US3777496A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vacuum type servo device
Assignee: Astemo Ltd
•
Filing: 1972-07-05
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Granted: 1973-12-11
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Expires: 1992-07-05
Abstract
Abstract A vacuum type servo device exhibiting an improved output pressure characteristic and free from any substantial echoing in the vacuum servo actuator. It includes a lost motion connection between the actuator rod and the hydraulic piston and a control valve arranged between the input and output fluid chambers of the hydraulic cylinder and which is normally open and closable upon initiation of the actuator operation. It also includes cushioning means arranged between the hydraulic piston and the actuator casing.
Inventors
- 👤 M Mizusawa
- 👤 H Takeuchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 15:05
CPC Classifications
B; B60; B60T; B60T13/00; B60T13/10; B60T13/24; B60T13/241; B60T13/242; B60T13/245
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
195 words
A vacuum type servo device comprising: a hydraulic assembly including a cylinder structure and a piston member slidably fitted in said cylinder structure and defining therein an input fluid chamber and an output fluid chamber on the opposite sides of the piston member; a vacuum servo actuator including a casing having a portion mounted on said cylinder and an actuator rod extending axially through said input fluid chamber in said cylinder structure and connected with said piston member for limited axial movement relative thereto; fluid passage means communicating said input and output fluid chambers with each other; control valve means arranged in said fluid passage means and closable with axial forward movement of said actuator rod relative to said piston member; a plug member slidably fitted in the open end portion of said input fluid chamber for abutting against said piston member in retracted position, and a cushioning member interposed between said plug member and said casing of said vacuum servo actuator, said cushioning member being so designed as to allow direct engagement of said plug member with said casing of said vacuum servo actuator when said cushioning member is compressed to a predetermined extent.
Claim 2
Dependent Claim
195 words
A vacuum type servo device comprising: a hydraulic assembly including a cylinder structure and a piston member slidably fitted in said cylinder structure and defining therein an input fluid chamber and an output fluid chamber on the opposite sides of the piston member; a vacuum servo actuator including a casing having a portion mounted on said cylinder and an actuator rod extending axially through said input fluid chamber in said cylinder structure and connected with said piston member for limited axial movement relative thereto; fluid passage means communicating said input and output fluid chambers with each other; control valve means arranged in said fluid passage means and closable with axial forward movement of said actuator rod relative to said piston member; a plug member slidably fitted in the open end portion of said input fluid chamber for abutting against said piston member in retracted position, and a cushioning member interposed between said plug member and said casing of said vacuum servo actuator, said cushioning member being so designed as to allow direct engagement of said plug member with said casing of said vacuum servo actuator when said cushioning member is compressed to a predetermined extent.
Claim 3
Dependent Claim
123 words
A vacuum type servo device as claimed in claim 1, in which said fluid passage means includes an axially extending bore and a radially extending bore formed in said piston member in communication with each other; and said control valve means includes a valve seat formed on said piston member at the inner end of said radially extending bore, a ball valve element fitted in said radially extending bore for seating engagement with said valve seat, and a valve controlling formation on the forward end of said actuator rod and including a terminal land portion and an adjacent reduced diameter portion operable with axial movement of said actuator rod relative to said piston member respectively to unseat and seat said ball valve element.
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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) | 1976-12-10 | 1977-06-11 | 1977-12-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-10 | 1981-06-11 | 1981-12-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-10 | 1985-06-11 | 1985-12-11 | $7700.00 | Window Closed / Lapsed |