US4938733A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Bicycle gear shifting method and apparatus
Assignee: Bank of America NA
•
Filing: 1989-12-21
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Granted: 1990-07-03
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Expires: 2009-12-21
Abstract
Abstract A bicycle derailleur gear shifting system having a rotatable handgrip actuator cam which is coupled with the derailleur shifting mechanism through a control cable system so as to control the derailleur mechanism. Separate actuator cams are associated with the front and rear derailleurs. For the down-shifting direction, at least the rear derailleur cam is configured so as to substantially compensate for increasing force of the derailleur return spring; so as to substantially compensate for numerous cumulative lost motions in the derailleur shifting mechanism and cable system, and for chain gap variations; and so as to overshift the chain a sufficient amount beyond the destination freewheel sprocket so that the chain will approach the destination sprocket in the same direction as it would in the up-shift direction, but not sufficient to cause a double shift, or derailling from the #1 sprocket. A front derailleur cam is configured to provide fine-tuning for "cross-over" riding. In one form of the invention a secondary overshift boost cam is added axially in tandem with the primary cam, and is adaptable to both the front and rear derailleur shift actuators.
Inventors
- 👤 Sam H. Patterson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 10:18
CPC Classifications
B; B62; B62M; B62M9/00; B62M9/04; B62M9/06; B62M9/10; B62M9/12; B62M9/121; B62M9/124; B62M9/1248; B62K; B62K23/00; B62K23/02; B62K23/04; B62M25/00; B62M25/02; B62M25/04; B62M25/045; B62M9/127; B62M9/131; B62M9/134; B62M9/1344; B62M9/1346; F; F16; F16C; F16C1/00; F16C1/10; F16C1/22; G; G05; G05G; G05G7/00; G05G7/02; F16C2326/00; F16C2326/20; F16C2326/28; Y; Y10; Y10T; Y10T74/00; Y10T74/20; Y10T74/20207; Y10T74/20256; Y10T74/20268; Y10T74/2028; Y10T74/20287; Y10T74/20396; Y10T74/20402; Y10T74/2042; Y10T74/20438
Claims Analysis
Total Claims: 44
Claim 1
Independent Claim
324 words
A bicycle derailleur gear shifting system, which comprises: derailleur shifting means having return spring means operatively associated with the rear wheel of the bicycle; primary shift actuator cam means rotatably mounted on the bicycle handlebar generally coaxially of the handlebar; control cable means having one end operatively associated with said primary cam means and the other end operatively connected to said derailleur shifting means, said cable means being biased toward said derailleur shifting means by said return spring means; said primary cam means being configured so that rotational movement thereof in one direction will cause said cam means to pull said cable means against the biasing force of said spring means so as to cause down-shifting of said shifting means, and rotation thereof in the opposite direction will release said cable means in the direction of the biasing force of said spring means so as to cause up-shifting of said shifting means; and secondary handgrip slip cam means rotatably mounted on the bicycle handlebar coaxially in tandem with said primary cam means for actuating said primary cam means, said slip cam means being axially located so that said primary cam means is biased against said secondary slip cam means by the force of said spring means; said slip cam means having a cam face engaged against said primary cam means whereby preliminary rotational movement of said slip cam means in the down-shift direction moves said primary cam means against the biasing force of said spring means to apply an overshift increment of cable pull against the biasing force of said spring means, further down-shifting movement of said slip cam means causing said down-shifting; and preliminary rotational movement of said slip cam means in the up-shift direction releases said primary cam means in the direction of said biasing force so as to release at least a portion of said overshift increment of cable pull, further up-shifting movement of said slip cam means causing said up-shifting.
Claim 2
Dependent Claim
324 words
A bicycle derailleur gear shifting system, which comprises: derailleur shifting means having return spring means operatively associated with the rear wheel of the bicycle; primary shift actuator cam means rotatably mounted on the bicycle handlebar generally coaxially of the handlebar; control cable means having one end operatively associated with said primary cam means and the other end operatively connected to said derailleur shifting means, said cable means being biased toward said derailleur shifting means by said return spring means; said primary cam means being configured so that rotational movement thereof in one direction will cause said cam means to pull said cable means against the biasing force of said spring means so as to cause down-shifting of said shifting means, and rotation thereof in the opposite direction will release said cable means in the direction of the biasing force of said spring means so as to cause up-shifting of said shifting means; and secondary handgrip slip cam means rotatably mounted on the bicycle handlebar coaxially in tandem with said primary cam means for actuating said primary cam means, said slip cam means being axially located so that said primary cam means is biased against said secondary slip cam means by the force of said spring means; said slip cam means having a cam face engaged against said primary cam means whereby preliminary rotational movement of said slip cam means in the down-shift direction moves said primary cam means against the biasing force of said spring means to apply an overshift increment of cable pull against the biasing force of said spring means, further down-shifting movement of said slip cam means causing said down-shifting; and preliminary rotational movement of said slip cam means in the up-shift direction releases said primary cam means in the direction of said biasing force so as to release at least a portion of said overshift increment of cable pull, further up-shifting movement of said slip cam means causing said up-shifting.
