Radiator shutter for arctic vehicles

Claim 1

In an arctic military vehicle having a liquid-cooled engine and an air-cooled radiator for cooling the coolant after its passage through the engine: the improvement comprising a shutter mechanism located in the supply air stream for the radiator to prevent overcooling of the coolant; said shutter mechanism comprising a plurality of rigid tubes extending transversely across the air stream, an elastomeric sleeve tightly encircling each tube along its entire length, means anchoring the ends of each sleeve to the ends of each associated tube, means for supplying pressurized fluid to each tube interior, and flow ports spaced along the length of each tube, whereby the pressurized fluid is caused to flow through the ports to balloon out the elastomeric sleeves, thereby reducing the air flow passage areas defined by exterior surfaces of said sleeves; each tube having an elliptical cross section oriented so that its major axis is parallel to the direction of the airstream; the flow ports in each tube being formed exclusively in laterally facing tube areas extending normal to the direction taken by the airstream, whereby the elastomeric sleeves are caused to balloon transverse to the airstream rather than parallel to the airstream.