Patent ID: 7424846
Filing Date: 2008-09-16
Classification: B23Q,F15B,Y10T

Abstract:
1. A pneumatically static balancer for a machine tool, which counterbalances or lightens a gravitational load generated by an own weight of a vertically moving driven member, the pneumatically static balancer comprising: a pneumatic cylinder supporting the driven member and allowed to move vertically; a pneumatically static bearing having a piston inserted into the pneumatic cylinder, the pneumatic static bearing being formed by feeding compressed air, which is in an interior of the pneumatic cylinder, into a small clearance formed between the pneumatic cylinder and the piston; a cylinder rod connected to an upper end of the piston; and a saddle supporting a leading end portion of the cylinder rod; wherein the piston comprises: a plurality of air communication holes communicating with the interior of the pneumatic cylinder; and a plurality of static pressure nozzles individually communicating with the air communication holes, the static pressure nozzles provided on an outer peripheral portion of the piston.