JP2828154B2 - Device for pushing the end of the long workpiece into the processing part - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an end portion of a long workpiece having a predetermined length, for example, an end portion of an aluminum material used as a constituent member of an aluminum sash frame previously cut to a predetermined length. In performing various processes on the workpiece, the workpiece is gripped by a gripping device, the workpiece is moved in the longitudinal direction together with the gripping device, and the end is automatically pushed into a fixed position of the processed portion. The present invention relates to an end pushing device.

[0002]

2. Description of the Related Art In addition to the above-described aluminum molds, generally, long workpieces cut to a predetermined length are subjected to various kinds of processing required for final assembly. Looking at the end processing of the aluminum mold material, not only several processing such as notching, punching, and punching are performed on the four end faces, but also each processing shape is various. These processes are mainly performed by press working, and generally, a series of processes are performed manually for each single product. Therefore, work efficiency is low and improvement of productivity by automation etc. is strongly desired. With conventional processing machines,
For example, the actual application
No. 61-162105 (Japanese Utility Model Application Laid-Open No. 63-71928)
Are shown in the microfilm. This structure
Moves the die to the specified position on the press machine.
The processing position of the mold based on this positioning
The distance between the stoppers against the end of the aluminum
Check the processing position of the Lumi-shaped material and the distance between the stoppers.
Numerical control is performed in order to adjust the values. However,
Since the processing position in the mold differs depending on the mold, the mold
When replacing the dies, manually replace the dies with a press
It must be positioned at a predetermined position on the machine. For this reason,
It is strongly desired to realize automation with improved work efficiency
I have.

In order to meet this demand, a multi-head press having a plurality of die sets provided with a predetermined mold has been conventionally employed, and the above-described series of processing is sequentially performed.
However, these operations are still manually performed, and the work load is large, and the number of sets of the die set is limited. Therefore, it is difficult to complete the series of processes in one operation. However, a plurality of multi-head presses had to be installed in parallel, and there was a problem in terms of space.

In order to solve the problem of the space and to save labor, for example, Japanese Unexamined Patent Publication (Kokai) No. 3-198930 discloses a processing method and a processing apparatus for an aluminum mold material for realizing complete automation. According to the processing apparatus disclosed in the publication, a large number of press machines equipped with different press dies each having a unique code are erected in multiple stages in parallel on the X-axis and Y-axis of the plane coordinates. A sash-type material supply device is installed on the side of the press machine, and the front surface of the plurality of press machines is moved by numerical control on the planes of the X-axis and the Y-axis, and simultaneously moved back and forth (Z-axis) toward the press machine. )
A moving device for gripping an aluminum material is provided. In processing the end portion of the aluminum shape, the gripping device horizontally grips one aluminum shape material which is sequentially supplied side by side by the supply device and waits on the side of the processing device, in a processing order set in advance. First, the aluminum mold is transferred to the front surface of the press machine for performing the first machining by moving on the plane of the X and Y axes, and the work end of the aluminum mold is directed into a desired mold of the press machine. To move along the Z axis, and press the end of the end into the press machine to perform desired press working. When this processing is completed, the gripping device retracts, pulls the aluminum material out of the mold, and then moves along the X-axis and the Y-axis while holding the aluminum material, and the front surface of the press machine for performing the next processing. Stop at Thereafter, the gripping device advances on the Z-axis and pushes the aluminum material into the press to perform the second pressing. Thereafter, the above operation is repeated according to the processing order, and all the processing is performed.

[0005]

However, the above-mentioned Japanese Patent Application Laid-Open
In a proposal for automation described in Japanese Patent Application Laid-Open No. 3-198930 , an aluminum workpiece, which is a long workpiece, is gripped by a gripping device, and the gripping device is moved to the front surface of a predetermined press machine on which a desired process is performed. Although a general system in a conventional machine tool for moving in the X, Y, and Z axis directions and a drive mechanism of a press machine are schematically illustrated, other configurations are only conceptually disclosed. In particular, no specific configuration is disclosed for the above-mentioned gripping device.

