Patent US4509408A successfully refreshed from Google Patents.
US4509408A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fluid pressure actuator
Assignee: KOWA SHOJI Ltd
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Filing: 1983-04-20
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Granted: 1985-04-09
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Expires: 2003-04-20
Abstract
Abstract A piston member is mounted in a cylinder body to be axially movable and unrotatable relative thereto. A ball nut retaining balls is fixed to the piston member, and a screw shaft having a helical groove in engagement with the balls is mounted to be rotatable and axially immovable relative to the cylinder body. The screw shaft makes many rotations when the piston under fluid pressure slightly advances axially inside the cylinder.
Inventors
- 👤 Takeshi Kuroda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 07:54
CPC Classifications
F; F15; F15B; F15B15/00; F15B15/02; F15B15/06; F15B15/068; F16; F16H; F16H25/00; F16H25/18; F16H25/20; F16H25/22; F16H25/2204
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
379 words
A fluid pressure actuator comprising, a cylinder body (1) a telescopic rod (10) disposed in a cylinder tube (2) of the body (1): a piston (9) disposed in the tube (2) and secured to one end of the rod (10); a screw shaft (14) disposed in and extending through the rod (10) and having a helically grooved portion (15), a support portion (16) and an output portion (17); a final output shaft (36) and rotation signal generator means (38) both connected to the output portion (17); a ball nut (23) having balls (24), said balls engaging with a helical groove of the grooved portion (15) and said ball nut secured to the piston (9); a rod cover (4) secured to the other end of the telescopic rod (10) and also to one end of the cylinder tube (2); a head cover (3) secured to the other end of the tube (2) and supporting the support portion (16); a pipe (57) extending between the head cover (3) and the rod cover (4) and passing through the piston (9); a further cylinder tube (50) coaxial with and enclosing the tube (2), the further tube (50) having a further head cover (51) and adapted to support the rod cover (4) slidable within said further tube (50); a still further tube (66) disposed in parallel to and outside the further tube (50), and still further tube (66) having one end secured to the head cover (3), and the other end secured to the further head cover (51); a further screw shaft (63) rotatably disposed in the still further tube (66) and engaging with a further ball nut (65) by means of a further plurality of balls (64), the ball nut (65) secured to an end of said tube (66); further rotation signal generator means (61) operatively connected to the further screw shaft (63); inlet and outlet ports (6), (7), of a pressure fluid said ports allowing communication between said pressure fluid and said tube providing means for driving the piston (9) in an axial direction; and further inlet and outlet ports (53) and (54) of the pressure fluid said further ports allowing communication between said pressure fluid and said further tube providing means for driving the rod cover (4) in an axial direction.
Claim 2
Dependent Claim
379 words
A fluid pressure actuator comprising, a cylinder body (1) a telescopic rod (10) disposed in a cylinder tube (2) of the body (1): a piston (9) disposed in the tube (2) and secured to one end of the rod (10); a screw shaft (14) disposed in and extending through the rod (10) and having a helically grooved portion (15), a support portion (16) and an output portion (17); a final output shaft (36) and rotation signal generator means (38) both connected to the output portion (17); a ball nut (23) having balls (24), said balls engaging with a helical groove of the grooved portion (15) and said ball nut secured to the piston (9); a rod cover (4) secured to the other end of the telescopic rod (10) and also to one end of the cylinder tube (2); a head cover (3) secured to the other end of the tube (2) and supporting the support portion (16); a pipe (57) extending between the head cover (3) and the rod cover (4) and passing through the piston (9); a further cylinder tube (50) coaxial with and enclosing the tube (2), the further tube (50) having a further head cover (51) and adapted to support the rod cover (4) slidable within said further tube (50); a still further tube (66) disposed in parallel to and outside the further tube (50), and still further tube (66) having one end secured to the head cover (3), and the other end secured to the further head cover (51); a further screw shaft (63) rotatably disposed in the still further tube (66) and engaging with a further ball nut (65) by means of a further plurality of balls (64), the ball nut (65) secured to an end of said tube (66); further rotation signal generator means (61) operatively connected to the further screw shaft (63); inlet and outlet ports (6), (7), of a pressure fluid said ports allowing communication between said pressure fluid and said tube providing means for driving the piston (9) in an axial direction; and further inlet and outlet ports (53) and (54) of the pressure fluid said further ports allowing communication between said pressure fluid and said further tube providing means for driving the rod cover (4) in an axial direction.
Claim 3
Dependent Claim
38 words
An actuator as defined in claim 1, wherein the final output shaft (36) is connected to the output portion (17) by means of a reduction mechanism (35), and said output portion (17) is provided with a brake (37).
Claim 4
Dependent Claim
20 words
An actuator as defined in claim 2, wherein the further screw shaft (63) is provided with a further brake (60).
Claim 5
Dependent Claim
25 words
An actuator as defined in claim 3, wherein the rotation signal generator means (38), and the further rotational signal generator means (61) are pulse encoders.
References Cited (Backward Citations)
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Cited
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JPS5520970A
Cited
SU920280A1
Cited
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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) | 1988-04-08 | 1988-10-08 | 1989-04-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-04-08 | 1992-10-08 | 1993-04-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-04-08 | 1996-10-08 | 1997-04-09 | $7700.00 | Window Closed / Lapsed |