TWI846925B - Racket holding system and stringing machine comprising such a system - Google Patents

Abstract

This racket (R) holding system (2) for a cradle of a stringing machine comprises at least two pairs of arms (4A~4D) movable in a primary plane corresponding to a stringing plane of the racket (R) held in the holding system (2). Each of the arms (4A~4D) includes a wedging part (6A~6D) provided with two Vs (8) having a V~shaped geometry intended to accommodate an outer edge (100) of a frame (10) of the racket (R).

Description

Racket holding system and stringing machine including the same

The present invention relates to a racket holding system for a stringing machine stand and a racket stringing machine including the holding system.

A racket stringing machine, in particular a racket stringing machine for tennis, badminton or squash, comprises a stand comprising a holding system in which the racket is held. The holding system generally comprises four wedging parts for clamping the frame of the racket.

In badminton, the recent trend is to use rackets with stringing tensions of up to 15kg, rather than the previous average of 12kg, in order to increase the return of impact force. In current stringing machines, this trend has resulted in racket frame fractures during stringing due to the significant deformations that the frame undergoes during the increasingly high tensions on the strings.

The object of the invention is to propose a new racket holding system which makes it possible to reduce the stress in the racket frame during the placement of the strings at a higher tension and to reduce the risk of the racket frame breaking.

To this end, the invention relates to a racket holding system for a support of a stringing machine, comprising at least two pairs of arms capable of moving in a main plane corresponding to the stringing plane of the racket held in the holding system. The holding system is characterized in that each of these arms comprises a wedging part provided with two V-shaped pieces having a V-shaped geometry intended to accommodate the outer edges of the frame of the racket.

Thanks to the invention, the number of contact points between the retention system and the racket frame is increased, which reduces the amplitude of the frame deformation during stringing and reduces the risk of the frame breaking at the points where it is free to deform.

According to an advantageous but optional aspect of the invention, such a retaining system may include one or more of the following features, and any technically feasible combination may be considered.

Each V-shaped piece comprises two contact pads in contact with the racket frame, each contact pad being mounted in a branch of the V-shaped piece and each of these pads being able to rotate along an axis of rotation aligned with one of the branches of the V-shaped piece.

The contact pad comprises a contact portion intended to be supported on the frame of the racket, and a pivot portion which is fastened to the contact portion and is rotatably mounted in the housing of the V-shaped piece.

The pivot portion has a cylindrical shape centered on the rotation axis of the contact pad.

Each wedging member is free to rotate about an axis of rotation perpendicular to the main plane relative to the arm to which the wedging member is mounted, and each arm includes a brake configured to lock the angular position of the wedging member about its axis of rotation.

Each arm includes a guide member that can be pivotally mounted on the wedging member and can be pivotally and slidably connected to the arm so as to guide the rotation of the wedging member relative to the arm.

One end of the guide connected to the arm includes an elliptical aperture into which a block fixed to the arm is inserted, and a stopper locks the position of the elliptical aperture relative to the block.

The system includes: a first connecting member, which connects the first and second wedging members located on the first side of the longitudinal axis of the retaining system; and a second connecting member, which connects the third and fourth wedging members located on the second side of the longitudinal axis of the retaining system, the first connecting member can be pivotally connected to the first wedging member and pivot and slide on the second wedging member through the elliptical aperture, and the second connecting member can be pivotally connected to the third wedging member and pivot and slide on the fourth wedging member through the elliptical aperture, and the position of the first wedging member relative to the elliptical aperture of the first connecting member can be locked by a brake, and the position of the fourth wedging member relative to the elliptical aperture of the second connecting member can be locked by a brake.

The system comprises two additional wedging elements configured to bear against the inner edge of the frame, respectively in the racket head region and in the intersection region between the frame and the central axis of the racket, and equipped with two V-shaped pieces intended to accommodate the inner edge of the frame of the racket.

The invention also relates to a stringing machine comprising a racket support frame provided with a retaining system as described above.

2: Maintain the system

3: Shell

4A: Arm

4B: Arm

4C: Arm

4D: Arm

6A: Wedged parts

6B: Wedged parts

6C: Wedged parts

6D: Wedge component

8: V-shaped piece

10: Framework

10A: Racket head

11: Handle

12: Brake parts

13: Center axis

14: Guide piece

15: Block

16: Wedged element

18: Wedged element

20: First connecting component

22: Second connecting component

30: Locking actuator

60: Board

62: Block

80: Contact pad

80a: Contact part

80b: Pivot part

82: Branch Department

84: Accommodation section

100:Outer edge

102: Inner edge

140: Elliptical opening

200: Elliptical opening

220: Elliptical opening

C: Line

CC: Center

P2: Main plane

R: racket

X2: longitudinal axis

X4: Rotation axis

X6: Rotation axis

X80: Rotation axis

XR: Longitudinal axis

α: angle

The invention will be better understood and other advantages of the invention will become more apparent from the following description of the holding system according to its principle, provided as a non-limiting example and with reference to the accompanying drawings, in which: FIG. 1 shows a holding system according to the invention in a top view, in which a racket is placed; FIG. 2 is an enlarged view of detail II of FIG. 1 ; FIG. 3 is a side view along arrow III in FIG. 1 , in which the racket is shown in cross section; FIG. 4 is a cross-sectional view of a V-shaped member of the holding system along plane IV-IV in FIG. 3 ; FIG. 5 is a view similar to FIG. 1 , for a holding system according to a second embodiment of the invention.

