MECHANISM FOR HOLDING AND ROTATING A WHEEL

Abstract

Mechanism for Holding and Rotating a Wheel The present invention relates to a mechanism (1) for holding and rotating a wheel for a tire mounting / dismounting device (2). The mechanism (1) comprises at least one articulated arm (5) receiving at its free end said mechanism (1). The mechanism (1) comprises at least one chuck (10) arranged to hold a wheel and transmission means (11) for rotating the chuck (10) about an axis (3) of rotation. The mechanism (1) is notable in that the transmission means (11) are of the flexible transmission type and comprise at least: - an actuator (31) arranged to be fixed on the arm (5) and rotating a drive pulley (32) about an axis (33) parallel to the axis (3) of rotation of the chuck (10), - a driven pulley (34) fixed to the end of the chuck (10) and rotating about said axis (3), and - a belt without end (35) surrounding the drive and driven pulleys (32,34). Fig 1

Description

Title of the invention: MECHANISM FOR HOLDING AND ROTATING A WHEEL Technical field of the invention

[0001] The present invention relates to the general field of mounting / dismounting tires for vehicles, primarily heavy goods vehicles. More specifically, it relates to a mechanism for holding and rotating a wheel for a tire mounting / dismounting device. State of the art

[0002] Many devices are already known that allow for the mounting / dismounting of tires, as well as their inflation, and that can be permanently installed in garages or in a light utility intervention vehicle.

[0003] The vast majority of known tire mounting / dismounting devices typically comprise at least a frame, an articulated arm at one end of said frame, a holding and rotation mechanism attached to the free end of said arm and arranged to secure and rotate a wheel around a first substantially horizontal axis of rotation, and a tool holder equipped with at least one tire mounting / dismounting tool, said tool holder being retractable and able to be translated relative to said arm to position said tool in different working positions. Furthermore, said arm and tool holder are movable in order to position the chuck and the tool in their respective working positions.

[0004] The multiple mobility of these tire mounting / dismounting devices is particularly interesting because it allows not only the wheel to be retrieved and manipulated and the tire to be dismounted / remounted without effort for the operator, but also very compact tire mounting / dismounting devices once the arm-tool holder assembly is folded onto the chassis.

[0005] On these tire mounting / dismounting devices, the holding and rotation mechanism includes in particular a chuck allowing the wheel to be gripped at the rim using expanding jaws.

[0006] Furthermore, given the rotation of the chuck and the efforts involved in mounting / dismounting the tire from the rim, the gripping force exerted by said jaws on the rim must be significant and durable.

[0007] For the rotational drive of the chuck, a conventional worm gear transmission is used. This type of transmission is advantageous because it is compact and offers a high reduction ratio.

[0008] However, it has a number of disadvantages, namely: requiring good lubrication, good sealing, and therefore good manufacturing precision, but also a significant energy requirement to compensate for its deplorable efficiency due to friction between the transmission elements. Summary of the invention

[0009] The aim of the present invention is therefore to propose an alternative to the known mechanism for holding and rotating a wheel for a tire mounting / dismounting device, said mechanism being compact, easy to implement and easy to maintain, while offering much better energy efficiency.

[0010] According to the invention, a mechanism for holding and rotating a wheel for a tire mounting / dismounting device is proposed, comprising at least one articulated arm at one end of a frame and receiving said mechanism at its free end, the latter comprising at least one chuck arranged to hold a wheel and transmission means for rotating the chuck around an axis of rotation, said chuck being of the expanding type and comprising at least a plurality of jaws and an actuator setting said jaws in motion, said mechanism being notable in that the transmission means are of the flexible transmission type and comprise at least: - an actuator arranged to be fixed to the arm and rotating a drive pulley around an axis parallel to the axis of rotation of the chuck, - a driven pulley fixed to the end of the chuck, located on the opposite side of the jaws, and rotating around said axis, and - an endless band surrounding the drive and driven pulleys so that the rotation of the drive pulley causes the rotation of the driven pulley, and therefore the rotation of the chuck.

[0011] Advantageously, the actuator is then of the high-torque type.

[0012] The actuator control means enabling the expansion of the chuck jaws advantageously pass through the endless belt.

