The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 04, 1993
Filed:
Feb. 21, 1992
Carl N Mortenson, Midland, MI (US);
Magline, Inc., Pinconning, MI (US);
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.