PRESSURE CONTROL DEVICE OF WIPER

PURPOSE:To make the whole composition compact, by rotating a worm shaft crossing square to the wiper arm drive springing direction by a motor, and making the springing length controllable freely by a movable body screwed to and opposed to the worm shaft and links. CONSTITUTION:One end of a driving spring 5 is fixed to a wiper arm retainer 4, and a wiper blade is squeezed to the window surface by the driving force. A worm shaft 9 crossing square to the driving direction of the spring 5 is furnished and rotated by a motor 15 through gears 10 and 16. A movable body 11 opposing to the worm shaft 9 is screwed to the worm shaft 9, and a plate 13 to fix the other end of the driving spring 5 is made movable through the first link 8 and the second link 12, to control the functioning length of the driving spring 5. In such a way, an adequate window surface squzzing pressure can be obtained by controlling the functioning length in a high speed running Furthermore, no useless burden is inflicted to the motor, and the whole composition can be made light-weight and compact.