GB621582A - Power unit, particularly for windscreen wipers - Google Patents

Abstract

621,582. Windscreen-cleaners. O'SHEI, W. E. Sept. 4. 1946, No. 26584. [Class 138(i)] [Also in Groups XXVI, XXXV and XXXVII] A power unit for actuating windscreencleaners comprises electric driving means and vacuum driving means for simultane-- ously driving the wiper blade or blades. The unit may take the form of a suction motor acting as a booster for the electric driving means which maintain the unit running during those periods when the suction is insufficient to drive the suction motor. As shown in Fig. 1, a suction motor 1 and electric motor 2 are provided with a common driving shaft 3, and the control valve 4 for the motor 1 is mechanically coupled with the switch 5 controlling the motor 2; if desired, the operation of the valve 4 to stop the motor 1 may apply suction to one side of this motor for the purpose of parking the blade. In a modification, the valve 4 and switch 5 are not directly coupled, but the shaft 3 carries a cam for operating the switch 5 so that the latter is opened when the valve 4 is operated to stop the motor 1 and move the blade to parking position; the coupling between the motor 2 and shaft 3 includes a lost-motion connection whereby the movement of the shaft to parking position does not affect the motor 2. In a further modification, the cleaner is driven by a combined suction and electric motor as shown in Fig. 3, the central cylindrical section 29 of which is a fluid motor constructed as described in Specification 557,232, [Group XXVI], and provided with tubular extensions 31, 32 co-operating with solenoids 35, 36 ; these solenoids are controlled by switches 37, 38 associated with the ears 39, 40 of the valve 41 of the fluid motor. The application of suction to opposite ends of the suction motor energizes the corresponding solenoid so as to assist the action of the suction, and, in the event of the suction falling, the motor continues to operate under the action of the solenoids. In an alternative construction, two cleaners 50, 51, Fig. 4, are driven through pinions 52, 53 from a rack 54 which is driven by an electric motor 55 and a suction motor 57 ; the motor 57 is remotely controlled by a valve 59 associated with a switch 60 for controlling the motor 57 so that, when the switch 60 is opened, suction is fed to one side of the motor 57 in order to park the blades. Specifications 535,419, 546,483 and 557,377, [all in Group XXVI], are referred to.