Screw tap machining equipment

Abstract

The invention provides screw tap machining equipment, and belongs to the technical field of machining equipment. The screw tap machining device solves the problem that an existing screw tap machining device is low in feeding precision. The screw tap machining equipment comprises a machine base and a floating base for positioning a screw tap, the floating base is located above the machine base, elastic steel sheets are vertically fixed to the front side and the rear side of the machine base correspondingly, the front side and the rear side of the floating base are fixed to the upper ends of the elastic steel sheets correspondingly, and at least one elastic supporting block is arranged between the front side and the rear side of the machine base and the front side and the rear side of the floating base correspondingly. A first mounting base protruding towards the floating base is arranged on the machine base, a second mounting base is arranged on the floating base, a concave cavity allowing one part of the mounting base to be inserted is formed in the second mounting base, a swing arm is hinged to the first mounting base, a main shaft is connected to the second mounting base in the vertical direction, and the swing arm on the first mounting base can swing to push the main shaft to move in the front-back direction. According to the screw tap machining equipment, large displacement deviation is avoided, and the feeding precision can be further improved.

Description

Technical Field

[0001] The invention belongs to the technical field of mechanical processing equipment and relates to a tap processing equipment. Background Art

[0002] When processing a tap, the two ends of the tap must be supported first, and then the tap is processed by the cutter head, because the tap needs to have a slight radial displacement during processing.

[0003] For example, Chinese patent application [Authorization Announcement No.: CN217413383U] discloses a feeding mechanism of a grinder for processing taps, including a base plate and four support columns fixedly installed on the rear side of the upper end of the base plate of the tap to be processed, a material discharge box fixedly installed on the upper ends of the four support columns, the material discharge box includes a first box body, a pushing device is provided at the front of the material discharge box, the pushing device includes a first driving motor, a material transmission device is fixedly installed on the right side of the upper end of the base plate, the material transmission device includes a first fixed shaft, a grinding device is fixedly installed on the front side of the upper end of the base plate, the grinding device includes a frame, a second driving motor is fixedly installed at the front end of the frame, a first rotating shaft is fixedly installed at the output end of the second driving motor through a coupling, a first telescopic frame is fixedly installed on the end of the first rotating shaft away from the second driving motor, an electromagnet is fixedly installed on the end of the first telescopic frame away from the first rotating shaft, a support frame is fixedly installed on the top middle of the upper end of the frame, and a grinding tool is fixedly installed on the upper end of the frame.

[0004] The above structure drives the tap to be processed to rotate by the first telescopic frame. However, the tap has very high processing accuracy requirements during processing. Simply relying on the movement of the first telescopic frame cannot accurately control the feed accuracy, which affects the processing accuracy of the tap. Summary of the Invention

[0005] The purpose of the present invention is to address the above-mentioned problems in the existing technology and to propose a tap processing device. The technical problem to be solved by the present invention is: how to solve the problem of low feeding accuracy of the existing tap processing equipment.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A tap processing equipment includes a machine base and a floating seat for positioning the tap, the floating seat is located above the machine base, and is characterized in that elastic steel sheets are fixed vertically on the front and rear sides of the machine base, the front and rear sides of the floating seat are respectively fixed on the upper ends of the elastic steel sheets, and at least one elastic support block is provided between the front and rear sides of the machine base and the floating seat, the machine base is provided with a mounting seat 1 protruding toward the floating seat, the floating seat is provided with a mounting seat 2, the mounting seat 2 is provided with a concave cavity for inserting a part of the mounting seat, the mounting seat 1 is hinged with a swing arm, the mounting seat 2 is vertically connected to a main shaft, and the swing arm on the mounting seat 1 can push the main shaft to move in the front and rear directions by swinging.

