Tensioning device for use particularly with vehicle safety belts
US3937487A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 7, 1975 |
| Grant date | Feb 10, 1976 |
| Priority date | — |
| Expiry date | Jan 7, 1995 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB60R22/28
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A tensioning device which also provides for damped return movement, such as for use in tensioning a vehicle safety belt comprises a casing, a main piston movable within the casing by high pressure gases issuing from a pyrotechnic charge, a rod firmly attached to the piston and carrying an attachment buckle for the belt, and a piston jamming mechanism for preventing movement of the piston in one direction but allowing damped movement thereof in the opposite direction. The jamming mechanism is actuated in response to displacement of an auxiliary piston included in the main piston structure away from its initial position where it is held by a frangible element designed to break when the pressure of the combustion gases exceeds a particular level. The main piston preferably works in an outer piston which is slidable in the casing and also provided with a jamming mechanism whereby two phases of damping are provided for.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.