Patent ID: 6364601
Filing Date: 2002-04-02
Classification: B66C

Abstract:
A lifting device, comprising:a horizontal framework having a pair of horizontal supporters connected to a pair of horizontal connectors; at least a pair of horizontal carriages slidably inserted into said horizontal connectors approximately perpendicular to said horizontal supporters; a horizontal drive mechanism, comprising a pulley and belt system, wherein said horizontal drive mechanism may move said horizontal carriages within said horizontal connectors, wherein the pulley and belt system comprises: a first shaft connected to said horizontal motor; a frame shaft having first and second ends connected to said first shaft; a pair of speed reduction gear units wherein said speed reduction gear units connect to said first and second ends of said frame shaft; a pair of pulley and belt drive assemblies connected to said pair of speed reduction gear units; a pair of inboard pinion gears and a pair of outboard pinion gears driven in synchronized motion through said pulley and belt drive assemblies; and, a pair of gear racks moved by said pair of inboard and said pair of outboard pinion gears wherein said gear racks move said extension supporters horizontally; at least a pair of extension units disposed on opposite sides of said horizontal supporters and connected to said horizontal carriages wherein said extension units remain approximately parallel when said horizontal drive mechanism moves said horizontal carriages toward or away from said horizontal framework; at least a telescoping mast unit having a plurality of telescoping mast assemblies, connected to said extension unit and approximately perpendicular to said horizontal framework, vertically moving toward and away from said extension unit; and at least a fork tine assembly mounted on one of said telescoping mast assemblies, having at least a pair of tines spaced-apart from each other.