Device for varying a stroke
US4858439A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 17, 1988 |
| Grant date | Aug 22, 1989 |
| Priority date | — |
| Expiry date | Feb 17, 2008 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02M2200/705
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A stroke variable device comprising a large diameter cylinder and a small diameter cylinder which are interconnected to each other. A large diameter piston and a small diameter piston are slidably inserted into the large diameter cylinder and the small diameter cylinder, respectively, and a cylinder chamber is formed between the inner end of the large diameter piston and the inner end of the small diameter piston. A first seal member is arranged to surround the projecting outer end of the large diameter piston, and a second seal member is arranged to surround the projecting outer end of the small diameter piston. One end of the first seal member is fixed to the projecting outer end of the large diameter piston, and the other end thereof is fixed to the housing of the device to form a first hermetically sealed chamber therein. In addition, one end of the second seal member is fixed to the projecting outer end of the small diameter piston, and the other end thereof is fixed to the housing of the device to form a second hermetically sealed chamber therein. The cylinder chamber and both hermetically sealed chambers are filled with oil.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.