FR3056188B1 - CYCLE WITH DIRECT TRANSMISSION. - Google Patents

Abstract

The present invention relates to a cycle comprising a pedal provided with two pedals (1) and a transmission device (14), adapted to transmit the movement of the pedals (1) to the rear wheel so as to drive it in rotation, said transmission device (14) comprising two rear rods (17) movable in rotation about the driving axle (15) of the driving wheel, and able to perform an alternating oscillatory movement, one of the rear rods (17) driving the wheel rotates in one direction, while the other performs the movement in the opposite direction, and is then released from the wheel by a freewheel device.

Description

Direct transmission cycle

The present invention is in the field of cycles. A cycle is defined as a vehicle having at least two wheels and powered at least in part by the muscular energy of the people on that vehicle.

A cycle usually includes a pedalboard. It comprises an axis on which are fixed two cranks, each provided with a pedal, and a plateausolidaire axis. To advance the cycle, the cyclist pushes with his feet alternately on each pedal, thus printing a rotational movement at the pedal axis. This rotates the plate, and through a chain, the rear wheel of the cycle.

The movement of the pedals is generally circular. This movement is not optimal because only the downward vertical component of the movement allows the cyclist to transmit energy efficiently to the pedalboard. The circular movement includes a large horizontal component.

In addition, friction in the transmission chain lose energy to the system and requires regular maintenance.

GB2251586 proposes a cycle without chain, which has the advantage of simplified maintenance, and an infinite number of transmission ratios possible, however the mode of transmission of the movement is quite complex, with a large number of mechanical parts. The same document presents a cycledont the pedal observes an elliptic movement, which optimizes the effort of the cyclist. However this document does not suggest to combine the two features. GB2251586 was published in 1992, and since that day no solution combining a chainless transmission and an elliptical movement pedals has been proposed. There is therefore a long-standing need to propose a cycle with a more efficient transmission, while providing the cyclist with a more appropriate movement of the legs.

The present invention aims to overcome at least in part these disadvantages. For this purpose, it proposes a cycle comprising a pedal provided with two pedals and a transmission device, adapted to transmit the movement of the pedals to the rear wheel so as to drive it in rotation, characterized in that said transmission device comprises two rear movable rods around the driving axis of the driving wheel, and able to operate an alternating oscillatory movement, one of the rear rods driving the wheel enrotation in one direction, while the other performs the movement in opposite direction, and is then released from the wheel by a freewheel device.

Thanks to these provisions, the transmission requires little maintenance and allows a reduction of friction.

According to other characteristics:

Said pedal may include a device for ovalizing the trajectory of the pedals; thus the trajectory of the pedals makes it possible to optimize the cyclist's effort, said ovalizing device may comprise a mobile upper plate rotatably about an upper rotation axis, and a mobile lower plate in rotation around a lower axis of rotation, and a drive means connecting said lower platen to said upper platen, one of said pedal being fixed to said drive means, and connected to one of said rear shafts, constituting a simple and robust means of making said ovality device may comprise a crown fixed, internally toothed, a pinion held rotatably about a secondary rotary axis by a crank movable in rotation about a primary axis of rotation concentric with the ring so as to force the pinion to engage the ring, a pedal arm integral with said pinion, and a fixed pedal movable in rotation at the end of the pedal arm, eg thus avoiding the use of a chain and thus reducing the problems of wear and friction, the distance between the axis of rotation of the pedal and the axis of secondary rotations can be between half and three -quarts of resistance between the axes of primary and secondary rotation, resulting in a pedal path sufficiently far from a circular trajectory to optimize the effort of the cyclist, without being too close to a rectilinear oscillatory movement that would be uncomfortable for the cyclist, the distance between the axis of rotation of the pedal and the axis of secondary rotations may be greater than the distance between the axes of primary and secondary rotation, which results in a movement where the pedal is forward when the pinion is towards the back and vice versa, and the lapal is upwards when the pinion is up and vice versa, and allows a realization with a crown well p The small diameter, resulting in a gain in weight, the pitch diameter of the pinion can be equal to half the diameter of the crown, so that during a turn of the pinion in the crown, said pinion performs a turn on itself On the contrary, as a simple means of obtaining a vertical axis oval pedal path, the transmission device may comprise two front rods fixed to each pedal, each front rod being articulated with one of said rear rods about a hinge, so that said rods rods beforetransmitting the movement of the pedals in said oscillatoiroirternterné movement of said rear rods, to achieve the invention without linear swirling, but only joints, the vertex of the angle formed by said articulation can be turned towards the high, which allows the cyclist to avoid a training effort when passing from the top of the oval, where the leg has the least ficacity, and to avoid the articulation too close to the ground, and derisquer to touch the ground, the front rod can be shorter than the rod back, to minimizethe effort of drive of the axis motor at the moment when the pedal passes directly from the oval, and thus to concentrate this driving force in the downward part of the trajectory of the pedal, the transmission device may comprise two front rods fixed to each pedal, each front rod sliding in a said rear rods, or vice versa, so that said forward rods transmit the movement of the pedals in said alternating oscillatory movement of the said rear ditties, to minimize the bulk of said rods during the movement.

