US3797264A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low-temperature pumping device
Assignee: Air Liquide SA
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Filing: 1972-11-27
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Granted: 1974-03-19
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Expires: 1992-11-27
Abstract
Abstract An improved low-temperature pump and apparatus for producing very high vacua and ultra-vacua with a pumping speed which can be varied at will, comprises a pumping chamber, a gas-evacuation opening formed in the said chamber, a pumping body located at a distance from the said chamber and adapted to form a main lowtemperature pumping surface, comprising also means for cooling the said body to a very low temperature and, if so desired, means for forming a head screen at a moderately cold temperature around and at a distance from the said main low-temperature pumping body, such as an internal wall of the heat-insulating chamber and a gas-permeable reflector baffle, the said pump further comprising a wall-screen continuous thermal relation with a cold element of the said low-temperature pump, forming an auxiliary low-temperature pumping surface and disposed in a valve conduit adapted to be controlled to the chamber to be evacuated, said valve being equipped with a clapper device adjustable in position and adapted to close the opening in the said pumping chamber, and also with means for putting the said wall-screen into operation, said latter means being controlled in dependence on the position of the said closure clapper, forming through said wall-screen a passage of minimum conductivity in the minimum opening position of said clapper and with increasing conductivity between the minimum and maximum opening positions of the said clapper. The invention is especially applicable to furnaces or ovens operating under very high vacua.
Inventors
- 👤 J Thibault
- 👤 J Boissin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 02:23
CPC Classifications
B; B01; B01D; B01D8/00; F; F04; F04B; F04B37/00; F04B37/06; F04B37/08
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
146 words
A low-temperature pumping device of the kind comprising a pumping chamber, a gas-evacuation opening in said chamber, a pumping body located at a distance from said chamber and adapted to form a main low-temperature pumping surface, comprising also means for cooling said body to a very low temperature and, if so required, means for forming a heat screen at a moderately cold temperature around and at a distance from said main lowtemperature pumping body, such as an internal wall of the heatinsulating chamber and a gas-permeable reflector baffle; said device further comprising trapping means adapted to be brought to a cold and possibly very cold temperature and disposed in the vicinity of said chamber opening, together with means for putting said trapping means at least partially into operation at a cold and possibly very cold temperature, said trapping means forming part of said low-temperature pumping surface.
Claim 2
Dependent Claim
146 words
A low-temperature pumping device of the kind comprising a pumping chamber, a gas-evacuation opening in said chamber, a pumping body located at a distance from said chamber and adapted to form a main low-temperature pumping surface, comprising also means for cooling said body to a very low temperature and, if so required, means for forming a heat screen at a moderately cold temperature around and at a distance from said main lowtemperature pumping body, such as an internal wall of the heatinsulating chamber and a gas-permeable reflector baffle; said device further comprising trapping means adapted to be brought to a cold and possibly very cold temperature and disposed in the vicinity of said chamber opening, together with means for putting said trapping means at least partially into operation at a cold and possibly very cold temperature, said trapping means forming part of said low-temperature pumping surface.
Claim 3
Dependent Claim
34 words
A low-temperature pumping device as claimed in claim 1, in which said means for putting said trapping means into operation comprise a continuously cooled shutter adjustable in position across the opening in said chamber.
Claim 4
Dependent Claim
37 words
A low-temperature pumping device as claimed in claim 2, in which said adjustable shutter is in thermal contact with a tank adapted to receive a fluid at a moderately cold temperature, such as liquid nitrogen, for example.
Claim 5
Dependent Claim
38 words
A low-temperature pumping device as claimed in claim 2, in which said shutter adjustable in position is actuated by control means provided with a passage-bushing fluid-tight to ultra-vacuum, said means acting through the intermediary of a bellows device.
Claim 6
Dependent Claim
17 words
A low-temperature pumping device as claimed in claim 4, in which said shutter-actuating means is mechanically operated.
Claim 7
Dependent Claim
16 words
A low-temperature pumping device as claimed in claim 4, in which said shutter-actuating means is magnetic.
Claim 8
Dependent Claim
29 words
A low-temperature pumping device as claimed in claim 4, in which said shutter-actuating means is adapted to co-operate through said bellows device with a push-rod associated with said shutter.
Claim 9
Dependent Claim
32 words
A low-temperature pumping device as claimed in claim 4, in which said shutter-actuating means is adapted to co-operate through said bellows device with a toothed rack and pinion associated with said shutter.
Claim 10
Dependent Claim
55 words
A low-temperature pumping device as claimed in claim 1, in which said trapping means comprise an auxiliary trapping surface interposed between said chamber opening and a gas-permeable screen facing the said main trapping surface, and in which said means for putting said trapping device into operation comprise adjustable means for supplying a very cold fluid.
