Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
  • B62M—RIDER PROPULSION OF WHEELED VEHICLES OR SLEDGES; POWERED PROPULSION OF SLEDGES OR SINGLE-TRACK CYCLES; TRANSMISSIONS SPECIALLY ADAPTED FOR SUCH VEHICLES
  • B62M11/00—Transmissions characterised by the use of interengaging toothed wheels or frictionally-engaging wheels
  • B62M11/04—Transmissions characterised by the use of interengaging toothed wheels or frictionally-engaging wheels of changeable ratio

Definitions

• the present invention relates to a gearbox, in particular for a cycle, and more specifically to a gearbox comprising in a fixed housing: - a motor plate intended to receive a rotation torque, and a receiver plate able to transmit a circular motion, said trays being mounted around a hub rotatably relative to the housing, facing each other, and each having a flange which protrude, in the direction of the opposite flange, several coaxial circular teeth; a central support disposed in the housing between the plates;
• At least one device for transmitting motion between the plates comprising at least one pinion capable of meshing with one of the teeth of at least one plate opposite which it is arranged, the or each pinion being rotatably mounted on a rocker assembled to the central support pivotally;
• the document FR 2 641 515 describes a gearbox for cycles in which the spacing means comprise balls resting on the back of the engine plate and cooperating with ramps projecting from the internal face of a pressure plate connected to the pedalboard. .
• the spacing means comprise balls resting on the back of the engine plate and cooperating with ramps projecting from the internal face of a pressure plate connected to the pedalboard. .
• the clutch it is necessary to cause an angular displacement of the pressure plate relative to the motor plate. For this, the cyclist must temporarily stop pedaling, which is not practical.
• the document FR 2 757 128 proposes a gearbox for cycles in which the spacing of the plates is obtained by a hydraulic system.
• the gearbox has a complex structure and is expensive.
• the invention aims to overcome the disadvantages of the prior art by providing spacing means having a simplified structure.
• Another object of the invention is to provide a robust gearbox, not requiring delicate adjustments.
• the invention relates to a gearbox as shown above, wherein the spacing means comprise a spacer member which, mounted on the central support pivotally about a transverse axis without possibility translationally relative to said support, can pivot, when the selection means are actuated to move from one speed to another, an engaged position, wherein the or each pinion meshes with a toothing of the corresponding plate, at a position disengaged, in which the plates are spaced from one another, said spacer member comprising at least one support member arranged to cooperate with a first bearing surface formed on a member integral in axial translation of a first plate and with a second bearing surface formed on an integral element in axial translation of a second plate, to cause, during the pivoting of the spacer member ve rs the disengaged position, the spacing of the central support relative to the second plate and the
• the spacing of the trays is obtained automatically during the change of speed, without the cyclist having to stop pedaling.
• the actuation of the spacing means can be obtained by a simple control rod.
• the invention makes it possible to maintain one of the two fixed plates in translation by providing the housing.
• the spacer member has for example the shape of a ring mounted to slide and pivot on the hub, this ring may comprise three support members arranged substantially at 120 ° and arranged to cooperate each with a first and a second surfaces of 'support.
• the first and second bearing surfaces are formed by a ramp formed on a finger protruding axially towards the spacer member from a first, respectively from a second sleeves mounted on the hub part and other of the central support.
• the support member of the spacer member comprises for example a roller of substantially radial axis, disposed in an axial housing open at its two axial ends, housing in which the bearing surfaces can be engaged.
• the spacing means comprise a lever which, mounted on the central support pivotally about a transverse axis, without the possibility of translation relative to said support, is associated with the spacer member, said lever being arranged to pivot relative to said support when the selection means are actuated to move from one speed to another and cause pivoting of the spacer member to the disengaged position.
• the spacer member is biased towards the engaged position by return means.
• the spacer member may comprise retaining means forming axial stops which, when the spacer member is in the engaged position, cooperate with the elements on which are formed the first and second bearing surfaces to prevent the inadvertent spacing of the trays.