FIG. 1 shows a holding system 2 for a racket R. The holding system 2 is intended to be mounted on a support of a stringing machine (not shown). Such a stringing machine is used in particular for stringing badminton rackets, but can also be used for stringing rackets for playing other sports, in particular tennis or squash.

The racket R is a badminton racket and includes a frame 10, a handle 11, and a central axis 13 connecting the handle 11 and the frame 10. The central axis 13 defines a longitudinal axis XR of the racket R. The racket R includes a set of strings C stretched inside the frame 10.

The holding system 2 comprises two pairs of arms 4A, 4B, 4C and 4D, which are movable in a substantially horizontal main plane P2 corresponding to the plane of a set of lines C of the racket R held in the holding system 2. The holding system 2 defines a longitudinal axis X2 which coincides with the longitudinal axis XR of the racket R placed in the holding system 2.

The arms 4A, 4B, 4C and 4D are arranged as follows: the two arms 4A and 4B are arranged on one side of the head 10A of the racket R relative to the longitudinal axis X2, that is, they are arranged in the area of the frame 10 opposite to the handle 11. The two arms 4A and 4B can rotate in the plane P2, that is, they can rotate around the rotation axis X4 perpendicular to the plane P2. The arms 4A and 4B are installed in the housing 3, which includes a locking actuator 30 so that the position of the arms 4A and 4B can be locked.

The holding system 2 also comprises two further arms 4C and 4D, which are situated along the longitudinal axis X2 on one side of the handle 11, i.e. opposite the head 10A of the racket. These arms 4C and 4D are also capable of rotating in the plane P2 about a rotation axis X4 perpendicular to the plane P2 and are mounted in a second housing 3 which comprises a brake 30 for locking the position of the arms 4C and 4D.

The holding system 2 comprises a total of four arms 4A, 4B, 4C and 4D, Two of the four arms (4A and 4C) are located on one side of the longitudinal axis X2, and two of the four arms (4B and 4D) are located on the other side.

Each of the arms 4A, 4B, 4C and 4D comprises a corresponding wedging member 6A, 6B, 6C and 6D intended to accommodate the frame 10. Each wedging member 6A, 6B, 6C or 6D is capable of rotating relative to the arm 4A, 4B, 4C or 4D supporting it in the plane P2, i.e., it is capable of rotating about an axis X6 perpendicular to the plane P2. Thus, the retaining system 2 comprises four wedging members 6A, 6B, 6C and 6D.

Each arm 4A, 4B, 4C or 4D comprises a brake 12 configured to lock the angular position of the wedging member 6A, 6B, 6C or 6D about its rotation axis X6. The brake 12 can be, for example, a screw or a magnetic device arranged around the rotation axis X6.

Each wedging member 6A, 6B, 6C or 6D is provided with two V-shaped pieces 8 having a V-shaped geometry, which are intended to accommodate the outer edges 100 of the frame 10 of the racket R. Each wedging member 6A, 6B, 6C or 6D has a plate 60 extending parallel to the plane P2 and hinged to the arm 4A, 4B, 4C or 4D around the axis X6. The V-shaped piece 8 extends from the plate 60. The V-shaped piece 8 is respectively formed by two branches 82 inclined relative to each other, thereby defining a "V" shape, the opening of which is oriented towards the frame 10 of the racket R. More generally, the V-shaped piece 8 is in the form of a claw configured to clamp the frame 10 of the racket R thanks to two surfaces distributed above and below the plane P2.

Each V-shaped piece 8 comprises two contact pads 80 that come into contact with the frame 10 of the racket R. Each pad 80 is mounted in one of the branches 82 of the V-shaped piece 8. The pads 80 are made of a flexible synthetic material to form a flexible fitting that makes it possible to prevent the edge 100 of the frame 10 from being scratched by the V-shaped piece 8. The frame 10 is thus in contact with the V-shaped piece 8 at two points, respectively above and below the plane P2.

In general, the frame 10 is held by at least eight contact areas in the plane P2, and since each V-shaped piece 8 comprises two contact points with the frame 10, there are a total of sixteen contact points with the frame 10. The presence of eight contact points in the plane P2 makes it possible to reduce deformation of the frame 10 during threading and therefore reduce the risk of breakage.