An oval shape with a vertical axis should be understood in the context of the present invention as a closed path deviating from the circle by a vertical dimension larger than the horizontal dimension. The ellipse, defined by the constancy of the sum of the distances to two foci, and the oblong, defined by two semicircles connected by two segments of the straight line, are two particular cases of a so-called oval.

The present invention will be better understood on reading the detailed description which follows, with reference to the appended figures in which:

Figure 1 is an overview of a cycle according to the invention.

FIG. 2 is a sequence view of the operation of the pedalboard comprising a device for ovalizing the trajectory of the pedals according to a first embodiment of the invention, and a transmission device with articulation,

FIG. 3 is a sequence view of the operation of the pedalboard comprising a device for ovalizing the trajectory of the pedals according to a first embodiment of the invention, with a sliding transmission device,

Figure 4 is a sequence view of the operation of the pedalcomportant an ovalization device of the path of the pedals according to a second embodiment of the invention.

Figure 5 is a sequence view of the operation of the pedalcomportant an ovalization device of the path of the pedals according to a variant of the second embodiment of the invention.

As shown in FIG. 1, the movement of the pedals is transmitted to the back of the cycle by means of a transmission device 14. The transmission device 14 is fixed at one of its ends to a pedal 1, and at its other end to the motor shaft 15 of the rear wheel. In a preferred embodiment of the invention, shown in FIG. 2, the transmission device 14 iscomposed of a front rod 16 and a rear rod 17 hinged about a articulation 18. The movement of the pedal 1 oscillates the rear rod 17 around the motor axis 15. The axis motor 15 is provided with a freewheel device, so that when the rear rod 17 rises, it rises freely, without braking the movement in the opposite direction of the wheel, whereas when it goes down, it drives the wheel in its direction of rotation . The motor shaft 15 further comprises a gear reduction device, where appropriate with a gear change, to allow the pedaling forces to be adjusted between a circulation on the flat, and a climbing flow, for example.

According to an advantageous embodiment of the invention, the front rod 16 may be shorter than the rear rod 17, which has the advantage of minimizing the driving effort of the motor shaft 15 at the moment when the pedal 1 passes to the point of the oval, and so to concentrate this effort of training in the descending part of the trajectory of the pedal 1.

According to an advantageous embodiment of the invention, the articulation 18 between the lobes before 16 and rear 17 is disposed upwards, which has the advantage that it avoids a training effort to the passage of the bottom of the oval where the lower leg has the least efficiency. The training effort required to pass the peaks of the oval will then be at the passage of the top summit of the oval. Furthermore, it prevents said articulation 18 too close to the ground, and risk touching the ground in certain configurations.

It is also possible, as illustrated in FIG. 3, to realize the transmission device 14 by sliding the front rod 16 in the rear rod 17, or conversely in the form of a telescopic device. The pedal 1 being maintained by the chain 7, then produces the output or retraction of the front rod 16 in the rear rod 17. In a similar manner to the embodiment of FIG. 2, the descent of the rear rod 17 produces a motor force on the rear wheel, while its rise, by the freewheel system, is carried out freely.

The pedal of the cycle according to the invention shown in FIG. 1 has two pedals1. According to an advantageous embodiment of the invention, the crankset comprisesan ovalization device 2 of the trajectory of the pedals. In order to advance the cycle, the cyclist alternately presses each pedal. Pedals follow a trajectory whose vertical component is larger than the horizontal component. This allows for optimal use of the cyclist's strength, which is easier to press down with his feet.

