Patent ID: 6176468
Filing Date: 2001-01-23
Classification: B66F,Y10S

Abstract:
A mechanical lifting jack having a vertical support provided with a series of apertures, an upper lifting assembly and a lower follower assembly having a lifting foot slidably mounted on the vertical support and engagable therewith at predetermined positions, an operating handle pivotally connected by a yoke to the lifting assembly for vertical movement, a safety link pivotally connected at an upper end to the handle and at a lower end to the lower follower assembly, and a reversing member pivotable between a lifting position for lifting a load by reciprocal movement of the handle causing upward movement alternately of the lifting and lowering assemblies and a lowering position for lowering the load by reciprocal movement of the handle causing downward movement alternately of the lifting and lowering assemblies,a latching member extending between opposed arms of the yoke, movable between a latching position and a retracted position and biased to the latching position,a lever projecting from the handle operatively connected to the latching member, to move the latching member between the latching position and the retracted position, anda rotationally fixed toothed element extending into a space between the arms of the yoke,whereby when the latching member is engaged into the toothed element the handle is prevented from substantial upward and downward movement and depression of the lever retracts the latching member from the toothed element and allows the handle to move through its normal operating motion.