This invention relates to a gear shifting system especially adapted to bicycles.
For a bicycle, known gear shifting systems all work according to the same principle: it is the transmitter control means (most often attached to the handlebars) that provides the values required for movement of the gear shifting means (receiver control means: derailleur, for example). The major disadvantage of these systems, the transmission (linking) means (cable, for example) between the transmitter control means (play and parasitic tolerances already accumulated to it) and the gear shifting means, always more or less changes the efficiency between the desired movement of the gear shifting means and the movement obtained. This change is amplified by use over time, which is reflected by a drop in reliability, precision, comfort and even sometimes safety.
Parallel to classic separate controls, classic grip systems of derailleur synchronization do exist and especially one of my preceding inventions, filed at the INPI (European patent application) under No. 95450012.0 and called “Synchroshift” by the EGS Company, consisted of a single gear shifting control grip that synchronized traditional derailleurs.
Although delivering the desired synchronization result, this “Synchroshift” is again more delicate and more sensitive than the aforementioned traditional control means with respect to the quality of the cables and sheaths used; their maintenance is sometimes and even often tedious.
Another major disadvantage: the mediocre intrinsic efficiency (accumulation of play and production tolerances) that said grip, also with derailleurs, transmits. This lack of tolerance on the “passband” sometimes causes difficult or faulty changing of ratios.
Another disadvantage, and not the least, this “Synchroshift” dictates that the grip have a relatively significant size and thus volume, which adversely affects the at least visual desire to seem light.
According to a first characteristic, by integrating the values necessary for movement of the movement means for shifting gears to at least one of said gear shifting means, the system according to the invention is designed to eliminate these disadvantages and especially this poor control tolerance, or at least to considerably improve the efficiency between the controlled movement and the movement obtained, while offering more varied, to say nothing of universal, ergonomy and a “more sexy look” as well as a greater variety of synchronization combinations.
According to the invention the system comprises:
The name of the derailleur(s)—Hi-Fi (for High Fidelity)—would be perfectly well suited as a commercial name for the programmed front and/or rear derailleur(s) according to the invention. The synchronization system according to the invention that is based on at least one of the derailleurs according to the invention could be temporarily or definitively called “Synchroflash.”
According to particular embodiments:
The means of transmission (linkage) and possible synchronization between the transmitter control mean(s) (MCE) and the reduction ratio shifting means (front=MRF and rear=MRR) can be:
directly by at least one cable for each derailleur (for example grip/front derailleur and grip/rear derailleur),
in series by at least one cable (for example: grip/front derailleur/rear derailleur/grip (optionally) for example).
in parallel by at least one cable (for example: grip/front derailleur/grip); and at the same time between them (for example: by cable (toothed belt . . . ) front derailleur/rear derailleur/front derailleur (optionally) for example).
There is a major possibility, therefore, according to the invention, of modifying the staging of the gear shifting, by simply changing at least one of the front and/or rear derailing programs (cam(s)).
Added as shown, to the possibilities of geometrical adjustment (in three directions) according to the invention, this front derailleur according to the invention can claim versatility of use.
The attached drawings illustrate the invention:
With reference to these drawings, generally everything with the same function has the same reference number. Preferably, certain parts very particular to the invention are referenced with a number in the hundreds that corresponds to the illustrative figure:
The overall system according to the invention is referenced (1).
The crankset box is referenced (W).
The transmitter control means (twistgrip) is referenced (X).
In the embodiment of the system (1) according to
In this case, the most current and most interesting, (with respect to the lateral movement of the chain for derailing: It is easier for the derailleur return springs to cause the chain to “fall” into a cog or smaller rim than vice versa), the front derailleur (Y1) under the pulling force of the cable (4A) is moved from the small chainring “A” toward the largest chainring “C.” A return spring (202) drops the chain again toward the smaller chainrings.
Likewise, under the positive pulling force of the cable (5A), the rear derailleur (Z1) is moved from the smallest cog “1” to the largest cog “9.” A return spring (34) again moves the chain down toward the smaller cogs.