[0008] When processing the tap, it is necessary to first position the tap on the floating seat. A mounting seat 1 is provided on the machine base, and a mounting seat 2 is provided on the floating seat. A swing arm is hinged on the mounting seat 1, and the swing arm pushes the main shaft to move in the front and rear directions, so that the entire floating seat is moved. At this time, the tap will also have a small movement angle, which facilitates the processing of the tap and improves the processing accuracy. In order to ensure the stability of the floating seat when moving, elastic steel sheets are fixed on the front and rear sides of the machine base. On the one hand, they support the floating seat, and on the other hand, they improve the stability of the swing of the floating seat. In order to further improve the supporting effect of the floating seat, elastic support blocks are respectively provided between the front and rear sides of the machine base and the floating seat to improve the supporting effect of the machine base on the floating seat. In combination with the shape setting of the mounting seat 1 and the setting of the concave cavity, when the mounting seat 2 moves excessively relative to the mounting seat 1, it will abut against the mounting seat 2 through the cavity wall of the concave cavity to achieve abutment limitation, avoid large displacement deviation, and further improve the feed accuracy.

[0009] In the above-mentioned tap processing equipment, support bar 1 is fixed on both the front and rear sides of the machine base along the left and right directions, and support bar 2 is fixed on both the front and rear sides of the floating seat along the left and right directions. Support bar 1 presses the corresponding elastic steel sheet to the machine base through fasteners, and support bar 2 presses the corresponding elastic steel sheet to the floating seat through fasteners. The elastic support block is arranged between support bar 1 and support bar 2 located on the same side.

[0010] The setting of support bar one and support bar two realizes a stable connection of the elastic steel sheet, and the elastic support block is set between support bar one and support bar two, so that the elastic supporting force of the machine base and the floating seat are concentrated on the elastic steel sheet, making the supporting force more concentrated, thereby improving the supporting effect, thereby ensuring stability during movement, and playing a role in improving the feeding accuracy.

[0011] In the above-mentioned tap processing equipment, the mounting seat 1 and the mounting seat 2 are close to each other in the front-to-back direction, the transverse cross-section of the mounting seat 1 is convex, and there is a swing gap between the cavity walls of the mounting seat 1 and the mounting seat 2.

[0012] The setting of the swing gap ensures that when the floating seat is driven to swing normally, the mounting seat 1 and the mounting seat 2 will not contact each other, which will not affect the movement accuracy of the floating seat, thereby avoiding excessive movement of the floating seat while also not affecting its normal use.

[0013] In the above-mentioned tap processing equipment, one elastic steel sheet is located on the upper part of the machine base, and the other elastic steel sheet is located on the lower part of the machine base. Both elastic steel sheets are in the shape of long strips and are arranged in the left-right direction.

[0014] The position setting of the two elastic steel sheets makes the overall shape of the floating seat and the machine base triangular, which has high stability, and the support effect is better through the support on both sides of the upper and lower parts.

[0015] In the above-mentioned tap processing equipment, a driven gear ring is rotatably connected to the swing arm, a cam ring is fixed to the inner side of the driven gear ring, the main shaft is passed through the cam ring, the inner wall of the cam ring has an arc-shaped convex portion protruding radially inward, and the convex portion rests on the outer wall of the main shaft. The swing arm is also provided with a driving gear meshing with the driven gear ring, and the floating seat is also provided with a floating adjustment structure that can drive the driving gear to rotate.

[0016] The floating adjustment structure adjusts the initial position of the swing arm before the floating seat starts to move. Specifically, the floating adjustment structure drives the driving gear to rotate, and the rotation of the driving gear drives the driven gear ring to rotate, so that the convex part of the cam ring on the inner side of the driven gear ring pushes the main shaft to move slightly, thereby achieving the purpose of adjusting the initial position of the main shaft. It can meet the needs of adjusting the feed depth movement of taps of different sizes and improve the applicability of tap processing equipment.

[0017] In the above-mentioned tap processing equipment, the outer wall of the protrusion is arc-shaped, and the protrusion is located on the side of the cam ring close to the mounting seat.

[0018] Since the movement of the floating seat is only a slight movement, when different taps need to be processed, the feed depth required for the tap changes little. Therefore, when adjusting the initial position of the spindle, it is only necessary for the cam ring to have a convex portion on the side close to the mounting seat, and there is no need to set a large convex portion structure, so as to achieve the improvement of the applicability of the tap processing equipment.

[0019] In the above-mentioned tap processing equipment, the floating adjustment structure includes a knob rotatably connected to the floating seat, the upper end of the knob is located outside the floating seat, the lower end of the knob is hinged to a connecting rod in the left-right direction, the lower end of the connecting rod is hinged to a swing rod in the front-back direction, and the lower end of the swing rod is vertically inserted into the driving gear.

