Patent US3780904A successfully refreshed from Google Patents.
US3780904A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pressure compensating door catch assembly
Assignee: Fedders Corp
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Filing: 1971-09-23
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Granted: 1973-12-25
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Expires: 1991-09-23
Abstract
Abstract A pressure compensating door catch assembly for the door to a pressurized enclosure is provided. The assembly includes a strike affixed to the door, a catch affixed to the enclosure and a catch spring which exerts a biasing force on the catch. The force of the catch spring is determined by the bending moment arm of the spring which, in turn, is determined by the position of a shiftable fulcrum. The position of the fulcrum is governed by the pressure within the enclosure through a diaphragm and connecting rod.
Inventors
- 👤 C Stanford
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 16:21
CPC Classifications
E; E05; E05B; E05B51/00; E05B51/02; Y; Y10; Y10T; Y10T292/00; Y10T292/08; Y10T292/0801; Y10T292/0814; Y10T292/0817
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
160 words
An improved catch assembly for the door to a pressurized enclosure comprising: a diaphragm mounted within said enclosure, said diaphragm having one surface exposed to the pressure within said enclosure and an opposite surface exposed to ambient pressure, a strike mounted to said door, a catch mounted to said enclosure and adapted to capture said strike, and pressure responsive means engaging said catch and adapted to exert a variable biasing force on said catch, said pressure responsive means including an elongated spring element having one end engaging said catch and biasing said catch toward said strike; a fulcrum shiftable along the length of said spring element, the position of said fulcrum determining the biasing force exerted by said spring element on said catch; and a rod interconnecting said diaphragm and said fulcrum wherein said fulcrum is shifted by said rod in response to deflections of said diaphragm caused by variations of the pressure differential on the surfaces of said diaphragm.
Claim 2
Dependent Claim
160 words
An improved catch assembly for the door to a pressurized enclosure comprising: a diaphragm mounted within said enclosure, said diaphragm having one surface exposed to the pressure within said enclosure and an opposite surface exposed to ambient pressure, a strike mounted to said door, a catch mounted to said enclosure and adapted to capture said strike, and pressure responsive means engaging said catch and adapted to exert a variable biasing force on said catch, said pressure responsive means including an elongated spring element having one end engaging said catch and biasing said catch toward said strike; a fulcrum shiftable along the length of said spring element, the position of said fulcrum determining the biasing force exerted by said spring element on said catch; and a rod interconnecting said diaphragm and said fulcrum wherein said fulcrum is shifted by said rod in response to deflections of said diaphragm caused by variations of the pressure differential on the surfaces of said diaphragm.
Claim 3
Dependent Claim
77 words
The catch assembly in accordance with claim 1 wherein said elongated spring element is longitudinally aligned wth said rod, said spring element one end being furthest from said diaphragm, and said diaphragm is positioned within said enclosure so that an increase in pressure within said enclosure deflects said diaphragm toward said spring element whereby said increase in pressure will shift said fulcrum toward said spring element one end thereby reducing the effective length of saiD spring element.
Claim 4
Dependent Claim
17 words
The invention in accordance with claim 1 wherein said enclosure comprises a positive pressure clothes drying machine.
Claim 5
Dependent Claim
166 words
In combination, an enclosure adapted to be pressurized, a door providing access to the interior of said enclosure, a diaphragm mounted within said enclosure, said diaphragm having one surface exposed to the pressure within said enclosure and an opposite surface exposed to ambient pressure, a strike mounted to said door, a catch mounted to said enclosure and adapted to capture said strike, and pressure responsive means engaging said catch and adapted to exert a variable biasing force on said catch, said pressure responsive means including an elongated spring element having one end engaging said catch and biasing said catch toward said strike; a fulcrum shiftable along the length of said spring element, the position of said fulcrum determining the biasing force exerted by said spring element on said catch; and a rod interconnecting said diaphragm and said fulcrum wherein said fulcrum is shifted by said rod in response to deflections of said diaphragm caused by variations of the pressure differential on the surfaces of said diaphragm.
Claim 6
Dependent Claim
166 words
In combination, an enclosure adapted to be pressurized, a door providing access to the interior of said enclosure, a diaphragm mounted within said enclosure, said diaphragm having one surface exposed to the pressure within said enclosure and an opposite surface exposed to ambient pressure, a strike mounted to said door, a catch mounted to said enclosure and adapted to capture said strike, and pressure responsive means engaging said catch and adapted to exert a variable biasing force on said catch, said pressure responsive means including an elongated spring element having one end engaging said catch and biasing said catch toward said strike; a fulcrum shiftable along the length of said spring element, the position of said fulcrum determining the biasing force exerted by said spring element on said catch; and a rod interconnecting said diaphragm and said fulcrum wherein said fulcrum is shifted by said rod in response to deflections of said diaphragm caused by variations of the pressure differential on the surfaces of said diaphragm.
Claim 7
Dependent Claim
76 words
The catch in accordance with claim 4 wherein said elongated spring element is longitudinally aligned with said rod, said spring element one end being furthest from said diaphragm and said diaphragm is positioned within said enclosure so that an increase in pressure within said enclosure deflects said diaphragm toward said spring element whereby said increase in pressure will shift said fulcrum toward said spring element one end thereby reducing the effective length of said spring element.
Claim 8
Dependent Claim
17 words
The invention in accordance with claim 4 wherein said enclosure comprises a positive pressure clothes drying machine.
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) | 1976-12-24 | 1977-06-25 | 1977-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-24 | 1981-06-25 | 1981-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-24 | 1985-06-25 | 1985-12-25 | $7700.00 | Window Closed / Lapsed |