US3824904A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Linear actuator
Assignee: Doosan Bobcat North America Inc
•
Filing: 1971-12-23
•
Granted: 1974-07-23
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Expires: 1991-12-23
Abstract
Abstract A linear actuator of the piston and cylinder type having sleeves with spherical surfaces for the piston and the rod on which the piston is mounted for providing improved resistance to lateral forces.
Inventors
- 👤 P Visser
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 11:18
CPC Classifications
F; F15; F15B; F15B15/00; F15B15/08; F15B15/14; F15B15/1423; F15B15/1447; F15B15/1433
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
185 words
In a linear actuator having an outer cylinder member with an inner surface and an inner reciprocal piston mounted on a rod which projects from one end of the cylinder member, the improvement which comprises a spherical external surface on the piston, a first annular sleeve member located between the said spherical external surface on the piston and the inner surface of the cylinder member and in sliding contact with the said cylinder member, the said first sleeve member having an internal surface conforming to and in contact with the said spherical external surface on the piston, portions of said piston spherical surface extending through and beyond each end of said first annular sleeve member, a second annular sleeve member located between the rod and cylinder member, the said second sleeve member having an outer spherical surface, and a spacer member located wholly within the outer cylinder member, the said spacer member having an outer surface abutting the inner surface of the cylinder member and having an inner surface conforming to and in contact with the said outer surface of the said second sleeve member.
Claim 2
Dependent Claim
185 words
In a linear actuator having an outer cylinder member with an inner surface and an inner reciprocal piston mounted on a rod which projects from one end of the cylinder member, the improvement which comprises a spherical external surface on the piston, a first annular sleeve member located between the said spherical external surface on the piston and the inner surface of the cylinder member and in sliding contact with the said cylinder member, the said first sleeve member having an internal surface conforming to and in contact with the said spherical external surface on the piston, portions of said piston spherical surface extending through and beyond each end of said first annular sleeve member, a second annular sleeve member located between the rod and cylinder member, the said second sleeve member having an outer spherical surface, and a spacer member located wholly within the outer cylinder member, the said spacer member having an outer surface abutting the inner surface of the cylinder member and having an inner surface conforming to and in contact with the said outer surface of the said second sleeve member.
Claim 3
Dependent Claim
32 words
In a linear actuator as specified in claim 1, a gap in each of the said sleeve members permitting the flow of fluid between the opposite ends of the sleeve members respectively.
Claim 4
Dependent Claim
47 words
In a linear actuator as specified in claim 2, sharp edges at the ends of the sleeve members adjacent their mating surfaces with the rod and cylinder respectively for assisting in preventing the entry of dirt and foreign material between the sleeves and their respective mating surfaces.
Claim 5
Dependent Claim
34 words
In a linear actuator as specified in claim 1, the improvement in which the center of the spherical surfaces on both of the said sleeves is located on the longitudinal centerline of the actuator.
Claim 6
Dependent Claim
25 words
In a linear actuator as specified in claim 1 in which the said spacer mEmber is composed of two annular parts for ease of assembly.
Claim 7
Dependent Claim
81 words
A linear actuator as specified in claim 1 in which the said first sleeve member is of material different from that of the said piston whereby during lateral loading the load transmitted between the said piston and the said first sleeve member is approximately uniform over their mating spherical surfaces, and the said second sleeve member likewise is of material different from that of the said spacer member whereby lateral loading results in approximate uniform loading over their mating spherical surfaces.
References Cited (Backward Citations)
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US3169455A
Cited
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Cited
US3695150A
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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) | 1977-07-22 | 1978-01-21 | 1978-07-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-22 | 1982-01-21 | 1982-07-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-22 | 1986-01-21 | 1986-07-23 | $7700.00 | Window Closed / Lapsed |