In a first embodiment of the invention, illustrated in FIGS. 2 and 3, the ovalization device 2 comprises an upper rotation axis 3 and a lower derotation axis 4 fixed to the cycle frame. The axes of rotation (3, 4) are horizontal, offset vertically, and perpendicular to the direction of movement of the cycle. The ovalization device 2 also comprises an upper plate 5, rotatable around the upper axis of rotation 3, and a lower plate 6, rotatable about the lower axis of rotation 4. The ovalization device 2 comprises still a driving means 7, for example a chain 7 or a belt, connecting the plates (5, 6). The pedal 1 is fixed on one of the links of the chain 7. In the case where the plates (5, 6) are of substantially the same diameter, the trajectory followed by the chain 7 and thus by the pedal 1 is of oblong type, which corresponds to a embodiment of an oval, as in the present invention. At the other end of the axes of rotation (3, 4) are also an upper plate 5, a lower plate 6, a chain 7 and a pedal 1. The upper plates 5 are fixed on the same axis of upper rotation 3, they are solid in rotation around the upper axis of rotation 3. The lower plates 6 being fixed on the same lower axis of rotation 4, they are integral in rotation about the lower axis of rotation 4. By the action of the chains 7, all the plates (5, 6) are thus integral in rotation. The second pedal 1is placed on the second chain 7 so that when a pedal 1descend, the second pedal 1 rises due to solidarity rotationplateaux (5, 6). It is also possible to join only one of the pairs of trays 5 or 6, the other then being driven by the chain or belt at a prescribed speed.

Of course, the chain could also be replaced by a belt, and the plates by pulleys, with identical functions. It is considered in the context of the present invention that this embodiment is included in what is covered by trays and a chain.

In a second embodiment of the invention, shown in FIG. 4 and 5, the ovalization device 2 comprises a primary axis of rotation 8 concentric to a ring 9, toothed internally, both fixed relative to the frame of the cycle. To facilitate comprehension and avoid overloading a single pattern, shepherd 9 has been represented in four situations over a period that is to be understood as a period of time, and the ring 9 is well fixed with respect to the cycle frame. At the end of the primary axis of rotation 8 is fixed a crank 10, mobile enrotation around the primary axis of rotation 8, and carrying a pinion 11, mobile enrotation around a secondary axis of rotation 12. The pinion 11 is integrally connected to a pedal arm 13. The pinion 11 is engaged in lacouronne 9. At the end of the pedal arm 13 is fixed a pedal 1. When the cyclist presses the pedal 1, he turns the arm of pedal 13 and thus the pinion 11. The pinion 11 then moves inside the ring 9. Lacouronne 9 has a pitch diameter twice greater than the pitch diameter of the pinion 11, which has the consequence that when the pinion 11 moves in lacouronne 9, it performs a complete turn in the opposite direction of the rotation of the manna 10. The pitch diameters of the crown 9 and the pinion 11 are the diameters of two circles, one concentric to the ring 9 and the other concentric to the pig no 11, whose tangential velocities are equal and passing through the points of contact, approximately in the middle of the toothing. If the pinion has a pitch diameter of half that of the crown, this equates to the fact that the number of teeth in the pinion is half the number of teeth in the crown.

As the pedal arm 13 is integral with the pinion 11, it extends and shortcitalternatively the crank 10, which gives the pedal 1 an oval trajectory.The ovalization device 2 is made so that when the pinion 11 is found at the top of the ring 9, the pedal arm 13 is substantially vertical, the end on which the pedal 1 is fixed facing upwards. Thus the large axis of the oval traversed by the pedal 1 is substantially vertical, and the movement of the pedal 1 has a vertical component greater than horizontal sacomposante.

According to a preferred embodiment shown in FIG. 4, the distance between the axis of rotation of the pedal 1 and the secondary axis of rotation 12 is less than the distance between the axes of primary rotation 8 and secondary rotation 12. In the eventcontraire, the trajectory of the pedal 1 would be reversed, and if these distances were equal, the trajectory of the pedal 1 would then oscillate rectilinear which is less comfortable for the cyclist.

However, the distance between the axis of rotation of the pedal 1 and the secondary rotation axis 12 must not be too short, a null distance corresponding to a circular movement of the pedal 1.

