JAW, WHEEL-HOLDER UNIT AND TYRE CHANGING APPARATUS

Abstract

A jaw (1) for clamping a wheel rim comprises a body (2) extending along a longitudinal orientation (L). The body (2) includes: a connecting portion (22) configured to be connected to the head of the wheel-holder unit; a base portion (21) extending along the longitudinal orientation (L); a first abutment wall (23) extending from the base portion (21) along a clamping orientation (R); a second abutment wall (24) extending from the base portion (21) along the clamping orientation (R) in a spacing-apart direction (VA) and longitudinally spaced from the first abutment wall (23) by a working distance (DL); an abutment surface (251), longitudinally interposed between the first abutment surface (23) and the second abutment surface (24) and including a first portion (251A) and a second portion (251B, 251C), disposed at an advanced position relative to the first portion (251A) in the spacing-apart direction (VA) of the clamping orientation (R) to come into contact with the wheel rim. The second portion is spaced from the first abutment wall (23) along the longitudinal orientation (L) by a first abutment distance (D1), greater than 30% of the working distance (DL).

Claims

1. A jaw for clamping a wheel rim in a tyre changing apparatus provided with a wheel-holder unit having a head, the jaw comprising a body extending along a longitudinal orientation, the body including: a connecting portion configured to be connected to the head of the wheel-holder unit; a base portion extending along the longitudinal orientation; a first abutment wall, extending from the base portion along a clamping orientation, perpendicular to the longitudinal orientation, in a spacing-apart direction, and along a transverse orientation, the transverse orientation being perpendicular to the longitudinal orientation and to the clamping orientation; a second abutment wall extending from the base portion along the clamping orientation in the spacing-apart direction, along the transverse orientation and longitudinally spaced from the first abutment wall by a working distance; an abutment surface, longitudinally interposed between the first abutment wall and the second abutment wall and smoothly connected thereto to delimit the body in the spacing-apart direction, between the first abutment wall and the second abutment wall, wherein the abutment surface comprises a first portion, smoothly connected to the first abutment wall, and a second portion, smoothly connected to the first portion and to the second abutment wall and including an inclined portion inclined relative to the first portion and relative to the longitudinal orientation, wherein the second portion of the abutment surface is located at an advanced position relative to the first portion in the spacing-apart direction of the clamping orientation, to come into contact with the wheel rim, wherein the second portion is spaced from the first abutment wall along the longitudinal orientation by a first abutment distance, greater than 30% of the working distance.

2. The jaw according to claim 1, comprising a switch element, movable between a first position, where it is at an advanced position relative to the abutment surface, in the spacing-apart direction of the clamping orientation, and a second position, where it is on the outside of the connecting zone, longitudinally interposed between the first abutment wall and the second abutment wall, and wherein the switch element comprises an inclined wall, configured to come into contact with the wheel rim and having a first end, which is proximal to the first abutment wall and which is aligned with the first portion of the abutment surface along the clamping orientation.

3. The jaw according to claim 2, wherein the first end of the inclined wall is spaced from the first abutment wall by a second abutment distance which is less than 30% of the working distance.

4. The jaw according to claim 2, comprising a first operating configuration, in which the switch element is at the first position and in which the inclined wall of the switch element is configured to abut against the wheel rim, and a second operating configuration, in which the switch element is at the second position and in which the second portion of the abutment surface is configured to abut against the wheel rim.

5. The jaw according to claim 2, wherein the switch element is removable from the body and wherein the second position of the switch element is a position where the switch element is removed from the body.

6. The jaw according to claim 2, wherein the second end of the inclined wall is at the same height or at a position behind the second end of the second abutment wall in the spacing-apart direction of the clamping orientation.

7. The jaw according to claim 2, wherein the body comprises a pin and a connecting hub made in the base portion, and wherein the switch element comprises a mounting hole, the pin being inserted into the connecting hub and into the mounting hole when the switch element is at the first position, so as to connect the switch element to the body of the jaw.

8. The jaw according to claim 2, wherein the switch element comprises a protrusion, protruding at least partly along the clamping orientation and, when the switch element is at the first position, extending along the longitudinal orientation, and wherein the abutment surface comprises a corresponding guide groove, extending along the longitudinal orientation, and wherein, when the switch element is at the first position, the protrusion is coupled to the guide groove of the abutment surface.