• a radial clearance can be provided between the support member of the spacer member and firstly the first bearing surface and secondly the second bearing surface , said radial clearance being sufficient to allow a small pivoting of the spacer member to the disengaged position, so that the elements on which are formed the first and second bearing surfaces are released retaining means.
• the or each device for transmitting motion between the plates comprises two pinions meshing with each other, each pinion being able to mesh with one of the teeth of the plate opposite which it is arranged.
• the two trays turn in the same direction.
• the second plate forms the receiving plate and is integral with the housing in axial translation.
• the chain or the belt associated with the receiving plate works in a fixed plane.
• the gearbox may further comprise a motor disk intended to be rotated by the crank shaft of the cycle, the motor disk being rotatable relative to the housing and connected to the motor plate by at least two elastic members arranged to rotate the motor disk and the motor plate in rotation and bias the motor plate towards the receiving plate while allowing the axial translation of said motor plate relative to the motor disk.
• the or each device for transmitting motion between the trays comprises a single pinion adapted to mesh with one of the teeth of each of the trays. The two trays turn in opposite directions.
• the gearbox may comprise an actuating member mounted on the hub slidably along the axis transverse to the central support and bearing radially at its periphery connecting parts each engaged in a rocker and arranged to pivot the rockers relative to the central support when the actuating member is moved along the transverse axis by the speed selection means.
• a cycle comprising two gearboxes according to this second embodiment, mounted one on the pedal, the other on the axis of the rear wheel, and associated by means of the chain, may further comprise, mounted on the frame, a control device comprising:
• FIGS. 1 to 17 illustrate a first embodiment of the invention
• FIGS. to 27 a second embodiment of the invention:
• Figure 1 is a perspective view of a cycle comprising a gearbox according to a first embodiment of the invention
• Figures 2 and 3 are perspective views partially cutaway of the receiving plate, respectively of the motor plate, the gearbox;
• Figure 4 is a perspective view of a circular toothing of a tray
• 2 Figure 5 is a sectional view of the box in the engaged position speeds, with a maximum speed ratio
• Figure 6 is a sectional view of the gearbox in the disengaged position, with a minimum speed ratio
• Figure 7 is a perspective view of the central support provided with rockers and sprockets
• Figure 8 is a perspective view of the central support alone
• Figures 9 and 10 are perspective views of a rocker and the control rocker;
• Figure 11 is a partial perspective view of the gearbox in the engaged position, the rockers and the gears are not shown;
• Figure 12 is a perspective view of the spacer member
• Figures 13 and 14 are perspective views of the sleeves on the motor side, respectively on the receiver side;
• Figure 15 is a perspective view of the lever and the spacer member in the engaged position, showing the radial clearance between the rollers and the ramps;
• Figure 16 is a partial perspective view of the gearbox in the disengaged position, the rockers and the gears not being shown;
• Figure 17 is a partial perspective view of the interior of the gearbox
• Figure 18 is a perspective view of two speed boxes according to a second embodiment of the invention, mounted on a cycle (not shown) and associated by means of the chain;
• FIG. 19 is a perspective view of the elements of the figures
• Figure 23 is a perspective view of the two plates and pinions assembled to the actuating member
• Figure 24 is a sectional view of the rear gearbox in the disengaged position; and Figures 25 to 27 illustrate the control device, respectively in complete mounted position, in the mounted position without the protective covers and exploded (partially).
• FIG. 1 shows a cycle 1 comprising a gearbox 2 which makes it possible, when a user rotates the shaft 3 of the pedalboard by pressing the pedals 4, to rotate a chain 5, and thus the rear wheel of cycle 1.
• the gearbox 2 comprises a housing 6, fixed relative to the frame 7 of the cycle 1, traversed by a hub 8 of axis 9 transverse to the longitudinal direction of advance of the cycle 1. In the hub 8 is engaged the shaft 3 of the crankset.
