Dual mode shock absorber and method
US4623049A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 1, 1985 |
| Grant date | Nov 18, 1986 |
| Priority date | — |
| Expiry date | Aug 1, 2005 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16F9/486
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
Tubular members (22, 24) define a pressure chamber (26) and a reserve chamber (28) between them. A first variable metered hydraulic orifice area is provided between chambers (26, 28) by openings (32) in a metering tube (30). A second metered hydraulic orifice area is provided by fixed orifice (94). In a first mode of operation, both such areas are open during an initial retraction of members (22, 24). Control tube (34) is coaxial with metering tube (30) and has openings (36). In the first mode, latch (62) locks tubes (30, 34) together with openings (32, 36) aligned. Relative extension of members (22, 24) following the initial retraction causes pressure in chamber (28) to rise above pressure in chamber (26) and latch (62) to release control tube (34). Spring (40) moves tube (34) into a closed position in which it blocks openings (32). Shock absorber (20) then operates in its second mode in which fixed orifice (94) remains open and openings (32) remain closed. Relief valve (96) relieves excessive pressure buildup in chamber (26) in the second mode. Subsequent full extension of members (22, 24) automatically resets shock absorber (20) for operation in its first mode.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.