Wiper structure with variable wiping pressure

摘要

A vehicle windshield wiper structure has a wiper arm connected to a wiper head and supports a wiper blade which is adapted to be forced onto the surface of the windshield glass. A spring is provided to force the wiper blade into engagement with the windshield glass surface. The spring is engaged at one end with an intermediate portion of the wiper arm and at the other end with an end of a swingable lever which is pivotably mounted on the wiper head. The other end of the swingable lever is provided with a cam follower roller which is adapted to be engaged under a resilient force applied by the spring with a cam provided on a stationary part of the vehicle. The cam has a profile which is slanted at the opposite end portions so that the resilient force depressing the wiper blade into engagement with the windshield glass surface is decreased at each end of the stroke of movement of the wiper to thereby decrease the noise which may otherwise be produced when the wiper movement is inverted.