Patent ID: 6336390
Filing Date: 2002-01-08
Classification: F15B

Abstract:
A linear actuator with an air cushion mechanism comprising:two air cylinder mechanisms each of which has a slidable piston and pressure chambers on opposite sides of said piston and which are arranged in parallel with each other; a pedestal in which said air cylinder mechanisms are mounted; a slide table mounted for sliding relative to said pedestal and driven by said air cylinder mechanisms; through holes for connecting corresponding pressure chambers of said two air cylinder mechanisms; a pair of ports for supplying compressed air to said respective pressure chambers of either one of said air cylinder mechanisms; and at least one air cushion mechanism common to both said air cylinder mechanisms for stopping said pistons of said two air cylinder mechanisms at at least one of forward and reverse stroke ends in a cushioned manner; wherein said air cushion mechanism has an exhaust hole which is provided to a position adjacent to at least one of said ports and which communicates with said pressure chambers at positions closer to chamber ends, a flow rate restricting mechanism which is connected between said exhaust hole and said port and which restricts a flow rate of exhaust discharged from said pressure chambers, and cushion packing which is mounted to an outer peripheral face of one of said pistons and which gets over said port on an exhaust side immediately before said piston reaches said stroke end to cause said compressed air in said pressure chambers to be discharged only from said exhaust hole.