US3686708A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydraulic cushioning device
Assignee: PTC Aerospace Inc
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Filing: 1970-10-05
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Granted: 1972-08-29
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Expires: 1990-10-05
Abstract
Abstract A unidirectionally operative hydraulic damping device. A piston attached to a piston shaft is reciprocally moved within a cylinder having a blind end and an open end with the piston shaft extending out through the open end. A flexible diaphragm is hermetically sealed to the piston or the piston shaft at or near the junction therebetween. The flexible diaphragm is also circumferentially hermetically sealed to the cylinder wall at the open end of the cylinder. A cushion valve means is located at the piston, thereby allowing free movement of the piston in one direction relative to the cylinder but restricting movement in the opposite direction. Hydraulic fluid is confined between the blind end of the cylinder and the flexible diaphragm is varying proportions on either side of the piston, depending upon the position of the piston in the cylinder.
Inventors
- 👤 Emanuel J Dinoia
- 👤 Henry B Klatte
- 👤 Theodore R Breunich
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 09:30
CPC Classifications
B; B60; B60N; B60N2/00; B60N2/50; B60N2/52; B60N2/522; B60N2/525; B60N2/527; F; F16; F16F; F16F9/00; F16F9/10; F16F9/14; F16F9/16; F16F9/18; F16F9/19
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
217 words
A unidirectionally cushioned hinge for a member biased by gravity to a normally closed position comprising two relatively rotatable members connected to each other at an axis, a cylinder having a blind end and an open end and connected to one of said relatively rotatable members, a piston assembly comprising a piston reciprocally movable relative to and within said cylinder and a piston shaft fastened to said piston and extending out of said open end of said cylinder and connected to the other of said relatively rotatable members, a flexible diaphragm sealed to said piston assembly in the vicinity of said piston and circumferentially sealed to said open end of said cylinder, said flexible diaphragm folding back on itself as said piston is moved toward the open end of said cylinder, hydraulic fluid confined in said cylinder between said blind end of said cylinder and said diaphragm, and a cushion valve means located at said piston and allowing substantially free movement of said piston in one direction relative to said cylinder when said member is lifted against the force of gravity to an open position, and restricting the rate of movement of said piston in the opposite direction relative to said cylinder when said member is released from an open position to return to its closed position.
Claim 2
Dependent Claim
217 words
A unidirectionally cushioned hinge for a member biased by gravity to a normally closed position comprising two relatively rotatable members connected to each other at an axis, a cylinder having a blind end and an open end and connected to one of said relatively rotatable members, a piston assembly comprising a piston reciprocally movable relative to and within said cylinder and a piston shaft fastened to said piston and extending out of said open end of said cylinder and connected to the other of said relatively rotatable members, a flexible diaphragm sealed to said piston assembly in the vicinity of said piston and circumferentially sealed to said open end of said cylinder, said flexible diaphragm folding back on itself as said piston is moved toward the open end of said cylinder, hydraulic fluid confined in said cylinder between said blind end of said cylinder and said diaphragm, and a cushion valve means located at said piston and allowing substantially free movement of said piston in one direction relative to said cylinder when said member is lifted against the force of gravity to an open position, and restricting the rate of movement of said piston in the opposite direction relative to said cylinder when said member is released from an open position to return to its closed position.
Claim 3
Dependent Claim
13 words
The unidirectionally cushioned hinge of claim 1 wherein said hydraulic fluid is incompressible.
Claim 4
Dependent Claim
95 words
The unidirectionally cushioned hinge of claim 1 wherein said piston is of a diameter which is less than the diameter of said cylinder, said cushion valve means comprising a flexible gasket member attached to one side of said piston and having an annular rim adapted to sealingly engage the walls of said cylinder when the piston is moving in said opposite direction relative to the cylinder, said annular rim being movable away from the walls of said cylinder by fluid passing between said piston and cylinder when said piston is moved in said one direction.
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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) | 1975-08-29 | 1976-02-28 | 1976-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-29 | 1980-02-28 | 1980-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-29 | 1984-02-28 | 1984-08-29 | $7700.00 | Window Closed / Lapsed |