9. The jaw according to claim 1, comprising a wear element, located on an abutment surface of the first abutment wall and configured to come into contact with a wheel rim.

10. The jaw according to claim 1, wherein the first abutment wall and the second abutment wall each comprise a respective top surface including a corresponding plurality of studs.

11. The jaw according to claim 1, wherein the body comprises a socket, located at a position behind the first abutment wall along the longitudinal orientation in a direction of insertion oriented from the first abutment wall to the second abutment wall, and wherein the jaw comprises an extension, coupled to the socket and comprising an interface surface including a respective plurality of studs.

12. The jaw according to claim 1, wherein the first portion of the abutment surface is perpendicular to the first abutment wall.

13. A wheel-holder unit for a tyre changing apparatus, the wheel-holder unit comprising a head, the head being rotatable about an axis of rotation, and a lift actuator, connected to the head to move it along a trajectory having at least a vertical component, parallel to the weight force, wherein the head includes a plurality of jaws which are angularly spaced around the axis of rotation and which are movable towards and away from each other between a position where they are distal from, and a position where they are proximal to, the axis of rotation of the head, wherein each jaw of the plurality of jaws is a jaw for clamping a wheel rim in a tyre changing apparatus provided with a wheel-holder unit having a head, the jaw comprising a body extending along a longitudinal orientation, the body including: a connecting portion configured to be connected to the head of the wheel-holder unit; a base portion extending along the longitudinal orientation; a first abutment wall, extending from the base portion along a clamping orientation, perpendicular to the longitudinal orientation, in a spacing-apart direction, and along a transverse orientation, the transverse orientation being perpendicular to the longitudinal orientation and to the clamping orientation; a second abutment wall extending from the base portion along the clamping orientation in the spacing-apart direction, along the transverse orientation and longitudinally spaced from the first abutment wall by a working distance; an abutment surface, longitudinally interposed between the first abutment wall and the second abutment wall and smoothly connected thereto to delimit the body in the spacing-apart direction, between the first abutment wall and the second abutment wall, wherein the abutment surface comprises a first portion, smoothly connected to the first abutment wall, and a second portion, smoothly connected to the first portion and to the second abutment wall and including an inclined portion inclined relative to the first portion and relative to the longitudinal orientation, wherein the second portion of the abutment surface is located at an advanced position relative to the first portion in the spacing-apart direction of the clamping orientation, to come into contact with the wheel rim, wherein the second portion is spaced from the first abutment wall along the longitudinal orientation by a first abutment distance, greater than 30% of the working distance.

14. A method for mounting or demounting a wheel tyre on or from the corresponding rim, comprising the following steps: preparing a tyre changing apparatus, including a wheel-holder unit comprising a head, which rotates about an axis of rotation. and a plurality of jaws, which are angularly spaced around the axis of rotation of the head; moving the head and the wheel rim towards each other along a longitudinal orientation parallel to the axis of rotation to position the plurality of jaws inside the wheel; moving the jaws along a clamping orientation perpendicular to the axis of rotation towards or away from each other between a position distal from, and a position proximal to, the axis of rotation of the head; clamping the wheel rim with the plurality of jaws, where the rim is in contact with each jaw at an abutment surface thereof which is interposed along the longitudinal orientation between a first abutment wall and a second abutment wall, which are spaced from each other by a working distance; wherein the abutment surface comprises a first portion and a second portion, including an inclined portion that is inclined relative to the first portion, and wherein, in the step of clamping, the second portion is interposed along the clamping orientation, between the first portion and the rim, to come into contact with the wheel rim before the first portion does, and wherein the second portion is spaced from the first abutment wall, along the longitudinal orientation, by a first abutment distance, greater than 30% of the working distance.

15. The method according to claim 14, comprising a step of reconfiguring, in which a switch element of each jaw is moved between a working position, where it is superposed on the abutment surface to define a first configuration of the jaw, and a rest position, where the abutment surface is directly facing the rim to define a second configuration of the jaw, and wherein, in the first configuration of the jaw, the rim comes into contact with an inclined wall of the switch element, where the inclined wall is at least partly aligned with the first portion of the abutment surface along the clamping orientation.

16. The method according to claim 15, wherein, for each jaw, the first end of the inclined wall is spaced from the first abutment wall by a second abutment distance which is less than 30% of the working distance.

