GB761619A - Improvements in or relating to windscreen wiper mechanisms - Google Patents

Abstract

761,619. Windscreen cleaners. GENERAL MOTORS CORPORATION. July 29, 1954 [Aug. 26, 1953], No. 22200/54. Class 138(1) A windscreen wiper mechanism comprises a bearing member 18, Fig. 3, a shaft 21 journalled in the member 18 for oscillation about its longitudinal axis; a rocker arm 17 mounted within the bearing and shaft for pivotal movement (at 23) about an axis normal to the shaft axis, a wiper arm 16 carried by the rocker arm and means mounted in the bearing member 18 for positively rocking the rocker arm 17 as the shaft 21 is oscillated. The invention is applied to auxiliary wipers 15, 15<SP>1</SP>, Fig. 2, which are operated in tandem with main wipers 14, 14<SP>1</SP> for a curved windscreen 10, having a frontal portion 11 and substantially parallel side portions 12. The wiper shaft 21, Fig. 7, is slotted at 22 and pivoted in the slot 22, on a transerve pin 23 and under the urge of a leaf spring 32, is the rocker arm 17. The inner edge of the arm 17 engages a ball bearing 31 housed in a radial opening 24 in the shaft 21 which opening intersects the slot 22. The ball 31 also engages a cam surface 27, having portions 28, 29, 30, Figs. 4 and 6, of a cam member 26 secured in a radial slot 25, Fig. 3, in the bearing member 18, the surface 28 being concentric with the shaft 21 whereas the surfaces 29, 30 are tangential to the shaft. In the positions of the rocker arm 17, shown in Figs. 3 and 4, the wiper blade 15 is disposed in the full line position depicted in Fig. 9, i.e. on that portion of the windscreen of extreme curvature. As the shaft 21 is oscillated to either side of the position shown in Fig. 4, e.g. to the position shown in Fig. 6, the ball engages one or other of the surfaces 29, 30 and the blade 15 and arm 16 adopt either one of the positions shown in dotted lines in Fig. 9 due to the rocking movement of the arm 17.