Abstract: The joining web of a pair of molded wiper blades is successfully laser slit to produce a pair of sharp, square cornered edges. The wiper blade pair is first securely supported in a fixture beneath the laser lens housing. The laser beam is oriented with the focal point slightly above the surface of the web, rather than at or below it. The laser is set with a low power setting and short pulse length, all designed to minimize the otherwise harmful heat effects. When the beam is run straight down the web, too acceptably sharp edges are produced.

Abstract: A specially designed and attached anti-wind lift airfoil also acts to reduce wiper chatter in several ways. The foil is fixed to and runs along side the blade support, bracing and stiffening it. In addition, masses molded inside the foil, plus its own mass, increase the total mass and moment of inertia of the wiper in operation, which acts to counteract the sticking effect. The foil is somewhat resilient, and is fixed to the blade support at widely spaced points, with its center section unsupported. If the blade does stick and slip in operation, undulations are thereby set up in the resilient airfoil, absorbing and damping out the energy that would otherwise show up as chatter.