GB663848A - Improvements in fluid actuated air compressors - Google Patents

Abstract

663,848. Compressors. TRICO PRODUCTS CORPORATION. Jan. 26, 1948 [Jan. 27, 1947], No. 2332/48. Class 8 (i) In a pump and pneumatic motor comprising a motor piston and a pump piston working in separate chambers and connected for movement in unison, the motor piston being operated by a fluid pressure differential obtained from a source of suction in the engine of a motor vehicle and having an automatic valve for reversing the fluid pressure differential, a valve is provided operation of which places the source of suction in communication with the automatic valve and concurrently and selectively places the source of suction and the positive pressure output in communication with ports of air accessory to provide a pressure differential thereon. A motor chamber 46 contains a piston 48 coupled to a piston 64 in a pump chamber 17. The pistons are coupled through a lost motion connection to a valve rod 60 controlling a valve 65 which connects a suction connection 38 to either of ports 58, 59 communicating with opposite ends of opposed cylinders 50. These cylinders have pistons 51 connected by a rod 53 carrying a slide valve 40 which alternately connects a central port connected to the suction connection 38, with ports 43, 44 communicating with opposite sides of the motor piston 48. A selection valve 31 is mounted on the pump cylinder head and comprises a removable head 10 having a pressure chamber 11 supplied from the pump and a suction chamber 12 connected to a source of suction by a port 23. A shaft 18 is secured at one end to a valve 19 having a duct 34 which on rotation of the shaft 18 connects a passage 35 from the suction chamber 12 to either of two ports connected to opposite sides of the accessory while exposing the other to the pressure chamber 11. The port 23 is controlled by a valve 22 operated by an arm 24 secured to the shaft 18 and biased to a closed position by a coil spring 29. The suction connection 38 is connected to a port in the suction chamber 12. An arm 31 is secured to the shaft 18 and is connected to an actuating wire at 32. In a modification the selector valve 31 may be separate from the motor and pump unit. Specification 638,242 is referred to.