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
  • B62M11/14—Transmissions characterised by the use of interengaging toothed wheels or frictionally-engaging wheels of changeable ratio with planetary gears
  • B62M11/16—Transmissions characterised by the use of interengaging toothed wheels or frictionally-engaging wheels of changeable ratio with planetary gears built in, or adjacent to, the ground-wheel hub
• • 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 deformable system by a centrifugal force used in particular in an automatic gearshift device such as that used on a bicycle.
• the invention also relates to a transmission device equipped with such a deformable system.
• a transmission device in particular for a bicycle, comprising leading and driven gears defining transmission ratios.
• This transmission device comprises centrifugal force deformable systems which are associated with some of these gears to control the engagement of a gear when the bicycle equipped with the transmission device reaches a predetermined speed.
• the deformable systems described in these documents comprise a turntable around a sensitive axis and equipped with four flyweights.
• the weights are connected to the plate by a hinge axis parallel to the sensitive axis to pivot between a close position in which the weights are elastically biased by a return member and a position apart when the platen has a speed of rotation such that the centrifugal force has on the weights an action surpassing the action of the return member.
• pawls are interposed between a driving element and a driven element of the transmission and are controlled by the deformable system to couple them in rotation during its passage from one position to the other.
• the passage of the weights from one position to another being determined by the centrifugal force exerted on them and which depends on the speed of rotation of the plate, such a system is sometimes called mechanical tachometer.
• Each weight comprises a massive part constituting the bulk of the mass of the weight and at least one connecting part to one of the other masses.
• the link portion includes a lever arm extending from the hinge opposite the solid portion.
• a system that can be deformed by a centrifugal force, comprising a turntable rotatable about a sensitive axis and magnets, each connected to the plate by an articulation of axis parallel to the sensitive axis for pivoting between a close position in which the weights are recalled by an elastic member and a position apart when the platen has such a speed that the centrifugal force has on the weights an action greater than an action of the elastic member, each mass-burbot having a solid portion and at least one connecting portion to an adjacent flyweight, the solid portion and each connecting portion lying on the same side of a radius passing through the sensitive axis and articula- tion.
• the return member comprises a spring connecting the weights two by two.
• each flyweight has an annular sector shape.
• the weights substantially form a crown.
• the balancing of the system is then optimal.
• the deformable system comprises a first and a second series of at least two weights, the first series being superimposed on the second series and the weights of the first series being mounted on the plate to pivot in a direction opposite to the direction of pivoting of the weights of the second series, each weight of the first series having connecting portions facing the connecting portions of two adjacent weights of the second series, the connecting portions of the weights of the first series and the connecting portions of the weights of the second series comprising reciprocal mutual guide reliefs.
• This embodiment is simple and can be realized for a relatively small cost.
• the invention also relates to a transmission device comprising a driving element connected to an element driven by an epicyclic gear comprising a planet carrier and a coaxial sun gear, the planet carrier being equipped with satellites meshing on a fixed central axis and on the sun gear, freewheel pawls being mounted between the driving element and the planet and controlled pawls being mounted on the movable driving element between a position engaged with the planet carrier and a disengaged position, a system de- formable being fixedly mounted in the driven element opposite the ratchets controlled so that the weights are in contact with the ratchets controlled and allow the passage of these from their disengaged position to their engaged position when they are moved from their close position towards their discarded position.
• FIG. 1 is a schematic view in elevation of a first series of flyweights of a deformable system in accordance with the invention, the flyweights being in the separated position,
• FIG. 2 is a view similar to FIG. 1 of a second series of flyweights of this deformable system, the flyweights being in the separated position,
• FIG. 3 is a schematic view in elevation of the deformable system according to the invention, the flyweights being in the separated position,
• FIG. 4 is a schematic view in elevation of this deformable system, the weights being in close position
• FIG. 5 is a partial diagrammatic cross-sectional view of this deformable system
• FIG. 6 is a schematic cross-sectional view of a transmission device with a change of automatic ratio differential type.
• the deformable system according to the invention comprises a plate 2 comprising two coaxial rings 3.1, 3.2 and kept spaced by spacers 4.
• the crowns 3 have a central axis 5 (perpendicular to the plane of the drawings) intended to constitute the sensitive axis of the deformable system 1.
• a series of three flyweights generally designated 6.1 is mounted on the plate 2 by pins 7.1 and a series of three flyweights generally designated 6.2 is mounted on the plate 2 by pins 7.2 so that the weights 6.1, 6.2 s' extend between crowns 3.1, 3.2.
• the pins 7.1, 7.2 are of axis parallel to the central axis 5 and are mounted on the weights 6.1, 6.2 so that the weights 6.1, 6.2 rotate in opposite directions when subjected to a centrifugal force resulting from the rotation of the plate 2 about the central axis 5.
• the pins 7.1 are substantially at 120 ° from each other, the pins 7.2 are substantially at 120 ° from each other and the pins 7.1 are offset by about 60 ° compared to the pivots 7.2.
• Each flyweight 6.1, 6.2 has substantially the shape of an annular segment forming a solid portion 8.1, 8.2 having an end 9.1, 9.2 on which is mounted the pivot 7.1, 7.2 and opposite a free end 10.1, 10.2.
• the annular segment extends about 120 ° so that the weights 6.1, 6.2 of a series form substantially a ring.