[0020] By turning the knob, the knob drives the swing arm to rotate, and the swing arm can drive the driving gear to rotate to adjust the initial position of the main shaft. After the adjustment is completed, the swing arm still remains inserted in the driving gear and always maintains a vertical setting, moving with the swing of the swing arm. The knob is rotatably connected to the floating seat, so the front and rear and left and right directions can be achieved through the left and right articulation of the connecting rod and the front and back articulation of the swing arm. Displacement, then, is achieved by maintaining the vertical setting of the swing arm when the swing arm swings. The connection between the swing arm and the knob is achieved, thereby ensuring the accuracy of the feed.

[0021] In the above-mentioned tap processing equipment, the lower end of the knob is provided with a limit sleeve, and the limit sleeve has a hinge groove with an opening facing downward. The upper end of the connecting rod is provided with a hinge shaft 1 that passes through the hinge groove and can slide vertically. A buffer spring is provided between the connecting rod and the limit sleeve. The connecting rod has an installation cavity for the upper end of the swing rod to be embedded. The connecting rod and the swing rod are hinged by a hinge shaft 2, and there is a swing gap between the cavity wall of the installation cavity and the outer side wall of the swing rod.

[0022] Due to the opening of the hinge groove on the limit sleeve, the hinge axis 1 of the connecting rod can slide vertically along the hinge groove, and the swing arm moves with the swing of the swing arm and maintains the vertical setting. At this time, the connecting rod swings when the swing arm moves and the hinge axis 1 slides vertically along the hinge groove when swinging. The buffer spring plays a buffering role when the connecting rod slides vertically, and also improves the reset efficiency, and improves the stability during readjustment and swinging. Moreover, through the cooperation of the hinge axis 2 and the swing gap, the swing arm can always maintain the vertical setting when the swing arm swings, and the swing of the connecting rod does not affect the vertical setting of the swing arm, further ensuring the stability of the feed.

[0023] In the above-mentioned tap processing equipment, a limit plug is also provided on the swing arm, and an annular limit groove is opened at the lower end of the swing arm along the circumferential direction. The plug head of the limit plug is embedded in the limit groove and can slide relatively in the limit groove. The outer wall of the plug head of the limit plug is arc-shaped.

[0024] The setting of the limit plug improves the stability of the swing arm setting, realizes the support and limit of the upper and lower ends of the swing arm, makes the swing arm more stable when swinging, and prevents one end from being suspended in the air, and also plays a certain positioning effect.

[0025] In the above-mentioned tap processing equipment, the swing arm is provided with a mounting hole for placing the driven gear ring and a fracture communicating with the mounting hole, and a locking bolt capable of locking the fracture is further provided in the swing arm.

[0026] By setting the locking bolt and the port, the driven gear ring can be locked by the locking bolt after the initial position adjustment of the main shaft is completed, thereby avoiding relative displacement between the main shaft and the driven gear ring when the swing arm swings, and further improving the swing accuracy and feed accuracy of the tap processing equipment.

[0027] Compared with the prior art, the present invention has the following advantages:

[0028] 1. Elastic steel sheets are fixed on the front and back sides of the machine base. On the one hand, they support the floating seat, and on the other hand, they improve the stability of the floating seat's swing. In order to further improve the supporting effect of the floating seat, an elastic support block is provided between the machine base and the floating seat to improve the supporting effect of the machine base on the floating seat. In addition, combined with the shape setting of the mounting seat one and the setting of the concave cavity, when the mounting seat two moves excessively relative to the mounting seat one, the cavity wall of the concave cavity will abut against the mounting seat two to achieve abutment limitation, avoid large displacement deviation, and further improve the feed accuracy.

[0029] 2. The floating adjustment structure adjusts the initial position of the swing arm before the floating seat starts to move. Specifically, the floating adjustment structure drives the driving gear to rotate, and the rotation of the driving gear drives the driven gear ring to rotate, so that the convex part of the cam ring on the inner side of the driven gear ring pushes the main shaft to move slightly, thereby achieving the purpose of adjusting the initial position of the main shaft. It can meet the needs of adjusting the feed depth movement of taps of different sizes, thereby improving the applicability of tap processing equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a structural schematic diagram of the present invention.

[0031] Figure 2 It is a top view of the present invention.

