Vacuum system
US4204812A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 22, 1978 |
| Grant date | May 27, 1980 |
| Priority date | — |
| Expiry date | Feb 22, 1998 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF04B9/127
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
Disclosed is a vacuum pump device that is adapted to create a vacuum source from a source of high pressure air. The device comprises a piston actuated in one direction by compressed air and in the opposite direction by a power return spring. The compressed air moves the piston to load the spring and the spring moves the piston to create a vacuum. A special dumping valve is also provided which is actuated toward the end of the return stroke of the piston to cause a sudden increase in the pressure differential across the piston to prevent stalling of the piston when loading is such that the piston moves very slowly, thereby assuring that the vacuum pump will cycle as often as is necessary to maintain the desired vacuum.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.