Patent ID: 6022183
Filing Date: 2000-02-08
Classification: B66F,Y10S

Abstract:
A machine for lifting massive objects featuring a lifting force multiplier effect comprisinga frame;a primary hydraulic cylinder mounted on said frame including a casing containing a piston chamber having an effective cross-sectional area A.sub.1 and a piston rod which is reciprocally movable relative to said primary casing between a first position and a second position;at least one secondary hydraulic cylinder mounted on said frame, each said secondary cylinder including a casing containing a piston chamber, the sum total of whose effective volumes V.sub.2 is at least equal to the effective volume V.sub.1 of said primary chamber and the sum total of whose effective cross-sectional areas A.sub.2 is greater than the area A.sub.1, each said secondary cylinder also including a piston rod which is reciprocally movable vertically relative to its corresponding casing between a fully retracted position and a fully extended position, a high pressure end of each said secondary chamber being hydraulically connected to a high pressure end of said primary chamber;a force input assembly operatively connected to said primary piston rod for movement therewith and being adapted for application thereto of an externally generated force F.sub.1 for moving said primary piston rod relative to said primary casing from said first position to said second position to transfer a volume of hydraulic fluid, under pressure, from said primary chamber to each said secondary chamber in substantially equal proportions to move each said secondary piston rod in unison from a retracted position toward said fully extended position; anda lift carriage assembly responsively connected to each said secondary piston rod for selective engagement with a massive object to be lifted, said carriage assembly being movable from a fully lowered position to a fully raised position to lift said object with an upwardly directed force F.sub.2 upon movement of each said secondary piston rod from said fully retracted position to said fully extended position, the force F.sub.2 being at least equal to the combined weight of said carriage assembly and said object, when engaged for lifting, and being essentially equal to the force F.sub.1 multiplied by A.sub.2 /A.sub.1.