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
  • B62M9/00—Transmissions characterised by use of an endless chain, belt, or the like
  • B62M9/16—Tensioning or adjusting equipment for chains, belts or the like
• • 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
  • B62M9/00—Transmissions characterised by use of an endless chain, belt, or the like
  • B62M9/04—Transmissions characterised by use of an endless chain, belt, or the like of changeable ratio
  • B62M9/06—Transmissions characterised by use of an endless chain, belt, or the like of changeable ratio using a single chain, belt, or the like
  • B62M9/10—Transmissions characterised by use of an endless chain, belt, or the like of changeable ratio using a single chain, belt, or the like involving different-sized wheels, e.g. rear sprocket chain wheels selectively engaged by the chain, belt, or the like
  • B62M9/12—Transmissions characterised by use of an endless chain, belt, or the like of changeable ratio using a single chain, belt, or the like involving different-sized wheels, e.g. rear sprocket chain wheels selectively engaged by the chain, belt, or the like the chain, belt, or the like being laterally shiftable, e.g. using a rear derailleur
  • B62M9/121—Rear derailleurs
  • B62M9/126—Chain guides; Mounting thereof

Definitions

• the present invention relates to a rear derailleur device, optimized, for a bicycle, more particularly but not exclusively suitable for bicycles also comprising a front derailleur and a set of chainrings, the assembly being controlled by a synchronized control handle.
• a rear derailleur device optimized, for a bicycle, more particularly but not exclusively suitable for bicycles also comprising a front derailleur and a set of chainrings, the assembly being controlled by a synchronized control handle.
• the chain length is reduced.
• the derailleur according to the present invention provides a derailleur whose ground clearance is significantly increased, whose operation does not disturb the design of the bicycle frame so that it can be mounted on the existing fleet without modification, provided that there is, preferably, a means of limiting chain crossing to reduce the chain length, the manufacture of which requires immediately industrially achievable parts, the operation of which is identical for user, whose putting into service makes it possible to keep the sets of pinions and chainrings existing on the bicycle, and whose cost remains in the price range of the derailleur on the market.
• the rear derailleur device is characterized in that it is equipped with a front derailleur, a chain connecting a set of pinions and at least one chainring, and possibly a synchronized control.
• a front derailleur a chain connecting a set of pinions and at least one chainring, and possibly a synchronized control.
• the mobile tensioning plate comprises a support arm, a tension arm, mounted to pivot relative to said support arm and first and second tension rollers, mounted to rotate freely at the ends of the tension arm, as well as a spring which biases the tension arm anti-clockwise, the chain passing over the first tension roller and under the second tension roller.
• the tension arm is mounted on a pivoting axis relative to the support arm, and this axis is disposed substantially in the middle of said tension arm or, according to a variant, this axis coincides with the axis of rotation of the second roller.
• the guide / derailment means comprise a deformable parallelogram which carries at its end, immediately downstream of the movable tension plate and in alignment with the latter, a guide / derailleur roller mounted to rotate freely, the chain passing over this guide / derailleur roller.
• the guide / derailleur roller is supported by means of adjustment in translation in the plane of the chain.
• the guide / derailleur roller comprises complementary lateral guide means such as at least one flange.
• connection means are provided interposed between the movable tension plate and the guide / derailment means, so to subject the chain tensioning forces and the restoring forces of the guide means.
• the device comprises a lubricant casing to wrap at least the rear derailleur, the sprockets, the chainrings and the chain.
• FIG. 1 a side elevation view of the rear derailleur according to the invention, mounted on a bicycle comprising a set of pinions to which said derailleur is assigned,
• FIG. 2 a schematic functional view of the derailleur in a first position, showing a set of chainrings with its front derailleur
• FIG. 3 a schematic functional view of the derailleur identical to that of FIG. 2 but in a second position
• FIG. 4 a view of an alternative embodiment in which the axis of rotation of the tension plate coincides with the axis of rotation of a roller
• FIG. 5 a side elevational view of an alternative embodiment with a return spring of parallelogram and common tension, in the case of a rocking arm with two rollers
• - Figure 6 a view according to another variant, in the case of a movable arm with a single roller.
• Figure 1 there is partially shown the frame 1 0 of a bicycle with the axis 1 2 of the wheel hub, equipped with a set 1 4 of sprockets 1 6, in this case 7 sprockets a to g. from the biggest to the smallest.
• the frame 1 0 comprises in a known and nonlimiting manner, two tubes 1 8 and 20 welded together, the two tubes forming a plate 22 for receiving the rear derailleur according to the invention.
• a chain 24 connects the set 1 4 of rear sprockets to the front chainrings, this chain being symbolized by a dashed line so as to retain the necessary clarity in the figure.
• a control cable for the rear derailleur is referenced 26 with its sheath 28, it comes from a derailleur control, not shown because this control does not intervene directly in the invention.
• the derailleur according to the invention comprises three essential parts, a base 30, derailleur support, a deformable parallelogram 32 for guiding / derailleur and a movable tension plate, so as to separate the guiding / derailleur functions and the tension functions.
• the base 30 comprises a body 36, mounted for rotation about an axis 38, integral with the plate 22 for receiving the frame 1 0.
• This body is recalled in the direction of the arrow 40, that is to say the opposite direction to that of known type derailleurs, by a spring symbolized at 42.
• This base 30 is fixed in lateral translation. It comprises, in this case, an intermediate plate with adjustment means with stops shown in Figure 1 by screws.
• a pulley 46 mounted freely in rotation about an axis 48, parallel to the axis 38 of pivoting of the base, receives in its groove the cable 26 to ensure good guidance.
• a wing 50 coming from manufacture with the base extends substantially perpendicular to the plane of said base 30, and this wing supports the parallelogram 32, deformable guide / derail.
