Abstract: A two stage motorized servo-actuator having a worm driven high reduction gear train providing a rotary output. The motor shaft has a worm and co-axially therewith, a beveled pinion. The motor worm is continuously engaged with a first stage gear. The first stage gear has an input sector gear disposed co-axially and rotatable therewith. The input sector gear intermittently engages an output gear. The output gear has a beveled output sector gear disposed co-axially and rotatably therewith. Upon disengagement of the input sector gear with the output gear, the beveled pinion engages the beveled output sector gear to drive the output gear directly. Once the input sector gear is disengaged from the output gear, a return spring on the output gear can reverse drive the motor through the beveled pinion to return the output gear to a desired position in the event of motor failure in operation.

Abstract: A butterfly valve having a plastic body with a one-piece valve member formed of thermoplastic elastomer with an integral hub with torque transmitting surfaces which are engaged by lugs on a rigid shaft received in the hub and the shaft is journalled for rotation in the valve body. The valve member has integral thin blade portions extending in opposite directions from the hub with a thickened rim formed about the periphery of the blade with the edge of the rim preferably chamfered. The preferred butterfly member has integral stiffening ribs extending centrally from the hub along the blades to the rim.

Abstract: A valve of the type for controlling engine coolant flow to a heater core having a resilient butterfly valve formed of thermoplastic elastomeric material. The outer periphery is sufficiently resilient to absorb actuator overtravel in the seated condition. The butterfly has formed integrally therewith a central hub with torque-transmitting surfaces molded therein and a pair of oppositely disposed stiffeners extend outwardly from the hub in the central region of the butterfly. Assembly is simplified by placing the butterfly in the body and inserting a winged actuator shaft through journal holes in the body into the butterfly hub such that the wings on the shaft engage the torque-transmitting surfaces in the hub.