Speed change mechanism
OwnerRobert P. Davidowinventor
Life of this patent
Estimating the term…
Abstract
A speed change mechanism, principally for use on a bicycle, is provided in which a plurality of driving gears and an associated plurality of driven gears are coupled by a plurality of drive chains, such that each driving gear and its associated driven gear form a gear pair, with each gear pair providing a different input-to-output drive ratio. The driving gears are fixedly mounted to a driving shaft that is operatively coupled to a power input, such as a pedal and crank assembly of a bicycle, and the driven gears are rotatably disposed around a driven hub, with means provided for shifting between and engaging one of the driven gears to the driven shaft, with the driven shaft further operatively coupled to an output gear that will transmit power to a rear wheel of a bicycle, for example.
Claims17
A speed change mechanism capable of effecting speed changes during both kinetic and static conditions comprising:
- a bicycle frame, said bicycle frame having a front wheel and a rear wheel connected thereto;
- a driving gearset comprising a plurality of driving gears fixedly secured to a drive shaft;
- a driven gearset comprising a plurality of driven gears rotatably mounted around an exterior surface of a driven hub, and disposed laterally along a central axis of said hub;
- wherein said shaft of said driving gearset and said driven hub of said driven gearset are retained in position along parallel axes, and wherein each of said plurality of driven gears has a different one of said plurality of driving gears associated therewith;
- said associated driven gears and driving gears forming a plurality of gear pairs;
- a plurality of gear pair chains, each of said plurality of gear pairs being operatively coupled by an associated one of said plurality of gear pair chains;
- said driving gears and said driven gears making up said gear pairs being so constructed and arranged to provide a different input to output drive ratio for each of said plurality of gear pairs;
- a traveler disposed in an interior of said driven hub, said traveler having means for engaging a selected driven gear to rotationally couple said selected driven gear to said driven hub, said traveler and said hub being so constructed and arranged to allow said traveler to move laterally within said hub to engage each of said driven gears;
- said driven gear engaging means being so constructed and arranged to engage only one driven gear of said plurality of driven gears at a time;
- at least one cable operatively coupled to said traveler for moving said traveler laterally within said hub;
- a shifter mechanism coupled to said cable for selectively applying and releasing tensile forces on said cable;
- a power input mechanism for applying power to and rotating said driving gears;
- and
- a power output member operatively coupled to said driven hub and rotatable therewith.
Dependencies are inferred from the claim text.