GB539230A - Improvements in or relating to air or gas compressors - Google Patents

Abstract

539,230. Actuating compressors ; brakes; fluid pressure servomotors. HERZMARK, N. Jan. 29, 1940, No. 1753. [Class 8 (i)] [Also in Groups XXIX and XXXIV] A compressor, such as is described in Specification 517,371, is actuated by epicyclic gearing comprising an internally toothed cage a driven by the motor and meshing with planetary pinions b carried by the end flange e<SP>1</SP> of a brake drum e, the pinions driving a sun wheel d<SP>1</SP> fixed to the compressor shaft when the drum e is stopped by a coil brake f surrounding the drum and having a loose end adapted to be pressed against the drum by a roller h pressed upwards by a spring i<SP>2</SP> against a crosshead h<SP>1</SP> carrying the roller. The crosshead is supported by pegs h<SP>2</SP> extending from a piston which is depressed by admission of air to its interior through valves p, q during a certain range of pressures. Thus as the delivery pressure rises, air passing through passages g<SP>5</SP> first depresses diaphragm p<SP>2</SP> and allows valve p to be closed by its spring, some air still leaks past the valve through a leaky passage g' and a port g<SP>8</SP> to the interior of the brake piston without affecting operation ; as the pressure rises higher the diaphragm q<SP>2</SP> is depressed allowing the valve q to fall and the air to pass this valve and depress the brake piston, stopping the compressor. The compressor remains out of operation during a fall of pressure until the valve p is opened, venting the brake piston and allowing the brake to be re-applied and the compressor re-started.