Claim 3
Dependent Claim
76 words
A bicycle derailleur gear shifting system as defined in claim 1, wherein said cam face of said slip cam means is configured so as to release a portion of said overshift increment under the influence of said spring means upon release of said slip cam means at the completion of a down-shifting event, the remainder of said overshift increment being released under the influence of said spring means at the commencement of a subsequent up-shifting event.
Claim 4
Dependent Claim
47 words
A bicycle derailleur gear shifting system as defined in claim 2, wherein said primary cam means and said cam face of said slip cam means are configured so as in tandem to substantially compensate for the lost motions in said derailleur shifting means and said cable means.
Claim 5
Dependent Claim
34 words
A bicycle derailleur gear shifting system as defined in claim 3, wherein said cable means embodies housing means which is substantially compressionless, thereby making lost motion in said cable means small and substantially predictable.
Claim 6
Dependent Claim
70 words
A bicycle derailleur gear shifting system as defined in claim 3, wherein said derailleur shifting means is a rear derailleur shifting means, and said cable means comprises a first relatively short cable housing section proximate said cam means and a second relatively short cable housing section proximate said derailleur shifting means, with a relatively long unhoused length of said cable means extending between said first and second cable housing sections.
Claim 7
Dependent Claim
58 words
A bicycle derailleur gear shifting system as defined in claim 3, wherein said derailleur shifting means is a front derailleur shifting means, and said cable means comprises a relatively short cable housing section proximate said cam means, with a relatively long unhoused length of said cable means extending between said cable housing section and said derailleur shifting means.
Claim 8
Dependent Claim
43 words
A bicycle derailleur gear shifting system as defined in claim 2, wherein said primary cam means and said cam face of said slip cam means are configured so as in tandem to substantially compensate for chain gap variations in said derailleur shifting means.
Claim 9
Dependent Claim
106 words
A bicycle derailleur gear shifting system as defined in claim 2, wherein said derailleur shifting means is a front derailleur shifting means, and said primary cam means is configured with first and second locations which causes said derailleur shifting means to substantially align the bicycle chain with respective first and second derailleur chain wheels during parallel riding, and a third location which causes said derailleur shifting means to substantially align the chain with one of said chain wheels during cross-over riding; adjustment of said slip cam means between its partial and complete release positions enabling fine-tuning of said front derailleur shifting means to avoid chain rasp.
Claim 10
Dependent Claim
63 words
A bicycle derailleur gear shifting system as defined in claim 8, wherein said primary cam means is configured with a fourth location which causes said derailleur shifting means to substantially align the chain with the other said chain wheel during cross-over riding; adjustment of said slip cam means between its partial and complete release positions enabling fine-tuning of said front derailleur shifting means.
Claim 11
Dependent Claim
49 words
A bicycle derailleur system as defined in claim 2, wherein said derailleur shifting means is a front derailleur shifting means having three chain wheels; adjustment of said slip cam means between its partial and complete release positions enabling fine-tuning of said front derailleur shifting means to avoid chain rasp.
Claim 12
Dependent Claim
53 words
A bicycle derailleur gear shifting system as defined in claim 1, wherein said cam face of said slip cam means is configured so as to release substantially the complete said overshift increment under the influence of said spring means upon release of said slip cam means at the completion of a down-shifting event.
Claim 13
Dependent Claim
30 words
A bicycle derailleur gear shifting system as defined in claim 1, wherein said primary cam means is engaged over the outside of the handlebar proximate an end of the handlebar.
Claim 14
Dependent Claim
32 words
A bicycle derailleur gear shifting system as defined in claim 1, wherein said primary cam means is engaged over the outside of the handlebar substantially inboard of an end of the handlebar.
Claim 15
Dependent Claim
40 words
A bicycle derailleur gear shifting system as defined in claim 1, wherein said primary cam means is configured so as to substantially compensate for increasing force of said return spring means in the down-shifting direction of said derailleur shifting means.
Claim 16
Dependent Claim
36 words
A bicycle derailleur gear shifting system as defined in claim 1, wherein said primary cam means is configured so as to substantially compensate for the lost motions in said derailleur shifting means and said cable means.
Claim 17
Dependent Claim
34 words
A bicycle derailleur gear shifting system as defined in claim 15, wherein said cable means embodies housing means which is substantially compressionless, thereby making lost motion in said cable means small and substantially predictable.