The distance between the axis of rotation of the pedal 1 and the secondary axis of rotation12 is preferably between one-half and three-quarters of the distance between the primary and secondary 8 and secondary rotation axes 12.

According to another embodiment of the invention shown in FIG. 5, the distance between the axis of rotation of the pedal 1 and the secondary axis of rotation 12 is greater than the distance between the primary 8 and secondary 12 rotation axes, and thus the pinion descends from the rear when the pedal descends by the The advantage of this embodiment is the smaller size of lacouronne and pinion, which reduces the weight of the device.

It could also be provided that the ring 9 has an internal rubbing strip instead of an internal toothing, and the pinion 11 has an internal rubbing strip, instead of a toothing, with identical functions. In the context of the present invention, it is considered that this embodiment is included in what is covered by a ring 9, and a pinion 11.

The second pedal 1 must, as usually for the cycle pedals, move in a parallel path, but in reverse position, that is, high when the first pedal 1 is low, and vice versa. For this purpose, it can be provided that at the other end of the primary axis of rotation 8se also find a ring 9, a crank 10, a secondary rotational axis 12, a pinion 11, a pedal arm 13 and a second pedal 1, arranged so that when one pedal goes up, the other pedal goes down.

One can also provide a shaft connecting the two pedals 1, held in soncentre by a ball joint fixed on the frame of the cycle, free rotation, with anisdependient annex, for example with a linkage adapted, forcing the second pedal 1 to be horizontal, for a good foot support.

Claims (2)

1. Cycle comprising a pedal with two pedals (1), and a transmission device (14), adapted to transmit the movement of the pedals (1) to the rouarrière so as to drive it in rotation, characterized in that saiddevice transmission (14) comprises two rear rods (17) mobile enrotation around the motor axis (15) of the drive wheel, and able to operate alternating oscillatory movement, one of the rear rods (17) causing the roueen rotation in one direction, while the other performs the movement in opposite direction, and is then released from the wheel by a freewheel device. 2. Cycle according to the preceding claim, further comprisinganovation device (2) of the trajectory of the pedals. 3. Cycle according to the preceding claim, wherein said device ofoalisation (2) comprises an upper plate (5) rotatable about an axis of greater rotation (3), and a lower plate (6) mobile enrotation around a lower axis of rotation (4), and a driving means (7) connecting said lower plate (6) to said upper plate (5), one of said pedal (1) being fixed on said drive means (7), and connected to one of said rear rods (17). 4. Cycle according to claim 2, wherein said ovalization device (2) comprises a ring gear (9) fixed, toothed internally, a pinion (11) maintained rotatable about a secondary axis of rotation (12) parune crank (10) movable in rotation about a primary axis of rotation (8) concentric with the ring gear (9) so as to force the pinion (11) to mesh with the crown (9), a pedal arm (13) integral with said pinion (11), and a pedal (1) fixed rotatably to the end of the pedal arm (13). 5. Cycle according to the preceding claim, wherein the distance between the axis of rotation of the pedal (1) and the secondary axis of rotation (12) is between half and three-quarters of the distance between the axes of rotationprimaire (8) and secondary (12). 6. Cycle according to claim 4, wherein the distance between the axis of rotation of the pedal (1) and the secondary axis of rotation (12) is greater than the distance between the axes of primary rotation (8) and secondary (12) ). 7. Cycle according to one of claims 4 to 6, wherein the pitch diameter of the pinion (11) is equal to half of the pitch diameter of the ring (9), except that during a turn of the pinion (11) in the crown (9), said pinion (11) turns on itself in the opposite direction. 8. Cycle according to one of the preceding claims, wherein the transmission device (14) comprises two front rods (16) attached to each pedal (1), each front rod (16) being articulated with one of said rear rods (17). around a hinge (18), so that said forward rods (16) transmit the movement of the pedals (1) in said self-oscillating movement of said rear rods (17). 9. Cycle according to the preceding claim, wherein the apex of the angleformed by said hinge (18) is turned upwards, and preferably the front piece (16) is shorter than the rear rod (17). 10. Cycle according to one of claims 1 to 7, wherein the transmitting device (14) comprises two front rods (16) attached to each pedal (1), each front rod (16) sliding in one of said rear rods (17). ), or inversely, so that said forward rods (16) transmit the movement of the pedals (1) to said alternating oscillatory movement of the said rear ditties (17).