The windshield wiper has long been an attractive subject for development efforts, particularly to improve operating characteristics and cleaning effectiveness over extended periods. The demand for a better combination of high performance and long service life, however, remains unsatisfied. Incremental gains toward that goal have been made but always at the expense of significant penalty. Recently the trend has been toward the use of new materials of fabrication, silicone rubber attracting considerable attention in spite of its well-known high coefficient of friction characteristic because of its noted durability and utility over a broad range of operating conditions. To bring the silicone rubber friction coefficient down to a reasonable and acceptable level for windshield wiper purposes, others have added various materials in compounding it. Also attempts have been made to coat or cover silicone wiper blades with low friction coefficient materials such as Teflon.sup.T plastic or other elastomeric tetrafluoroethylene polymer having similar properties. In all instances, however, either the desired friction coefficient was not reached or the service life was considerably less than required because of rapid loss of the covering material.
USPTO Backgrounds
USPTO Backgrounds