Crank-gear for bicycle or similar locomotion vehicle
US4793208A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 7, 1987 |
| Grant date | Dec 27, 1988 |
| Priority date | — |
| Expiry date | Jan 7, 2007 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T74/2167
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
This crank-gear includes cranks centered on a first axis and respectively mounted on shafts journalled into one another in the bicycle crank-gear case. Each shaft bears a guide cooperating with sliders which are fixed to rotate with the sprocket plates actuating the chain with an orbital movement around a second axis. In view of the offset between the first and second axes and the relative arrangement of the cranks and guides the cranks are aligned with one another only when horizontal. Furthermore, when one of the cranks is at bottom dead center the other crank is forwardly offset by a certain distance relative to top dead center. An improved pedalling efficiency is thereby obtained.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.