Patent ID: 8413958

Claim:
A lifter with linkage mechanism comprising: a frame ( 1 ), being movable on the floor; a lifting mechanism ( 2 ) disposed on the upper portion of said frame ( 1 ), including a lifting arm ( 21 ) with a lifting driving box, a first end of said lifting arm ( 21 ) being pivoted on said frame ( 1 ), and a second end of said lifting arm ( 21 ) being jointed with a linkage mechanism; wherein said frame ( 1 ) including a horizontal base seat ( 12 ), two vertical columns ( 11 ) with vertical guiding grooves ( 111 ) respectively coupled to two sides of said base seat ( 12 ), and a crossbeam coupled between said two columns ( 11 ); said linkage mechanism being two four-bar linkage mechanisms ( 23 ), which is disposed between the two columns ( 11 ) and jointed with a loading plate ( 4 ) and said lifting arm ( 21 ) respectively; a first end of said loading plate ( 4 ) and said four-bar linkage mechanism ( 23 ) being jointed with said column ( 11 ) and being movable along said vertical guiding groove ( 111 ); each of said four-bar linkage mechanism ( 23 ) includes: a first bar ( 231 ), which is jointed with the lifting arm ( 21 ), a second bar ( 232 ), whose first end is rotatably jointed with said loading plate ( 4 ), whose second end is pivoted on the second end of said first bar ( 231 ), a third bar ( 233 ) whose first end is rotatably jointed with a second end of said second bar ( 232 ); a fourth bar ( 234 ) whose upper end is rotatably jointed with a second end of said third bar ( 233 ), an upper wheel ( 5 ) disposed on the upper end of said fourth bar ( 234 ), a lower wheel ( 6 ) disposed on a lower end of said fourth bar ( 234 ), and said upper wheel ( 5 ) and said lower wheel ( 6 ) are both able to roll along the vertical guiding groove ( 111 ).