Patent US3601220A successfully refreshed from Google Patents.
US3601220A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Retractable ladder
Assignee: Individual
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Filing: 1970-01-05
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Granted: 1971-08-24
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Expires: 1990-01-05
Abstract
Abstract A retractable ladder for attachment to a vertical support. The ladder is attached by two legs each of which is hinged to both a wall and the ladder. The resulting arrangement is a parallelogram-type linkage. A spring is provided tending to pull the ladder in toward the wall. When the ladder is in the open position, the torque in the direction to open the ladder is at a maximum and the spring force is insufficient for retracting the ladder. When the ladder is in the closed or retracted position, the opening torque is at a minimum and the spring force is sufficient to keep the ladder closed.
Inventors
- 👤 Richard Saucier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 19:32
CPC Classifications
B; B60; B60R; B60R3/00; B60R3/02; E; E02; E02F; E02F9/00; E02F9/08; E02F9/0833
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
238 words
A retractable ladder and platform device to be mounted on a vehiclE having pivotal mounts to receive such a device for movement between a closed clearance position and an open working position in which a person can climb on the ladder and stand on the platform, said device comprising: a vertically oriented ladder; upper and lower collapsible support means for mounting said ladder on pivotal mounts on a vehicle for said movement; one of said support means having a platform extension extending beyond the width of said ladder and moveable with said support means; each of said upper and lower collapsible support means including a pair of mounting arms pivoted at one end to said ladder and at the other end to pivotal mounts on a vehicle; all of said mounting arms being in parallel array and being substantially horizontal in said open position and substantially vertical in said closed position; stop means in operative engagement with said support arms defining said open working position; and spring bias means for maintaining said ladder and support arms in said closed position; said spring bias means being insufficient to raise said ladder and upper and lower collapsible support means out of said open position and the weight of said ladder and support means being substantially completely carried by the pivotal mounts on the vehicle in the closed position with said spring bias means maintaining he same in said closed position.
Claim 2
Dependent Claim
238 words
A retractable ladder and platform device to be mounted on a vehiclE having pivotal mounts to receive such a device for movement between a closed clearance position and an open working position in which a person can climb on the ladder and stand on the platform, said device comprising: a vertically oriented ladder; upper and lower collapsible support means for mounting said ladder on pivotal mounts on a vehicle for said movement; one of said support means having a platform extension extending beyond the width of said ladder and moveable with said support means; each of said upper and lower collapsible support means including a pair of mounting arms pivoted at one end to said ladder and at the other end to pivotal mounts on a vehicle; all of said mounting arms being in parallel array and being substantially horizontal in said open position and substantially vertical in said closed position; stop means in operative engagement with said support arms defining said open working position; and spring bias means for maintaining said ladder and support arms in said closed position; said spring bias means being insufficient to raise said ladder and upper and lower collapsible support means out of said open position and the weight of said ladder and support means being substantially completely carried by the pivotal mounts on the vehicle in the closed position with said spring bias means maintaining he same in said closed position.
Claim 3
Dependent Claim
46 words
A device in accordance with claim 1 wherein said spring bias means includes an elongated tension spring and a flexible connector secured at one end to said ladder and at the other end to a rigid point on the vehicle on which said device is mounted.
Claim 4
Dependent Claim
28 words
A device in accordance with claim 1 wherein said spring bias means provides a continuous force tending to move said ladder and support means into the closed position.
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) | 1974-08-23 | 1975-02-22 | 1975-08-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-23 | 1979-02-22 | 1979-08-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-23 | 1983-02-22 | 1983-08-24 | $7700.00 | Window Closed / Lapsed |