[0032] Figure 3 yes Figure 2 Cross-sectional view along AA.

[0033] Figure 4 yes Figure 3 A partial enlarged view of point A in the middle.

[0034] Figure 5 yes Figure 2 Cross-sectional view along BB.

[0035] Figure 6 It is a side view of the present invention.

[0036] Figure 7 yes Figure 6 Cross-sectional view along CC.

[0037] Figure 8 yes Figure 6 Cross-sectional view along DD.

[0038] Figure 9 It is a partial structural diagram of the present invention.

[0039] In the figure, 1. machine base; 11. mounting seat 1; 12. driving shaft; 12a. driving cam; 13. support bar 1; 2. floating seat; 21. mounting seat 2; 21a. concave cavity; 22. main shaft; 23. support bar 2; 3. elastic steel sheet; 4. elastic support block; 5. swing arm; 51. driven wheel; 52. driven gear ring; 53. cam ring; 53a. convex portion; 54. driving gear; 55. limit plug; 56. fracture; 57. mounting hole; 6. swing gap; 7. floating adjustment structure; 71. knob; 71a. limit sleeve; 71b. hinge groove; 72. swing rod; 72a. limit groove; 73. connecting rod; 73a. hinge shaft 1; 73b. mounting cavity; 74. return spring; 75. hinge shaft 2; 76. swing gap; 8. locking bolt; 9. spring. DETAILED DESCRIPTION

[0040] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solutions of the present invention, but the present invention is not limited to these embodiments.

[0041] like Figure 1 As shown, the tap processing equipment includes a machine base 1 and a floating base 2 for positioning the tap, and the floating base 2 is located above the machine base 1.

[0042] Specifically, if Figure 1-8 As shown, elastic steel sheets 3 are vertically fixed on the front and rear sides of the machine base 1, and the front and rear sides of the floating seat 2 are respectively fixed on the upper ends of the elastic steel sheets 3. At least one elastic support block 4 is provided between the front and rear sides of the machine base 1 and the floating seat 2. A mounting seat 11 protruding toward the floating seat 2 is provided on the machine base 1, and a mounting seat 21 is provided on the floating seat 2. A concave cavity 21a is provided on the mounting seat 21 for partially inserting the mounting seat 11. The mounting seat 11 is hinged with a swing arm 5, and the mounting seat 21 is vertically connected to the main shaft 22. The swing arm 5 on the mounting seat 11 can push the main shaft 22 to move in the front and rear directions. The machine base is also rotatably connected to a drive shaft 12, and a drive cam 12a is sleeved on the drive shaft 12. A driven wheel 51 is fixedly connected to the swing arm 5 and abuts against the drive cam 12a.

[0043] When processing the tap, it is necessary to first position the tap on the floating seat 2, by providing a mounting seat 11 on the machine base 1, a mounting seat 21 on the floating seat 2, and a swing arm 5 hinged on the mounting seat 11. The existing motor drives the drive shaft 12 to rotate, and the drive cam 12a on the drive shaft 12 rotates together, pushing the driven wheel 51 on the swing arm 5 to move, so that the swing arm 5 swings, and the swing of the swing arm 5 pushes the main shaft 22 to move in the front and rear directions, thereby moving the entire floating seat 2. At this time, the tap will also have a small movement angle, which facilitates the processing of the tap and improves the processing accuracy. In order to ensure the stability of the floating seat 2 when moving, the machine base Elastic steel sheets 3 are fixed on the front and rear sides of 1. On the one hand, they support the floating seat 2, and on the other hand, they improve the stability of the swinging of the floating seat 2. In order to further improve the supporting effect of the floating seat 2, elastic support blocks 4 are respectively provided between the machine base 1 and the front and rear sides of the floating seat 2 to improve the supporting effect of the machine base 1 on the floating seat 2. In addition, combined with the shape setting of the mounting seat 11 and the setting of the cavity 21a, when the mounting seat 21 moves excessively relative to the mounting seat 11, the cavity wall of the cavity 21a will abut against the mounting seat 2 21 to achieve abutment limitation, avoid large displacement deviation, and further improve the feeding accuracy.