Claim 18
Dependent Claim
69 words
A bicycle derailleur gear shifting system as defined in claim 15, wherein said derailleur shifting means a rear derailleur shifting means, and said cable means comprises a first relatively short cable housing section proximate said cam means and a second relatively short cable housing section proximate said derailleur shifting means, with a relatively long unhoused length of said cable means extending between said first and second cable housing sections.
Claim 19
Dependent Claim
58 words
A bicycle derailleur gear shifting system as defined in claim 15, wherein said derailleur shifting means is a front derailleur shifting means, and said cable means comprises a relatively short cable housing section proximate said cam means, with a relatively long unhoused length of said cable means extending between said cable housing section and said derailleur shifting means.
Claim 20
Dependent Claim
32 words
A bicycle derailleur gear shifting system as defined in claim 1, wherein said primary cam means is configured so as to substantially compensate for chain gap variations in said derailleur shifting means.
Claim 21
Dependent Claim
90 words
A bicycle derailleur gear shifting system as defined in claim 1, wherein said derailleur shifting means is a rear derailleur shifting means, and said primary cam means and said cam face of said slip cam means are configured so as in tandem to cause said derailleur shifting means to move the bicycle chain a sufficient amount beyond the destination freewheel sprocket of said derailleur shifting means in a down-shifting event so that the chain will approach the destination sprocket in the same direction as it would in an up-shifting event.
Claim 22
Dependent Claim
46 words
A bicycle derailleur gear shifting system as defined in claim 20, wherein said primary cam means and said cam face of said slip cam means are configured so that said movement of the bicycle chain beyond said destination sprocket is insufficient to cause a double shift.
Claim 23
Dependent Claim
59 words
A bicycle derailleur gear shifting system as defined in claim 20, wherein said destination sprocket is the largest freewheel sprocket, and said primary cam means and said cam face of said slip cam means are configured so that movement of the bicycle chain beyond said destination sprocket is insufficient to cause the chain to derail from said destination sprocket.
Claim 24
Dependent Claim
55 words
A bicycle derailleur gear shifting system as defined in claim 20, wherein said primary cam means and said cam face of said slip cam means are configured so that said movement of the bicycle chain beyond said destination sprocket is insufficient to cause the chain to rasp against the next sprocket beyond said destination sprocket.
Claim 25
Dependent Claim
81 words
A bicycle derailleur gear shifting system as defined in claim 1, wherein said derailleur shifting means is a front derailleur shifting means, and said primary cam means is configured with first and second locations which causes said derailleur shifting means to substantially align the bicycle chain with respective first and second derailleur chain wheels during parallel riding, and a third location which causes said derailleur shifting means to substantially align the chain with one of said chain wheels during cross-over riding.
Claim 26
Dependent Claim
42 words
A bicycle derailleur gear shifting system as defined in claim 24, wherein said primary cam means is configured with a fourth location which causes said derailleur shifting means to substantially align the chain with the other said chain wheel during cross-over riding.
Claim 27
Dependent Claim
178 words
In a bicycle derailleur gear shifting system having a rear derailleur shifting mechanism, a shift actuator having primary shift cam means and secondary slip cam means operatively associated with said primary cam means so as to actuate said primary cam means, and control cable means operatively associating said primary cam means with said shifting mechanism, a method of performing down-shifting events from a relatively smaller origin freewheel sprocket to a relatively larger destination freewheel sprocket, which comprises the sequential steps of: first slipping said slip cam means relative to said primary cam means a first increment of movement to actuate said primary cam means a take-up increment of movement to take up at least some of the cumulative lost motion in said derailleur mechanism and said cable means; and then moving said slip cam means and said primary cam means synchronously a second increment of movement a further amount so as to further actuate said primary cam means sufficiently to move the bicycle chain at least substantially the distance between the centers of said origin and destination sprockets.
Claim 28
Dependent Claim
178 words
In a bicycle derailleur gear shifting system having a rear derailleur shifting mechanism, a shift actuator having primary shift cam means and secondary slip cam means operatively associated with said primary cam means so as to actuate said primary cam means, and control cable means operatively associating said primary cam means with said shifting mechanism, a method of performing down-shifting events from a relatively smaller origin freewheel sprocket to a relatively larger destination freewheel sprocket, which comprises the sequential steps of: first slipping said slip cam means relative to said primary cam means a first increment of movement to actuate said primary cam means a take-up increment of movement to take up at least some of the cumulative lost motion in said derailleur mechanism and said cable means; and then moving said slip cam means and said primary cam means synchronously a second increment of movement a further amount so as to further actuate said primary cam means sufficiently to move the bicycle chain at least substantially the distance between the centers of said origin and destination sprockets.