17. The method according to claim 14, wherein each jaw is moved between a first operating configuration, in which the switch element is at the first position and in which the inclined wall of the switch element is configured to abut against the wheel rim, and a second operating configuration, in which the switch element is at the second position and in which the second portion of the abutment surface is configured to abut against the wheel rim.

18. The method according to claim 14, wherein each jaw includes a wear element, located on an abutment surface of the first abutment wall, wherein the wear element and comes into contact with a wheel rim.

19. The method according to claim 14, wherein, for each jaw, the first abutment wall and the second abutment wall each comprise a respective top surface including a corresponding plurality of studs.

20. The method according to claim 14, wherein, for each jaw, the body comprises a socket, located at a position behind the first abutment wall along the longitudinal orientation in a direction of insertion oriented from the first abutment wall to the second abutment wall, and wherein the jaw comprises an extension, coupled to the socket and comprising an interface surface including a respective plurality of studs.

Description

BRIEF DESCRIPTION OF THE DRAWING FIGURES

[0057] These and other features will become more apparent from the following detailed description of a preferred embodiment, illustrated by way of non-limiting example in the accompanying drawings, in which:

[0058] FIG. 1 shows a perspective view of a tyre changing apparatus for mounting or demounting a tyre on or from the respective rim;

[0059] FIG. 2 shows a perspective view of a jaw according to this disclosure, in a first operating configuration;

[0060] FIGS. 3A and 3B show, respectively, a first and a second perspective view of the jaw of FIG. 1 in a second operating configuration;

[0061] FIG. 4 shows a side cross section of the jaw of FIGS. 3A and 3B;

[0062] FIGS. 5A and 5B illustrate the jaw in the operating configuration of FIG. 2 and in the operating configuration of FIG. 3, respectively, in contact with a wheel flange; and

[0063] FIGS. 6A and 6B illustrate a first embodiment and a second embodiment of an extension of the jaw of FIG. 2 or 3.

DETAILED DESCRIPTION

[0064] With reference to the accompanying drawings, the numeral 1 denotes a jaw for holding a wheel in a tyre changing apparatus.

[0065] The jaw 1 extends along a longitudinal orientation, between a first end 1A and a second end 1B. The jaw 1 also extends along a transverse orientation T, perpendicular to the longitudinal orientation T. The jaw 1 also extends radially along a clamping orientation R, perpendicular to the transverse orientation T and to the longitudinal orientation L.

[0066] The jaw 1 comprises a top surface 10, a first lateral surface 11, a second lateral surface 12 and a bottom surface 13.

[0067] In an embodiment, at least for some types of flanges, the top surface 10 of the jaw 1 is configured to come into contact with a flange of the wheel.

[0068] In a preferred embodiment, the jaw 1 comprises a body 2. In a preferred embodiment, the body 2 is a mechanical part moulded in one piece. At all events, even in the case where the body is moulded in one piece, different portions of the body 2 may be distinguished.

[0069] The body 2 comprises a base portion 21. The base portion 21 is opposite to the top surface 10 of the jaw. The base portion 21 defines the bottom surface 13 of the jaw 1. The base portion 21 comprises a connecting zone 22 which is configured to engage a corresponding connecting element of a wheel-holder unit. In an embodiment, the connecting zone 22 comprises a first hole 221 and a second hole 222, configured to receive respective connecting pins by which the jaw 1 is connected to the corresponding wheel-holder unit. The first hole 221 and the second hole 222 are spaced along the clamping orientation R. The first hole 221 and the second hole 222 are located in the proximity of the first end 1A of the jaw, along the longitudinal orientation L.

[0070] For convenience of description, the term “direction of insertion” VI is used herein to identify the direction along the longitudinal orientation L, directed from the first end 1A to the second end 1B of the jaw 1.

[0071] The body 2 comprises a first abutment wall 23. In an embodiment, the first abutment wall 23 is located downstream of the connecting zone 22 along the longitudinal orientation in the direction of insertion VI.

[0072] The first abutment wall 23 extends from the base portion 21 along the clamping orientation R between a first end 23A and a second end 23B.

[0073] The first abutment wall comprises a top surface 231, at the second end 23A of the first abutment wall 23, a first lateral surface 232 and a second lateral surface 233. The first lateral surface 232 is perpendicular to the longitudinal orientation L and facing in the direction opposite to the direction of insertion VI. The second lateral surface 233 is perpendicular to the longitudinal orientation L and facing in the direction of insertion VI.