By the way, taking the end processing of the aluminum mold as an example of the long workpiece, the cross-sectional shape of the aluminum mold is not a simple rectangle but a complicated shape. Since it has a thin hollow structure, it is extremely easily deformed even by a small impact. In addition, this type of aluminum material has a wide variety of dimensions, and it is possible to accurately position the end portion in the machining position according to the respective dimensions by numerical control or the like, but in this case, it is extremely complicated. A procedure design and a complicated mechanism for the procedure are required.

Under these circumstances, in order to realize complete automation in processing the end of a long workpiece, for example, instead of a conventional foot-operated foot switch,
A mechanism that combines the detection and activation of the positioning of a microswitch etc. is installed in the processing part as the operating mechanism of the press machine, and when the end of the workpiece is pushed into the predetermined position of the processing part,
It is conceivable to detect the end position and start positioning and starting at the same time, accuracy of processing, economy,
It is also desirable from the viewpoint of work efficiency and the like.

However, in the case of the above numerical control,
Or even in the case of the micro switch,
When the workpiece gripped by the gripping device is moved on the Z-axis and its end is to be pushed into a predetermined position of the processing portion to be positioned, the edge of the workpiece having a complicated cross section as described above It is easy to come into contact with peripheral equipment, and this contact causes a problem that the workpiece is deformed.
In particular, long workpieces gripped in one place by the gripping device
The product is liable to shake and sway.
Susceptible to impact. This cannot be solved even if a known impact sensing means such as a strain gauge is employed.

The present invention has been made in view of the above circumstances, and a main object of the present invention is to move a workpiece in the Z-axis direction toward a processing portion, for example, when the end portion of the device is in the vicinity of the processing portion. Another object of the present invention is to provide an end pushing device for preventing the workpiece from being deformed or damaged even if it comes into contact with the workpiece.

[0010]

In order to achieve the above object, the present invention moves a long workpiece, which is gripped by a gripping device, in a longitudinal direction together with a gripping device, and moves the processed end portion to a processing portion. A push-in device for pushing the workpiece end to a set position, a feed position and a feed speed being controlled by numerical control, and a saddle portion moving back and forth toward a working portion on a long table; The main part of the device is a device for pushing an end of a long workpiece to a processed portion, which is provided with support means for the gripping device coupled to the portion via a buffer means.

More specifically, the cushioning means includes a hard rubber molded body or a metal spring. The saddle portion and the support means have a plate-like member having a predetermined length. Shock absorbing means are arranged at the four corners of the two plate-like members, and at the same time, the saddle portion and the supporting means are connected at a substantially central portion thereof so as to be capable of a slight relative movement with a predetermined degree of freedom.

[0012]

According to a control command according to a preset procedure in a state where a workpiece is gripped by a gripping device, for example, the workpiece is arranged in a grid pattern in the processing device disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 3-198930. An X-axis moving device and a Y-axis moving device operate on the front surfaces of a number of punching machines, and the gripping device moves along the X-axis and the Y-axis, and stops at a predetermined front of the punching machine. After the stop, the servomotor is started by the control command to rotate its output shaft. The feed screw is rotated by the rotation of the output shaft, and the saddle portion fixed to the feed nut and the gripping device connected to the saddle portion via the buffering means are integrally turned on the table toward the processing portion. Will be sent out.

In this way, the gripping device grips the workpiece and advances a predetermined stroke with its front end toward the processing portion, and when the tip of the workpiece reaches a predetermined position in the processing portion,
The tip contacts, for example, a stopper. The impact sound at this time is detected, and the rotation of the servomotor is stopped. Of course, instead of stopping the rotation of the servo motor by detecting the impact sound, the drive of the servo motor may be controlled by ordinary numerical control.

By the way, in the case of a workpiece having an easily deformable material or structure, such as an aluminum mold, when the front end face abuts against some obstacle, if the reaction is large, the normal end pushing device requires the workpiece to be processed. The product is easily deformed or damaged by a large impact. In particular, gripping at one place with a gripping device
Long workpieces that are held are susceptible to run-out and shaking
And is easily affected by peripheral equipment. However, according to the present invention, when the aluminum material to be processed abuts not only on the stopper but also on peripheral equipment of the processing portion, the shock is alleviated by the buffer means interposed between the saddle and the gripping device, thereby reducing the impact. thereby preventing deformation or damage of the workpiece, bunch
Run-out of a long workpiece gripped in one place by a holding device
And shaking are suppressed.