Claim 29
Dependent Claim
30 words
A method according to claim 26, which comprises minimizing said cumulative lost motion and making it more predictable by providing said cable means with housing means that is substantially compressionless.
Claim 30
Dependent Claim
35 words
A method according to claim 27, which comprises further minimization of said cumulative lost motion by providing said cable means with relatively short cable housing means and a relatively long cable portion that is unhoused.
Claim 31
Dependent Claim
35 words
A method according to claim 26, which comprises moving said slip cam means a sufficient amount to actuate said primary cam means sufficiently to substantially compensate for chain gap variations in said derailleur shifting means.
Claim 32
Dependent Claim
92 words
A method according to claim 26, which comprises first moving said slip cam means a sufficient amount to actuate said primary cam means sufficiently to cause the bicycle chain to first move beyond said destination sprocket, and then allowing said slip cam means and said primary cam means to move back sufficiently under the influence of the derailleur return spring to cause the chain to move back to substantial alignment with said destination sprocket, whereby the chain approaches the destination sprocket in the same direction as it would in an up-shifting event.
Claim 33
Dependent Claim
25 words
A method according to claim 30, wherein the bicycle chain is not moved beyond said destination sprocket a sufficient amount to cause a double shift.
Claim 34
Dependent Claim
40 words
A method according to claim 30, wherein said destination sprocket is the largest freewheel sprocket, and wherein the bicycle chain is not moved beyond said destination sprocket a sufficient amount to cause the chain to derail from said destination sprocket.
Claim 35
Dependent Claim
34 words
A method according to claim 30, wherein the bicycle chain is not moved beyond said destination sprocket a sufficient amount to cause the chain to rasp against the next sprocket beyond said destination sprocket.
Claim 36
Dependent Claim
77 words
A method according to claim 30, wherein release of said slip cam means at the end of a down-shifting event enables the derailleur return spring to slip said slip cam means back relative to said primary cam means at least a portion of said first slipping increment of movement so as to enable the derailleur return spring to move said primary cam means sufficiently to remove at least a portion of its said take-up increment of movement.
Claim 37
Dependent Claim
61 words
A method according to claim 34, wherein said slip cam means is allowed to slip back relative to said primary cam means only a portion of said slipping increment of movement at the end of a down-shifting event, whereby said primary cam means will maintain a portion of its said take-up increment of movement at the end of a down-shifting event.
Claim 38
Dependent Claim
26 words
A method according to claim 35, wherein the remainder of said take-up increment of movement is automatically released at the beginning of the next up-shifting event.
Claim 39
Dependent Claim
60 words
A method according to claim 34, wherein said slip cam means is allowed to slip back relative to said primary cam means substantially the entire said slipping increment of movement at the end of a down-shifting event, whereby said primary cam means will release substantially all of its said take-up increment of movement at the end of a down-shifting event.
Claim 40
Dependent Claim
24 words
A method according to claim 26, wherein said shift actuator comprises cam means rotatably mounted on the bicycle handlebar generally coaxially of the handlebar.
Claim 41
Dependent Claim
24 words
A method according to claim 38, wherein said shift actuator comprises cam means rotatably mounted on the bicycle handlebar generally coaxially of the handlebar.
Claim 42
Dependent Claim
120 words
In a bicycle derailleur gear shifting system having a front derailleur shifting mechanism with a chain cage and a plurality of chain wheels, a shift actuator having primary shift cam means and secondary slip cam means operatively associated with said primary cam means so as to actuate said primary cam means, and control cable means operatively associating said primary cam means with said shifting mechanism, a method of fine-tune alignment of said chain cage with the bicycle chain at the end of a shifting event which comprises slipping said slip cam means relative to said primary cam means to cause movement of said primary cam means a sufficient amount to avoid chain rasp of said chain against said chain cage.
Claim 43
Dependent Claim
120 words
In a bicycle derailleur gear shifting system having a front derailleur shifting mechanism with a chain cage and a plurality of chain wheels, a shift actuator having primary shift cam means and secondary slip cam means operatively associated with said primary cam means so as to actuate said primary cam means, and control cable means operatively associating said primary cam means with said shifting mechanism, a method of fine-tune alignment of said chain cage with the bicycle chain at the end of a shifting event which comprises slipping said slip cam means relative to said primary cam means to cause movement of said primary cam means a sufficient amount to avoid chain rasp of said chain against said chain cage.
Claim 44
Dependent Claim
14 words
A method according to claim 40, wherein said derailleur system comprises three chain wheels.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-07-02 | 1994-01-01 | 1994-07-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-07-02 | 1998-01-01 | 1998-07-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-07-02 | 2002-01-01 | 2002-07-03 | $7700.00 | Window Closed / Lapsed |