US3889778A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Platform lift
Assignee: Individual
•
Filing: 1973-07-26
•
Granted: 1975-06-17
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Expires: 1993-07-26
Abstract
Abstract This disclosure describes a scissors type platform lift device which comprises a narrow rectangular base and a corresponding narrow rectangular platform substantially parallel to and above the base. The platform is supported by two pairs of scissors which comprise a pair of rectangular tubular structural members which are hinged together at a first end and are hingedly supported respectively on the base member and the platform at their other ends. There are two pairs of channel struts which are of equal length with the members, and are supported on a horizontal shaft through the centers both the members and the struts. One strut on each side of the member in the top scissors and one strut on each side of the member in the bottom scissors. A first end of the pairs of struts are hinged together and the free ends of the struts carry shafts with rollers, which respectively roll on the top of the base member and on the undersurface of the platform member. A hydraulic cylinder and piston means is connected between the two hinged members. Ratchet means on the base is provided to restrain the longitudinal moment of the bottom rollers so that once lifted into elevated position by the hydraulic cylinder, the scissors can be locked. A collapsible ladder means is provided in a vertical position at one end of the base with a corresponding part of the ladder attached to the platform.
Inventors
- 👤 Gerald Dean Dotts
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:28
CPC Classifications
B; B66; B66F; B66F11/00; B66F11/04; B66F11/042; E; E04; E04G; E04G1/00; E04G1/18; E04G1/22
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
31 words
The vertically adjustable work platform means as in claim 1 including vertical, extensible ladder means, one end fastened to said base means and the other end fastened to said platform means.
Claim 2
Dependent Claim
29 words
The vertically adjustable work platform means as in claim 2 in which said ladder means is placed at the second ends of said base means and said platform means.
Claim 3
Dependent Claim
19 words
The vertically adjustable work platform means as in claim 1 including outrigger support means attached to said base means.
Claim 4
Dependent Claim
16 words
The vertically adjustable work platform means as in claim 1 including wheels on said base means.
Claim 5
Dependent Claim
60 words
The vertically adjustable work platform means as in claim 1 including two spring means, one on each side of the longitudinal axis of said base means, supporting an axle and wheels to transport said platform, one end of each of said springs hinged to said base means, and including means to raise and lower the other ends of said springs.
Claim 6
Dependent Claim
22 words
The vErtically adjustable work platform means as in claim 6 in which said means to raise comprises hydraulic cylinder and piston means.
Claim 7
Dependent Claim
63 words
The platform means as in claim 7 in which said means to raise and lower said other ends of said springs comprises: a. first lever means connected to said springs; b. second lever means connected to said first lever means; c. hydraulic piston and cylinder means for operating said second lever means; and d. means to lock said springs in the lowered position.
Claim 8
Dependent Claim
320 words
A vertically adjustable work platform, comprising: a. base structure means of rectangular configuration adapted to be used in a substantially horizontal plate; b. top work platform means of rectangular configuration substantially parallel to said base means; c. a pair of rectangular tubing structural members each of length L, hinged together at one end in a vertical plane, the second end of the lower member hinged to a first end of said base means, the second end of the upper member hinged to a first end of said platform means; d. a first pair of channel struts of length L, one on each side of said lower member, rotatable about a transverse shaft through said lower member at the midpoints of said member and said struts; e. a second pair of channel struts of length L, one on each side of said upper member rotatable about a transverse shaft through said upper member at the midpoints of said member and said struts; f. the first ends of each pair of struts hinged together; g. roller means attached to the second ends of said struts, those on the lower pair of struts adapted to roll along the top surface of said base means, and those on the upper pair of struts adapted to run on the underside of said platform means; h. hydraulic cylinder and piston means connected between said two hinged members; and i. two spring means, one on each side of the longitudinal axis of said base means, supporting an axle and wheels to transport said platform, one end of each of said springs hinged to said base means, and including means to raise and lower the other ends of said springs, comprising: first lever means connected to said springs; second lever means connected to said first lever means; hydraulic piston and cylinder means for operating said second lever means; and means to lock said springs in the lowered position.
Claim 9
Dependent Claim
42 words
The vertically adjustable work platform means as in claim 9 including ratchet means between said base means and the second ends of said lower pair of struts; whereby said second ends can be locked at any selected position along said base means.
Claim 10
Dependent Claim
31 words
The vertically adjustable work platform means as in claim 9 including vertical, extensible ladder means, one end fastened to said base means and the other end fastened to said platform means.
Claim 11
Dependent Claim
29 words
The vertically adjustable work platform means as in claim 11 in which said ladder means is placed at the second ends of said base means and said platform means.
Claim 12
Dependent Claim
19 words
The vertically adjustable work platform means as in claim 9 including outrigger support means attached to said base means.
Claim 13
Dependent Claim
16 words
The vertically adjustable work platform means as in claim 9 including wheels on said base means.
Claim 14
Dependent Claim
52 words
The platform means as in claim 11 including cable means wound around pulley means on selected ones of the shafts forming the hinges for said struts, and means responsive to said cable means for operating said ratchet means to permit lowering said platform under control of said hydraulic cylinder and piston means.
References Cited (Backward Citations)
US1892340A
Cited
US3131753A
Cited
US3135401A
Cited
US3259369A
Cited
US3373844A
Cited
US3485321A
Cited
US3464519A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-06-16 | 1978-12-16 | 1979-06-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-16 | 1982-12-16 | 1983-06-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-16 | 1986-12-16 | 1987-06-17 | $7700.00 | Window Closed / Lapsed |