It follows that preferably for the operation of the grip (X), a cable (4A) (or one part) is wound when the other (5A) (or another part) unwinds and vice versa.
In spite of everything, and mainly to not have to compress exactly at least the return springs of the two derailleurs at the same time (since the very great majority, if not all of the available combinations through the ratios of chainring/cog combinations on the market necessitate (to have optimum staging of the gears for changing the chainrings) changing the cogs in the same direction, increasing or decreasing the size), the invention calls for the action of one of the cams to be the reverse in accordance with a return spring that is also inverse to it. The return force of a derailleur partially compensates at the level of exertion on the grip (X) for the return force of the other derailleur, thus improving the ease and comfort of use.
In the embodiment of the system (1) according to
One cable (7B) closes the connection between the derailleurs (Y2) and (Z2) and the grip (X), since the cams (301) and (601) are double action; it is especially interesting no matter what the direction of lateral displacement adopted by the derailleurs (Y2) and (Z2) that said derailleurs work without any return spring (or with springs that are relatively very slightly calibrated and very soft to just ensure a slight tension in the cables (4B), (5B) and (7B)).
In this case, the control force of the user through the grip (X) and said cables (4B), (5B), (7B) allows all derailings to be implemented.
The control kinematics of this version is preferably the following: by turning the grip (X) in the direction of the first gear 1 toward the last gear 14, the cable (4B) is wound into the cable groove of the grip (X) where the head of said cable is housed. The pull applied to this cable is transferred through the sheath(s) (6) and various stops of the sheath(s) (not shown) as far as the pulley integral (directly or not) with the cam (301) to which it hooks (cable grip). This causes rotation of said cam that acts according to the program (machined or cast, for example) on the derailing fork.
Preferably to avoid using overly long cables, the head of another cable (7B) is housed in the pulley of the cam (301). This cable (7B) under the action of rotation of the pulley of the cam (301) is subjected to pulling that is transmitted there also through the sheath(s) (6) and the sheath stops. This pulling movement is transmitted to a cable grip (40) housed in the pulley that is integral (directly or not) with the cam (601) of the rear derailleur (Z2). This action of the cable (7B) causes rotation of the pulley and thus of the cam (601), in doing so the cam directly (or almost directly) causes programmed movements (by machining or by casting for example) of derailing that will be obtained by a roller (33).
At the same time, another cable (5B) integral with the same cable grip (40) (or another) unwinds from the pulley of the cam (601) to wind onto the grip (X) through sheath(s) (6) and stop(s) of the sheath(s).
A counter-rotational action on the grip (X) will cause the reverse kinematics.
In the embodiment of the system (1) according to
To control the rear derailleur (Z3), the cam (402) acts via a pin (403) that follows in contact and as freely as possible the profile of said cam (402); this pin (403) is integral with a connecting rod (404) that pivots around an axis (405) integral with one arm (20A) of the derailleur (Y3).
On this connecting rod (404), there is a housing near the free end to receive the head (7D) of the cable (7C).
By actuating this connecting rod (404), the cam (402) transmits its program (synchronized with the front derailleur (Y3) since said cam (402) is integral with the cam (401)) to the rear derailleur (Z3) via the cable (7C).
In a particularly advantageous manner, the invention calls for this front derailleur (Y1) to be able to benefit from geometrical adjustment in three directions:
adjustment in height so as to satisfy the largest number of the largest chainrings, “C” in this case; for this, for example, the front derailleur (Y1) will be implemented with at least one first fixed part (8) integral with the frame (2) and/or the crankset box (W) and/or its crankset tube (3). At least one second movable part, the arms (16) and (20) (separate or one-piece) slide on the fixed part (8).
This movable part supports what is critical of the derailing elements of said derailleur.
To fix the movable part (16 and 20) on the fixed part (8), a screw (17) stops the sliding at the desired adjustment height by tightening the arms (16) and (20) against the fixed part (8).