• each plate 10, 11 comprises a series of coaxial circular teeth 12 disposed in an overmolded flange 13, the teeth 12 facing each other inside the housing 6.
• each plate comprises ten teeth 12.
• a motor disk 14 On the housing 6 is rotatably mounted a motor disk 14 having a central opening 15 star cooperating with the shaft 3 of the pedal.
• the motor disk 14 is thus rotated under the pedaling action of the cyclist.
• Six substantially axial springs 16 arranged at 60 ° around the hub 8 are connected on the one hand to the motor disk 14 and on the other hand to the motor plate 10, at the level of cavities 17. These springs 16 allow the driving in rotation of the motor plate 10 by the motor disk 14 and, as will be seen below, the displacement in axial translation of the motor plate 10 relative to the motor disk 14.
• a support 19 is mounted on the hub 8, movable in axial translation but fixed in rotation.
• the support 19 is generally plane and arranged centrally between the plates 10, 11.
• On the support 19 are mounted on the one hand a control rocker 20, shown in Figure 10, and on the other hand N rockers 21, such as illustrated in Figure 9, where N is between 1 and 5, each rocker 20, 21 being rotatably connected to adjacent rockers.
• a rocker 21 comprises a rod 22 having end portions inclined relative to its longitudinal direction.
• the rod 22 comprises substantially in its central part a fastening member 23 provided with two pairs of notches 24 opposite.
• the control rocker 20 is of similar overall structure, but has an extension 25 beyond an inclined portion.
• the rockers 20, 21 are mounted on the support 19 by snapping into the grooves 26, and can pivot relative to the support 19 about the axis of their rod 22, located substantially in the plane of said support 19.
• the inclined end portions of the tilters 20, 21 are connected to each other.
• each rocker is rotatably connected to the adjacent rockers by a cardan 27, which has many advantages (mechanical precision, no adjustment required, speed of assembly, reduced cost).
• the support 19 comprises four rockers. including a control rocker, arranged at right angles to the periphery of the support 19, the control rocker 20 being arranged vertically. This structure allows a good distribution of efforts on the gears.
• each rocker On each rocker are fixed two pinions 28, latched by their axis in the notches 24 of the fastener.
• the pinions 28 of the same rocker substantially identical, meshing with each other.
• one of the pinions 28 is intended to mesh with a toothing 12 of the motor plate 10
• the other pinion 28 is intended to mesh with a toothing 12 of the receiving plate 11, the toothing 12 of the receiving plate 11 being determined relative to the toothing 12 of the motor plate 10 in that the two pinions 28 are located in the same plane.
• a polyurethane ring 29 is interposed between each pinion 28 and the corresponding rocker 20, 21, between the rotating part of the pinion 28 and the portion of the pinion 28 fixed relative to the rocker 20, 21 (that is to say its support axis snapped onto the rocker). This gives the system greater flexibility and makes the mechanism quieter.
• On the support 19 is also mounted a notched sector 30, disposed in a substantially horizontal plane, and in an opening 31 of which is fixed the extension 25 of the control rocker 20.
• the notched sector 30 forms curved housings between two adjacent notches, for example substantially cylindrical housing with a vertical axis.
• the opening 31 has for example a square section.
• an arm 32 associated with a rod (not shown) or, alternatively, a cable or a jack.
• the cyclist actuates said rod, it causes, via the arm 32, the rotation of the control rocker 20 around the vertical axis of its rod 22 and, consequently, by means of the universal joints 27, an identical rotation of the rockers 21.
• the inclination of the pinions 28 relative to the plates 10, 11 varies, which allows the cyclist to select the desired speed according to the toothing 12 in which the pinions 28 meshing.
• a limit-stop element 71 integral with the support 19, makes it possible to limit the rotation of the control rocker. 20 and thus to define an extreme position of inclination of the pinions 28.
• the gearbox 2 is provided with spacing means of the two plates.