• This parallelogram 32 comprises two arms 52 and 54, lower and upper, articulated on the one hand, relative to the wing 50 of the base around two axes 56 and 58 and on the other hand, relative to a part 60 guide, around two axes 62 and 64.
• An anchor 66 allows the cable 26 to be fixed to the upper arm 54.
• the guide piece 60 is therefore movable in translation along a straight line substantially parallel to a generator of the virtual cone of revolution formed by the set of pinions, thanks to the deformable parallelogram, as is the case for known derailleurs.
• This guide part 60 comprises a guide / derailleur roller 68 mounted for free rotation about an axis 71, visible only in FIGS. 2 and 3.
• a lateral flange 72 is associated with this guide / derail roller 68, centered on the same axis 71, so that the plane of the flange is parallel to the plane of the guide / derail roller.
• the assembly of the guide / derailment roller 68 and of its flange 72 is adjustable in translation, in the plane defined by the chain, by the active pinion of the pinion set and by the active plate of the plate set, so that the he assembly can be arranged as close as possible to the pinions and above all in the best position to ensure good derailment.
• This flange 73 is disposed substantially opposite the flange 72 of the guide / derail roller 68. This flange is adjustable in position along a line connecting the axis of rotation 12 to the axis 71 of rotation of the roller 68, to stick as close as possible to the virtual cone formed by the pinions.
• the guide piece 60 extends towards the front of the bicycle by a support arm 74.
• the end 76 of this arm carries a bearing 78 in which rotates an axis 80 integral with the plate 34 movable in rotation.
• a spring 82 shown in broken lines, provides the return in the direction of arrow 84.
• the movable tensioning plate 34 comprises a tensioning arm 86, which is the element integral with the axis 80.
• the pivot point is substantially the middle of the arm in the embodiment shown in Figure 1. It is noted that this movable arm 86 has a reduced length compared to the length of the various parts such as the deformable parallelogram or the support arm.
• this tension arm 86 there is disposed a tension roller 88, 90, respectively first and second, mounted free to rotate.
• the passage of the chain 24 is noted on the first tension roller 88, under the second tension roller 90, on the guide / derail roller 68, in front of the guide flange 72, behind the lateral pressure flange 73 and under the corresponding pinion of set 1 4 of pinions 1 6.
• the chain 24 is on the small plate A of the three plates A, B and C of the set of plates 92 with its front derailleur referenced 94 and on the fourth pinion d.
• This position corresponds substantially to the longest length of chain to be recovered, since the chainring / pinion combination selected corresponds to the smallest peripheral length among the preferentially accessible combinations.
• the soft strand 24M of the chain is guided by the roller 68 which is pressed against the chain 24 because the base 30 is returned in the direction of the arrow 40 by the spring 42.
• the roller 68 for guide / derail is exactly in the plane of the corresponding pinion.
• the movable plate 34 ensures the tension and the recovery of the unused chain length.
• the arm 86 has pivoted in the direction of the arrow 84, in its extreme position, the first roller 88 being at the top and the second roller 90 being at the bottom.
• the chain passage is then of the pronounced S type, which corresponds to a very long path.
• the tension arm 86 is then brought back, by a rotation opposite to that generated by the return spring 82, in a position in which the S is weakly pronounced and lying, which leads to an almost linear chain tracing.
• a return spring interposed between the two arms 52 and 54 of the deformable parallelogram so as to spread the parallelogram and lead the chain from the largest sprocket a to the smallest g, this spring then being compressed by the force exerted by the user through the cable 26. It turns out that very often the restoring force is insufficient to ensure frank and efficient derailment. In addition, the effort to be exerted on the cable is significant, which may require additional reduction.
• FIG. 5 which corresponds to the embodiment of FIG. 1 with the same references for the identical elements, a sector 102 of pulley 102 secured to the axis 80 supporting the arm 34 has been connected by a cable 100. tension, with one 1 04 of the ends of the return spring 1 06 of the deformable parallelogram of the guide / derailment means.
• the pulley sector 10 2 is arranged so that the cable passes over it and rotates in the direction of arrow 84 when traction is exerted on the cable 100.
• the spring 1 06 is wound to allow interaction between the force resulting from the chain tension and the force necessary for recalling the parallelogram.
• the chain tensioning action is thus obtained in whole or in part by the reaction of the parallelogram return spring 106. Indeed, it is possible to remove the return spring 82, or possibly to keep it in certain cases but by modifying the power which must be very limited.
• the mounting of the base on an axis of rotation with a return spring is essentially provided in the main embodiment so as to allow disassembly of the rear wheel, but it is quite possible to provide it fixed, especially if the frame includes a single-arm or dismantling means from the rear.
• the derailleur according to the invention makes it possible to envisage having the whole derailleur device, comprising the two front and rear deraille as well as the chain in a sealed casing, which avoids any damage to the mechanics and the pinions and leads to reduced maintenance, increased reliability and better yields through suitable and continuous lubrication.
• This casing solution is perfectly suited to mountain bikes but also to city bikes which prevents users from getting dirty.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Transportation (AREA)
• Mechanical Engineering (AREA)
• Devices For Conveying Motion By Means Of Endless Flexible Members (AREA)

Priority Applications (8)

Applications Claiming Priority (2)

Publications (1)

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Citations (7)

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• 1997
  • 1997-02-26 FR FR9702573A patent/FR2759968B1/fr not_active Expired - Fee Related
• 1998
  • 1998-08-26 AU AU90792/98A patent/AU9079298A/en not_active Abandoned
  • 1998-08-26 WO PCT/FR1998/001854 patent/WO2000012379A1/fr active IP Right Grant
  • 1998-08-26 CN CN98814212.0A patent/CN1108947C/zh not_active Expired - Fee Related

Patent Citations (7)

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