To facilitate height adjustment of the movable part (16, 20), after loosening the screw (17), it is enough to turn the eccentric gear (19) by its hexagonal concave central part, so that said eccentric gear (19) turning centered as it is supported in the fixed part (8) will preferably push on the screw (17), driving the arms (16 and 20) up by the screw. Once the height adjustment (free space recommended between the bottom of the fork (9) and the tip of the tooth of the chainring “C” (for example the most highly eccentric) is implemented, it is simply enough to tighten the screw (17) to lock the desired adjustment. With a smaller degree of potentiality of adjustment, the eccentric gear (19) will be able to act on the rising but also on the lowering of the mobile part (16, 20).
adjustment in length, by the tilt that the fixed part (8) and thus the entire derailleur (Y1) could take. Effectively by turning around the axis of the crankset (W), the fixed part in height (8) (without modifying this said height) makes it possible to longitudinally adjust the lateral pressure point applied by the fork (9) to the chain. To do this, the fixed part (8) is arranged on its lower end in a collar (half-split or detachable) that surrounds by a groove (or a projection, a shoulder . . . ) the crankset box (W) (and/or its tube (3)), preferably on a flange (64) made on the screw/bearing (63). This flange (64) could be replaced by a washer (R) tightened between the screw/bearing (63) and the tube (3) of the crankset, and that would have a diameter greater than the screw/bearing (63) and the tube (3) to allow hooking and rotation of the collar (8).
To refine the adjustment and to maintain it, a screw (24) housed in the arm (20), for example, would be supported on the tube of the frame (2).
To lock the adjustment, at least one tightening (or connecting) screw (18) stops the collar (8) on the crankset box (W).
adjustment in width by the possibility that the male relief of the crankset box or the female relief of the adjustable part (the groove . . . of the collar (8)) mentioned above is wider than the female or male relief of the fixed part (flange (64) . . . ). This lateral play thus allows optional wedging to obtain the desired offset. Another approach consists in that the washer (R) (not shown) has an S section (a profile), which allows two potential adjustments by simply turning. In suggesting several types of washers (R) with different profiles, the adjustment possibilities are equally multiplied.
If the front derailleur is equipped with a single-action cam (201), the return spring (202) of the fork (9) is critical. In this case, according to the invention, said spring (202) will be able to be more or less taut (calibrated, pretensioned) at will. Actually, this spring (202), anchored on one end to a bell crank (21), is wound and can turn around one coaxial axis of said spring (202). On this axis, the other end of the spring (202) is anchored on a notched stop (14) and kept in position by a screw head (15) that works with said notches. The bell crank (21) pivotally bears the fork (9) via axles/rivets (13).
One axis (22) integral with the arm (20) ensures rotation of the cam/pulley (201). Split on its end next to the spring (203), said axis will be used as a fixed stop for the spring (203). The other end of the spring (203) will be used to bring back the cam/pulley (201) by anchoring it there.
The end of the fork (9) will be used to support a bearing in which the pin (12) that works with the cam (201) turns freely.
While the front derailleurs are equipped with a single-action or double-action cam, the stop screws (10) and (11) of the fork (9) are optional.
The cam (201) turns on a bearing (plain or roller) with a housing (222) that can have a shoulder and a clip groove for holding said bearing.
At least one cable grip (23) is housed in at least one recess (223).
The housing (203A) that accommodates the spring (203) can be sealed by a cover (not shown).
Preferably, this type of derailleur (Y2) works without any return spring; this results in that the cam/pulley (301) is actuated by a cable (4B) that makes it turn in one direction and another cable (7B) that makes the cam/pulley (301) turn in the other direction. Preferably, a single cable grip (23) makes the cables (4B) and (7B) integral (that can be but one and the same cable).
The cam (301) turns on a bearing (plain or roller) with a housing (322) that can have a shoulder and a clip groove for holding said bearing.
At least one cable grip (23) is housed in at least one recess (323).
The pulley (304) of the cam is clearly visible here (
Preferably, this type of derailleur (Y3) works without any return spring; this results in that the cam/pulley (401) is actuated by a cable (4C) that causes it to turn in one direction and another cable (5C) that causes the cam/pulley (401) to turn in the other direction. Preferably, a single cable grip (23) makes the cables (4C) and (5C) integral (this can only be one and the same cable).
