High visibility mast for lift trucks

Claim 1

In a lift truck, a mast assembly supported on said truck, said mast assembly comprising: a pair of vertically extending laterally spaced-apart mast uprights, said mast uprights each including inner and outer relatively movable telescoping members, load bearing carriage means including forks thereon supporting a load to be lifted, said carriage means being movably mounted upon said mast uprights, carriage lift actuator means mounted upon said mast uprights for selectively moving said carriage means relative to said outer members, said lift actuator means being mounted upon said mast uprights entirely laterally outwardly thereof, thereby leaving the space between said mast uprights unobstructed for good operator visibility, said actuator means including a pair of hydraulic jacks having cylinder portions and rod portions extendible from said cylinder portions, said cylinder portions being fixedly mounted upon said outer members, and chain means connected at first and second points to said outer members and said carriage, respectively, sheave assembly means for said chain means, said sheave assembly means being mounted upon and movable with said rod portions of said hydraulic jacks, wherein said sheave assembly means include a sheave support member and vertically extending pin means and flange plate means mounted upon said inner members for engaging said pin means upon extension of said rod portions to transmit movement of said rod portions to said inner members.