Patent ID: 7410148

Claim:
A mobile commercial power unit for use with a jack stand, and for use with a lift bridge; said power unit comprising: a generally rectangular frame having a central longitudinal axis; a forward end for operating a jack stand; a middle portion for retaining the lifting mechanism; a rearward end for controlling the power unit; a bottom thereof having an elongated rectangular slot, that is a little wider than the width of the base assembly of the jack stand, with the slot opening in the forward end of the bottom and extending to the middle portion thereof, and having a pair of separated elongated extensions extending from the respective side of the slot to the side of the frame, for straddling one or more of the jack stands and retaining the jack stand in the slotted opening therein; and a rearward portion that is angled longitudinally upwardly a few degrees for facilitating mobility of the power unit, and having a hydraulic cylinder with a control valve and an actuator piston thereon attached along the longitudinal center thereof, a pair of longitudinal flanges extending upwardly from the bottom of said frame, with each flange having a “U” shaped retaining channel facing inwardly and attached horizontally along the middle portion of said frame, and having a pair of wheels attached to the exterior sides of the flanges on lateral axels near the rearward end of said frame; a pair of lift arms acting in parallel having forward ends, central portions and rearward ends and interconnected at the rearward ends thereof by a lateral push bar, and with the respective end of said push bar slidably retained within the respective longitudinal retaining channel of said frame; and with the forward ends of said lift arms extendable upwardly at the forward end of said frame; a pair of frusta-conical disc pivotally attached to the inner sides of the forward ends of each lift arm, with the greater diameter of the discs extending inwardly so that the upper surface thereof inclines upwardly at an acute angle ranging from about 15° to about 30°, for engaging a lifting plate of the jack stand; a pair of connecting arms acting in parallel having forward ends and rearward ends with the respective forward end pivotally connected near the forward end of the respective flange of said frame, and with the respective rearward end pivotally connected near the central portion of said respective lift arm; and the hydraulic cylinder having an extendable and retractable ram at the forward end thereof attached to said lateral push bar; so that when the ram is extended, the rearward ends of said lift arms are translated forward along the longitudinal retaining channels in the respective flange of said frame and the forward ends of said lift arms are extended upwardly at the forward end of said frame.