A set of strings of a racket usually starts with the "main strings", i.e. the strings extending along the longitudinal axis XR. Therefore, the greatest deformations and the greatest risk of breaking occur during this phase and on the lateral parts of the frame 10, i.e. extending between the head 10A of the racket and the intersection of the frame 10 and the central axis 13. These are the parts that are held respectively by four contact points formed by four V-shaped pieces 8. Therefore, the risk of breaking on these parts is significantly reduced.

According to one embodiment, each arm 4A, 4B, 4C or 4D comprises a guide 14 which can be pivotally mounted on the plate 60 of the wedging member 6A, 6B, 6C or 6D and which can be pivotally and slidably connected to the arm so as to guide the wedging member 6A, 6B, 6C or 6D in rotation relative to the arm 4A, 4B, 4C or 4D.

The first end of the guide 14 is rotatably mounted on the block 62 of the plate 60. The guide 14 has a rotational freedom around the block 62 about an axis perpendicular to the plane P2.

One end of the guide 14 connected to the arm 4A, 4B, 4C or 4D includes an elliptical orifice 140 into which the block 15 fixed to the arm 4A, 4B, 4C or 4D is inserted. The block 15 can slide in the elliptical orifice 140, thereby allowing the block 15 to translate in the elliptical orifice 140 in the plane P2 and allowing the guide 14 to rotate around the block 15 about an axis perpendicular to the plane P2.

In this case, a stopper 12 provided with an arm 4A, 4B, 4C or 4D locks the position of the block 15 in the elliptical opening 140. The stopper 12 may be a mechanical stopper (such as a screw) or a magnetic stopper arranged around the block 15.

Each of the contact pads 80 is capable of rotating about a rotation axis X80 of the pad 80 which is aligned with one of the branches of the V-shaped member 8.

The contact pad 80 comprises a contact portion 80a intended to be supported on the frame 10 of the racket R, and a pivot portion 80b which is fastened to the contact portion 80a and is mounted in the housing 84 of the V-shaped member 8 so as to be rotatable about the rotation axis X80.

The hinge portion 80b has a cylindrical shape centered on the rotation axis X80. The accommodation portion 84 also has a cylindrical shape similar to the cylindrical shape of the hinge portion 80b.

Ideally, the contact between pad 80 and frame 10 must be normal; however, rackets have different shapes, so this is not always the case. The rotational freedom of pad 80 makes it possible to adapt to the shapes of different types of rackets, in particular round, teardrop or slightly angled shapes, which form different supports on the wedging parts 6A, 6B, 6C or 6D. The pivot angle of pad 80 about its rotation axis X80 can be, for example, between 3 degrees and 5 degrees (inclusive).

The contact pads 80 are consumable parts that can be replaced when they are worn by contact with the racket. The cylindrical shape of the hinge 80b allows sliding contact. Therefore, the pad 80 can be removed from the V-shaped piece 8 along the rotation axis X80, and a new pad 80 can be inserted into the housing 84 along the rotation axis X80.

According to one embodiment, the retaining system 2 comprises two additional wedging elements 16 and 18, generally referred to in the field of stringing machines as "billiards". The first wedging element 16 is configured to bear against the inner edge 102 of the frame 10 in the region of the racket head 10A. The second wedging element 18 is configured to bear against the inner edge 102 in the region located at the intersection of the frame 10 with the central axis 13. These two wedging elements 16 and 18 are intended to reduce the inward deformation of the frame 10 during the stringing of the main string. Thus, in the plane P2, the retaining system 2 comprises eight external bearing points and two internal bearing points. Advantageously but optionally, the ten support points can be evenly distributed on the frame 10, for example by being offset relative to each other by a constant angle α, taken relative to the center CC of the set of lines C. Ideally, this angle α can be 36°.

According to an embodiment not shown, the two wedging elements can each be equipped with two V-shaped pieces similar to the V-shaped pieces 8 of the wedging parts 6A, 6B, 6C and 6D and intended to accommodate the inner edge of the frame 10. In this case, the retaining system 2 includes four internal bearing points.

According to an alternative embodiment shown in FIG. 5 , the retaining system 2 may include: a first connecting member 20 connecting the plates 60 of the two wedging members 6A and 6C located on a first side of the longitudinal axis X2; and a second connecting member 22 connecting the plates 60 of the two wedging members 6B and 6D located on the other side of the longitudinal axis X2. The first connecting member 20 can be pivotally connected to the wedging member 6C and can be pivotally and slidably connected to the wedging member 6A through an elliptical aperture 200. The second connecting member 22 can be pivotally connected to the wedging member 6B and can be pivotally and slidably connected to the wedging member 6D through an elliptical aperture 220. By eliminating the possibility of sliding provided by the elliptical orifice 200, the position of the connecting part 20 relative to the wedging part 6A can be locked by a locking device such as the brake 12. Similarly, by eliminating the possibility of sliding provided by the elliptical orifice 220, the position of the connecting part 22 relative to the wedging part 6D can be locked by a locking device such as the brake 12. By locking the connecting parts 20 and 22 in place respectively, a simultaneous blocking operation of the wedging parts 6A and 6C on the one hand and of the wedging parts 6B and 6D on the other hand is obtained.