Further, according to the present invention, a first support plate made of a somewhat long plate is fixed to the upper surface of the saddle member, and a similarly long second support plate is fixed to the lower surface of the gripping device. When the buffer means is interposed at the four corners of the first support plate and the second support plate and connected by a regulating member which allows the relative movement of the two support plates at a substantially central position thereof, the work piece may be obstructed. In order to minimize the elastic deformation of the shock-absorbing means when it comes into contact with the first support member, and at the same time, to restrict a large relative movement between the first and second support plates while allowing a slight relative movement between the first and second support plates. , Does not cause significant deformation of each support plate.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be specifically described below with reference to the accompanying drawings. 1 is a longitudinal sectional view showing a handling portion having an end pushing device of the present invention, FIG. 2 is a positive plane view be shown by incising a portion of the handling portion, a portion of FIG. 3 is the same handling unit dissected a flat plane diagram to indicate.

The handling unit is described in Japanese Patent Laid-Open No. 3-1
No. 98930 corresponds to an unillustrated handling device for an aluminum material in a processing device disclosed in Japanese Patent Application Laid-Open No. 98930, which grips the aluminum material horizontally and extends along the Z axis based on a control command from a control panel (not shown). It has the function of moving forward and backward with the end in the direction toward the processing portion.

As shown in FIG. 1, the handling unit according to the present embodiment includes a gripping device G for an aluminum material and a rotation positioning device RP for rotating about the Z-axis while holding the aluminum material and positioning the pushing posture of the aluminum material. , The gripping device G
And an end pushing device Pz of an aluminum mold for moving the rotation positioning device RP back and forth along the Z axis. Of these, the gripping device G and the rotary positioning device RP are not direct objects of the present invention. Therefore, it is natural that the two devices are not limited to the illustrated examples, and may adopt a known gripping device. It is not necessary to provide the rotation positioning device RC as in the disclosed processing device.

Since the present invention is directly applied to the end pushing device Pz of the handling section as described above, the following description will be focused on the same end pushing device Pz. 1 to 3, reference numeral 1 denotes a table made of a long plate material having a concave cross section, and a guide rail 2 is provided on the upper surface of both side protruding portions 1 a of the table 1 over the entire length.
Are fixedly integrated. A servomotor 3 is fixedly mounted on the rear end (the right end in FIG. 1) of the table 1. A feed screw 4 is connected to an output shaft 3a of the servomotor 3, and both ends of the feed screw 4 The table 1 is rotatably supported by a support member 5 erected in a recess 1b of the table 1 via a bearing 6. Further, at the joint between the output shaft 3a of the servo motor 3 and the feed screw 4 and at the front end (left end in FIG. 1) of the table 1, the front and rear ends of a cover 7 covering the upper surface of the feed screw 4 described later are supported and fixed. A support member 8 for fixing is fixed.

A feed nut 9 is screwed into the feed screw 4, and the feed nut 9 is a block 1 that encloses the nut 9.
0 and is fixed to the lower surface of the saddle member 11. As shown in FIGS. 1 and 2, the saddle member 11 is made of a plate-like material having a concave cross section in which a total of four rail sliding members 12 are protruded in front, rear, left and right of the lower surface. Sliding grooves 12a are formed on the lower surface, and each sliding groove 12a is fitted to a pair of left and right guide rails 2 extending on the upper surface of the table 1. The end of the cover 7 is fixed to the support member 8 fixed to the front and rear of the table 1 so as to penetrate the space of the upper surface concave portion 11a of the saddle member 11 back and forth. Therefore, when the feed screw 4 rotates, the saddle member 11 moves on the table 1 on the guide rail 2.
Will move back and forth along. In this embodiment, a ball screw and a ball nut are used as the feed screw 4 and the feed nut 9.

On the upper surface of the saddle member 11, a first support plate 13 which is set longer than the length of the saddle member 11 and whose both sides 13a in the width direction are bent downward in FIG. The saddle member 11 and the first support plate 13 form a saddle portion of the present invention. Further, a second support plate 15 is fixed above the first support plate 13 through a buffering means, except for a part of the center which is slightly longer than the first support plate 13. In this embodiment, a hard elastic rubber molded body 14 is used as the buffer means, and the structure thereof has a thin flange portion 14a extending back and forth on the upper surface as shown in FIGS. Has a thin concave shape, and the upright portions 14c at the front and rear thereof have a substantially rhombic cross section. Needless to say, the material and structure of the buffering means are not limited to the rubber molded body 14, and various metal springs can be used, for example.