Claim 11
Dependent Claim
32 words
A low-temperature pumping device as claimEd in claim 9, in which said auxiliary trapping surface has an annular form substantially coaxial with said chamber opening and having substantially the same transverse extension.
Claim 12
Dependent Claim
49 words
A low-temperature pumping device as claimed in claim 9, in which said adjustable supply means of a very cold fluid comprise an admission pipe coupled to a low point of a helium tank and a vapour-evacuation pipe, at least one of these pipes being fitted with a regulating valve.
Claim 13
Dependent Claim
51 words
A low-temperature pumping device as claimed in claim 9, in which said adjustable supply means of very cold fluid comprise an admission pipe connected to an upper point of a helium tank and a vapour-evacuation pipe, together with means for putting the helium vapour in said tank under a variable pressure.
Claim 14
Dependent Claim
23 words
A low-temperature pumping device as claimed in claim 12, in which said pressure-varying means are preferably an electric resistance immersed in said tank.
Claim 15
Dependent Claim
215 words
A low-temperature pump of the kind comprising a pumping chamber, a gas-evacuation opening formed in said chamber, a pumping body located at a distance from said chamber and adapted to form a main low-temperature pumping surface, comprising also means for cooling said body to a very low temperature and, if so required, means for forming a heat screen at a moderately cold temperature around and at a distance from said main low-temperature pumping body, such as an internal wall of the heat-insulating chamber and a gas-permeable reflector baffle, said pump further comprising a wall-screen continuously in thermal relation with a cold element of the low-temperature pump, forming an auxiliary low-temperature pumping surface and disposed in a valve conduit adapted to be connected to a chamber to be evacuated, said valve being equipped with a clapper adjustable in position and adapted to close the opening in said pumping chamber, and also with means for putting said wall-screen into operation, in which said means for putting said wall-screen into operation are controlled in dependence on the position of said closure clapper, forming through said wall-screen a passage of minimum conductivity in positions of small opening of said clapper and with increasing conductivity between a small opening of said clapper and a maximum opening position of said clapper.
Claim 16
Dependent Claim
215 words
A low-temperature pump of the kind comprising a pumping chamber, a gas-evacuation opening formed in said chamber, a pumping body located at a distance from said chamber and adapted to form a main low-temperature pumping surface, comprising also means for cooling said body to a very low temperature and, if so required, means for forming a heat screen at a moderately cold temperature around and at a distance from said main low-temperature pumping body, such as an internal wall of the heat-insulating chamber and a gas-permeable reflector baffle, said pump further comprising a wall-screen continuously in thermal relation with a cold element of the low-temperature pump, forming an auxiliary low-temperature pumping surface and disposed in a valve conduit adapted to be connected to a chamber to be evacuated, said valve being equipped with a clapper adjustable in position and adapted to close the opening in said pumping chamber, and also with means for putting said wall-screen into operation, in which said means for putting said wall-screen into operation are controlled in dependence on the position of said closure clapper, forming through said wall-screen a passage of minimum conductivity in positions of small opening of said clapper and with increasing conductivity between a small opening of said clapper and a maximum opening position of said clapper.
Claim 17
Dependent Claim
117 words
A low-temperature pump as claimed in claim 14, in which the means for putting said wall-screen into operation, controlled by the position of said closure clapper, are constituted by a control rod coaxial with said screen, said rod also carrying said also coaxial clapper, said wall-screen being mounted between said clapper and said main low-temperature pumping surface and being able to pass freely into said pumping chamber opening, and having a diameter slightly less than said opening, said chamber opening serving as a seating for said clapper, said trapping wall-screen being continuously in thermal relation with the cold element of said pump through the intermediary of a member constituted by a flexible and extensible conductor of heat.
Claim 18
Dependent Claim
40 words
A low-temperature pump as claimed in claim 15, in which said flexible conductor of heat is a metallic braid and said cold element is a collar coaxial with said chamber opening and having substantially the same diameter as said wall-screen.
Claim 19
Dependent Claim
31 words
A low-temperature pump as claimed in claim 15, in which said trapping wall-screen is connected to said clapper by a compression spring mounted on a rod coaxial with said control rod.
Claim 20
Dependent Claim
43 words
A low-temperature pump as claimed in claim 15, in which said wall-screen is composed of a plurality of parallel and coaxial discs mounted on said control rod, said discs having a diameter slightly smaller than that of the opening in said pumping chamber.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-03-18 | 1977-09-17 | 1978-03-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-18 | 1981-09-17 | 1982-03-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-18 | 1985-09-17 | 1986-03-19 | $7700.00 | Window Closed / Lapsed |