• the spacer member 33 has the general shape of a ring. It is mounted around the hub 8, in a manner that is mobile in rotation and in translation relative to the axis 9. It is also housed substantially in the central opening 34 of the support 19, on the side of the motor plate 10, and secured in translation, but not in rotation, relative to said support 19 by means of clips 35.
• the spacer member 33 comprises three substantially identical housings 36, each having orthogonally to the axis 9 of the hub 8 a rectangular section. Each housing 36 is thus delimited by first and second radial walls 37, 38, and is open to both of them. axial ends. In each housing 36 is provided a substantially radial axis 39.
• This axis 39 is not centrally disposed in the housing 36 but offset to the first radial wall 37 of the housing 36.
• On each of the axes 39 are mounted two rollers 40, providing a space between them and the second radial wall 38 of the housing 36.
• a bar 41 is disposed substantially axially outside each housing 36, against the second radial wall 38.
• Each bar 41 has projections 42 extending on either side of the ring towards the housing 36 corresponding, being spaced axially from the axial ends of said housing 36.
• the spacer member 33 comprises radial tabs 43 each provided with a notch 44.
• the spacing means of the two plates also comprise a lever 45 extending substantially parallel to the support 19 and horizontally, on the side of the motor plate 10.
• the lever 45 has a first end portion 46 connected to the support 19, under the notched sector 30 , pivotally about an axis 69 parallel to the axis 9 of the hub 8, and a second end portion 47 curved downwards, and having notches 48.
• the lever 45 is assembled to the spacer member 33 by means of a connecting element 49 having at its ends two axial journals 50, 51 snapped respectively into the notches 48 of the lever and the notches 44 of the tabs 43 of the spacer member 33.
• the lever 45 further comprises a lateral branch 52 extending substantially axially towards the receiving plate 11, from the first end portion 46 of the lever 45.
• the lever 45 comprises a cylinder 53 rotatably mounted about its axis, and able to cooperate with one of the housings formed between two notches of the toothed sector 30.
• This cylinder 53 is disposed on the lateral branch 52 of the lever 45. It has a substantially vertical axis, and is set in a casing 70 (not shown in FIG. the rotation of said cylinder 53 about its axis.
• the cylinder 53 could be replaced by a tooth extending parallel to the support 19, towards the first end portion 46 of the lever 45, said tooth being adapted to cooperate with the notches of the notched sector 30.
• a spring 54 disposed substantially parallel to the lever 45 is provided between the support 19 and the lever 45.
• the spacing means of the two plates finally comprise a first sleeve 55 and a second sleeve 56, respectively shown in FIGS. 13 and 14.
• Each sleeve 55, 56 comprises a ring 57 engaged around the hub 8 and from which three axial fingers 58 project at 120 °.
• Each finger 58 has at its end an inclined surface forming a ramp 59.
• the first sleeve 55 is intended to be placed between the motor plate 10 and the support 19. Its ring 57 has three holes 60 at 120 ° in each of which is housed a ball 61 engaged in a groove 62 formed axially on the hub 8. The first sleeve 55 can slide axially on the hub 8 without the possibility of rotation.
• the first sleeve 55 is mounted on the hub 8 so that the ring 57 is housed in the central opening of the motor plate 10 and the fingers 58 extend towards the support 19, the shoulder 63 formed between the ring 57 and the fingers 58 bearing against a bearing 64 interposed between said ring 57 and the motor plate 10.
• each finger 58 comprises a main portion 65 connected to the ring 57 extended by a substantially triangular end portion 66, which has an inner diameter and an outer diameter larger than the inner diameter, respectively the outer diameter of the main portion 65.
• An outer shoulder 67 is thus formed between the main portion ale 65 of each finger 58 and the end portion 66 of said finger, while there is a space between the end portion 66 of the finger and the hub 8.
• the second sleeve 56 is intended to be placed between the receiving plate 11 and the support 19, the ring 57 being fixed to the hub 8.
• the second sleeve 56 and the hub 8 can be made in one piece.
• the second sleeve 56 is mounted on the hub 8 so that the fingers 58 extend towards the support 19.