Within the scope defined by the patent application, the features and modifications of the embodiments described above can be combined to form new embodiments of the present invention.

2: Maintain the system

3: Shell

4A: Arm

4B: Arm

4C: Arm

4D: Arm

6A: Wedged parts

6B: Wedged parts

6C: Wedged parts

6D: Wedge component

8: V-shaped piece

10: Framework

10A: Racket head

11: Handle

12: Brake parts

13: Center axis

16: Wedged element

18: Wedged element

30: Locking actuator

100:Outer edge

102: Inner edge

CC: Center

R: racket

X2: longitudinal axis

X4: Rotation axis

X6: Rotation axis

XR: Longitudinal axis

α: angle

Claims (10)

A holding system (2), which is a holding system for a racket (R), used for a support of a stringing machine, comprising at least two pairs of arms (4A-4D), the arms being movable in a main plane (P2) corresponding to the stringing plane of the racket (R) held in the holding system (2), characterized in that each of the arms (4A-4D) comprises a wedging component (6A-6D), the wedging component being provided with two V-shaped pieces (8), the V-shaped pieces having a V-shaped geometry, intended to accommodate the outer edge (100) of the frame (10) of the racket (R). A holding system according to claim 1, wherein each V-shaped member (8) comprises two contact pads (80) in contact with the frame (10) of the racket (R), each contact pad being mounted in a branch (82) of the V-shaped member (8), and each of these contact pads (80) being capable of rotating along a rotation axis (X80) aligned with one of the branches (82) of the V-shaped member (8). A holding system according to claim 2, wherein the contact pad (80) comprises a contact portion (80a) intended to be supported on the frame (10) of the racket (R), and a pivot portion (80b) which is fastened to the contact portion (80a) and is rotatably mounted in the housing (84) of the V-shaped member (8). A retaining system according to claim 3, wherein the pivot portion (80b) has a cylindrical shape centered on the rotation axis (X80) of the contact pad (80). A retaining system according to one of claims 1 to 4, wherein each wedging member (6A-6D) is freely rotatable relative to the arm (4A-4D) on which the wedging member is mounted about a rotation axis (X6) perpendicular to the main plane (P2), and wherein each arm (4A-4D) includes a brake (12) configured to lock the angular position of the wedging member (6A-6D) about its rotation axis (X6). A retaining system according to claim 5, wherein each arm (4A-4D) comprises a guide member (14) which can be pivotally mounted on the wedging member (6A-6D) and can be pivotally and slidably connected to the arm (4A-4D) so as to guide the wedging member (6A-6D) to rotate relative to the arm (4A-4D). A retaining system according to claim 6, wherein one end of the guide member (14) connected to the arm (4A-4D) includes an elliptical orifice (140), a block (15) fixed to the arm is inserted into the elliptical orifice, and wherein the brake member (12) locks the position of the elliptical orifice (140) relative to the block (15). A retaining system according to one of claims 1 to 4, wherein the retaining system comprises: a first connecting member (20) connecting the first and second wedging members (6A, 6C) located on a first side of a longitudinal axis (X2) of the retaining system (2); and a second connecting member (22) connecting the third and fourth wedging members (6B, 6D) located on a second side of the longitudinal axis (X2) of the retaining system (2), wherein the first connecting member (20) can be pivotally connected to the first wedging member (6C) and can be connected to the retaining system (2) through an elliptical hole (20). 0) pivots and slides on the second wedging member (6A), and wherein the second connecting member (22) can be pivotally connected to the third wedging member (6C) and pivots and slides on the fourth wedging member (6D) through the elliptical opening (220), and wherein the position of the first wedging member (6C) relative to the elliptical opening (200) of the first connecting member (20) can be locked by a brake (12), and the position of the fourth wedging member (6D) relative to the elliptical opening (220) of the second connecting member (22) can be locked by a brake (12). A retention system according to one of claims 1 to 4, wherein the retention system comprises two additional wedging elements (16, 18) configured to bear against the inner edge (102) of the frame (10) in the racket head region (10A) of the racket (R) and in the intersection region between the frame (10) and the central axis (13) of the racket (R), respectively, and wherein the two additional wedging elements (16, 18) are provided with two V-shaped pieces intended to accommodate the inner edge (102) of the frame (10) of the racket (R). A racket stringing machine, characterized in that it comprises a racket support bracket, which is provided with a retaining system (2) according to one of claims 1 to 9.