Patent GB-752941-A (GB)
Title: Improvements in or relating to a windshield cleaning system
IPC: B60S1/50
Filed: 1954-05-12
Abstract: 752,941. Windscreen washers. TRICO PRODUCTS CORPORATION. May 12, 1954 [May 28, 1953], No. 13927/54. Class 138(1)  In a combined windscreen wiper and windscreen washersystem, operation of the washer system causes the wiper system to operate and after the washer system ceases to operate, a time delay mechanism ensures that the wiper system will continue for a predetermined number of wiping strokes before it also ceases to operate. Referring to Fig. 1, a pneumatic motor 5, in communication with an engine intake manifold 11 by a pipe 10 under the control of a valve 12, oscillates a wiper arm 3 by a crank 53 on the motor shaft 7 and a linkage 6. The valve 12 is operable manually from a rotatable knob 17, rack and pinion mechanism 19 and a cable 15. The washer unit comprises a liquid reservoir 20, a pump 21 and a pneumatic motor 22 for operating the pump, which motor communicates with the intake manifold 11 through a pipe 23 under the control of an electromagnetically operated valve 24 controlled by a switch 27 operable by a pushbutton 28 projecting through the knob 17. The pump piston 21' is connected with the piston 30 of the motor 22 so that when the piston 30 is raised by applying suction to the cylinder 29 liquid will be drawn into the pump cylinder. When the piston 30 reaches the top of its cylinder the suction inlet valve 33 is closed and the cylinder 29 is vented to atmosphere and a spring 31 then causes the pump piston 21<SP>1</SP> to effect its delivery stroke to form liquid through a pipe 35 to a nozzle 36. The interior of the cylinder 29 also communicates by a pipe 47 and nipple 46 with an auxiliary pneumatic motor 45, Fig. 3, mounted on the cover 5' of the motor 5. Connected to the diaphragm of the motor 45 is a slidable carriage 37 urged to lift, in Fig. 3, by a spring 49. In the position shown a spring- urged pivoted pawl 43 engages a tooth, 44 and the carriage 37 which is connected by a pivoted spring-urged lever 49 (the inoperative position of which is shown in dotted line) to a link 50 in turn connected to the slide valve 12. A stop 49" on the lever 49 prevents rotation thereof in an anti-clockwise direction fro.m the dotted line position. When suction is applied to the washer motor the motor 45 is also operated to move the carriage 37 to the position-shown in Fig. 2, where it is retained by the pawl 43 engaging a tooth 44<SP>1</SP>. Movement of the. carriage also causes, through the lever 49 and link 50, the valve 12 to open and thus to start the wiper motor and after the pump 21 has completed its delivery stroke the wiper motor will continue to operate until such time as the carriage is released from the pawl 43. The time delay mechanism to effect such release comprises a ratchet wheel 51 rotated on the carriage 37, against a friction washer 52 in equal increments by a pivoted pawl 56 having a spring-loaded nose piece 57 engaging the ratchet wheel after acting positively in one direction of movement and yielding to idly wipe the ratchet wheel 51 in the other direction of movement. The pawl 56 is urged to a central position by a spring blade 59 and is oscillated by a wiping lug 53<SP>1</SP> on a member 53a integral with the crank 53, Fig. 1. As appears from Fig. 2, the ratchet wheel is rotated one tooth during every other stroke of the crank 53 until, after a predetermined number of strokes dependent upon the number of teeth on the wheel 51, a pin 54 thereon engages an arm 55 of the pawl 43 to cause the latter to be disengaged from the carriage 37 which thereafter causes the valve 12 to close. The wiper motor 5 may be operated independently of the washer since the cable 15, Fig. 2, is not directly connected thereto. Under these conditions the ratchet wheel would be in the position shown in Fig. 3, and the pawl 56 would oscillate without effect. Also the lever 49 would move to the full line position shown in Fig. 3 against its spring 49<SP>1</SP> in 1 response to the valve opening movement In a modification described with reference to Fig. 8 (not shown) the auxiliary motor is dispensed with and the washer unit replaced by a pedal-operated bulb which bulb contains the liquid to be ejected. The foot pedal is connected by a cable to the carriage 37. If desired the wiper motor, auxiliary motor, and pump motor may all be electrically operated instead of as described and the lever 49 on the carriage 37 would then operate a control switch. Specification 736,380 is referred to. Reference has been directed by the Comptroller to Specifications 662,241 and 667,656.