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:
Feb. 10, 1987
Filed:
Aug. 01, 1984
David E Bennett, deceased, late of Waukesha, WI (US);
by Barbara Bennett, personal representative, Milwaukee, WI (US);
Kelley Company, Inc., Milwaukee, WI (US);
Abstract
A hydraulically operated dockboard comprising a ramp which is hinged at its rear edge to the frame of the dockboard, and a lip is hinged to the forward edge of the ramp. A main hydraulic cylinder unit connects the frame and the ramp, and by operating the cylinder unit the ramp can be pivoted upwardly from a horizontal cross traffic position to an upwardly inclined position. A lip cylinder interconnects the ramp and the lip and acts to pivot the lip from a downwardly hanging pendant position to an extended position. A hydraulic line is connected to the lip cylinder, and a control valve interconnects the hydraulic line to either a supply line or a return line that is connected to the reservoir of the hydraulic system. The control valve is normally biased to a first position where the lip cylinder is connected to the return line. When it is desired to extend the lip, fluid is supplied through the supply line to pressurize the control valve and move the control valve to a second position where it connects the supply line to the lip cylinder to thereby introduce fluid to the lip cylinder to pivot the lip to the extended position. When the lip is subsequently lowered into engagement with the bed of a carrier, pressure on the control valve is released causing the control valve to return to its first position where the lip cylinder is connected to the return line. When the carrier pulls away from the dock, the lip will fall by gravity, causing fluid to flow the lip cylinder through the control valve to the reservoir.