• the weights 6.1, 6.2 are mounted on the plate 2 so that the direction of orientation of the ends 9.1, 10.1 and the direction of orientation of the ends 9.2, 10.2 are opposite.
• Each flyweight 6.1 has a portion close to its end 9.1 extending facing a corresponding portion of a first flyweight 6.2 ' and a portion adjacent its end 10.1 extending facing a corresponding portion of a second flyweight 6.2 adjacent to the first such that each flyweight 6.1 straddles a portion of two adjacent flyweights 6.2.
• each weight 6.2 a groove 11 in an arc of a circle is formed in the portion of the masking portion. sive 8.2 adjacent to the end 9.2 and a groove 12 arcuate circle of greater length is formed in the portion of the solid portion 8.2 adjacent the free end 10.2.
• the grooves 11, 12 are centered on axes parallel to the central axis 5.
• a lug 13 extends in lateral projection of the portion of the solid portion 8.1 adjacent to the end 9.1 to be received in the groove 11 of a first flyweight 6.2 and a lug 14 extends in lateral projection of the portion of the solid portion 8.1 adjacent the free end 10.1 to be received in the groove 12 of a second flyweight 6.2 adjacent to the first.
• the two sets of weights 6.1, 6.2 are thus superimposed and the grooves 11, 12 and the lugs 13, 14 form reciprocal mutual guide reliefs constituting connecting portions of the weights 6.1, 6.2 to each other.
• the reciprocal mutual guide reliefs comprise at least one guide flank laterally delimiting the groove 11, 12 and a lug 13, 14 projecting laterally to slide along the guide flank.
• the connecting parts are an integral part of the massive parts
• each weight therefore extend on the same side of a radius R crossing the central axis 5 and the axis of the pivots 7.1, 7.2.
• the return springs 15 are therefore three in number and extend at least partially in recesses 16.1, 16.2 arranged next to the solid parts 8.1, 8.2 of the weights 6.1, 6.2.
• the weights 6. 1, 6. 2 can pivot between a close position (shown in Figure 4) and a remote position (shown in Figure 3).
• the return springs 15 exert on the flyweights 6. 1,
• the weights 6. 1, 6. 2 are brought to the discarded position when the plate 2 is rotated about the central axis 5 and that the centrifugal force which is exerted on the 6.1, 6.2 has an action surpassing the action of the return springs 15.
• the deformable system of the invention is used for example to act on pawls solidarisant in rotation of the first and second coaxial elements of the transmission chain.
• the pawls are fixed on the first of these elements around the second element which is provided on the outside with reliefs, such as teeth, to cooperate with the pawls.
• the deformable system is mounted around the pawls so that the weights release the pawl to allow its engagement in the reliefs of the second element during their passage from their close position to their spaced apart position.
• the mounting of such a deformable system in a gear change transmission device is similar to that shown in particular in EP-A-0 758 970.
• the weights whatever their positions, define a substantially continuous circular internal contour.
• a differential transmission or planetary gear
• the pawls would be secured to a rotating support movable relative to the plate.
• Such a differential type transmission device is shown in FIG. has three reports, but only the passage between the first two reports (named first and second) will be detailed here to simplify the description. It goes without saying that this device can have more reports and include one or more deformable systems.
• This device is housed in the hub 50 of a bicycle wheel mounted, in known manner, for pivoting on a fixed axis 51.
• the fixed axis 51 is externally provided with teeth 52 on which meshes 53 are fitted to rotate on a planet carrier
• a planetary gear 55 is mounted to pivot on the planet carrier 54 and has an internal toothing meshing with the satellites 53.
• a drive core 56 is mounted to pivot in the hub 50 and at one end of the carrier. 54.
• the drive core 56 is integral with a pinion 57 meshing on the transmission chain of the bicycle.
• a deformable system 1 is fixedly mounted in the hub 50 opposite pawls 58, said second pawls, mounted on the drive core 56 to be movable between a disengaged position (shown in Figure 6) and an engaged position in which they co-operate with wolf teeth 59 provided externally on said end of the planet carrier 54.
• Pawls 60 said ratchets first, are mounted between the drive core 56 and the sun gear.
• the pawls 60 are freewheeling pawls 55 to rotate them as long as the drive core 56 has a higher rotational speed than the sun gear 55.
• the pawls 60 are free wheel pawls.
• the deformable system 1 does not turn at the same speed as the drive core 56.
• the circular internal contour substantially continuous weights 6.1, 6.2 allows to always have a weight against a pawl 58.
• the invention is not limited to the embodiment described and can be made to implement variants without departing the the scope of the invention as defined by the claims.
• the system may comprise weights, not superimposed and disposed on either side of the sensitive axis, having ends articulated to the plate for pivoting in opposite directions and opposite ends connected to each other by a knee joint forming the connecting part.
• the reciprocal mutual guide reliefs may also include a rib projecting from the flyweights.
• the flyweights can be rotatably mounted on axles connecting the rings 3.1, 3.2 or clamped on axles having rotatably connected ends to the rings 3.1, 3.2.
• the weights may have a shape different from that described.
• the use of six weights is advantageous because it allows a better distribution of the masses and improves the compensation of parasitic forces. It is nevertheless possible to modify the number of weights. In this way, it is possible to produce a deformable system with four weights.
• the return member may be a spring interposed between a flyweight and the plate. Different types of return members are usable including the tension springs or compression.
• the structure of the transmission device may be different from that described.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Transportation (AREA)
• Mechanical Engineering (AREA)
• One-Way And Automatic Clutches, And Combinations Of Different Clutches (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=37268569

Family Applications (1)

Country Status (3)

Family Cites Families (12)

• 2006
  • 2006-05-16 FR FR0604355A patent/FR2901235B1/fr not_active Expired - Fee Related
• 2007
  • 2007-05-11 WO PCT/FR2007/000802 patent/WO2007132087A1/fr active Application Filing
  • 2007-05-11 EP EP07731443A patent/EP2018315A1/de not_active Withdrawn

Non-Patent Citations (1)

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