Patent ID: 6942198

Claim:
A lifter comprising: a hollow main upright, said hollow main upright having a top side and a bottom side; a frame pivoted to said hollow main upright; a link coupled between said hollow main upright and said frame; a winch carried on said frame; at least one hollow auxiliary upright axially movably mounted in said hollow main upright, said at least one hollow auxiliary upright each having a top side and a bottom side; a lifting upright axially movably mounted in said at least one hollow auxiliary upright; at least one first pulley respectively provided at the top side of said hollow main upright; at least one second pulley respectively provided at the top side of each said hollow auxiliary upright; at least one first cable, said at least one first cable each having a first end fixedly fastened to said winch and a second end extended through one said at least one first pulley and then extended into the inside of said hollow main upright and fixedly fastened to the bottom side of one said at least one hollow auxiliary upright and adapted to lift said at least one hollow auxiliary upright out of said hollow main upright upon operation of said winch; and at least one second cable respectively extended through said at least one second pulley and coupled between the top side of said hollow main upright and the bottom side of said lifting upright and adapted to lift said lifting upright upon operation of said winch after said at least one hollow auxiliary upright has been extended out of said hollow main upright.