Patent US3871725A successfully refreshed from Google Patents.
US3871725A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Self leveling mechanism for tray cart
Assignee: GS Blakeslee and Co
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Filing: 1974-03-18
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Granted: 1975-03-18
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Expires: 1994-03-18
Abstract
Abstract The tray cart has main frame means including an upright mast, and a horizontal carrier supported for vertical movement in the upright mast. Spring units are secured between the main frame means and the opposed ends of a floating cross bar. Means for transmitting and reversing the direction of force between the carrier and the cross bar are carried by the upright mast, have connection with the carrier, and have connection with the cross bar adjustably lengthwise thereof.
Inventors
- 👤 Erik O Vilen
- 👤 Vytas Zygas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 23:35
CPC Classifications
B; B65; B65G; B65G1/00; B65G1/02; B65G1/04; B65G1/06; B65G1/07
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
179 words
For use in a tray cart having main frame means including an upright mast, and a horizontal carrier supported for vertical movement in the upright mast: self leveling mechanism for the carrier comprising a free-floating cross bar, a pair of laterally spaced upright spring units adjacent the lower end of the upright mast, said spring units being secured at their lower ends to the main frame means and at their upper ends to the opposed ends of said cross bar, means for transmitting and reversing the direction of force between the carrier and said cross bar, said force transmitting means being carried by the upright mast adjacent the upper end thereof and having connection with the carrier, means connecting said force transmitting means to said cross bar intermediate of the ends of the latter whereby said spring units impose a tension on said cross bar and said force transmitting means and thereby urge the carrier upwardly, and said connecting means being adjustably positionable lengthwise of said cross bar for varying the effective tension of said pair of spring units.
Claim 2
Dependent Claim
179 words
For use in a tray cart having main frame means including an upright mast, and a horizontal carrier supported for vertical movement in the upright mast: self leveling mechanism for the carrier comprising a free-floating cross bar, a pair of laterally spaced upright spring units adjacent the lower end of the upright mast, said spring units being secured at their lower ends to the main frame means and at their upper ends to the opposed ends of said cross bar, means for transmitting and reversing the direction of force between the carrier and said cross bar, said force transmitting means being carried by the upright mast adjacent the upper end thereof and having connection with the carrier, means connecting said force transmitting means to said cross bar intermediate of the ends of the latter whereby said spring units impose a tension on said cross bar and said force transmitting means and thereby urge the carrier upwardly, and said connecting means being adjustably positionable lengthwise of said cross bar for varying the effective tension of said pair of spring units.
Claim 3
Dependent Claim
41 words
The self leveling mechanism of claim 1 wherein said cross bar is formed with a plurality of lengthwise spaced apertures, and including a locating pin inserted in one of said apertures for positioning said connecting means lengthwise of said cross bar.
Claim 4
Dependent Claim
96 words
The self leveling mechanism of claim 1 wherein said force transmitting means comprises a pulley with a hub and a side disc rotatably mounted in the upright mast on a horizontal axis, a first flexible force transmitting element secured at its one end to the carrier and at its other end to said disc and being engageable with the periphery of said disc, and a second flexible force transmitting element secured at its one end to said connecting means and at its other end to said hub and being engageable with the periphery of said hub.
Claim 5
Dependent Claim
109 words
The self leveling mechanism of claim 3 wherein said one end of said first flexible force transmitting element is secured to the carrier at one side thereof; wherein said pulley includes a second side disc; and wherein said force transmitting means further comprises a drum rotatably mounted in the upright mast on an axis laterally spaced from and parallel to said axis of said pulley, and a third flexible force transmitting element secured at its one end to the other side of the carrier and at its other end to said second disc and being engaged over said drum and being engageable with the periphery of said second disc.
References Cited (Backward Citations)
CA626159A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-17 | 1978-09-16 | 1979-03-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-17 | 1982-09-16 | 1983-03-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-17 | 1986-09-16 | 1987-03-18 | $7700.00 | Window Closed / Lapsed |