In the present embodiment, 4
The cushioning means 14 are fixed to the four corners of the first support plate 13 at the bottoms 14b, and the flanges 14a
Are fixed to the lower surface of the second support plate 15, respectively. Further, as shown in FIGS. 1 and 2, a roller 15a is rotatably attached to a lower end of a substantially central portion of the second support plate 15, and the roller 15a is The first support plate 13 is fitted into a concave portion of a concave fitting member 13b fixed at a position facing the first support plate 13.

In this embodiment, the positioning device RP is mounted and fixed on the second support plate 15, and the aluminum device holding device G is rotatably supported by the positioning device RP. As shown in FIGS. 1 and 2, the rotary positioning device RP includes a main body 16 having a substantially ring-shaped body 16 having a bearing portion 16a at an upper portion and a fixed flange portion 16b at a lower portion, and the bearing portion 16a. Support block 17 for fixedly supporting a step motor 18 fixed on the upper surface of the
Consists of A shaft body 20 having an intermediate gear 19 fixed at one end is rotatably supported on a bearing portion 16a of the main body 16,
The fixed flange portion 14b is fixed to the upper surface slightly forward of the center of the second support plate 15 so that the ring surface of the main body 16 is orthogonal to the longitudinal axis of the table 1.
Further, a gear 21 is fixed to an output shaft 18 a of a step motor 18 supported at a rear portion of the support block 17, and the gear 21 meshes with the intermediate gear 19. Further, the sound wave detector 22 is provided on the front surface of the support block 17, but the sound wave detector 22 does not always need to be provided.

The rotary positioning device R having such a configuration
On the inner diameter surface of P, the gripping device G is a ring-shaped bearing member 2.
3 so as to be freely rotatable. Grip device G
Is composed of a ring-shaped main body 24 having an outer diameter substantially equal to the inner diameter of the rotary positioning device RP, and a mold gripping portion 25 protruding and fixed to the front and rear of the main body 24.

On the outer peripheral surface of the main body 24, there are provided a plurality of O-ring fitting grooves 24a formed in the circumferential direction on the surface abutting against the inner peripheral surface of the rotation positioning device RP, and the ring-shaped bearing portion 16a. It has a notch 24b to be tightly fitted and fixed, and external teeth 24c formed on the outer peripheral surface facing the intermediate gear 19. The main body 24 is connected to the rotation positioning device RP via the ring-shaped bearing portion 16a as described above.
The O-ring 26 is simultaneously fitted into the O-ring fitting groove 24a at the same time, and a ring-shaped member formed between the O-ring fitting groove 24a and the O-ring 26 is formed. Is used as a pneumatic supply / discharge passage of the mold gripping portion 25 to an operation air cylinder 28 described later. Therefore, the main body 16 of the rotation positioning device RC
Is formed with an air supply / discharge path (not shown) communicating with the O-ring fitting groove 24a.
An air supply / discharge path (not shown) is also formed between the O-ring fitting groove 24a formed in the air cylinder 4 and each of the air cylinders 28. Further, the main body 1 of the rotation positioning device RC
A desired number of support brackets 27 are provided on the front and rear surfaces with the air cylinder protruding forward and backward from the respective surfaces. The external teeth 24c are meshed with the intermediate gear 19 of the rotation positioning device RP.

