Improvements in or relating to air-presses

摘要

399,929. Dashpots. JACKSON, C. E. and HUNT, T. J., 30, Paradise Street, Birmingham. June 4, 1932, No. 15711. [Class 108 (iii).] In an air-press such as is used for inserting or removing mandrels, bushes, ballbearings, &c. the rate of movement is checked by a second piston in an auxiliary cylinder containing oil or other liquid. Compressed air to effect the power stroke is supplied to the top of the power cylinder a against the resistance of the spring e which returns the piston. A control piston j is mounted in the cylinder g with lost motion on the rod d which has a shoulder l and carries a spring-pressed disc valve m adapted to close holes o in the piston. The two sides of the cylinder g are connected by a pipe r and a passage s controlled by a needle valve or by a sleeve valve t provided with a series of graduated radial ports v, Fig. 5, whereby the rate of flow may be controlled. The down movement of the piston j is controlled, but the up movement is free.