Pump assembly for obtaining a high vacuum
US5039280A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 14, 1990 |
| Grant date | Aug 13, 1991 |
| Priority date | — |
| Expiry date | Aug 14, 2010 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF04B49/022
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A pumping assembly for obtaining a high vacuum, the assembly comprising a primary pump (4) and a secondary pump (1) associated in series, the inlet of the secondary pump (1) being taken from an enclosure (3) to be evacuated, the assembly further including means (7) for starting the secondary pump (1) when the pressure upstream from the primary pump (4) drops below a value P.sub.1, the assembly being characterized in that a passive tank (10) followed by an isolating valve (11) are interposed between the outlet (12) from the secondary pump (1) and the inlet (13) to the primary pump (4), and in that it includes control means (7) for closing the isolating valve (11) and stopping the primary pump (4) when the pressure in said passive tank (10) reaches a value P.sub.2 <P.sub.1, and for opening the isolating valve (11) and restarting the primary pump (4) when the pressure in said passive tank ( 10) returns to the pressure P.sub.1.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.