GB994457A - Improvements relating to exterior rear-view mirrors for vehicles - Google Patents

Abstract

994,457. Reciprocating pumps. DESMO Ltd. June 27, 1961 [June 28, 1960], No. 22542/60. Heading F1A. [Also in Division B7] Relates to a liquid pump for operating a hinged movable part carrying a mirror in a remotely controlled rear-view vehicle mirror device (see Division B7). The movable part 20, Fig. 18, is raised from the inoperative position shown in Fig. 16 by supplying oil under pressure to a cylinder 69 from the pump 61 and pipe 68, the pump being operated by a solenoid 59 energized cyclically by a "flasher unit" 58 through a time delay switch 83 from the vehicle battery 60, the switch maintaining its contacts closed for a predetermined time after manual operation. As shown in Fig. 17, the solenoid 59 operates a plunger 62 against the urge of a spring 73 to move the piston 63 of the pump 61 in a bore 64. Fluid is supplied to the bore from a reservoir 65 and pipe 66 and leaves the bore 64 through a non-return outlet valve 67 and passes through the pipe 68 to the cylinder 69. The solenoid is energized repeatedly during a period sufficient to produce a working pressure of 30 1b./sq. inch which is sufficient to maintain the mirror raised against spring action. When the switch 83 opens the mirror is retained in the raised position by the maintaining of the pressure in the pipe 68 and cylinder 69 because of the non-return valve 67. However on energizing the solenoid again the pressure is increased to about 50 1bs./sq. inch which is sufficient to open a relief valve 75 against the action of a spring 77, adjustable by a screw cap 78. When the valve 75 is opened the fluid pressure acts on an annular flange 80 which is of such an area that the valve will remain open even when the pressure falls below the 30 1bs./sq. inch necessary to maintain the mirror raised and when this occurs the mirror is returned to its inoperative position by a spring (not shown). The pump may be pneumatically operated.