speed of rotation is progressively reduced by the reduction gears up to obtaining, on the operating shaft, (the one that provides the torque required for bending the pipe) a mechanical torque of about 1400-1600 Nm or more depending on the model and a number of revolutions per minute of 1.5 up to 3 (for example a thousand times lower than the initial value present on the output shaft of the drive motor). Obviously, according to the known formula which provides the power, the product M · ω would be constant were the losses to be ignored. The number of revolutions (also for the machine of the present invention) is purely indicative and may vary widely, for example even by a power of 10 or more. All this depends on the dimensions of the machine and the pipes intended to be bent. Similar arguments can also be raised regarding the value of the torque provided by the output shaft.

The operating shaft which provides the power required for bending the metal pipe is made integral to the matrix (substantially a wheel with peripheral groove which receives part of the pipe). The operating shaft projects from the external body of the machine, vertically upwards, perpendicularly to the upper metal plate of the external body, and it for example bears an end with square-shaped head (or hexagonal-shaped head, etc.) to be introduced into a central hole of the matrix, with shape complementary and concentric to the geometric axes of the matrix itself (as well as the operating shaft after mounting). In this manner, the matrix is driven in rotation by the operating shaft. The pipe to be bent is locked on a bracket integral with the matrix (which cooperates with a counter-matrix), and the bracket draws the pipe therealong bending it. This system is generally known.

The counter-matrix is driven by an opposition screw so that the pipe moves away from the groove.

Other systems for bending pipes are known in the art but they do not regard the present invention. For example, in the so-called "thrust" system the pipe tends to flatten on the external side during the bending given that the drawing of the material cannot be controlled, given the absence of an opposition element like the counter-matrix which "copies" the second half of the pipe (the first is "copied by the matrix").

Thus, in the art regarding the present invention, the function of the counter-matrix is actually that of reducing the lateral deformations of the pipe. The pipe obtained through this process is usually much more rigid in the curving area of the pipe with respect to the straight area of the pipe, given that it has been "denied" of a part of the extension thereof. Thus, the fact that the pipe curving method, by utilizing the matrix and the counter-matrix, is preferred to other alternative methods, such as the thrust technique in which there is substantially just one curving/bending of the material without (or with little) drawing the same, is also due to this reason.

In another method, there is used a core within the pipe which prevents the pipe from collapsing inwards, maintaining the internal diameter of the pipe unvaried in the critical area immediately after the point of tangency in which the curve starts to form. The internal cores have been made in various forms such as for example adjustable and they are suitably held so as not to be drawn therealong by the pipe during the curving, specifically by the great forces involved in the bending process.

The machine of the present invention belongs to the category of machines for bending pipes, which do not utilize an internal core, and which do not utilize the thrust system either. In other words, the present invention exclusively regards a machine in which the curving is obtained simply through a matrix and a counter-matrix, without the use of a core within the metal pipe.

A first problem of the machines of this "inherent" prior art lies in the fact that they are little versatile given that they do not allow to easily vary the type of matrix using the same machine. The operating shaft couplable on its upper part in the hole of the matrix is shaped to normally adapt to only one type of matrix.

It would be advantageous to be able to use the same machine, and thus only one power takeoff of the operating shaft, however making the machine adaptable to various types of matrices and counter-matrices, for example even of the prior art type and manufactured by various specialized companies. In this manner, the machine would be directly reconfigurable according to the various types of the metal pipe bending tools.

A second problem of the inherent prior art lies in the fact that the respective metal pipes bending machines are little versatile, given that any failure on the drive motor or the reduction gears, and/or the electrical control unit requires the direct intervention of a technician from the manufacturing company. At times it may be quite difficult to identify the failure and the specific component to be replaced from among many different mechanical and electrical components. The replacement of a component may require that pieces/components be demounted in advance, with ensuing waste of time and money.

Even the assembly of the machines of the prior art is complex to perform and it can be done by the manufacturing company alone. This implies that the machine should be transported from manufacturer to the customer already assembled, and this implies (when transporting from one country to another) additional customs costs with respect to the transport of a set of parts that can be classified as "spare parts".

All in all it would be useful for those using this type of pipe bending machines to have a much simpler and versatile machine, capable of facilitating assembly and maintenance, and which is immediately reconfigurable and easily adjustable/couplable to various types of matrices and relative counter-matrices. Thus, a general object of the present invention is that of overcoming the aforementioned drawbacks.