[0044] like Figure 1 、 Figure 3 、 Figure 4 and Figure 7 As shown, support bar 13 is fixed on both the front and rear sides of the machine base 1 along the left and right directions, and support bar 2 23 is fixed on both the front and rear sides of the floating seat 2 along the left and right directions. Support bar 13 presses the corresponding elastic steel sheet 3 on the machine base 1 through fasteners, and support bar 2 23 presses the corresponding elastic steel sheet 3 on the floating seat 2 through fasteners. The elastic support block 4 is arranged between support bar 13 and support bar 2 23 on the same side. The mounting seat 1 11 and the mounting seat 2 21 are close to each other along the front and rear directions. The transverse cross-section of the mounting seat 11 is convex. There is a swing gap 6 between the cavity walls of the concave cavity 21a of the mounting seat 11 and the mounting seat 2 21. One of the elastic steel sheets 3 is located at the upper part of the machine base 1, and the other elastic steel sheet 3 is located at the lower part of the machine base 1. The elastic steel sheets 3 are both long strips and arranged along the left and right directions.

[0045] like Figure 3 、 Figure 4 、 Figure 5 and Figure 8As shown, a driven gear ring 52 is rotatably connected to the swing arm 5, and a cam ring 53 is fixed to the inner side of the driven gear ring 52. The main shaft 22 is passed through the cam ring 53. The inner wall of the cam ring 53 has an arc-shaped convex portion 53a that protrudes radially inward. The convex portion 53a abuts against the outer wall of the main shaft 22. The swing arm 5 is also provided with a driving gear 54 that meshes with the driven gear ring 52. The floating seat 2 is also provided with a floating adjustment structure 7 that can drive the driving gear 54 to rotate. The outer wall of the convex portion 53a is arc-shaped. The convex portion 53a is located on the side of the cam ring 53 close to the mounting seat 11. The floating adjustment structure 7 includes a knob 71 rotatably connected to the floating seat 2. The upper end of the knob 71 is located outside the floating seat 2, and the lower end of the knob 71 is along the outer wall of the floating seat 2. The left and right directions are hinged with a connecting rod 73, and the lower end of the connecting rod 73 is hinged with a swing rod 72 along the front and rear directions. The lower end of the swing rod 72 is vertically inserted into the driving gear 54, and the lower end of the knob 71 has a limiting sleeve 71a, which has a hinge groove 71b with an opening facing downward. The upper end of the connecting rod 73 is provided with a hinge shaft 1 73a that passes through the hinge groove 71b and can slide vertically. A buffer spring 74 is provided between the connecting rod 73 and the limiting sleeve 71a. The connecting rod 73 has a mounting cavity 73b for the upper end of the swing rod 72 to be embedded. The connecting rod 73 and the swing rod 72 are hinged by the hinge shaft 2 75, and a swing gap 76 is provided between the cavity wall of the mounting cavity 73b and the outer wall of the swing rod 72.

[0046] like Figure 9 As shown, a limit plug 55 is also provided on the swing arm 5, and an annular limit groove 72a is opened along the circumferential direction at the lower end of the swing rod 72. The plug head of the limit plug 55 is embedded in the limit groove 72a and can slide relatively in the limit groove 72a. The outer wall of the plug head of the limit plug 55 is arc-shaped.

[0047] like Figure 8 As shown, the swing arm 5 is provided with a mounting hole 57 for placing the driven gear ring 52 and a break 56 connected to the mounting hole 57. A locking bolt 8 that can lock the break 56 is also provided in the swing arm 5, and a spring 9 is provided between the locking bolt 8 and the swing arm 5.

[0048] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Persons skilled in the art may make various modifications, additions, or substitutions to the described specific embodiments without departing from the spirit of the present invention or exceeding the scope of the appended claims.

Claims

1. A tap processing device, comprising a machine base (1) and a floating seat (2) for positioning the tap, wherein the floating seat (2) is located above the machine base (1), and is characterized in that: The front and rear sides of the machine base (1) are both vertically fixed with elastic steel sheets (3), the front and rear sides of the floating seat (2) are respectively fixed to the upper ends of the elastic steel sheets (3), and at least one elastic support block (4) is provided between the front and rear sides of the machine base (1) and the floating seat (2). The machine base (1) is provided with a mounting seat 1 (11) protruding toward the floating seat (2), the floating seat (2) is provided with a mounting seat 2 (21), the mounting seat 2 (21) is provided with a concave cavity (21a) for partially inserting the mounting seat 1 (11), the mounting seat 1 (11) is hinged with a swing arm (5), the mounting seat 2 (21) is vertically connected with a main shaft (22), and the swing arm (5) on the mounting seat 1 (11) can push the main shaft (22) to move in the front and rear directions when it swings.

