Mobile wheelchair lift and brakes therefore
US4926973A · kind A · utility
Inventor
Key dates
| Filing date | Dec 9, 1988 |
| Grant date | May 22, 1990 |
| Priority date | — |
| Expiry date | Dec 9, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T74/159
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A lightweight frame supports a wheelchair platform for up and down movement between four vertical standards, one at each corner. A lifting mechanism includes a winch supported between two of the standards and connected to the platform by cables which pass over pulleys mounted in an upper cross bar pivotally secured and extending between the two posts with the pivot being offset from the longitudinal axis of the crossbar thereby giving a camming or offset partial rotational movement. The winch includes a one way clutch which is disengaged when the platform is elevated but engages automatically as soon as the platform starts to descend thus locking a brake drum to the winch. A brake band extends around the drum and is operatively connected to an offset pin on the upper crossbar by rigid links so that as soon as the platform starts to descend, the brake is automatically applied thus preventing inadvertent downward movement of the platform unless the friction or resistance between the drum and band is overcome by actuation of the winch for controlled lowering of the platform. Wear is automatically compensated for by the linkage between the brake pad and the pin on the upper cross bar w…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.