A further object of the present invention lies in providing the consumers of a pipe bending machine, not part of an internal core, such machine being provided with a pipe deburring system. In this manner, without changing the machine, the operator may directly remove the burr (which are normally formed after an operation of cutting a metal pipe), both from the internal edge of the metal pipe and from the external edge of the same. Regarding the latter object of the present invention, it is preferable to have devices and means previously available/obtainable on the market. This implies that the manufacturing costs of the machine of the invention, which shall thus also perform the function of the deburring device, shall substantially remain low and thus shall be convenient for the purchaser.

Description of the invention

The present inventive concept consists in providing a machine for bending metal pipes, which is formed by a plurality of separate modules, even of the type already available in the market, but selected and assembled so as to obtain the desired objective, i.e. a versatile modular machine equipped in such a manner to possibly perform (in a specific embodiment) also the function of a deburring device and in any case be couplable with various types of matrices for bending metal pipes without having to modifying the remaining structure of the machine.

Thus, for the inventor of the present invention, it is fundamental to obtain this object, using a limited number of modules, otherwise the drawbacks revealed by the prior art would remain. Actually, also as observable in the detailed description of the embodiments thereof, the invention attains the objects thereof using just a rather limited number of modules. Thus, the modules may also be shipped/delivered separately to the end user (a hydraulic systems manufacturer, or an artisan etc.) as spare parts, reducing the customs costs, and the end user may see to the assembly within a short period of time, for example within half an hour. Otherwise, the user may directly purchase the modules of the machine of the invention (most of these are commercial components) and does the assembly alone, exclusively according to the disclosures provided for by the present patent application, so as to attain the relative objects.

Thus, specifically the present invention consists in having purposely assembled a limited series of modules, substantially at least partly already separately available in the market, but for performing a plurality of functions that no machine in the prior art could perform simultaneously. Each module has the advantage of grouping a considerable number of components in a single body, thus facilitating maintenance and assembly. As regards maintenance it will be sufficient to replace the specific module subject of failure.

Specifically, in a possible embodiment of the invention such modules are; the external body (or protection casing) of the machine, the electrical control unit which can be introduced into a special housing compartment, the motor coupled to the reduction point (i.e. the gear motor), the removable covering plate, the bending group (matrix, counter-matrix, mechanism for adjusting the position and for opposition of the counter-matrix) and lastly the operating shaft couplable to the power take-off (hollow shaft) of the reduction point.

The removable covering plate supports at least part of the tools required for bending the metal pipe, i.e.: the matrix and the counter-matrix, as well as the mechanism of support, for opposition and for adjusting the position of the counter-matrix.

Preferably, the power take-off of the reduction point consists in a hollow shaft which rotates (during the operation of the machine) with the same number of revolutions per minute as the matrix, said hollow shaft being obviously arranged beneath the covering plate, and the latter having a passage hole required for the passage of the operating shaft connectable to the matrix, which is of the interchangeable type and which can be introduced through said passage hole of the covering plate and (at the opposite end) into the hole of the hollow shaft. Thus, the operating shaft is actually an independent module, in the form of "male shaft" which can be inserted into the hollow shaft of the "gear motor module", so as to obtain flexibility in the connection between the gear motor and various types of interchangeable matrices. The "operating shaft" module is simply dropped vertically through the passage hole of the removable covering plate and inserted into the hollow shaft (also directed vertically) of the gear motor. The operating shaft for example has a key which being engaged in a respective longitudinal recess on the lateral panel of the hole of the hollow shaft of the gear motor, guarantees the synchronous driving in rotation of the operating shaft. The end user may be provided with a range of various "operating shaft" modules of different type and adaptable/couplable to the various matrices. This means that each operating shaft shall have an upper end (projecting from the upper covering plate) suitably configured for a specific matrix: for example, the operating shaft module may have, on its upper part, a triangular shaped (or square-shaped, etc.) head which can be inserted into a complementary triangular- shaped (or square-shaped, etc.) hole of the corresponding matrix.

