WIPER DEVICE

PURPOSE:To considerably reduce the shock noise at the inversion of a wiper, by changing the crank arm length into oval locus for one rotation of the crank arm while slowing the rolling motion speed of a wiper shaft in front and rear of the upper and lower inverting positions. CONSTITUTION:When rotating a wiper motor output shaft 26 with uniform speed, the center of a rotary shaft 24 pivoted to the other end of a crank arm 21 having one end fixed to the output shaft 26 will move along a circular locus A. Since a small external tooth gear 25 in the rotary shaft 24 gearing with a large static external tooth gear 27 provided on a wiper motor housing 28 will spin together with the revolution of on said locus A, a ball bearing 22 on an eccentric plate 23 integral with the rotary shaft 24 will revolve around said shaft 24 with the radius of r to describe an oval locus B. Consequently a wiper shaft 31 will perform the rolling motion where the speed will drop in the vicinity of the inversion by means of a lever 30 coupled through the ball bearing 22 and a conrod 29.