[0074] In an embodiment, the top surface 231 of the first abutment wall 23 includes a first plurality of studs (bosses, spikes) 2311.

[0075] In an embodiment, the first abutment wall 23 comprises a recess 234, made at the second lateral surface 233. In an embodiment, the jaw 1 comprises a first wear pad 14. The first wear pad 14 is located inside the recess 234. In an embodiment, the depth of the recess is less than the thickness of the first wear pad 14 so that the first element to be abutted is the first wear pad 14 and not the second lateral surface 233 of the first abutment wall 23. In other words, the first wear pad 14 protrudes from the second lateral surface 233. The recess 234 is made between the first end 23A and the second end 23B of the first abutment wall 23, along the clamping orientation R. In an embodiment, the recess 234 has a square, rectangular or circular shape. The first wear pad 14 is shaped to match the recess 234 and is therefore square, rectangular or circular, depending on the embodiment selected for the recess 234.

[0076] In an embodiment, the recess 234 comprises a hollow 2341 on its bottom wall 234′. In an embodiment, the first wear pad 14 also comprises a corresponding pin. The pin of the first wear pad 14 engages in the hollow 2341 of the recess 234. This shape fit creates a more stable coupling between the recess 234 and the first wear pad 14.

[0077] In an embodiment, with regard to the first abutment wall 23, the first lateral surface 232 is smaller in surface extension than the second lateral surface 233 because the base portion 21 is connected to the first lateral surface 232 at a point higher up (further away from the bottom surface 13 of the jaw 1 along the clamping orientation R) than the connecting point where the base portion 21 is connected to the second lateral surface 233. This aspect is important because it allows more effectively limiting the bending stresses on the first abutment wall 23 which are, in most cases (predominantly) directed in the direction opposite to the direction of insertion VI.

[0078] The body 2 comprises a second abutment wall 24. In an embodiment, the second abutment wall 24 is located downstream of the first abutment wall 23 along the longitudinal orientation in the direction of insertion VI.

[0079] The second abutment wall 24 extends from the base portion 21 along the clamping orientation R between a first end 24A and a second end 24B.

[0080] The second abutment wall comprises a respective top surface 241, at its second end 24A, a respective first lateral surface 242 and a respective second lateral surface 243. The first lateral surface 242 is perpendicular to the longitudinal orientation L and facing in the direction opposite to the direction of insertion VI: in other words, it faces the first abutment wall 23. The second lateral surface 243 is perpendicular to the longitudinal orientation L and facing in the direction of insertion VI.

[0081] In an embodiment, the top surface 241 of the second abutment wall 24 includes a second plurality of studs (bosses, spikes) 2411.

[0082] In an embodiment, the second abutment wall 24 comprises a recess 244, made at the second lateral surface 243. In an embodiment, the jaw 1 comprises a second wear pad 15. The second wear pad 15 is located inside the recess 244 of the second abutment wall 24. In an embodiment, the depth of the recess 244 is less than the thickness of the second wear pad 15 so that the first element to be abutted is the second wear pad 15 and not the second lateral surface 243 of the second abutment wall 24. In other words, the second wear pad 15 protrudes from the second lateral surface 243. The recess 244 is made between the first end 24A and the second end 24B of the second abutment wall 24, along the clamping orientation R. The recess 244 may have a square, rectangular or circular shape. The second wear pad 15 is shaped to match the recess 244 and is therefore square, rectangular or circular, depending on the embodiment selected for the recess 244.

[0083] In an embodiment, the recess 244 comprises a hollow 2441 on its bottom wall 244′. In an embodiment, the second wear pad 15 also comprises a corresponding pin. The pin of the second wear pad 15 engages in the hollow 2441 of the recess 244. This shape fit creates a more stable coupling between the recess 244 and the second wear pad 15.

[0084] In an embodiment, the first lateral surface 242 is smaller in surface extension than the second lateral surface 243 because the base portion 21 is connected to the first lateral surface 242 at a point higher up (further away from the bottom surface 13 of the jaw 1 along the clamping orientation R) than the connecting point where the base portion 21 is connected to the second lateral surface 243.

[0085] This aspect is important because it allows more effectively limiting the bending stresses on the second abutment wall 24 which are, in most cases (predominantly) directed in the direction opposite to the direction of insertion VI.

[0086] The base portion 21 comprises an abutment portion 25. The abutment portion 25 is interposed between the first abutment wall 23 and the second abutment wall 24 along the longitudinal orientation L.