In a particular preferred embodiment of the invention, the machine also comprises a deburring system, constituted by a "deburring module" provided with an adapter. The adapter may form a single body with the deburring module, but it is preferable (as observable hereinafter) to use a deburring module formed by two pieces, i.e. a deburring device of the commercial type and adapter removable and fixable (in two various ways or directions) to the deburring device for executing the machining process (deburring) of the piece. This shall be illustrated in detail hereinafter. According to the present invention, the adapter is inserted into a hole constituting a second power take-off of the pipe bending machine, at an angular reduction gear between the motor and reduction point of the "gear motor module". Such angular reduction gear may for example be formed by an "endless screw/worm screw" torque, in which the endless screw corresponds to the output shaft of the drive motor and in the worm screw there is obtained a hole of said second power take-off. The reduction of the number of revolutions, performed by the reduction gear, is such that the worm screw for example at 140 revolutions per minute, hence the second power take-off rotates the adapter and hence the deburring module at 140 revolutions per minute (such value is not obviously binding but solely indicative), compatibly with the conical millers of the conventional machines, i.e., considering that the conventional deburring devices rotate at about 100 revolutions/minute during the deburring operation, said second power take-off may be used for performing the deburring operations on the metal pipe cut previously (or subjected to any other machining operation). Deburring is usually carried out on a different machine, i.e. separate, and the present invention allows, through this solution, using the same machine even for deburring a pipe that has been cut (or machined generally) previously. Therefore, it is observable that the machine of the present invention has the characteristic of being modular and multifunctional simultaneously.

The machine is extremely easy to assemble and it does not require specialized personnel. No wiring is required given that the electrical plugs are already entirely arranged on a rear or lateral part of the "control unit" module (as if they were computer plugs), which advantageously form a box which can be laterally inserted drawer- like into a compartment inside the external body of the machine. Thus, a further advantage of the present invention is that of avoiding the wiring operations.

In a particular variant, the present invention also allows bending pipes both to the right and to the left (as described in detail and claimed in a parallel patent application of the company applying for the present patent). In this particular case, the matrix preferably has a removable drawing member preferably made up of a U-bolt (U-shaped bracket). The matrix shall thus have a structure preferably symmetric and it shall be overturnable on the operating shaft, as described in detail in the aforementioned parallel patent application having the title "Improved machine for bending metal pipes both to the right and to the left, with respect to the direction of insertion of the pipe".

In this particular variant of the present invention, regarding a machine suitable for bending pipes both to the right and to the left, the "gear motor module" is a reversible gear motor, capable of operating in both directions of rotation of the motor, and whose power take-off of the "operating shaft module" develops a mechanical torque M preferably identical in both directions of rotation. This kind of gear motor is available on the market and thus it can be used directly for obtaining a modular machine according to the invention, which has an even greater functionality, given that it can bend pipes both to the right and to the left without using a core within the pipe (see the mentioned parallel application of the same Applicant of the present patent application).

Brief description of the drawings

In the following detailed description, the present invention is described based on a preferred non-limiting and non-binding embodiment thereof, shown in the attached drawings, wherein: FIGURE 1 is a perspective view of the modular machine for bending metal pipes, according to a preferred embodiment of the present invention, during a leftwards bending operation; FIGURA 2 is an exploded view of the modular machine according to the present invention shown in Fig. 1 (some parts were omitted for the sake of simplification of the drawing);

FIGURE 3A also shows the deburring module, absent in Figs 1 and 2 (also in this case parts of the machine were omitted for the sake of simplifying the drawing,);

FIGURE 3B shows, separately and in partial longitudinal section, a particular embodiment of the deburring module, while it is milling the edge of the pipe, internally (at the lower part in figure 3B) and respectively externally (at the top part in figure 3B). Detailed description of the present invention

In the following detailed description a same detail is indicated in all the figures still using the same reference number, so as to avoid confusion.

Furthermore, though being more detailed than the previous general description of the inventive concept of the present invention, the following description is however limited to the details strictly useful for the understanding of the invention and the applications thereof, without getting into details that are already known or obvious to a man skilled in the art. Thus, the object of the present detailed description is exclusively that of allowing an average man skilled in the art to understand the attained technical progress, and be able to apply, if willing, the present invention. The specific processes of manufacturing the machine, the materials used, the variability intervals of the various process parameters (mechanical torque required for bending, the speed of rotation of the motor and of the matrix), as well as the specific shape of the matrix and of the counter-matrix, of the drawing bracket, etc, the external shape of the machine and/or the sizes thereof, the details of the means for adjusting the position of the counter-matrix, etc represent details that the man skilled in the art may modify at will without departing from the scope of protection of the present invention.

That said, Fig 1 shows a general view of the machine of the invention according to any non- limiting or non-binding preferred embodiment of the present invention.

The machine, indicated in its entirety with reference n° 1, comprises a lower part la which houses the drive motor (not visible given that it is arranged inside the external body 2 of the machine) and an upper part lb which substantially houses the reduction gear unit (or reduction point), also not visible Fig 1 given that it is concealed inside the external body 2 of the machine 1.

The drive motor and the reduction point together form the "gear motor module", which shall be described hereinafter with reference to Fig 2.

