GB1438388A - Air spring cylinder assemblies - Google Patents

Abstract

1438388 Pneumatic springs; cams COORS CONTAINER CO 18 July 1973 34241/73 Headings F2S and F2K A rotating cam 40 for imparting reciprocating motion to a sliding element in a machine is maintained in contact with the cam follower 41 by a pneumatic spring 10 whose force can be adjusted depending on the position and acceleration of the cam, so that the resultant force between the cam and the follower is approximately constant throughout the cycle. The pneumatic spring (depicted in more detail in Fig. 1, not shown) comprises a piston 26, 28 sliding in a cylinder and having an extension 21 of varying cross-section which more or less obstructs an orifice 24 on the cylinder. Air from a tank 36 is admitted continuously to the cylinder chamber 37 at 40 p.s.i. through a valve 35, and discharged through the orifice 24, and may or may not be supplied at 40 p.s.i. to the cylinder chamber 38 depending on the spring force required. In the position of the cam shown, the piston is at a position in the cylinder where the extension 21 greatly restricts the discharge orifice 24. The pressure in the chamber 37 therefore builds up to 177 p.s.i. to provide a spring force larger than that tending to separate the cam from its follower.