[0087] The abutment portion 25 extends longitudinally from the first abutment wall 23 to the second abutment wall 24 terminating thereat at a respective first transition point 25A and second transition point 25B.

[0088] The abutment portion 25 comprises an abutment surface 251, facing radially opposite to the bottom surface 13 of the jaw 1. In an embodiment, therefore, the abutment surface is, at least in one operating configuration, part of the top surface 10 of the jaw 1: that is, the surface adapted to come into contact with the rim flange.

[0089] In a preferred embodiment, the abutment surface 251 includes a flat portion 251A, where the abutment surface 251 is substantially parallel to a plane defined by the longitudinal orientation L and the transverse orientation T.

[0090] In a preferred embodiment, the abutment surface 251 includes an inclined portion 251B, where the abutment surface 251 is substantially inclined at an angle different from 0° and 180° to the plane defined by the longitudinal orientation L and the transverse orientation T. Preferably, at its inclined portion 251B, the abutment surface 251 is substantially inclined at an angle of between 30° and 60° A to the longitudinal orientation L (that is, to a plane parallel to the longitudinal orientation L and to the transverse orientation T).

[0091] In an embodiment, the first abutment wall 23 and the second abutment wall 24 are longitudinally spaced by a working distance DL.

[0092] In an embodiment, the longitudinal extension of the flat portion 251A of the abutment surface 251 is less than 9/10 of the working distance DL and greater than 1/10 of the working distance DL. In an embodiment, the longitudinal extension of the flat portion 251A of the abutment surface 251 is less than 8/10 of the working distance DL and greater than 2/10 of the working distance DL.

[0093] In an embodiment, the longitudinal extension of the flat portion 251A of the abutment surface 251 is less than 7/10 of the working distance DL and greater than 3/10 of the working distance DL.

[0094] In an embodiment, the abutment surface 251 comprises an additional flat portion 251C. The flat portion 251A is in contact with the first abutment wall 23 at the first transition point 25A. The additional flat portion 251C is in contact with the second abutment wall 24 at the second transition point 25B. Thus, along the longitudinal orientation L, the inclined portion 251B is interposed between the flat portion 251A and the additional flat portion 251C.

[0095] The additional flat portion 251C is not essential but defines a notch which may acts as a functional abutment for coupling the abutment portion 25 to other mechanical components.

[0096] In an embodiment, the first abutment wall 23 and the second abutment wall 24 are spaced by a working distance DL. More specifically, the working distance DL is the longitudinal distance between the first lateral surface 232 of the first abutment wall 23 and the second lateral surface 243 of the second abutment surface 24.

[0097] The flat portion 251A—that is, the first portion 251A—is spaced along the longitudinal orientation L by a first abutment distance D1, which is greater than 30% of the working distance DL.

[0098] In an embodiment, the flat portion 251A has a longitudinal extension of between 10 mm and 50 mm. In an embodiment, the flat portion 251A has a longitudinal extension of between 15 mm and 45 mm. In an embodiment, the flat portion 251A has a longitudinal extension of between 20 mm and 35 mm. In an embodiment, the flat portion 251A has a longitudinal extension equal to 29.5 mm.

[0099] In an embodiment, the inclined wall 251B is inclined to the longitudinal orientation L at an angle between 10° and 50°.

[0100] In an embodiment, the inclined wall 251B is inclined at an angle between 20° and 45° to the longitudinal orientation L.

[0101] In an embodiment, the inclined wall 251B is inclined at an angle between 30° and 40° to the longitudinal orientation L.

[0102] In an embodiment, the inclined wall 251B is inclined at an angle of 36° to the longitudinal orientation L.

[0103] In an embodiment, the abutment portion 25 comprises a guide groove 252. The guide groove 252 is made in the abutment surface 251. The guide groove 252 has a longitudinal extension.

[0104] In an embodiment, the guide groove 252 extends from the flat portion 251A of the abutment surface 251 and terminates at the inclined portion 251B of the abutment surface 251.

[0105] In an embodiment, the guide groove 252 extends along the full longitudinal length of the flat portion 251A and terminates at the first abutment wall 23. In an embodiment, the guide groove 252 extends along the full longitudinal length of the inclined portion 251B of the abutment surface 251, stopping at the additional flat portion 251C, if present, or giving onto the second abutment wall 24 in the case where the additional flat portion 251C is not present.

