US3759488A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Safety catch for hydraulic jacks for automobiles
Assignee: Individual
•
Filing: 1971-12-16
•
Granted: 1973-09-18
•
Expires: 1991-12-16
Abstract
Abstract A rolling hydraulic auto jack has a shaft which telescopes to raise and lower an auto. The invention provides a metal channel or block which fits around the shaft to preclude a telescoping retraction thereof. This channel or block is a safety stop which keeps the jack from inadvertently lowering the auto, even if the hydraulic system fails.
Inventors
- 👤 P Lukas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 15:10
CPC Classifications
B; B66; B66F; B66F17/00; B66F3/00; B66F3/24; B66F3/25; B66F3/30; B66F5/00; B66F5/04
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
143 words
A rolling auto jack, said auto jack comprising: a hydraulic cylinder, a shaft telescopingly movable in said cylinder, linkage means connected to the end of said shaft for translating shaft motion into raised and lowered jack positions, a safety means to prevent retraction of said shaft into said cylinder in the event of malfunctioning of said cylinder, said safety means comprising a propping block, said propping block having a propping position preventing retraction of said shaft and a non-propping position enabling retraction of the shaft, said propping block in the propping position being contiguous to said shaft between said linkage means and said cylinder, said propping block normally in the non-propping position removed from said shaft when said shaft is in the retracted position, and spring means for automatically forcing said block into the propping position responsive to an extension of said shaft.
Claim 2
Dependent Claim
143 words
A rolling auto jack, said auto jack comprising: a hydraulic cylinder, a shaft telescopingly movable in said cylinder, linkage means connected to the end of said shaft for translating shaft motion into raised and lowered jack positions, a safety means to prevent retraction of said shaft into said cylinder in the event of malfunctioning of said cylinder, said safety means comprising a propping block, said propping block having a propping position preventing retraction of said shaft and a non-propping position enabling retraction of the shaft, said propping block in the propping position being contiguous to said shaft between said linkage means and said cylinder, said propping block normally in the non-propping position removed from said shaft when said shaft is in the retracted position, and spring means for automatically forcing said block into the propping position responsive to an extension of said shaft.
Claim 3
Dependent Claim
19 words
The catch of claim 1 and means for manually releasing said catch by moving it to a non-propping position.
Claim 4
Dependent Claim
83 words
A rolling auto jack, said jack comprising a hydraulic cylinder, a shaft telescopingly moving in said cylinder, linkage means connected to the end of said shaft for translating shaft motion to raised and lowered shaft positions, a safety catch to prevent retraction of said shaft into said cylinder, said safety catch comprising a propping block fitting adjacent said shaft between said linkage means and said cylinder, and said propping block comprising a U-shaped channel partly surrounding said shaft when in said propping position.
Claim 5
Dependent Claim
83 words
A rolling auto jack, said jack comprising a hydraulic cylinder, a shaft telescopingly moving in said cylinder, linkage means connected to the end of said shaft for translating shaft motion to raised and lowered shaft positions, a safety catch to prevent retraction of said shaft into said cylinder, said safety catch comprising a propping block fitting adjacent said shaft between said linkage means and said cylinder, and said propping block comprising a U-shaped channel partly surrounding said shaft when in said propping position.
Claim 6
Dependent Claim
30 words
The catch of claim 3 and a pair of arms pivotally attached to said U-shaped channel and rigidly attached to a tubular bearing fitting into the frame of said jack.
Claim 7
Dependent Claim
30 words
The catch of claim 4 and a tab attached to said bearing, and said release means comprises means for moving said tab to rotate said bearing and move said block.
References Cited (Backward Citations)
US2998224A
Cited
US3135555A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-09-17 | 1977-03-19 | 1977-09-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-17 | 1981-03-19 | 1981-09-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-17 | 1985-03-19 | 1985-09-18 | $7700.00 | Window Closed / Lapsed |