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US 2001/0041641 A1Published application
Transmission system for a bicycle
AssigneeSalomon S.A.
InventorsJean-Pierre Mercat, Bertrand Cauvin
Life of this patent
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AssigneeSalomon S.A.
InventorsJean-Pierre Mercat, Bertrand Cauvin
Estimating the term…
A transmission system provided for a bicycle, including a primary transmission sub-assembly having a set of rear sprockets, whose number of teeth, from one sprocket to the next sprocket in the ascending order, varies according to a ratio of the numbers of teeth that is greater than or equal to a value n such as n greater than 1. The invention also includes a control of the transmission system, as well as a bicycle that includes the transmission system and the control for same. The transmission system includes a single chain wheel for driving the chain, associated with a bottom bracket assembly, and a secondary transmission sub-assembly having at least two drive output ratios, whose ratio of the highest drive speed to the lowest drive speed is equal to a value R between 1 and n so as to introduce at least one intermediate transmission ratio between two successive sprockets.
A transmission system for a bicycle having a frame, a front wheel, a rear wheel with a hub and a hub shaft, and a drive bottom bracket assembly with a crank axle, including a transmission chain, a primary transmission sub-assembly having a set of sprockets provided to be mounted on the rear wheel, whose number of teeth varies generally, for at least a portion of them, along a geometric progression with a ratio of the numbers of teeth of two adjacent sprockets greater than or equal to a value n such as n greater than 1, with a rear derailleur provided for transferring the chain from a given sprocket to an adjacent sprocket, a secondary transmission sub-assembly associated with the bottom bracket assembly having at least two drive output ratios, whose ratio of the highest drive speed to the lowest drive speed is equal to a value R comprised between 1 and n, wherein the ratio R is close to 1 and wherein the secondary transmission sub-assembly includes a single crown for driving the chain and carries out a change in ratio by maintaining the chain in the same plane.
A bicycle having a frame, a front wheel, a rear wheel with a hub and a hub shaft, a drive bottom bracket assembly with a crank axle, including a transmission chain, a transmission system having a primary transmission sub-assembly having a set of sprockets provided to be mounted on the rear wheel, whose number of teeth varies generally, for at least a portion of them, along a geometric progression with a ratio of the numbers of teeth of two adjacent sprockets greater than or equal to a value n such as n greater than 1, with a rear derailleur provided for transferring the chain from a given sprocket to an adjacent sprocket, a secondary transmission sub-assembly associated with the bottom bracket assembly having at least two drive output ratios, whose ratio of the highest drive speed to the lowest drive speed is equal to a value R comprised between 1 and n, wherein the ratio R is close to 1, and wherein the secondary transmission sub-assembly includes a single crown for driving the chain and carries out a change in ratio by maintaining the chain in the same plane.
Dependencies are inferred from the claim text.