Land vehicles – Wheeled – Tiltable vehicles – stabilized by attendant or article
Patent
1992-02-21
1993-05-04
Mitchell, David M.
Land vehicles
Wheeled
Tiltable vehicles, stabilized by attendant or article
280641, B62B 302
Patent
active
052074390
ABSTRACT:
A hand truck with an upright main frame and a handle part at its upper end has a forwardly extending nose at its lower end for supporting a load thereon which rests back against the main frame when the main frame is in vertically rearwardly tilted position, and a wheel and axle assembly at its lower end to support it for travel. An auxiliary support frame, having a ground engaging wheel at its lower end is pivotally connected near its upper end to the main frame for movement from the main frame to a spread position. A rearwardly extendible first link structure, pivotally connected to the main frame, is hingedly connected to a second link structure, pivotally connected to the auxiliary frame. Force exerting, compressible spring mechanism, connected pivotally to one of the link structures and to one of the main frame and attachment frame, exerts a moment arm force moving the link structures through an in-line position to locked over-center position when the auxiliary frame is spread, and positively resists inadvertent movement of the link structures out of locked position, while positively forcing the link structures and auxiliary frame to folded position once the link structures have been moved back from over-center position and through the in-line position.
REFERENCES:
patent: 2249123 (1941-07-01), Fleck et al.
patent: 3064990 (1962-11-01), Salvucci
patent: 3850441 (1974-11-01), Peters et al.
patent: 3997182 (1976-12-01), Mortenson
patent: 4681330 (1987-07-01), Misana
patent: 4762333 (1988-08-01), Mortenson
patent: 5042827 (1991-08-01), Mortenson
Magline, Inc. brochure.
Magline Inc.
Mitchell David M.
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