[0106] In an embodiment, the transverse extension of the abutment surface is variable along the longitudinal orientation L.

[0107] More specifically, in an embodiment, the transverse extension of the abutment surface 251 in the proximity of the first abutment wall 23 is greater than the transverse extension of the abutment surface 251 in the proximity of the second abutment wall 24.

[0108] For convenience of description, the term “spacing-apart direction” VA is used in this disclosure to denote the direction from the bottom surface 13 to the top surface 11 of the jaw 1, along the clamping orientation R.

[0109] In an embodiment, the jaw 1 comprises a switch element 3.

[0110] The switch element 3 is movable between a working position PL, where it is positioned downstream of the abutment portion 25 in the spacing-apart direction VA along the clamping orientation R, and a rest position PR. At the rest position PR, the switch element 3 may adopt one of the following positions: a position where it is radially misaligned with the abutment portion; a position where the switch element 3 is radially aligned with the abutment portion 25 but where it is positioned upstream of the bottom surface 13 in the spacing-apart direction VA; a removed position where the switch element 3 is spaced from and completely clear of the body 2 of the jaw.

[0111] Thus, at the working position PL, the switch element 3 is superposed on the abutment surface 251 to define another interface adapted to come into contact with the rim flange.

[0112] More specifically, the switch element 3 comprises an inclined wall 31 which extends from a first end 31A and a second end 31B and which acts as an abutment for the rim flange instead of the abutment surface 251.

[0113] In an embodiment, the inclined wall 31 of the switch 3, when the latter is at the first operating position, is parallel to the inclined portion 251B of the abutment surface 251.

[0114] Therefore, at least two operating configurations of the jaw 1 can be defined: [0115] a first operating configuration, in which the switch element is at the rest position PR and in which the flange abuts against the abutment surface 251 and the first abutment wall 23 (the first wear pad 14); [0116] a second operating configuration, in which the switch element is at the working position PL and in which the flange abuts against the switch element 3 and the first abutment wall 23 (the first wear pad 14).

[0117] Thus, the jaw 1 is configurable between the first operating configuration and the second operating configuration by modifying the position of the switch element 3.

[0118] Thanks to these features, which allow the jaw to be reconfigured, an operator can use the same jaw 1 to work on wheels having different rim flange thicknesses.

[0119] More in detail, when working on wheels whose flange thickness is relatively large, the jaw 1 is in the first operating configuration (switch element 3 at the rest position PR) and the flange abuts against the abutment surface 251.

[0120] For smaller flange thicknesses, on the other hand, the jaw 1 is at the second operating configuration (switch element 3 at the working position PL) and the flange abuts against the inclined wall 31 of the switch element 3.

[0121] The first end 31A of the inclined wall 31 is spaced from the first abutment wall 23 by a second abutment distance D2, which is smaller than the first abutment distance D1. More specifically, the second abutment distance D2 is less than 20% of the working distance DL, preferably less than 10% of the working distance DL.

[0122] In an embodiment, the switch element 3 comprises a first side wall 32 and a second side wall 33, which extend from the inclined wall 31.

[0123] The first and second side walls 32, 33 are parallel to each other. In an embodiment, the first side wall 32 comprises, at the end of it distal from the inclined wall 31, a first mounting hole 321 that passes through the first side wall 32.

[0124] In an embodiment, the second side wall 33 comprises, at the end of it distal from the inclined wall 31, a second mounting hole 331 that passes through the second side wall 33.

[0125] In an embodiment, the inclined wall 31 has a facing surface 311 and a coupling surface 312, opposite to the facing surface 311.

[0126] The switch element 3 comprises a protrusion 34 on the coupling surface 312. The protrusion 34 extends (protrudes) from the coupling surface 312.

[0127] In an embodiment, the inclined wall 31 includes a first interface portion 313 and a second interface portion 314 at its first end 31A and second end 31B.

[0128] In an embodiment, when the switch element 3 is at the working position, the inclined wall 31 is positioned above the abutment surface 251 along the clamping orientation in the spacing-apart direction VA.

[0129] In an embodiment, when the switch element 3 is at the working position PL, the coupling surface 312 is in contact with the abutment surface 251.

[0130] More specifically, the protrusion 34 of the switch element 3 is received in the guide groove 252.

