US3773292A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydraulic pole jack
Assignee: Reedrill Inc
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Filing: 1972-01-10
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Granted: 1973-11-20
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Expires: 1992-01-10
Abstract
Abstract The hydraulic jack has a pole gripping attachment with a swivel chain attachment means operable in a slot therein to provide for chain tightening with minimum piston movement and little or no eccentric loading of the piston. The cylinder is of single acting design with dual tandem spring return. High hydraulic pressure (over 6,000 PSI) is used to facilitate light weight and compact design features.
Inventors
- 👤 W Thiermann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 21:22
CPC Classifications
B; B66; B66F; B66F3/00; B66F3/24; B66F3/25; B66F3/36; B66F3/26
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
94 words
A hydraulic pole jack comprising a power cylinder adapted to be disposed adjacent to a pole and substantially parallel thereto with one element of the power cylinder fixedly supported, a chain adapted to wrap around the pole with its opposite end portions secured to the movable element of said power cylinder, swivel means having opposed aligned turnnions carried by the movable element of said power cylinder on opposite sides thereof, and means pivotally secured to each trunnion on a transverse axis with respect thereto and adjustably receiving the corresponding end portions of said chain.
Claim 2
Dependent Claim
94 words
A hydraulic pole jack comprising a power cylinder adapted to be disposed adjacent to a pole and substantially parallel thereto with one element of the power cylinder fixedly supported, a chain adapted to wrap around the pole with its opposite end portions secured to the movable element of said power cylinder, swivel means having opposed aligned turnnions carried by the movable element of said power cylinder on opposite sides thereof, and means pivotally secured to each trunnion on a transverse axis with respect thereto and adjustably receiving the corresponding end portions of said chain.
Claim 3
Dependent Claim
40 words
The jack of claim 1, and a sleeve member carrying said trunnions and adapted to slip over the upper end of said power cylinder, and abutment means on the movable element of said power cylinder to support said sleeve member.
Claim 4
Dependent Claim
72 words
The construction of claim 2 and pole gripping means mounted on said trunnions and comprising a channel member with its back adapted to engage the pole and with means in each side wall thereof adapted to receive said trunnions to provide for pivoting of said gripping means relative to said power cylinder generally upon the axis of said trunnions to substantially reduce any eccentric loading of the piston as it is extended.
Claim 5
Dependent Claim
67 words
The construction of claim 3 in which a slot is provided in each side wall of said gripping means and through which the corresponding trunnion extends, said slots providing for limited vertical movement of said gripping means relative to said power cylinder to increase the tightness of said chain upon the pole generally prior to actuation of said power cylinder and during initial actuation of the cylinder.
Claim 6
Dependent Claim
37 words
The construction of claim 4 in which said slots are inclined away from the back of saId gripping means to more effectively tighten said chain upon the pole as said gripping means drops relative to the pole.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-11-19 | 1977-05-21 | 1977-11-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-19 | 1981-05-21 | 1981-11-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-19 | 1985-05-21 | 1985-11-20 | $7700.00 | Window Closed / Lapsed |