Abstract: A variable-pitch racked bar has a row of rack teeth with a middle fixed pitch region and two end fixed pitch regions. A variable-pitch region is interposed between the middle fixed pitch region and each of the end fixed pitch regions. In the variable-pitch region, the pitch increases from the fixed, small-pitch middle region toward the fixed, large-pitch end regions. In the variable-pitch racked bar, the effective meshing width continuously decreases from the middle of the row of rack teeth toward both ends thereof.

Abstract: A cooling apparatus for a heat exchanger includes a shroud having a box-shaped main body covering one of the surfaces of a heat exchanger and a cylindrical portion penetrating through the main body. The axis of the cylindrical portion is substantially perpendicular to the bottom surface of the main body and part of the cylindrical portion is protruded with respect to the outline of the heat exchanger. A fan is disposed in the cylindrical portion of the shroud. The main body includes an enlarged portion disposed adjacent to and corresponding to the protruding part of the cylindrical portion. The bottom surface of the main body extends substantially from the entire periphery of the end portion of the cylindrical portion.

Abstract: A cooling fan assembly made of plastic material is composed of a plurality of fan blades and a boss and connected to a viscous fluid coupling device rotatably mounted through a bearing assembly on a driving shaft of an automotive vehicle. An axially resilient connecting member in the form of a plate spring is fixed to the boss of the fan assembly at one end thereof and to the coupling device at the other end thereof, whereby the inertia moment of the fan rotation causes the appropriate rotation of the fan assembly in spite of possible misalignment of the coupling device with respect to the driving shaft to thereby protect the bearing assembly from being damaged. Helical or waved springs may be interposed between the fan boss and the coupling device in place of the plate spring.