Patent US4834136A successfully refreshed from Google Patents.
US4834136A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pressure relief filter and valve and cryopump utilizing the same
Assignee: Azenta Inc
•
Filing: 1987-10-05
•
Granted: 1989-05-30
•
Expires: 2007-10-05
Abstract
Abstract A pressure relief valve in a cryopump is preceded by a filter element in a filter housing. The filter element is springloaded so that the filter element itself provides pressure relief with clogging of the filter. The housing may have a removable end cap. The filter is spring biased by a spring between the housing end cap and a filter end cap.
Inventors
- 👤 Edward L. Bourke
- 👤 James E. Cartwright
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:52
CPC Classifications
B; B01; B01D; B01D35/00; B01D35/14; B01D35/147; F; F04; F04B; F04B37/00; F04B37/06; F04B37/08; Y; Y10; Y10T; Y10T137/00; Y10T137/7722; Y10T137/7837; Y10T137/7904; Y10T137/7922; Y10T137/7929; Y10T137/7931; Y10T137/7932; Y10T137/794; Y10T137/8085
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
97 words
A cryopump having a pressure relief mechanism, the mechanism comprising: a filter element in fluid communication with a cryopump chamber, the filter element being permeable to fluid from the cryopump chamber; filter bypass means for bypassing the filter element with a pressure differential across the filter element above a predetermined level; and a pressure relief valve receiving filtered fluid from the filter element, such that the valve is in fluid communication with the cryopump chamber through the filter element for releasing filtered fluid from the cryopump chamber when the pressure in the chamber exceeds a predetermined level.
Claim 2
Dependent Claim
97 words
A cryopump having a pressure relief mechanism, the mechanism comprising: a filter element in fluid communication with a cryopump chamber, the filter element being permeable to fluid from the cryopump chamber; filter bypass means for bypassing the filter element with a pressure differential across the filter element above a predetermined level; and a pressure relief valve receiving filtered fluid from the filter element, such that the valve is in fluid communication with the cryopump chamber through the filter element for releasing filtered fluid from the cryopump chamber when the pressure in the chamber exceeds a predetermined level.
Claim 3
Dependent Claim
55 words
A cryopump as claimed in claim 1 wherein the filter element has a cylindrical housing and has an end cap, the end cap being spring biased toward an inlet to the filter element such that the filter element presses against the spring away from the inlet with a predetermined pressure differential across the filter element.
Claim 4
Dependent Claim
15 words
A cryopump as claimed in claim 2 wherein the filter element is of sintered material.
Claim 5
Dependent Claim
23 words
A cryopump as claimed in claim 2 wherein the filter housing comprises means for coupling an exhaust housing about the pressure relief valve.
Claim 6
Dependent Claim
50 words
A cryopump as claimed in claim 1 wherein the filter element has a housing which has internal threads at its inlet end for mounting to an exhaust conduit and external threads, complimentary to the internal threads, at an outlet end of the housing for mounting of a pressure relief valve.
Claim 7
Dependent Claim
39 words
A cryopump as claimed in claim 1 wherein the filter element is positioned in a housing having a removable end cap and a spring is positioned between the housing end cap and an end cap of the filter element.
Claim 8
Independent Claim
89 words
A method of relieving pressure in a cryopump comprising providing a filter element in fluid communication with a cryopump chamber and a pressure relief valve for receiving filtered fluid from the filter element, such that the valve is in fluid communication with the cryopump chamber through the filter element, releasing fluid from the cryopump chamber through the filter and pressure relief valve when the pressure in the chamber exceeds a predetermined level, and bypassing the filter element when the pressure differential across the filter element exceeds a predetermined level.
Claim 9
Independent Claim
89 words
A method of relieving pressure in a cryopump comprising providing a filter element in fluid communication with a cryopump chamber and a pressure relief valve for receiving filtered fluid from the filter element, such that the valve is in fluid communication with the cryopump chamber through the filter element, releasing fluid from the cryopump chamber through the filter and pressure relief valve when the pressure in the chamber exceeds a predetermined level, and bypassing the filter element when the pressure differential across the filter element exceeds a predetermined level.
Claim 10
Dependent Claim
51 words
A method as claimed in claim 7 wherein the filter element is cylindrical and has an end cap, the endcap being spring biased toward an inlet to the filter such that the filter element presses against the spring away from the inlet with a predetermined pressure differential across the filter element.
Claim 11
Dependent Claim
15 words
A method as claimed in claim 8 wherein the filter element is of sintered material.
Claim 12
Dependent Claim
39 words
A method as claimed in claim 7 wherein the filter element is positioned in a housing having a removable end cap and a spring is positioned between the housing end cap and an end cap of the filter element.
References Cited (Backward Citations)
US144844A
Cited
US2072271A
Cited
US2088226A
Cited
GB486602A
Cited
US2532568A
Cited
US3131718A
Cited
US3847819A
Cited
CH558462A
Cited
US4081171A
Cited
US4256470A
Cited
US4360037A
Cited
US4454722A
Cited
US4459208A
Cited
US4478617A
Cited
US4719938A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-05-29 | 1992-11-28 | 1993-05-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-05-29 | 1996-11-28 | 1997-05-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-05-29 | 2000-11-28 | 2001-05-30 | $7700.00 | Window Closed / Lapsed |