GB750735A - Improvements in means for washing the windscreens of motor vehicles - Google Patents

Abstract

750,735. Windscreen washers. DAIMLERBENZ AKT.-GES. April 20, 1954 [April 24, 1953], No. 11375/54. Class 138(1) [Also in Group XXVIII]. A windscreen washer installation comprises a vacuum operated motor pump device having automatically operated distributer valve means which vents the motor element to atmosphere at the end of the suction stroke of the.pump element and reconnects the motor element with the vacuum at the end of the delivery stroke of the pump element, and a manually releasable detent device for arresting the motor element at the end of the suction stroke of the pump element. The washer installation comprises a cylinder 3, having a piston 6 which serves as a combined motor and pump piston, a liquid tank 4 and a piston slide valve 14 for controlling an atmospheric port 10 and a vacuum port 11 both in the cylinder 3. The port 11 communicates by a pipe 13 with the induction manifold of the vehicle engine. The piston 6 has a peripheral groove 27 which can be engaged by a spring-urged detent 8. In the position shown in the Figure the piston is held by the detent and a spring 7 is compressed. The top face 37 of the piston has engaged a pin 16 on the valve 14 to move the latter so that the port 10 is open and the port 11 is closed. On releasing the detent by pulling a knob 24 and thus a cable or rod 25, the spring 7 causes the piston 6 to force liquid from the cylinder 3 past a valve 28, through a pipe 29, to a nozzle 30. At the end of such delivery stroke the lower face 32 of the piston engages another pin 17 on the valve 14 to move the latter and cause the port 10 to be closed and the vacuum-port 11 to be opened. The piston is then raised and sucks-up liquid from the tank 4 past a valve 36 into the cylinder 3. At the-end of this suction stroke the piston 6 is retained by the detent and the valve 14 is moved to close the port 11 and open the port 10. The washer is then in readiness for its next operation. In another embodiment the cylinder 3 is disposed horizontally and communicates with a vertical liquid chamber in turn communicating with the vertical liquid tank 4. A manually operable rod is slidable axially of and within the piston so that in the absence of a vacuum, the piston may be caused to effect the pump intake stroke by pulling the rod. Under normal conditions of operation, pushing of the rod causes release of the detent so that the delivery stroke of the pump is then effected by the spring 7, as before. The rod is also rotatable relatively to the piston so that on rotation it may be retained in its pushed-in position to render the detent inoperative so that the washer can then operate continuously. Instead of a single piston 6, the pump and motor may have separate but interconnected pistons. Moreover the pump may comprise a diaphragm, bellows, or the like instead of a piston and the detent may be operated electrically.