US3559532A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Travel servomotor
Assignee: Individual
•
Filing: 1968-10-23
•
Granted: 1971-02-02
•
Expires: 1988-10-23
Abstract
Abstract A servomotor for a power brake system which includes a pressure responsive wall in a chamber separated by a partition from the working chamber of the servomotor.
Inventors
- 👤 Stanley I Macduff
- 👤 Maxwell L Cripe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 12:23
CPC Classifications
B; B60; B60T; B60T8/00; B60T8/32; B60T8/34; B60T8/44; B60T8/447; B60T8/448; B60T8/449; B60T13/00; B60T13/10; B60T13/66; B60T13/72; B60T8/18
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
228 words
A fluid pressure servomotor comprising: a housing having first and second pressure chambers; movable wall means in said pressure chambers for movement in response to a pressure differential across said movable wall means; valve means in the first of said pressure chambers for controlling flow of fluid between said first pressure chamber and a pressure communicating port of the second of said pressure chambers, said valve means being actuated by a first force; first control means for interrupting fluid flow between said first chamber and said pressure communicating port upon receiving a a source of vacuum pressure connected to a vacuum communicating port in said second chamber; second control means for establishing communication between said pressure communicating port and said source of vacuum upon receiving a secOnd signal, said communication being terminated before reestablishing fluid flow between said pressure communicating port and said first chamber; force transmitting means operatively connected to said movable wall means in said second pressure chamber for exerting a second force which is greater than said first force in response to said pressure difference across said movable wall means and between said pressure communicating port and vacuum communicating port of said second chamber, said pressure difference moving said movable wall means in a given direction; and resilient means for returning said movable wall to its original position after said pressure difference has been removed.
Claim 2
Dependent Claim
228 words
A fluid pressure servomotor comprising: a housing having first and second pressure chambers; movable wall means in said pressure chambers for movement in response to a pressure differential across said movable wall means; valve means in the first of said pressure chambers for controlling flow of fluid between said first pressure chamber and a pressure communicating port of the second of said pressure chambers, said valve means being actuated by a first force; first control means for interrupting fluid flow between said first chamber and said pressure communicating port upon receiving a a source of vacuum pressure connected to a vacuum communicating port in said second chamber; second control means for establishing communication between said pressure communicating port and said source of vacuum upon receiving a secOnd signal, said communication being terminated before reestablishing fluid flow between said pressure communicating port and said first chamber; force transmitting means operatively connected to said movable wall means in said second pressure chamber for exerting a second force which is greater than said first force in response to said pressure difference across said movable wall means and between said pressure communicating port and vacuum communicating port of said second chamber, said pressure difference moving said movable wall means in a given direction; and resilient means for returning said movable wall to its original position after said pressure difference has been removed.
Claim 3
Dependent Claim
40 words
The fluid pressure servomotor, as recited in claim 1, wherein said first and second control means alternately remove and reapply pressure across said movable wall means in said second pressure chamber in response to said first and second signals, respectively.
Claim 4
Dependent Claim
53 words
The fluid pressure servomotor, as recited in claim 2, further comprises: movable wall means in said first chamber for providing feel to an operator of said servomotor, upon loss of vacuum pressure said movable wall means operating with said force transmitting means to convey substantially all of said small force through said servomotor.
Claim 5
Dependent Claim
48 words
The fluid pressure servomotor, as recited in claim 3, further comprises a third pressure chamber with a movable wall therein, said third pressure chamber being connected with said second chamber about said force transmitting means to provide a further increase in said second force over said first force.
Claim 6
Dependent Claim
20 words
The fluid pressure servomotor, as recited in claim 2, wherein said first and second control means are solenoid operated valves.
Claim 7
Dependent Claim
51 words
The fluid pressure servomotor, as recited in claim 5, further comprising: a diaphragmed cavity within the movable wall means in said first pressure chamber for giving feel to an operator of said braking system; and vacuum communicating means for maintaining pressure balance in all chambers during nonoperation of said braking system.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-02-01 | 1974-08-03 | 1975-02-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-02-01 | 1978-08-03 | 1979-02-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-02-01 | 1982-08-03 | 1983-02-02 | $7700.00 | Window Closed / Lapsed |