The machine also comprises a base 3 and an upper cover plate 4, removable but rigidly fixed to the external body 2, at the upper part of the latter. The base 3 can for example be fixed to the floor of a van used by a plumber, or alternatively, the base 3 can be fixed (or be made integral) to a metal structure or metal box which increases the vertical dimensions of the machine, for use in an industrial workshop, so as to save the operator the effort of bending when machining the piece (metal pipe 5), or for other purposes. It is thus understood that the machine 1 is of the type that can be adapted to various situations. For example, should the pipe 5 be very long, it may be advantageous to manufacture a machine 1 with extremely small vertical dimensions, so as to be possibly able to place the distal end (with respect to the machine) of the pipe 5 on a small temporary support in the workshop, in proximity to the floor, or even thereon. This would allow limiting the strain for the operator. It is thus clear that the machine can be configured variously. The base 3 and the external body 2 form a single piece in this particular embodiment. An alternative solution would be that of using a covering plate 4 obtained in a single piece with the parts la and lb, and separately obtain the base 3, possibly integral with an underlying structure or connectable to the underlying structure (which would be removable in this case, see above).

In order to avoid confusion, the parts 2, 3 and 4 (with underlying structure, if present) shall be generally referred to as "external protection module" of the control systems and of the internal mechanisms of the machine 1. The external protection module can thus be easily assembled by joining the components, and this does not require particular skills; for example it will be sufficient to fasten bolts 4a (Fig.1) for connecting the upper plate 4 to the external body 2.

The upper plate 4 is traversed by the operating shaft (not represented integrally in the figures) which, in a particular embodiment, could be simply "dropped" into the hollow shaft 30 (Fig. 2) constituting the last stage (power take-off) of the gear motor module 31 (Fig. 2). The operating shaft constitutes, as mentioned above, an independent module, or "male shaft", different from the hollow shaft 30 ("female shaft") included in the gear motor module 31.

Specifically, the "operating shaft" module is vertical, the lower end thereof (not shown) is engaged through a lateral key with a longitudinal groove of the hollow shaft 30 (also directed vertically); the operating shaft traverses a passage hole 4b (Fig 2) thus driving in rotation a matrix 6 which receives, through a central hole thereof, the upper end 7 (triangular-shaped in this case) of the same operating shaft not represented integrally. The operating shaft is thus an interchangeable module.

The arrow F (Fig. 1) indicates the direction of advancement of the pipe 5 between the matrix 6 and the counter-matrix 8.

The pipe bending group (matrix 6, counter-matrix 8, mechanism 1 1 for adjusting the position and for opposition of the counter-matrix 8) is described more extensively in the aforementioned parallel patent application, of the same Applicant, and it forms another module ("bending module" of the pipe 5) of the machine according to the present invention. Such bending module is for example capable (if the gear motor 31 is of the reversible type and suitably configured) of executing bending operations both to the right and to the left with respect to the direction of insertion F of the metal pipe 5 between the matrix and the counter-matrix.

The reference number 9 indicates the member for drawing the metal pipe 5, which draws and winds the metal pipe 5 around the groove of the matrix 6; the member 9 may be removable or non-removable (but in this case it is open on its upper part so as to be able to extract the pipe 5 at the end of the bending operation), and preferably forms a removable U-bolt 9 (U- shaped bracket) which can be fixed to the matrix 6 through an extractable pin 10 (Fig 1).

The control unit 12 forms a box which can be inserted drawer-like into the machine 1 (Figs 1 and 2). At the rear part, the control unit 12 has electrical power supply connectors; the electrical wires of the plugs which can be connected to such connectors could for example be guided outside the machine 1 by the flexible element 13. Thus, wiring is not required. The switches 14 and 15 are used for emergency stop and respectively for selecting the direction of rotation of the drive motor 32.

It should be observed that the counter-matrix 8, as mentioned previously (and as deducible by a man skilled in the art), may rotate slightly in a horizontal plane, around the vertical pin 16 thereof for mounting on the displaceable support 17 of the mechanism 11, for accompanying the movement of the metal pipe 5 in the rectilinear part thereof, which tends to radially move away from the matrix 6. The slight rotation of the counter-matrix 8 around the vertical pin 16 allows the metal pipe 5 to automatically "select" - during the operation of bending this metal pipe 5 - the optimal tangency point on the perimeter groove of the matrix 6. Such optimal tangency point varies, as known, as a function of the radius of the matrix 6 (i.e. of the bending intended to be obtained).