The other main difference consists in that the cam (402) that guides the rear derailleur is an integral part of said front derailleur (Y3) and is directly or indirectly integral with the cam/pulley (401). As indicated above, the rear cam (402) actuates a pin (403) that is integral (but preferably free to rotate) with a connecting rod (404) that pivots around an axis (405) and that bears on its other end the head (7D) of the cable (7C). This axis (405) is fixed on the arm (20A) that is similar to the arm (20) if it is only here that the arm extends in a curve toward the top to comprise a plate on which the stops of the cables (4C), (5C) and (7C) are screwed (preferably to comprise possibilities for tensioning and adjusting the cables).
Preferably, the cam (402) will have gear click notches (28) that work with the pin (403).
At least one cable grip (23) is housed in at least one recess (423). Advantageously, the cable grip (23) will rotationally link the cams (401) and (402).
The drive pulley of the two cams is preferably located between these two cams (401) and (402).
As indicated above, this embodiment uses a single-action cam (501). In this case, it is desirable according to the invention that one return spring (42) (helical, for example) is housed in the cam (501) that advantageously acts in this case as the receiving pulley of the cable (5A). A cable grip (40) makes the cable (5A) integral with the cam/pulley (501).
A pin (38) that is preferably free to rotate follows in contact the track of the cam (501); this pin is integral with the pivoting arm (35) that traditionally forms with the other pivoting arm (36) the deformable parallelogram of said derailleur (Z1). The movement applied by the cam (501) to the arm (35) is thus transmitted by the arm (36) to a derailing roller (wheel) (33).
The support arm (31) of the chain tension system (32) is integral with the movable ends of the arms (35) and (36). The other fixed ends of the arms (35) and (36) are integral with a support element (37) that makes it possible to fasten the derailleur (Z1) to the bicycle frame using a screw (41).
In this embodiment, a spring (34) traditionally ensures the return of a roller (33) and components that are attached thereto (arm (31), chain adjuster (32)).
A plate (30) integral with the element (37) allows stopping of the sheath (6) of the cable (5A).
The cam (501) turns on a bearing (plain or rolling) with a housing (539) that can have a shoulder and a clip groove for holding said bearing.
At least one cable grip (40) is housed in at least one recess (540).
The housing (542) that accommodates the spring (42) can be sealed by a cover (not shown).
Relief recesses (511) can be implemented.
The cam (601) turns on a bearing (plain or rolling), of which the housing (639) can have a shoulder and a clip groove for holding said bearing.
At least one cable grip (40) is housed in at least one recess (640).
The pulley (605) of the cam is quite apparent here (
A hole (610) allows passage of an “Allen” wrench to tighten the screw (41).
Relief recesses (611) can be implemented.
In traversing at least one sheath (6), a positive pulling cable (4A or 4B or 4C) is wound and is anchored by its head (4A′) in a groove of the grip (X).
In traversing at least one sheath (6), a negative pulling cable (5A or 5B or 5C) is wound and is anchored by its head (5C′) in a groove of the grip (X).
A grooved part (50) will accommodate a lining of flexible material.
Marks (51) will display the engaged gear relative to a fixed reference of the housing of the grip (X).
Click notches (52) work with a click spring (53) to feel and position the grip (X) on the desired gear (51).
The left bearing is integral with a threaded sleeve or bearing/screw (61), and the right bearing is integral with a threaded sleeve or bearing/screw (63); these threaded sleeves (61) and (63) are screwed on the tube (3) of the crankset. The threaded sleeve (63) has a relief (64) allowing hooking and rotation of the front derailleur.
The various figures attached to the description do not comprise exhaustive suggestions of embodiments.
The system according to the invention is especially designed to shift the reduction ratios (gears) of a bicycle.
Number | Date | Country | Kind |
---|---|---|---|
03/11266 | Sep 2003 | FR | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/FR04/02390 | 9/22/2004 | WO | 00 | 9/10/2008 |