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 viscous fluid clutch having a bimetallic coil includes an insulating retainer. A body of the retainer is mounted between the coil and an outer surface of the clutch housing. A flexible tab on the retainer is placed between a first end of the coil and a slot on the clutch housing to provide an interference fit and eliminate the need for adhesives. The body inhibits the transfer of radiant heat emanating from fluid inside the clutch to the coil. Preferably, the body and tab are integrally formed.

Abstract: A viscous fluid fan clutch assembly for a vehicle includes an internally-mounted pump plate for separating a working chamber from a reservoir. A plurality of discharge orifices are provided in the pump plate to permit the return of fluid from a pumping chamber to the reservoir. A fluid discharge channel is provided for each discharge orifice to receive fluid exiting the pumping chamber and to direct the fluid to an inner portion of the reservoir. A check valve is provided at the discharge channel to prevent the flowback of fluid from the reservoir to the discharge channel, particularly when the clutch assembly is not in operation.

Abstract: A preload control arm for controlling fluid flow through a viscous fluid clutch includes a rotatable control shaft mounted in the clutch. The control arm is secured to the control shaft so that flexible end portions of the control arm cover pump plate orifices in the clutch. A spring secured to the control shaft provides a force adajcent the end portions opposite the pump plate orifices to maintain the seal when the control arm is in the closed position.

Abstract: A viscous fan clutch employing flat wipers with angled edges secured on the inner annular periphery of the clutch body which scavage viscous fluid from the space between the inner diameter of the main body and the outer diameter of the clutch plate which controls the rate of discharge of pumping slots formed on the inside diameter of the body to optimize fluid flow from the working cavity to the storage cavity by way of a discrete intermediate cavity to reduce horsepower requirement when a low output speed during disengaged mode is desired or a faster rate of disengagement is required.

Abstract: A viscous fan clutch which employs a dynamic blocker ring positioned inside of the clutch between the pump plate and the clutch plate in such a manner that the fluid flow path is directed and not left to chance. The blocker ring, in effect, hydraulically separates the drive portion of the clutch from the pump and viscous fluid storage portion. The divider ring due to its location will provide support outboard of the bearing providing optimized durability.