GB510066A - Improvements in automatic windscreen wipers - Google Patents

Abstract

510,066. Windscreen-cleaners. ZEISS IKON AKT.-GES. Nov. 7, 1938, Nos. 32283 and 32284. Convention dates, Nov. 10, 1937, and Dec. 15, 1937. [Class 138 (i)] A windscreen-cleaner mechanism comprises means operable at will for lengthening the driving crank so as to increase the amplitude of oscillation of the wiper for parking purposes, and means operated automatically, as a consequence of such lengthening, for lifting the wiper off the surface of the screen before it is moved to parked position Means also may be provided for switching off the wiper motor when the wiper reaches its parked position. The wiper arm 1 is pivoted at 6 to a rock-shaft 2 which is axially slidable in a bearing 4 and carries a pinion 3 driven by a rack 5. When the crank which drives the rack is lengthened, a projection 8<1> on the pinion engages a fixed cam surface 8, so that the shaft 2 is moved axially. A fixed pin 9 then tilts the wiper arm clear of the screen. The crank 15 is slidably mounted on an eccentric sleeve 13 fixed by a pin 14 to a shaft 12 rotated by a motor 11. The disc 19 of the crank has a diametral groove 17 which is pressed into driving engagement with the pin 14 by a spring 16. When the wiper 29 is at rest and parked, the crank has an effective length R, Fig. 10. If, now, a button 21 is pushed, it first closes the motor contact 22, and then slides the crank out of engagement with the pin 14. Upon release of the button, the sleeve 13 having made one half revolution, the groove re-engages the pin 14, giving the crank an effective length r, Fig. 11. The crank now oscillates the wipers through their normal operative stroke by means of the link 23, racks 24, 24<1>, and pinions 28. Reciprocation of the rack oscillates contacts in a switch 33 in such a manner as to keep the motor circuit closed, although the contact 22 is now open. To stop and park the wipers, the button 21 is again pushed and released. This causes the groove to re-engage the pin 14 with the crank lengthened, so that the wipers are moved beyond the limits of their normal stroke, and lifted clear of the screen by the pins 9. At the same time, the motor circuit is broken at the switch 33. The racks 24, 24<1> are adjustable in a connecting member 27, for various sizes of vehicles. In a modification, the wiper shaft 2 is fixed, and the pin 9 is movable by means of a bell-crank lever and an abutment on the rack. The Specification as open to inspection under Sect. 91 states that the wiper may first be lifted from the screen, this operation automatically effecting the turning of the wiper. This subjectmatter does not appear in the Specification as accepted.