GEAR SUPPORT MECHANISM IN MOTOR UNIT CASE

摘要

PURPOSE:To keep the proper engagement of a rack and a pinion through simple constitution and assembly, by providing a rack holder with tongues as plate springs and using the flexural elasticity of the tongues to urge the rack to te pinion. CONSTITUTION:A receiving gear 4 is rotated by a motor 2 through a speed reduction gear mechanism 3 so that a rack 7 provided on a cam follower 6 is moved back and forth by a crank means comprising the cam follower and an eccentric cam 5 attached to the receiving gear. A pinion 9 fitted on a wiper shaft 8 is turned back and forth by the rack 7. A rack holder 10 is provided with a through hole 10a in which the wiper shaft 8 is movably fitted. A part of the rack holder 10 is bent as U at 10b to hold the rack 7 around it. Notches are provided at both the ends of the bottom of the bent portion 10b so that tongues 10d are formed as plate springs. The rack 4 is urged to the pinion 9 by the flexural elasticity of the tongues 10d.