The mold holding portion 25 includes an air cylinder 28 fixedly held on the support bracket 27 and a mold holding member 29 driven by the air cylinder 28. According to the present embodiment, the air cylinder 28 is arranged in a pair of first and second air cylinders 28a and 28b in front and behind of the main body 24 at a predetermined interval with respect to the center of the gripping of the mold material. Is done. One plate-shaped gripping member 29a orthogonal to the operating direction is fixed to the first air cylinder 28a, and is arranged in parallel to the second air cylinder 28b so as to face the plate-shaped gripping member 29a. A plate-like gripping member 30 having a shape material gripping surface is integrally attached. The second air cylinder 28b is provided with two plate-like gripping members 29b and 29c arranged in parallel and perpendicular to the operation direction thereof, and one plate-like gripping member 29b is provided with the second air cylinder 28b. Is directly driven by the air cylinder 28b of the other plate-like gripping member 2
9c has a fixed arrangement position. Therefore, the main body 2
When the pair of air cylinders 28a and 28b disposed in front and rear of the air cylinder 4 are operated in the direction of gripping the shape, the plate-shaped gripping members 29a, 29b and 29 are actuated.
The distance between c and 30 is reduced at the same time, and the outer surfaces of the profile are firmly gripped from four sides before and after the main body 23 in one place by the respective gripping surfaces. It is clear that the present invention is not limited to the illustrated embodiment, and any mechanism for gripping a shape member can be adopted. The rotation of the servo motor 3 may be controlled by value control.

In the handling section according to the present embodiment having the above-described configuration, the table 1 is cantilevered by a well-known moving member (not shown) that moves on the Y-axis, for example, via a bracket (not shown). And the end pushing device Pz is operated, and the gripping device G and the rotation positioning device RP integrally move forward and backward on the Z axis toward a processing portion (not shown). Further, the gripping device G rotates on the inner diameter surface of the rotation positioning device RP about the Z axis, and performs rotational positioning so that a preset processing surface of the aluminum mold material is accurately set in the processing portion.

Of these operations, the operation of the end pushing device Pz related to the present invention will be described in detail with reference to the drawings. The rotation positioning device RP is not directly targeted in the present invention, but has a novel configuration and function, and will be described in detail here. Further, as the gripping device G, a known mechanism can be employed as long as it is a mechanism capable of gripping a mold material, and thus the operation thereof will be briefly described in the following description.

Air of a required pressure is supplied from an air supply source (not shown) to a pair of air cylinders 28a and 28b via an O-ring fitting groove 24a formed in the main body 16 of the rotary positioning device RP and the gripping device G, Each air cylinder 2
8a and 28b are actuated to grip an aluminum material (not shown) between the plate-like gripping members 29a to 29c and 30. In this state, the gripping device G is moved from a control panel (not shown) based on a command from a control panel (not shown). For example, based on the instruction of
In the processing apparatus disclosed in Japanese Patent No. 98930, the front surfaces of a large number of punch machines arranged in a grid are moved along the X-axis and the Y-axis, and stopped at the front of a predetermined punch machine. During the movement or after the movement is stopped, if necessary, a command is issued from the control panel to start the step motor 18 of the rotation positioning device RP to rotate the gear 21 by a predetermined angle, and through the intermediate gear 19 The gripping device G is rotated by a desired angle (usually 90 ° or 180 °). By this rotation, the aluminum shape material gripped by the gripping device G is also changed to a desired processing surface when pressed into the processing portion.

Next, when the end pushing device Pz is in the state shown in FIG.
Is activated to rotate the output shaft 3a. The feed screw 4 is rotated by the rotation of the output shaft 3a, and the saddle member 11 fixed to the feed nut 9, the first support plate 13 fixed to the upper surface of the saddle member 11, and the first support plate 13 A second support plate 15 fixed via a rubber molded body 14; the rotation positioning device RP mounted and fixed to the second support plate 15; and the gripping device G rotatably supported by the rotation positioning device RP.
Are integrally sent out (to the left in FIG. 1) along the guide rail on the table 1.

In this way, while the rotation positioning device RP and the gripping device G are rotating and positioning the aluminum mold (not shown) and holding the aluminum mold, the front end of the aluminum mold is moved forward by a predetermined stroke toward a press section of a press (not shown). When the front end of the aluminum mold reaches a predetermined position in the press section, the front end contacts, for example, a stopper (not shown). The impact sound at this time is detected by the sound wave detector 22, and the rotation of the servo motor 3 is stopped. In the present embodiment, the rotation of the servomotor 3 is stopped by detecting the impact sound. However, when it is sufficient to simply push the end of the workpiece into a predetermined position, the normal numerical control is performed. May control the rotation of the servo motor 3.