[0131] In an embodiment, when the switch element 3 is at the working position PL, the first lateral surface 32 and the second lateral surface 33 extend in parallel with the first lateral surface 11 and the second lateral surface 12 of the jaw 1, respectively.

[0132] In an embodiment, when the switch element 3 is at the working position PL, the first interface portion 313 of the switch element is in contact with the first transition point 25A, preferably abutting against the flat portion 251A of the abutment surface 251.

[0133] In an embodiment, when the switch element 3 is at the working position PL, the second interface portion 314 of the switch element 3 is in contact with (abuts against) the additional flat portion 251C of the abutment surface 251.

[0134] In an embodiment, the base portion 21 comprises a connecting hub 211. Preferably, the connecting hub 221 is interposed between the first abutment wall 23 and the second abutment wall 24 along the longitudinal orientation L.

[0135] In an embodiment, the connecting hub 211 passes through the body 2 of the jaw 1 along the transverse orientation T.

[0136] In other embodiments, the base portion comprises two connecting hubs 211A, 211B, located on the first lateral surface 11 and on the second lateral surface 12, respectively. The connecting hubs 211A, 211B do not pass through the jaw body.

[0137] In an embodiment, when the switch element 3 is at the working position PL, the connecting hub 211 is aligned along the transverse orientation T with the first mounting hole 321 and the second mounting hole 331 of the switch element 3.

[0138] More specifically, the jaw 1 comprises a mounting pin 16. When the switch element 3 is at the working position PL, the mounting pin 16 passes through the first mounting hole 321, the second mounting hole 331 and the connecting hub 211, to lock the switch element 3 to the body 2 of the jaw 1. When the switch element 3 is at the rest position PR, the pin 16 is, in an embodiment, removed from the mounting holes.

[0139] In an embodiment, the jaw 1 comprises two mounting pins 16A, 16B, each configured to be inserted into a corresponding connecting hub 211A, 211B.

[0140] In an embodiment, when the switch element 3 is at the working position PL, each mounting pin 16A, 16B passes through the respective first or second mounting hole 321, 331 of the switch element 3 and is inserted into the respective connecting hub 211A, 211B of the body 2.

[0141] In an embodiment, the operating unit 2 comprises a socket 26. The socket 26 is located downstream of the first abutment wall 23 along the longitudinal orientation L in the direction of insertion VI.

[0142] The socket 26 is made in the body 2. The socket 26 extends along the clamping orientation R. In an embodiment, the socket 26 has a circular cross section. Alternatively, the socket 26 may have a rectangular or prismatic cross section.

[0143] In an embodiment, the jaw 1 comprises an extension 4.

[0144] The extension 4 is configured to be inserted into the socket 26. More specifically, the extension 4 is movable between an inserted position PI, where it is partly housed in the socket 26, and an extracted position, where the extension 4 is removed from the socket 26.

[0145] In an embodiment, when the extension 4 is at the inserted position PI, it extends radially between a first end 4A and a second end 4B. The extension 4 comprises an end fitting 41, configured to be inserted into the socket 26. The end fitting 41 is shaped to match the cross section of the socket 26.

[0146] The extension 4 comprises an interface element 42, located at the second end 4B. The interface element 42 comprises a plurality of spikes 421, oriented in the spacing-apart direction VA to come into abutment against an inside surface of the wheel rim.

[0147] In an embodiment, the jaw 1 comprises a tip 5, disposed along the longitudinal orientation L in the direction of insertion VI at an advanced position relative to the second abutment wall 24.

[0148] More specifically, in an embodiment, the tip 5 has a profile which includes a first stretch 51, a second stretch 52 and/or a third stretch 53. More specifically, the first stretch 51 of the tip 5 is smoothly connected to the second abutment wall 24 at the first lateral surface 242 thereof. In an embodiment, the first stretch 51 is flat and substantially parallel to the longitudinal orientation L.

[0149] The second stretch 52 is smoothly connected to the first stretch 51. The second stretch 52 is inclined relative to the first stretch 51. The second stretch 52 is inclined relative to the longitudinal orientation L.

[0150] The third stretch 53 is located at the end of the jaw 1 further away from the chuck and closer to the rim. The third stretch 53 is smoothly connected to the second stretch 52. The third stretch 53 is inclined relative to the second stretch 52. The third stretch 53 is inclined relative to the longitudinal orientation L. In an embodiment, the third stretch 53 is flat and parallel to the longitudinal orientation L.