[0013] Advantageously, the actuator is either of the type of orbital internal gear hydraulic motor, or a synchronous or asynchronous electric motor associated with a reducer of the strain wave type.

[0014] Preferably, the actuator can be modulated in rotational speed.

[0015] Advantageously, the endless belt is a synchronous belt or a chain and in that the first and second pulleys are provided with suitable teeth.

[0016] According to an advantageous embodiment, the chuck comprises at least: - a base on which the actuator is fixed on the opposite side of the jaws, - a plurality of sleeves, each fixed in a removable manner to said base, - a plate mounted pivoting at least on each of said sleeves around an axis perpendicular to the axis of rotation of the chuck and on which one of the jaws is mounted pivoting around an axis parallel to the axis of pivoting of said plate, - a connecting rod mounted pivoting at its ends on each jaw and on the associated sleeve around axes parallel to the pivot axis of said plate, and - a guide roller mounted pivoting on the platform around an axis parallel to the pivot axis of said platform.

[0017] Preferably, the respective pivot axes of the plate, the jaw and the connecting rod are positioned so that their projections onto a perpendicular plane correspond to the vertices of a parallelogram.

[0018] According to an advantageous embodiment, the actuator is advantageously of the cylinder type whose rod is fixed at one of its ends to a piston sliding inside a body and in that it is pivotally mounted on the free end of the arm of the tire mounting / dismounting device around the axis of rotation of the chuck.

[0019] Advantageously, the rod receives a push plate and a pull plate, each extending perpendicularly to the longitudinal axis of said rod and being spaced so as to receive between them the guide roller associated with each of the jaws, said guide roller then being able to slide in a direction perpendicular to the longitudinal axis of the rod. Brief description of the figures

[0020] Other advantages and features will become clearer from the following description of an embodiment of the invention with reference to the accompanying schematic figures in which:

[0021] [Fig-1] is a perspective view of a mechanism for holding and rotating a wheel according to the invention, fitted to a tire mounting / dismounting device shown partially,

[0022] [Fig.2] is a perspective view of a mechanism for holding and rotating a wheel of the [Fig.1] partially disassembled,

[0023] [Fig.3] is a partial perspective view of the chuck of the mechanism for holding and rotating a wheel of the [Fig.1],

[0024] [Fig.4] is a partial exploded perspective view of the chuck of the [Fig.3]

[0025] [Fig.5] is an exploded partial cross-sectional view of the mandrel of [Fig.3]. Description of the implementation methods

[0026] With reference to Figures 1 to 4, a mechanism 1 for holding and rotating a wheel according to the invention is shown in accordance with the invention. placed on a tire mounting / dismounting device 2, said mechanism 1 being arranged to secure and rotate a wheel around a substantially horizontal axis of rotation 3.

[0027] In a known manner, said tire mounting / dismounting device 2 comprises at least a frame 4, an arm 5 articulated at one end of said frame 4 and receiving at its free end said mechanism 1, and a tool holder 6 equipped with at least one tire mounting / dismounting tool, said tool holder 6 being able to move relative to said arm 5 to position said tool in working position, said tire mounting / dismounting device 2 further comprising a hydraulic unit, not shown, attached to the frame 4, able to distribute pressurized oil to at least indirectly, on the one hand, move the arm 5 in order to position the mechanism 1 and the tool in their respective working position and, on the other hand, possibly rotate the mechanism 1 around said axis 3 of rotation.

[0028] With reference to figures 3 and 4, the mechanism 1 for holding and rotating a wheel according to the invention is attached to the free end of the arm 5 of the tire mounting / dismounting device 2, advantageously attached to a frame 7 articulated on said free end, and includes at least one mandrel 10 arranged to hold a wheel, at the rim level and transmission means 11 allowing the mandrel 10, and consequently the mandrel 10 - wheel assembly, to be rotated around said axis 3 of rotation.

[0029] The chuck 10 is of the expanding type and comprises at least a plurality of jaws 12 and an actuator 13 moving said jaws 12 between a "closed" position in which the jaws 12 are in contact and an "open" position in which the jaws 12 are separated from each other.

