GB641526A - Improvements in windshield wipers - Google Patents

Abstract

641,526. Windscreen-cleaners. TRICOFOLBERTH, Ltd. June 14, 1948, No. 15987. [Class 138(i)] A windshield wiper arm comprises a mounting socket, an inner arm portion pivotally connected to the mounting socket, an outer arm portion which is movable relatively to the inner portion to vary the effective length of the arm, and a spring which urges the arm towards the windshield when the mounting socket is mounted on its actuating shaft, and has means whereby the pressure with which the arm is urged towards the windshield by the spring is automatically increased when the arm is lengthened, this increase in pressure being additional to any slight increase which may be due to the arm being rotated slightly about its pivot. The thickness of the outer arm 8, Fig. 1, gradually increases towards its inner end. Notches 9 on the arm 8 co-operate with one end 10 of a leaf-spring 11 supported intermediate its ends by a pin 12 carried by the inner arm 5. As the arm 8 is withdrawn from the arm 5 to alter the effective length of the wiper arm 1, the tension of the spring 11 is correspondingly increased. In another embodiment, Fig. 2, the ends of a coiled spring 19 are connected to a pin 20 on the mounting head 6 and at 18 to a wedge 17 co-operating between a fixed ramp 16 secured to the inner arm 5, and the outer arm 8 which is provided at its inner end with an upwardly bent portion 15. The distance between the anchoring points 18 and 20 is dependent on position of the arm 8 relative to the arm 5. The tension of the spring 19 is therefore increased as the effective length of the wiper arm is increased. In lieu of the bent portion 15, the inner end of the arm 8 may be provided with a wedge-shaped block in order to provide a greater supporting surface for the arm. To adjust the position of the arm 8 the tension of the spring 19 is first released by removing the wiper arm from its actuating spindle and turning the head 6 relative to the arm 5 so that the point 20 is moved nearer the point 18. Alternatively, the same object may be achieved by removing the wiper blade from the arm 8.