[0151] According to an aspect of it, this disclosure provides a wheel-holder unit for a tyre changing apparatus 100. The wheel-holder unit is configured to clamp and move the wheel during the mounting and demounting operations carried out by the tyre changing apparatus 100.

[0152] More specifically, the wheel-holder unit comprises a head which rotates about an axis of rotation A. The head is movable along the axis of rotation A towards and away from the wheel.

[0153] The head comprises a plurality of jaws, where each jaw 1 is a jaw according to one or more of the features described in this disclosure. The jaws 1 are angularly spaced around the axis of rotation A. The jaws 1 disposed on the head are movable along a clamping orientation R towards and away from each other in order to grip the wheel rim.

[0154] Each jaw 1 is connected to the head at its connecting zone 22, at the first hole 221 of the connecting zone and/or at the second hole 222 of the connecting zone.

[0155] According to one aspect of it, this disclosure provides a tyre changing apparatus 100 for mounting or demounting a tyre on or from the corresponding wheel rim. The tyre changing apparatus 100 comprises a wheel-holder unit 101 including one or more of the features described in this disclosure.

[0156] The tyre changing apparatus 100 includes a plurality of jaws 1 including one or more of the features described in this disclosure.

[0157] According to an aspect of it, this disclosure provides a method for mounting or demounting a wheel tyre on or from the corresponding rim.

[0158] The method comprises a step of preparing a tyre changing apparatus 100, including a wheel-holder unit 101 comprising a head 102, which rotates about an axis of rotation A, and a plurality of jaws 1, which are angularly spaced around the axis of rotation A of the head 102.

[0159] The method comprises a step of moving the head 102 along the axis of rotation A in a direction of insertion VI, to position the plurality of jaws 1 inside the wheel rim.

[0160] In an embodiment, the method comprises a step of moving the wheel along the axis of rotation A in a direction opposite to the direction of insertion VI—that is, towards the head 102 until the plurality of jaws are positioned inside the wheel rim. The method comprises a step of moving the jaws away from each other from a proximal position to a distal position relative to the axis of rotation A of the head 102.

[0161] The method comprises a step of gripping (a flange of) the wheel rim with the plurality of jaws 1, with the rim in contact with an abutment surface 251 of each jaw 1.

[0162] The abutment surface 251 of each jaw 1 used in this method comprises a first portion, which is parallel to the axis of rotation A of the chuck, and a second portion, which is inclined to and divergent from the axis of rotation A in the direction of insertion.

[0163] In the step of gripping, the second portion (the inclined portion) comes into contact with the wheel rim.

[0164] The method comprises a step of mounting and/or demounting in which a working tool comes into contact with the wheel tyre to mount it on, or remove it from, the respective rim.

[0165] The method comprises a step of moving the jaws towards each other from the distal position to the proximal position relative to the axis of rotation A of the head, so as to release the wheel after having performed the mounting or demounting operations.

[0166] In an embodiment, the method comprises a step of reconfiguring in which a switch element 3 of each jaw 1 is moved between a working position PL, where it is superposed on the abutment surface 251 along the clamping orientation R to define a first configuration of the jaw 1, and a rest position PR, where the abutment surface 251 is directly facing the rim to define a second configuration of the jaw.

[0167] In an embodiment, when the jaw is in the first configuration, the rim comes in to contact with an inclined wall 31 of the switch element 3.

[0168] In an embodiment, the step of reconfiguring comprises a step of removing, in which the switch element 3 is removed from the body 2 of the jaw 1 when it is at the rest position PR. The step of configuring comprises a step of engaging the switch element 3 to a body 2 of the jaw 1. More specifically, the switch element 3 comprises a first mounting hole 321 and a second mounting hole 331 which are aligned with a connecting hub 211 (or with two connecting hubs 211A, 211B). In a further possible embodiment (not illustrated), the switch element 3 is movable relative to the body 2 thanks to pins (connected to the switch element) which slide in respective slots made in the body 2; the role of the pins and the slots might be exchanged.

[0169] Next, a mounting pin 16 is inserted through the first mounting hole 321, through the second mounting hole 331 and through the connecting hub 211. Alternatively, if there are two mounting pins 16A, 16B, each of the mounting pins 16A and 16B is inserted into a respective mounting hole 321, 331 and into a respective connecting hub 211A, 211B. That way, the switch element 3 is fixed to the body 2 of the jaw 1.