| 摘要 |
1,180,532. Windscreen wipers. ROBERT BOSCH G.m.b.H. 2 May, 1968 [5 May, 1967], No. 20852/68. Heading A4F. [Also in Division F2] A windscreen wiper drive comprises an axially movable worm wheel 16, having its teeth 24 cut in the manner of bevel gear teeth, retained in mesh with a worm 15 by a stop which is adjustable or selfadjusting in the axial direction of the worm wheel to reduce or eliminate backlash. An electric motor 11 drives the worm 15 and the worm wheel 17 carries a crank (not shown) connected by a linkage to the wipers. In Fig. 1, a screw-adjustable stop 30 mounted on an end cover 20 of the gear housing acts on the end of the worm wheel shaft 17 via a ball 29. In Fig. 2 (not shown) the stop is a leaf spring (32) mounted on the cover (20). In Fig. 3, the stop is a plastics diaphragm 34 moulded to the end cover 36 and having an annular corrugation 39 surrounding a central bearing dome 38. An extension 40 of the diaphragm carries contacts 41 which co-operate with contact paths on the worm wheel to form an "end position switch". |
