Patent ID: 6279451
Filing Date: 2001-08-28
Classification: F15B,F16K

Abstract:
An air cylinder comprising:a cylinder tube,a piston sliding within the cylinder tube,first and second ports for respectively supplying and discharging compressed air to and from two pressure chambers separated by the piston, respectively,a discharge outlet for communicating with each pressure chamber, said discharge outlet being positioned closer to an end of said cylinder tube than an associated port of said chamber,a speed regulating mechanism comprising a throttling mechanism connected to a discharge outlet for stopping said piston in a cushioned manner by restraining the flow of discharging air from a first pressure chamber,and first and second piston packing rings disposed on the outer peripheral surface of said piston for defining two pressure chambers by contacting the inner peripheral surface of said cylinder tube, wherein said piston packing rings are situated such that, when said piston reaches the end of a stroke, said first packing ring, which is forward in said stroke direction, passes over said first port, but stops before a first discharge outlet and said second packing ring, which is rearward of the first packing ring in said stroke direction, stops before said first port, such that said piston packing rings also function, respectively, as cushion packings by discharging compressed air within one of said pressure chambers only through a discharge outlet.