2. The tap processing equipment according to claim 1, characterized in that: The front and rear sides of the machine base (1) are both fixed with support bars (13) along the left and right directions, and the front and rear sides of the floating seat (2) are both fixed with support bars (23) along the left and right directions. The support bars (13) press the corresponding elastic steel sheets (3) onto the machine base (1) through fasteners, and the support bars (23) press the corresponding elastic steel sheets (3) onto the floating seat (2) through fasteners. The elastic support block (4) is arranged between the support bars (13) and the support bars (23) located on the same side.

3. The tap processing equipment according to claim 1 or 2, characterized in that: The mounting seat 1 (11) and the mounting seat 2 (21) are both close to each other in the front-to-back direction, the transverse cross section of the mounting seat 1 (11) is convex, and there is a swing gap (6) between the cavity walls of the concave cavity (21a) of the mounting seat 1 (11) and the mounting seat 2 (21).

4. The tap processing equipment according to claim 1 or 2, characterized in that: One of the elastic steel sheets (3) is located at the upper part of the machine base (1), and the other elastic steel sheet (3) is located at the lower part of the machine base (1). Both of the elastic steel sheets (3) are in the shape of long strips and are arranged in the left-right direction.

5. The tap processing equipment according to claim 1 or 2, characterized in that: The swing arm (5) is rotatably connected to a driven gear ring (52), a cam ring (53) is fixed on the inner side of the driven gear ring (52), the main shaft (22) is passed through the cam ring (53), the inner wall of the cam ring (53) has an arc-shaped convex portion (53a) protruding radially inward, and the convex portion (53a) abuts against the outer wall of the main shaft (22), the swing arm (5) is also provided with a driving gear (54) meshing with the driven gear ring (52), and the floating seat (2) is also provided with a floating adjustment structure (7) capable of driving the driving gear (54) to rotate.

6. The tap processing equipment according to claim 5, characterized in that: The outer wall of the convex portion (53a) is arc-shaped, and the convex portion (53a) is located on a side of the cam ring (53) close to the mounting seat (11).

7. The tap processing equipment according to claim 5, characterized in that: The floating adjustment structure (7) comprises a knob (71) rotatably connected to the floating seat (2), the upper end of the knob (71) is located outside the floating seat (2), the lower end of the knob (71) is hinged to a connecting rod (73) in the left-right direction, the lower end of the connecting rod (73) is hinged to a swing rod (72) in the front-back direction, and the lower end of the swing rod (72) is vertically inserted into the driving gear (54).

8. The tap processing equipment according to claim 7, characterized in that: The lower end of the knob (71) is provided with a limiting sleeve (71a), and the limiting sleeve (71a) has a hinge groove (71b) with an opening facing downward. The upper end of the connecting rod (73) is provided with a hinge shaft (73a) that is inserted into the hinge groove (71b) and can slide vertically. A buffer spring (74) is provided between the connecting rod (73) and the limiting sleeve (71a). The connecting rod (73) has a mounting cavity (73b) for the upper end of the swing rod (72) to be embedded. The connecting rod (73) and the swing rod (72) are hinged by a hinge shaft (75), and a swing gap (76) is provided between the cavity wall of the mounting cavity (73b) and the outer wall of the swing rod (72).

9. The tap processing equipment according to claim 7, characterized in that: The swing arm (5) is further provided with a limit plug (55), and the lower end of the swing rod (72) is provided with an annular limit groove (72a) along the circumferential direction. The plug head of the limit plug (55) is embedded in the limit groove (72a) and can slide relatively in the limit groove (72a), and the outer wall of the plug head of the limit plug (55) is in an arc shape.

10. The tap processing equipment according to claim 5, characterized in that: The swing arm (5) is provided with a mounting hole (57) for placing the driven gear ring (52) and a break (56) communicating with the mounting hole (57). A locking bolt (8) capable of locking the break (56) is also provided in the swing arm (5).

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