US3874271A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Radial piston machine
Assignee: Individual
•
Filing: 1973-01-08
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Granted: 1975-04-01
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Expires: 1993-01-08
Abstract
Abstract The invention relates to pistons, piston shoes and associated safety means in fluid handling devices including hydraulic or pneumatic pumps, motors and transmissions, wherein recesses for the reception of portions of the piston shoes are provided in a fluid handling body and the walls which are adjacent to the recesses serve to prevent the escape of piston shoes from the recesses, wherein convex and concave semispherical engagement surfaces are provided on the pistons and piston shoes and wherein piston stroke enlargement means and friction preventing means may be associated with the piston shoes and/or pistons or the fluid handling body.
Inventors
- 👤 Karl Eickmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 02:17
CPC Classifications
F; F04; F04B; F04B1/00; F04B1/04; F04B1/10; F01; F01B; F01B1/00; F01B1/06; F01B1/0641; F01B1/0644
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
246 words
In a radial piston machine, a combination comprising a housing; a fluid handling body member provided in said housing and having substantially radially extending cylinders; an actuator member provided in said housing and having an endless guide surface, one of said members surrounding the other of said members; pistons reciprocably mounted in said cylinders and defining with said body member variable-volume working chambers remote from said guide surface, said chambers forming part of the respective cylinders and having inlets for admission and outlets for evacuation of a fluid medium; piston shoes associated with said pistons and slidable along said guide surface in response to rotation of one of said members relative to the other of said members to thereby reciprocate said pistons in the rEspective cylinders, at least a portion of each of said shoes having a polygonal cross sectional outline and said body member having polygonal recesses receiving said portions of said shoes with sufficient clearance to at least temporarily afford to said portions of said shoes the freedom of limited tilting movement in at least two different directions so as to enable said shoes to follow said endless guide surface of said actuator member while the machine is in operation, said pistons and said shoes being provided with normally abutting complementary curved surfaces having constant radii of curvature so as to enable said shoes to pivot on the respective pistons; and confining means for retaining said portions of said shoes in the respective recesses.
Claim 2
Dependent Claim
246 words
In a radial piston machine, a combination comprising a housing; a fluid handling body member provided in said housing and having substantially radially extending cylinders; an actuator member provided in said housing and having an endless guide surface, one of said members surrounding the other of said members; pistons reciprocably mounted in said cylinders and defining with said body member variable-volume working chambers remote from said guide surface, said chambers forming part of the respective cylinders and having inlets for admission and outlets for evacuation of a fluid medium; piston shoes associated with said pistons and slidable along said guide surface in response to rotation of one of said members relative to the other of said members to thereby reciprocate said pistons in the rEspective cylinders, at least a portion of each of said shoes having a polygonal cross sectional outline and said body member having polygonal recesses receiving said portions of said shoes with sufficient clearance to at least temporarily afford to said portions of said shoes the freedom of limited tilting movement in at least two different directions so as to enable said shoes to follow said endless guide surface of said actuator member while the machine is in operation, said pistons and said shoes being provided with normally abutting complementary curved surfaces having constant radii of curvature so as to enable said shoes to pivot on the respective pistons; and confining means for retaining said portions of said shoes in the respective recesses.
Claim 3
Dependent Claim
39 words
A combination as defined in claim 1, wherein said clearances suffice to allow said portions of said shoes to move with respect to said housing at least temporarily in the radial, axial and circumferential directions of said body member.
Claim 4
Dependent Claim
32 words
A combination as defined in claim 1, wherein said recesses and said portions of said shoes are rectangular, as considered in planes which are normal to the axes of the respective pistons.
Claim 5
Dependent Claim
28 words
A combination as defined in claim 1, wherein said portions constitute enlarged extensions of the respective piston shoes, as considered in the radial direction of the associated pistons.
Claim 6
Dependent Claim
32 words
A combination as defined in claim 1, wherein said curved surfaces are substantially hemispherical surfaces, one thereof being convex and the other thereof being concave and said concave surfaces having conical extensions.
Claim 7
Dependent Claim
33 words
A combination as defined in claim 1, wherein at least one of said complementary curved surfaces has a recess having a cross-sectional area slightly less than the cross-sectional area of the respective piston.
Claim 8
Dependent Claim
74 words
A combination as defined in claim 1, wherein the distance between said guide surface and said body member varies, as considered in the circumferential direction of said guide surfaces, and the maximum distance between said body member and said guide surface is less than the length of said portions of said shoes, as considered in the axial direction of said pistons, said length being greater than that of the maximum stroke of a piston.
Claim 9
Dependent Claim
31 words
A combination as defined in claim 1, wherein said fluid handling body has a ring-shaped wall adjacent to said recesses and said guide surface has an annular groove for said wall.
Claim 10
Dependent Claim
31 words
A combination as defined in claim 1, wherein the depth of said recesses, as considered in the axial direction of said pistons, exceeds the length of maximum strokes of said pistons.
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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) | 1978-03-31 | 1978-09-30 | 1979-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-31 | 1982-09-30 | 1983-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-31 | 1986-09-30 | 1987-04-01 | $7700.00 | Window Closed / Lapsed |