GB662241A - Improvements in or relating to a windshield washing system - Google Patents

Abstract

662,241. Windscreen washers. TRICO PRODUCTS CORPORATION. April 22, 1949 [April 28, 1948], No. 10792/49. Class 138 (i) [Also in Group XXVIII] A windscreen washer comprising a pump with a liquid displacing member having an intake stroke to draw in liquid from a reservoir and a delivery stroke for discharging liquid on to the windscreen and a manually operated control member whereby a source of power is caused to effect the intake stroke, has means operable by the pump on its intake stroke to render the source of power ineffective and means whereby the pump thereafter effects its delivery stroke independently of the release of the control member. In the embodiment shown in Fig. 1 engine suction is connected to a chamber 14, by a pipe 8, on operation of a foot or hand controlled valve button 11. A diaphragm 5 is thereby lifted against the urge of a spring'6 to cause liquid to be raised from a reservoir 4 into a chamber 7. As the diaphragm approaches the end of its intake stroke a spring 18 is compressed to unseat a vent valve or valves 13, whereby the chamber 14 is placed in communication with the atmosphere so that the spring 6 then causes the diaphragm to perform its discharge stroke to deliver the liquid in the chamber 7 to a nozzle 3 and on to the windscreen. Valve means (not shown) are provided in the passages connecting the pump to the reservoir and the nozzle. In another embodiment the diaphragm is replaced by a differential piston comprising a liquid displacing member and a larger motor piston, the motor piston operating a vent valve at the end of the intake stroke. In a further embodiment the liquid displacing member is operated by an electric solenoid and the displacing member at the end of the intake stroke opens a switch to de-energise the solenoid.