Platform lifting device mounted on a motor vehicle

Claim 1

A platform lifting device mountable on the floor of a vehicle comprising a mounting plate for mounting on said floor of said vehicle, a first connecting arm including a first end and a second end, said first end of said first connecting arm being pivotably connected to said mounting plate, a second connecting arm including a first end and a second end, said first end of said second connecting arm being pivotably connected to said mounting plate, a bearing arm including a first end and a second end, said first end of said bearing arm being pivotably connected to said second ends of both said first and second connecting arms at spaced apart locations on said bearing arm, whereby said pivotable connections at said first and second ends of said first and second connecting arms form a parallelogram, a lever member including a first end and a second end, said first end of said lever member being pivotably connected to said second end of said bearing arm, a jack member having a first end and a second end relatively movable between retracted and extended positions, said first end of said jack member being pivotably mounted to said first connecting arm at a point intermediate of said first and second ends thereof, and said second end of said jack member being pivotably mounted to said lever member at a point intermediate of said first and second ends thereof, a platform fixedly connected to said second end of said lever member, whereby retraction of said jack member causes said bearing arm to pivot about said pivotable connections with said first and second connecting arms at said first end of said bearing arm, in turn causing said parallelogram to deform in a manner so as to pivot said first and second connecting arms about said pivotable connections of said first and second connecting arms with said mounting plate, thereby lifting said platform.