| 摘要 |
PURPOSE:To facilitate the variation of press-contact force by installing an electromagnetic clutch onto a wiper shaft and adjusting the spring force of a tension spring which controls the press-contact force of a wiper blade, through a gear mechanism by utilizing the wiping force of the wiper in electric conduction state. CONSTITUTION:In the captioned apparatus in which, a wiper shaft 20 is moved in reciprocation by an arm 29 connected to a wiper motor (not shown in the figure), and a wiper blade is operated for wiping operation by swinging an arm head 32 fixed onto the wiper shaft 20, an electromagnet 25 which is brought into conduction when a car travels at a prescribed car speed or a certain wind speed is reached is provided. A clutch plate 28 equipped with a magnetic member 28b is attracted onto the electromagnet 25 against an elastic body 28a by the excitation of the electromagnet 25. Therefore, a spur gear 26 is fixed, and a spur gear 38 shifts, revolving around the spur gear 26 when the wiper operates in the wiping-up direction, and the spring force of a tension spring is increased through worm gear trains 36 and 37. |