• the end portion of each of the fingers 58 is then engaged in a housing 36 of the spacer member 33, in the space between the rollers 40 and the second radial wall 38, the ramp 59 being directed towards the rollers 40.
• the inner and outer diameters of the fingers 58 of the second sleeve 56 substantially correspond to the inner and outer diameters of the main portion 65 of the fingers 58 of first sleeve 55.
• each finger 58 of the second sleeve 56 is located in the housing 36 corresponding between the finger 58 of the first sleeve 55 and the hub 8.
• a substantially radial lug 68 is provided in the immediate vicinity of the finger 58, on the opposite side to the ramp 59.
• the two plates 10, 11 are spaced from each other by the appropriate distance so that the pinions 38 each mesh with a toothing 12 of a plate and allow the transmission from the rotational movement of the motor plate 10 to the receiving plate 11.
• the cylinder 53 of the lever 45 is then engaged between two notches of the notched sector 30 corresponding to the chosen gear ratio.
• the spring 54 urges the lever 45 towards the clutch position, that is to say engagement of the cylinder 53 in the notched sector 30.
• the lever 45 via the element of connection 49, holds the spacer member 33 and prevents it from pivoting about the axis 9 of the hub 8 in the clockwise direction (when viewing said spacer member 33 from the motor plate 10).
• the projections 42 provided on each bar 41 of the spacer member 33 thus cooperate with the shoulder 67 of the first sleeve 55, on the one hand, and the lug 68 of the second sleeve 56, on the other hand.
• the spacer 33 holds the sleeves 55, 56 axially, thus preventing the trays 10, 11 from moving apart.
• the dimensions of the sleeves 55, 56, and in particular the inclinations of the ramps 59, are determined to obtain the desired spacing between the plates 10, 11 and the support 19.
• the notches of the notched sector 30, in number identical to the number of teeth 12 of a plate, and the rockers 20, 21 are arranged to cause a suitable inclination of the pinions 28 and ensure that each pinion is engaged in a single toothing 12.
• the travel of the motor plate 10 is of the order of 15 to 20 mm, for example 17 mm.
• the motor disk 14 slides axially around the shaft 3 of the pedal, but can continue to rotate the motor plate 10 through the central opening 15 star.
• the cyclist continues to actuate the control rod to cause pivoting of the rockers 20, 21 and the notched sector, the cylinder 53 falls into the housing adjacent to the one he just left, under the effect of the spring 54.
• the motor plate 10 is brought closer to the support 19, resulting, through the shoulder 63, the return of the first sleeve 55 in the position where his fingers 58 are engaged in the housing 36 of the spacer 33, but also the axial displacement of the support 19 towards the receiving plate 11.
• the pinions 28 meshing each again with a toothing 12 of the plate 10, 11 corresponding.
• the lever 45 makes it possible to increase the displacement, that is to say, to cause, from a small displacement of the cylinder 53 between two housings (of the order of 1.5 mm), a rotation of amplitude more important of the spacer member 33 and, ultimately, a significant translation of the motor plate 10 relative to the receiving plate 11, as indicated above.
• the gearbox 2 according to the invention provides for mounting many parts by snapping. This results in ease and speed of assembly improved over the prior art. In addition, it is not necessary to adjust the position of the parts relative to each other, which generally requires a great deal of precision and time. Referring now to Figures 18 to 27 which illustrate a second embodiment of the invention.
• the cycle comprises two gearboxes, namely a front gearbox 2a which is mounted on the crankset, and a rear gearbox 2b which is mounted on the axis of the rear wheel.
• the right plate of the front gearbox 2a is the engine plate, which is rotated by the cyclist pressing the pedals and transmits the movement to the receiving plate (left) and thus to the plateau 18 carrying the chain 5.
• this movement is transmitted to the chain sprocket 72 so the rear gearbox 2b at the receiving plate (left) which transmits the movement to the receiving plate (right).
• each gearbox comprises three pinions 28, but of course a different number of gears can be provided.
