US3831494A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydraulic servomotor
Assignee: DBA SA
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Filing: 1973-05-17
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Granted: 1974-08-27
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Expires: 1993-05-17
Abstract
Abstract The servomotor comprises a boost piston whose movements depend on the pressure of fluid contained in an actuating chamber, said pressure being controlled by a distributing valve connected to a pressure fluid source and to a reservoir. The valve is operated by a push rod through the intermediary of a lever assembly responsive to the relative movement of the push rod and of the boost piston. The push rod, mounted coaxially to said boost piston, projects therein. The projecting end contains a helical groove whose top cooperates slidably with the surface of a cylindrical bore formed in the boost piston.
Inventors
- 👤 J Carre
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 22:19
CPC Classifications
B; B60; B60T; B60T13/00; B60T13/10; B60T13/12; B60T13/14; B60T13/142; B60T13/145; B60T13/146
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
168 words
A servomotor comprising a housing defining an actuating chamber therewithin, a piston slidably mounted in said actuating chamber, a distributing valve within said housing having an inlet port connected to a pressure source and an outlet port connected to the actuating chamber, an operator-operated push rod, said valve being responsive to movement of said operator-operated push rod to communicate successively higher fluid pressure levels to said outlet port as the push rod is moved from a released position in which said valve vents said actuating chamber, a supply channel communicating said outlet port to said actuating chamber, flow restrictive means separate from said valve in said supply channel, and a cavity located in said channel between said outlet port and said flow restrictive means, one end of said push rod being received in said cavity, said push rod presenting an area responsive to the pressure differential across said flow restrictive means to generate on said push rod a reaction force acting against the input force from the operator.
Claim 2
Dependent Claim
168 words
A servomotor comprising a housing defining an actuating chamber therewithin, a piston slidably mounted in said actuating chamber, a distributing valve within said housing having an inlet port connected to a pressure source and an outlet port connected to the actuating chamber, an operator-operated push rod, said valve being responsive to movement of said operator-operated push rod to communicate successively higher fluid pressure levels to said outlet port as the push rod is moved from a released position in which said valve vents said actuating chamber, a supply channel communicating said outlet port to said actuating chamber, flow restrictive means separate from said valve in said supply channel, and a cavity located in said channel between said outlet port and said flow restrictive means, one end of said push rod being received in said cavity, said push rod presenting an area responsive to the pressure differential across said flow restrictive means to generate on said push rod a reaction force acting against the input force from the operator.
Claim 3
Dependent Claim
28 words
A servomotor according to claim 1 including means for increasing the effective area of the flow restrictive means upon movement of said push rod from its released position.
Claim 4
Dependent Claim
35 words
A servomotor according to claim 1 wherein said flow restrictive means consists of at least one cut-out portion in at least one of the two mutually facing surfaces of the cavity and the push rod.
Claim 5
Dependent Claim
55 words
A servomotor according to claim 1 wherein said cavity presents a cylindrical bore portion coaxial with the push rod, said bore portion receiving said one end of the push rod, said one end being provided with a helical groove which cooperates with the surface of said cylindrical bore to define therewith said flow restrictive means.
Claim 6
Dependent Claim
166 words
A servomotor comprising a Housing defining an actuating chamber therewithin, a piston slightly mounted in said actuating chamber, a distributing valve having an inlet port connected to a pressure source and an outlet port connected to a cavity provided in said piston, a connecting mechanism responsive to the relative movements of the push rod and of the piston to operate said distributing valve, said connecting mechanism comprising an assembly of pivoting levers whose effective dimensions are such that during normal operation of the servomotor the ratio of the push rod stroke to the piston stroke is less than unity, a cavity within said housing slidably receiving one end of said push rod, said cavity being connected to said actuating chamber through flow restrictive means and to said outlet port, said one end of said push rod presenting a surface responsive to the pressure differential across said flow responsive means to create on said push rod a reaction force acting against the input force from the operator.
Claim 7
Dependent Claim
166 words
A servomotor comprising a Housing defining an actuating chamber therewithin, a piston slightly mounted in said actuating chamber, a distributing valve having an inlet port connected to a pressure source and an outlet port connected to a cavity provided in said piston, a connecting mechanism responsive to the relative movements of the push rod and of the piston to operate said distributing valve, said connecting mechanism comprising an assembly of pivoting levers whose effective dimensions are such that during normal operation of the servomotor the ratio of the push rod stroke to the piston stroke is less than unity, a cavity within said housing slidably receiving one end of said push rod, said cavity being connected to said actuating chamber through flow restrictive means and to said outlet port, said one end of said push rod presenting a surface responsive to the pressure differential across said flow responsive means to create on said push rod a reaction force acting against the input force from the operator.
Claim 8
Dependent Claim
28 words
A servomotor according to claim 5 including means for increasing the effective area of the flow restrictive means upon movement of said push rod from its released position.
Claim 9
Dependent Claim
35 words
A servomotor according to claim 5 wherein said flow restrictive means consists of at least one cut-out portion in at least one of the two mutually facing surfaces of the cavity and the push rod.
Claim 10
Dependent Claim
56 words
A servomotor according to claim 5 wherein said cavity presents a cylindrical bore portion coaxial with the push rod, said bore portion receiving said one end of the push rod, said one end being provided with a helical groove which cooperates slidably with the surface of said cylindrical bore to define therebetween said flow restrictive means.
Claim 11
Dependent Claim
37 words
A servomotor according to claim 5 further including a sliding valve secured to the piston to by-pass the flow restrictive means when the displacement of the piston from its release position is greater than a predetermined value.
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) | 1977-08-26 | 1978-02-25 | 1978-08-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-26 | 1982-02-25 | 1982-08-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-26 | 1986-02-25 | 1986-08-27 | $7700.00 | Window Closed / Lapsed |