By the way, in the case of a workpiece having an easily deformable material or structure, such as an aluminum mold, if the front end surface of the workpiece comes into contact with some obstacle, the reaction is large. The product is easily deformed or damaged by a large impact. In addition, the holding device can
The long workpiece held vibrates due to the operation of the gripping device
In response to this, vibration and shaking are likely to occur.
Liable to receive large impacts by contacting peripheral equipment. However, in the present invention, when the aluminum mold material to be processed abuts not only on the stopper but also on peripheral devices of the processing portion, the rubber molded body interposed between the saddle portion and the mold material gripping portion of the rotation positioning device RP or the like. The shock-absorbing means such as 14 reduces the impact, thereby preventing the workpiece from being deformed or damaged. In addition, one
Swaying and swaying of a long workpiece gripped in a place
It is.

Further, according to the above embodiment, the saddle member 11
The first support plate member 13 fixed to the upper surface of the base plate and the second support plate member 15 fixed to the lower surface of the rotation positioning device RP are formed of plate members having a certain length, and rubber moldings serving as buffer means are provided at four corners. Since the workpiece 14 is provided, it is possible to minimize the elastic deformation of the rubber molded body 14 when the workpiece comes into contact with an obstacle. At the same time, the first and second support plate members 13 and 15 are fitted with a rotary roller 15a on a substantially concave fitting member 13a at a substantially central portion of the first and second support plate members 13,15. Since the relative movement between the front and rear 15 is restricted and a slight movement in the left-right direction and a slight twist in the up-down and left-right directions are allowed, the respective support plate members 13 and 15 are not significantly deformed.

[0034]

As is clear from the above description, according to the end pushing device for a workpiece according to the present invention, the buffer means is interposed between the saddle portion and the support portion of the gripping device. When the workpiece is pushed into the processing part, even if the tip of the workpiece contacts the peripheral device, the buffer means acts to reduce the impact on the workpiece due to the collision, and Deformation and damage are prevented , and
Of a long workpiece gripped in one place
Is suppressed.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a handling unit in an end processing machine for a long workpiece provided with an end pushing device for a workpiece according to the present invention.

FIG. 2 is a front view showing a part of the handling unit cut away.

FIG. 3 is a plan view showing a part of the handling unit cut away.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Table 1a Projection part 1b recessed part 2 Guide rail 3 Servo motor 4 Feed screw 5, 8 Support member 6 Bearing 7 Cover 9 Feed nut 10 Block 11 Saddle member 12 Rail sliding member 12a Groove part 13 First support plate material 14 Rubber molding 14a Flange part 14b Bottom part 14c Standing part 15 Second support plate 16 Ring-shaped main body 16a Bearing block 16b Fixed part 17 Support block 18 Step motor 18a Output shaft 19 Intermediate gear 20 Shaft 21 Gear 22 Sound wave detector 23 Ring-shaped bearing 24 Ring-shaped main body 24a O-ring fitting groove 24b Notch 24c External teeth 25 Shaped material gripping part 26 O-ring 27 Support bracket 28a, 28b Air cylinder 29a to 29c, 30 Plate-shaped gripping member Pz Pushing end of long workpiece Device RP Rotary positioning device G Gripping device

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁶ , DB name) B21D 43/00 B21D 43/10

Claims (5)

(57) [Claims] 1. A workpiece for moving a long workpiece gripped by a gripping device (G) in a longitudinal direction together with a gripping device G, and for pushing an edge of the workpiece to a set position of a processing portion. An end pushing device (Pz), in which a feed position and a feed speed are controlled by numerical control, and a saddle portion (1) which advances and retreats on a long table toward a processing portion.
1, 12, 13) and the saddle portion (11, 12, 13)
And a support means (15) for the gripping device (G) coupled to the end portion of the long workpiece by a buffer means. 2. The method according to claim 1, wherein the buffer means is a hard rubber molded product (1).
2. The end pushing device according to claim 1, wherein the device is (4). 3. The end pushing device according to claim 1, wherein said buffer means is a metal spring. 4. The saddle portion and the support means have plate members (13, 15) having a predetermined length, and the buffer means is provided at four corners of the plate members (13, 15). The end pushing device according to claim 1, which is arranged. 5. The saddle portion and the support means,
5. The end pushing device according to claim 4, wherein the substantially central portion is connected so as to be able to slightly move with a predetermined degree of freedom.