[0030] For this purpose, with reference to [Fig. 4], said chuck 10 further advantageously comprises at least: - a base 14 on which said actuator 13 is fixed on the opposite side of the jaws 12, - a plurality of sleeves 15 each fixed, in a removable manner, on said base 14, advantageously by means of screws 16, - a plate 17 mounted pivoting at least on each of said sleeves 15 around an axis 18 perpendicular to the axis 3 of rotation of the chuck 10 and on which is mounted pivoting one of the jaws 12 around an axis 19 parallel to the axis 18 of pivoting of said plate 17, - a connecting rod 20 mounted pivotally at its ends on each jaw 12 and on the associated sleeve 15 around respectively the axes 21, 22 parallel to the pivot axis 18 of said plate 17, and - a guide roller 23 mounted pivoting on the plate 17 around an axis 24 parallel to the pivot axis 18 of said plate 17.

[0031] Advantageously, with reference to [Fig. 5], the respective pivot axes 18, 19, 21, 22 of the plate 17, the jaw 12, and the connecting rod 20 are positioned such that their projections onto a perpendicular plane correspond to the vertices of a parallelogram. This "deformable parallelogram" configuration prevents the jaws 12 from pivoting and thus keeps the gripping surface of the wheel rim parallel to the axis of rotation 3 of the chuck 10.

[0032] It is understood that, in order to effectively grip the wheel at the rim, the chuck 10 comprises at least three sleeve 15 - plate 17 - jaw 12 - connecting rod 20 assemblies, uniformly distributed angularly. However, the chuck 10 may have more than three sleeve 15 - plate 17 - jaw 12 - connecting rod 20 assemblies without departing from the scope of the present invention. Thus, in the embodiment shown in Figures 1 to 4, the chuck 10 comprises four sleeve 15 - plate 17 - jaw 12 - connecting rod 20 assemblies. Furthermore, with their particular configuration, each of the sleeve 15 - plate 17 - jaw 12 - connecting rod 20 assemblies can be fully assembled on a workbench and then mounted on the base 14 of the chuck 10, thereby facilitating its maintenance.

[0033] In addition, the chuck 10 is provided with reinforcement and protection plates 25, each arranged between two sleeves 15. These reinforcement and protection plates 25 allow the internal forces of the chuck 10 to be absorbed by the expansion force and the drive torque of the rim, but also to close the volume between the sleeve 15 - plate 17 - jaw 12 - connecting rod 20 assemblies for greater safety for the operator.

[0034] The actuator 13 is advantageously of the cylinder type in which the rod 26 is fixed at one of its ends to a piston 27 sliding inside a body 28 and can translate between at least one "retracted" position in which the rod 26 is retracted to the maximum in the body 28 and an "extended" position in which the rod 26 is at least partially extended from said body 28. Said actuator 13 may be of the electric or hydraulic type.

[0035] For reasons explained later, the actuator 13 is pivotally mounted on the free end of the arm 5 of the tire mounting / dismounting device 2 around the axis 3 of rotation of the chuck 10, the base 14 of the chuck 10 being fixed on one of the ends of the actuator 13 so that the rotation of the latter causes the rotation of the chuck 10 and, where applicable, of the chuck 10 - wheel assembly.

[0036] According to the embodiment shown in Figures 1 and 2, the body 28 of the actuator 13 passes completely through the frame 7 and is pivotally mounted on the latter. around the axis 3 of rotation of the chuck 10, the base 14 of the chuck 10 being then fixed on one of the ends of said body 28.

[0037] Furthermore, the free end of the rod 26 receives a push plate 29 and a pull plate 30, each extending perpendicularly to the longitudinal axis of said rod 26 and being spaced so as to receive between them the guide roller 23 associated with each of the jaws 12, said guide roller 23 being able to slide in a direction perpendicular to the longitudinal axis of the rod 26, the latter being parallel, and advantageously coaxial, to the axis 3 of rotation of the chuck 10. Thus, when the rod 26 moves from the retracted position to its extended position, each guide roller 23 slides in the direction of said rod 26, which has the effect of moving the associated jaw 12 from its "closed" position to its "open" position, and vice versa.