• the central support 19 (FIG. 19) comprises a main part in the general shape of a ring defining three lobes 73 open towards the axis 9, and an axial hollow tube 74 offset axially with respect to the overall plane of the ring and secured thereto. by three oblique screws 75.
• An actuating member 76 (FIG. 20) comprises a ring 77 extended by three tabs 78 whose free end forms a cylindrical housing 79 for a portion of a T-shaped connecting piece 80 forming a ball joint .
• the actuating member 76 comprises an axial rod 81 secured to the ring 77 by three oblique spokes 82 and extended by a return spring 83.
• the actuating member 76 is mounted on the hub, the rod axial 81 being inserted into the hollow tube 74.
• Each pinion 28 is rotatably mounted on a rocker 20, 21 about an axis 84 ( Figure 21), the rocker 20, 21 itself being pivotally mounted in a lobe 73 of the support central 19.
• the rocker 20, 21 comprises opposed cylindrical appendages 85 engaged in orifices 86 formed in the opposite walls of the lobes 73.
• each rocker 20, 21 has a cavity 87 receiving another part of the T-piece 80 (FIG. 22). Consequently, the displacement along the axis 9 of the actuating member 76 leads to the pivoting of the rockers 20, 21 around the axis 88 joining the two opposite orifices 86.
• lever 45 can be replaced by a hydraulic amplifier comprising a ball engaged in one of the slots of the notched sector 30, and connected to the spacer member 33 by pistons.
• the advantage of this structure is that a small displacement of the ball during a change of speed causes a large displacement of the spacer member 33 (multiplication of the amplitude of displacement by at least 5). It also avoids the presence of the lever 45 which is a long piece that can undergo significant deformation.
• a control device 89 for example mounted on the frame 7 of the cycle.
• the device 89 comprises a support plane 90, here triangular, provided with two pins 91 each extending on one side of the support, and defining a 92 axis transverse.
• a longitudinal input cable 93 passes through the support 90 and carries two rollers 94a, 94b of the same transverse axis, spaced apart from each other by a spring (not shown).
• the control device 89 also comprises a front selector 95a and a rear selector 95b substantially planar and each provided with a hole 96 for mounting each on a pin 91, on either side of the support 90.
• the selectors are thus mounted pivoting about the transverse axis 92.
• Each selector comprises a path of movement in broken line 97, provided with positioning notches 98, the roller 94a, 94b being able to move along the corresponding path and position itself in a notch 98.
• each selector 95a, 95b is integral with a lever 99a, 99b associated with an output cable 100a, 100b passing through a bent conduit 101a, 101b associated with one to the front gearbox 2a and the other to the rear gearbox 2b.
• the control device 89 is covered by a protective cover 102.
• a cyclist acts on the input cable 93, it causes, thanks to the rollers 94a, 94b, the pivoting of the selectors 95a, 95b according to a predefined kinematic thanks to the geometry of the displacement paths 97, and thus the pivoting of the levers 99a, 99b and the displacement of the output cables 100a, 100b.
• the cable 100a, 100b causes the axial displacement of the actuating member 76 (by pulling on the rod 81 or return to position by virtue of the spring 83) and thus the pivoting of the rockers 20 21.
• the invention is not limited to the embodiments described above as examples but that it encompasses all variants.
• the motor plate is fixed, the translational movement being transferred to the receiving plate.
• the gearbox according to the invention can be used in other areas than cycles, especially in other types of vehicles (for example in a kart).

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Transportation (AREA)
• Mechanical Engineering (AREA)
• General Details Of Gearings (AREA)

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• 2006
  • 2006-01-25 FR FR0600671A patent/FR2896479B1/fr not_active Expired - Fee Related
• 2007
  • 2007-01-25 EP EP07730860A patent/EP1976745A2/de not_active Withdrawn
  • 2007-01-25 WO PCT/FR2007/000142 patent/WO2007085733A2/fr not_active Ceased

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