Patent US3592443A successfully refreshed from Google Patents.
US3592443A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electric jack
Assignee: H & H Engineering Division
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Filing: 1969-07-29
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Granted: 1971-07-13
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Expires: 1989-07-29
Abstract
Abstract A jack powered by a reversible electric motor preferably for use with trailers for the support of the trailer tongue. The jack includes a column telescopically received within a supporting tube utilizing a threaded shaft and nut system to extend the column. The electric motor is connected to the shaft by means of a speed-reducing transmission incorporating a slip clutch responsive to predetermined torque operative upon the column reaching its extremes of movement to prevent stalling and stressing the motor and transmission.
Inventors
- 👤 Jack C Budrow
- 👤 Glenn A Reed
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 12:51
CPC Classifications
B; B60; B60D; B60D1/00; B60D1/58; B60D1/66; B60S; B60S9/00; B60S9/02; B60S9/04; B60S9/06
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
172 words
An electrically powered jack comprising, in combination, a support member adapted to be affixed to the member to be lifted, an elongated vertically oriented extensible column mounted on said support member having upper and lower ends, bearing means defined upon said support member supporting said column thereon for relative movement therebetween in the longitudinal direction of said column, a vertically oriented threaded sHaft rotatably mounted upon said support member, thread means defined on said column meshing with the threads defined on said threaded shaft whereby said column is displaced relative to said support member upon rotation of said shaft, a reversible electric motor mounted upon said support member, speed-reduction transmission means drivingly connecting said motor to said threaded shaft for rotating said shaft, first and second abutment means defined on said shaft engageable with said column determining the limits of movement of said column, torque-limiting means defined in said transmission means limiting the degree of torque transmitted from said motor to said shaft, and an electric switch controlling energization of said motor.
Claim 2
Dependent Claim
172 words
An electrically powered jack comprising, in combination, a support member adapted to be affixed to the member to be lifted, an elongated vertically oriented extensible column mounted on said support member having upper and lower ends, bearing means defined upon said support member supporting said column thereon for relative movement therebetween in the longitudinal direction of said column, a vertically oriented threaded sHaft rotatably mounted upon said support member, thread means defined on said column meshing with the threads defined on said threaded shaft whereby said column is displaced relative to said support member upon rotation of said shaft, a reversible electric motor mounted upon said support member, speed-reduction transmission means drivingly connecting said motor to said threaded shaft for rotating said shaft, first and second abutment means defined on said shaft engageable with said column determining the limits of movement of said column, torque-limiting means defined in said transmission means limiting the degree of torque transmitted from said motor to said shaft, and an electric switch controlling energization of said motor.
Claim 3
Dependent Claim
31 words
In an electrically powered jack as in claim 1, a unidirectional brake connected to said shaft resisting rotation of said shaft when said shaft is rotated in a column retracting direction.
Claim 4
Dependent Claim
60 words
In an electrically powered jack as in claim 2 wherein said unidirectional brake includes a first drum member having a cylindrical surface fixed to said shaft concentric therewith, a second drum member having a cylindrical surface frictionally connected to said support member concentric to said shaft, and a helical spring wrapped upon said surfaces of said first and second drums.
Claim 5
Dependent Claim
80 words
In an electrically powered jack as in claim 3 wherein said bearing means includes a thrust bearing, a friction pad defined on said support member concentric to said shaft and in opposed relation to said thrust bearing, said second drum being rotatably mounted and having a portion interposed between said friction pad and said thrust bearing whereby axial thrust forces imposed on said shaft and bearing determine the degree of frictional interconnection between said second drum and said support member.
Claim 6
Dependent Claim
60 words
In an electrically powered jack as in claim 1 wherein said support member comprises a vertically oriented tube having upper and lower ends, a mounting flange mounted on said tube, said column being telescopically received within said tube, and a housing removably attached to said tube upper end, said electric motor and speed-reduction transmission means being mounted on said housing.
Claim 7
Dependent Claim
49 words
In an electrically powered jack as in claim 5, said threaded shaft being located within said support member tube and said column and including an upper end disposed adjacent said tube upper end, and a key adapter fixed to said shaft upper end for engagement with said transmission means.
Claim 8
Dependent Claim
41 words
In an electrically powered jack as in claim 5 wherein said column comprises a tube keyed to said support member tube, a cap fixed to said column tube upper end, said thread member comprising an antifriction nut affixed to said cap.
Claim 9
Dependent Claim
64 words
In an electrically powered jack as in claim 7 wherein said shaft includes a lower end, said first abutment means being defined on said shaft lower end and engaging said cap upon said column tube being extended its maximum degree, said second abutment being defined adjacent said shaft upper end for engagement by said nut upon said column tube being retracted its maximum degree.
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) | 1974-07-12 | 1975-01-11 | 1975-07-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-12 | 1979-01-11 | 1979-07-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-12 | 1983-01-11 | 1983-07-13 | $7700.00 | Window Closed / Lapsed |