[0038] As described previously, the mechanism 1 for holding and rotating a wheel according to the invention also includes transmission means 11 for rotating the chuck 10. Advantageously, the transmission means 11 are of the flexible transmission type such as, for example, of the chain-pulley(s) or belt-pulley(s) type directly driving the chuck 10, i.e. without any other transmission or power reduction element.

[0039] This type of flexible transmission is interesting because it offers the following advantages: - operation with low energy losses, and therefore with better energy efficiency compared to that of a worm gear type transmission, - operation with minimal or no lubrication, - compactness, lightness and quiet operation, and - long operating life.

[0040] The transmission means 11 may also be of the external gear type, but this type of transmission requires significant lubrication.

[0041] Thus, according to the embodiment shown in Figures 1 and 2, the transmission means 11 comprise at least: - an actuator 31 fixed on the arm 5, advantageously on the frame 7, and rotating a drive pulley 32 around an axis 33 parallel to the axis 3 of rotation of the chuck 10, - a driven pulley 34 fixed on the end of the chuck 10, advantageously on the end of the body 28 of the actuator 13, located on the opposite side of the jaws 12, said driven pulley 34 then rotating about the axis 3 of rotation of the chuck 10, and - an endless belt 35 surrounding the driving and driven pulleys 32, 34 so that the rotation of the driving pulley 32 causes the rotation of the driven pulley 34, and therefore the rotation of the chuck 10 and, where applicable, of the chuck 10-wheel assembly.

[0042] According to the embodiment shown in Figures 1 and 2, the endless belt 35 is advantageously a synchronous belt, and the first and second pulleys 32, 34 are provided with suitable teeth. However, it is understood that the endless belt 35 could also be a chain, without departing from the scope of the present invention.

[0043] It is clear that with this configuration with the respective axes of rotation 33,3 of the driving and receiving pulleys 32,34 parallel to each other, the transmission means 11 are particularly compact.

[0044] Furthermore, the actuator 31 is advantageously either a hydraulic or electric motor that can be modulated in rotational speed.

[0045] Regarding the characteristics of the actuator 31, it is known that the maximum torque experienced at the chuck 10 - wheel assembly will not exceed 2000 Nm at 6 rpm. This maximum torque corresponds to the resisting torque due to the difficulty of removing the tire and opposing the rotation of said chuck 10 - wheel assembly. Given the overall reduction ratio of the transmission means 11, which is between 160 and 230, the actuator 31 is therefore of the high-torque type, meaning that the maximum torque at its shaft is between 500 and 600 Nm at 19 rpm. This maximum torque value is approximately twelve times higher than the maximum torque at the shaft of the worm gear drive motor commonly used in prior art wheel mounting and rotation mechanisms.

[0046] The reduction ratio, mentioned above, is also an important characteristic of the actuator 31, regardless of the embodiment chosen for the latter. Indeed, since the worm gear transmission has been replaced to improve the efficiency of the transmission means 11, it is necessary to maintain a similar reduction ratio, namely a value between 160 and 230.

[0047] Thus, assuming an actuator 31 of the hydraulic motor type, advantageously an orbital internal gear motor, this high value of the reduction ratio is obtained thanks to a high hydraulic displacement ratio, which acts as a hydraulic reducer.

[0048] Assuming an actuator 31 of the synchronous or asynchronous electric motor type, this high reduction ratio is achieved by means of a gearbox. For reasons of improved efficiency, said gearbox is advantageously of the strain-wave gear type, also called a harmonic gearbox. This type of gearbox also has the advantage of being compact, quiet, requiring little lubrication, and having low backlash.

[0049] Finally, the mechanism 1 for holding and rotating a wheel according to the invention is configured so that the control means of the actuator 13 allowing the expansion of the jaws 12 of the chuck 10 pass through the endless belt 35 in order to allow the replacement of the latter easily without needing to disconnect said control means (See [Fig.2]), which significantly simplifies the maintenance and servicing of said mechanism 1 for holding and rotating a wheel.

