Patent US3661052A successfully refreshed from Google Patents.
US3661052A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydraulic jack
Assignee: Messier SA
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Filing: 1970-01-09
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Granted: 1972-05-09
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Expires: 1990-01-09
Abstract
Abstract A hydraulic jack having two consecutive and completely different actions and its hydraulic operating means, the jack responding to the control order given by the operating means in the form of the supply pressure on a first input of the jack and the control pressure on a second input of the jack, while automatically effecting two consecutive actions in the same direction, the first action being a travel of large amplitude (naturally with a low force), while the second action develops a large force proportional to the control pressure (with a zero or very small travel), the disappearance of the control order resulting, by the operating means which apply the supply pressure to a third input of the jack, in the return movement of the travel of large amplitude only.
Inventors
- 👤 Rene Lucien
- 👤 Yves A Pascal
- 👤 Pierre M Ghobert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 15:26
CPC Classifications
F; F16; F16D; F16D65/00; F16D65/14; F16D65/16; F16D65/18; B; B60; B60T; B60T13/00; B60T13/10; B60T13/12; B60T13/14; B60T13/141; F15; F15B; F15B15/00; F15B15/20; F15B15/204; F16D2121/00; F16D2121/02
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
260 words
A hydraulic jack having two consecutive and complete different actions and a hydraulic operating means for furnishing a supply pressure under the action of a control pressure, said jack comprising a body, said body forming a first point of action and constituting a first cylinder, a first piston in said first cylinder and a first rod fast with said first piston and directed towards the side opposite to said first point of action, said first piston defining in said first cylinder a chamber on the rod side and a chamber on the side opposite to said rod, said first piston being provided with a peripheral groove, a clapper-valve between said groove and said rod-side chamber, said first rod forming a second cylinder, a second piston in said second cylinder, a second rod fast with said second piston and directed towards the side opposite to said first piston and forming a second point of action, said second piston defining in said second cylinder a chamber on the rod side and a chamber on the side opposite to said rod, and said hydraulic operating means responding to the control pressure when said pressure exceeds a selected threshold, by sending the supply pressure into said rod side chamber of said second piston on the one hand, and the control pressure into said peripheral groove of the said first piston on the other hand, and when said control pressure does not reach said threshold value, by sending the supply pressure into the chamber of said second piston on the opposite side to its rod.
Claim 2
Dependent Claim
260 words
A hydraulic jack having two consecutive and complete different actions and a hydraulic operating means for furnishing a supply pressure under the action of a control pressure, said jack comprising a body, said body forming a first point of action and constituting a first cylinder, a first piston in said first cylinder and a first rod fast with said first piston and directed towards the side opposite to said first point of action, said first piston defining in said first cylinder a chamber on the rod side and a chamber on the side opposite to said rod, said first piston being provided with a peripheral groove, a clapper-valve between said groove and said rod-side chamber, said first rod forming a second cylinder, a second piston in said second cylinder, a second rod fast with said second piston and directed towards the side opposite to said first piston and forming a second point of action, said second piston defining in said second cylinder a chamber on the rod side and a chamber on the side opposite to said rod, and said hydraulic operating means responding to the control pressure when said pressure exceeds a selected threshold, by sending the supply pressure into said rod side chamber of said second piston on the one hand, and the control pressure into said peripheral groove of the said first piston on the other hand, and when said control pressure does not reach said threshold value, by sending the supply pressure into the chamber of said second piston on the opposite side to its rod.
Claim 3
Dependent Claim
29 words
A jack and its hydraulic operating means as claimed in claim 1, in which saId hydraulic operating means comprises a hydraulic distributor controlled in dependence on the control pressure.
Claim 4
Dependent Claim
34 words
A jack and its operating means as claimed in claim 2, in which said jack comprises a braking means for maintaining by friction said first piston in the position in which it is located.
Claim 5
Dependent Claim
44 words
A jack and its operating means as claimed in claim 3, in which said jack body comprises an end member, an eye head, and a hollow axial rod, and forming a cylinder with two bores in which said first piston is adapted to slide.
Claim 6
Dependent Claim
38 words
A jack and its operating means as claimed in claim 3, in which said braking means comprises metal rings adapted to grip said hollow rod, and a hollow plug fast with said first piston and housing said rings.
Claim 7
Dependent Claim
57 words
A jack and its operating means as claimed in claim 1 comprising locking means including an elastic grip-clip fast with said second piston and adapted to engage in a shoulder of said first piston, and a locking piston with a compression spring adapted to slide in said first piston and to lock said clip in said position.
Claim 8
Dependent Claim
27 words
A jack and its operating means as claimed in claim 6, in which said elastic clip is adapted to open said clapper valve in the locked position.
Claim 9
Dependent Claim
33 words
A jack and its operating means as claimed in claim 1 in which said hydraulic operating means comprises a pressure-reducing valve which regulates the control pressure under the manual action of an operator.
Claim 10
Dependent Claim
46 words
A jack and its operating means as claimed in claim 1, in which said hydraulic operating means comprises a distributor which, under the manual action of an operator, sends the supply pressure into the chamber of said second piston on the side opposite to its rod.
References Cited (Backward Citations)
US3306031A
Cited
US3483798A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-05-09 | 1975-11-08 | 1976-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-09 | 1979-11-08 | 1980-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-09 | 1983-11-08 | 1984-05-09 | $7700.00 | Window Closed / Lapsed |