Reference 18 indicates a handle (gripping element) which facilitates the transport of the machine 1, should the latter be transportable (actually, for greater dimensions of the machine, the same may even not be transportable manually). It should be observed that the head of the machine 1, which supports the bending module described above, is preferably cantilevered, so as to facilitate - in some cases - the operation for bending the pipe 5 (see the aforementioned parallel patent application).

Now, specifically with reference to Fig 3A and Fig 3B now following is a description of the deburring module of the machine 1.

According to the present invention, the internal mechanisms of the machine 1 for bending metal pipes are also used for the deburring operation. As shown by Fig 2, a second power take-off 33 of the gear motor module 31 corresponds to a hole 33 which can be used for transmitting motion to the deburring module 40 (Fig. 3A), which is made up of a deburring device 42 (of the known type) and by an adapter 41. The end 41a of the adapter 41 is inserted - for this purpose - into said hole 33 of the gear motor module 31; a key or the like (not shown) on the end 41a shall for example be used for transmitting the rotary motion to the deburring device 42 rigidly connectable to 41. Specifically (also see Fig 3B) the deburring device 42 can be inserted in two different ways into a socket seat 43 of the adapter 41, and it can be locked therein through radial screws (or threaded dowels) which can be inserted into radial holes 44 of the socket 43. In an insertion method, the edge of the metal pipe 5 is milled internally by means of a conical male milling device (Fig 3B at the bottom), while in the other method of insertion the edge of the metal pipe 5 is milled externally by means of a female conical milling device (Fig 3B at the upper part).

The power take-off 33 (hollow shaft) is located at the angular reduction gear (part of the module 31) equivalent to the first reduction stage (see Figs 3 A and 2). Here, there is a reduction hence the number of revolutions of the adapter 41 shall correspond to that of the deburring devices of the prior art deburring machines specifically used for this purpose. Thus, the present invention provides a machine that is perfectly modular, easy to assemble and maintain, versatile adapted to perform several functions, and which also applies known mechanisms so as to avoid increasing production costs.

The machine of the present invention may preferably comprise a device for adjusting the speed of the drive motor 32, whose control knob may preferably be arranged in proximity of the stop button 14 and the device 15 for selecting the direction of rotation of the drive motor 32.

Once again, it should be observed that the present inventive concept of a modular machine, can also be generally applied to machines for bending metal pipes (through a matrix and a counter-matrix but without an internal core which can be inserted into the pipe), i.e. the machine for bending only to the right, or only to the left, or simultaneously to the right and to the left (the latter type of machine being the one described and claimed in the parallel patent application of the Applicant).

The machine of the invention does not require a specialized technician to perform wiring and assembly of the modules thereof, given that it can be mounted within a very short period of time even by unskilled people.

The present invention may be implemented in various ways, all falling within the same inventive concept.

For example, as mentioned, it is clear that the adapter 41 and the conical milling device 42 could also form a single piece, though in this case there would be the disadvantage of having to provide two separate deburring modules 40, for the two deburring operations (see Fig 3B). Furthermore, the adapter 41 could no longer be utilized when a milling device 42 has worn out.

Another obvious alternative to the present modular concept of the machine 1 lies in making the matrix 6 integral (in a single piece) with the operating shaft; this would imply wavering the possibility of connecting an independent module (operating shaft module) to various matrices 6, but there could be provided various matrices (a range of matrices) with relative operating shaft integral thereto, the entire piece being insertable, with the operating shaft (lower end), through the passage hole 4b (Fig 2) of the support surface 4 in the relative hollow shaft 30 of the gear motor 31.

Thus, it can be observed that the invention does not exclude the possibility of such obvious combinations between the various modules, which are clearly included in the present general inventive concept. List of reference symbols

1 pipe bending machine

la lower part

lb upper part

2 external body

3 base

4 upper covering plate

5 metal pipe

6 matrix

7 head for driving the matrix in rotation

8 counter-matrix

9 U-bolt/ drawing bracket

10 vertical pin of 9

11 mechanism for the adjustment and contrast of 8

12 electrical control unit

13 flexible element for electrical cables

14 emergency stop button

15 device for selecting the direction of rotation of the motor 32

16 vertical pin of 8

17 displaceable support (belonging to 11) of 8

18 handle

19 cantilevered head

20 space beneath the head 19

30 hollow shaft of the gear motor

31 gear motor module

32 drive motor (belonging to 31)

33 second power take-off (hollow shaft for the deburring device) debumng module adapter end of 41 deburring device seat/socket for 42 radial holes of 41