[0050] The mechanism 1 for holding and rotating a wheel according to the invention finds a particular application for a tire mounting / dismounting device mounted on a light utility vehicle to allow rapid intervention outside, but it goes without saying that it can be adapted on a tire mounting / dismounting device permanently installed in a garage or a shop specializing in vehicle maintenance and tire mounting / dismounting.

[0051] Finally, it goes without saying that the examples of mechanisms 1 for holding and rotating a wheel according to the invention which have just been described are only particular illustrations, in no way limiting of the invention.

Claims

Demands

1. A mechanism (1) for holding and rotating a wheel for a tire mounting / dismounting device (2) comprises at least one arm (5) articulated at one end of a frame (4) and receiving at its free end said mechanism (1), the latter comprising at least one chuck (10) arranged to hold a wheel and transmission means (11) for rotating the chuck (10) about an axis (3) of rotation, said chuck (10) being of the expanding type and comprising at least a plurality of jaws (12) and an actuator (13) moving said jaws (12), said mechanism (1) being characterized in that the transmission means (11) are of the flexible transmission type and comprise at least: - an actuator (31) arranged to be fixed on the arm (5) and rotating a drive pulley (32) about an axis (33) parallel to the axis (3) of rotation of the chuck (10), - a receiving pulley (34) fixed on the end of the chuck (10),located on the opposite side of the jaws (12), and rotating around said axis (3), and - an endless band (35) surrounding the driving and driven pulleys (32,34) so ​​that the rotation of the driving pulley (32) causes the rotation of the driven pulley (34), and therefore the rotation of the chuck (10).

2. Mechanism (1) according to claim 1 characterized in that the actuator (31) is such that the maximum torque at its axis is between 500 and 600 Nm at 19 rpm.

3. Mechanism (1) according to any one of claims 1 or 2 characterized in that the control means of the actuator (13) enabling the expansion of the jaws (12) of the chuck (10) pass through the endless belt (35).

4. Mechanism (1) according to any one of claims 1 to 3 characterized in that the actuator (31) is either of the hydraulic motor type, or a synchronous or asynchronous electric motor associated with a reducer.

5. Mechanism (1) according to claim 4 characterized in that the actuator (31) can be modulated in rotational speed.

6. Mechanism (1) according to any one of claims 1 to 5 characterized in that the endless belt (35) is a synchronous belt or a chain and in that the first and second pulleys (32,34) are provided with adapted teeth.

7. Mechanism (1) according to any one of claims 1 to 6, characterized in that the chuck (10) comprises at least: - a base (14) on which the actuator (13) is fixed on the opposite side of the jaws (12), - a plurality of sleeves (15), each fixed in a detachable manner to said base (14), - a plate (17) pivotally mounted at least on each of said sleeves (15) about an axis (18) perpendicular to the axis (3) of rotation of the chuck (10), and on which one of the jaws (12) is pivotally mounted about an axis (19) parallel to the axis (18) of pivoting of said plate (17), - a connecting rod (20) pivotally mounted at its ends on each jaw (12) and on the associated sleeve (15) about axes (21, 22) respectively, parallel to the axis (18) of pivoting of said plate (17), and - a guide roller (23) mounted pivoting on the plate (17) around an axis (24) parallel to the pivot axis (18) of said plate (17).

8. Mechanism (1) according to claim 7 characterized in that the respective pivot axes (18,19,21,22) of the plate (17), the jaw (12) and the connecting rod (20) are positioned so that their projections onto a perpendicular plane correspond to the vertices of a parallelogram.

9. Mechanism (1) according to any one of claims 1 to 8 characterized in that the actuator (13) is advantageously of the cylinder type whose rod (26) is fixed at one of its ends to a piston (27) sliding inside a body (28) and in that it is pivotally mounted on the free end of the arm (5) of the tire mounting / dismounting device (2) around the axis (3) of rotation of the chuck (10).

10. Mechanism (1) according to claims 7 and 9 characterized in that the rod (26) receives a push plate (29) and a pull plate (30), each extending perpendicularly to the longitudinal axis of said rod (26) and being spaced so as to receive between them the guide roller (23) associated with each of the jaws (12), said guide roller (23) which can then slide in a direction perpendicular to the longitudinal axis of the rod (26).

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