Temperature compensating valve assembly

In a valve assembly having a housing that is constructed of a material which will expand when heated and that comprises four flanged channels rigidly secured together to form a rectangle, and a plurality of airfoils inside the housing that can be rotated between valve open and valve closed positions, each airfoil being mounted on its own shaft that is journaled in the housing and has an external end portion extending through the housing, said plurality of shafts being parallel to one another and lying in the same plane at equidistant intervals, each shaft having a crank extending radially from the external end portion thereof for rotating said shaft, all of said cranks being the same length, and said plurality of cranks being linked together by drive arm means so that rotation of one of the cranks causes all of the cranks, shafts, and airfoils to rotate in unison, the IMPROVEMENT wherein the said drive arm means is comprised of enough three-link mechanisms to connect together all of the cranks, each said mechanism comprising

• a. a first floating link pivotally attached at its first end to the non-shaft end of one of the cranks and equal in length to each of the cranks,
• b. a second floating link of the same length as the first, pivotally attached at its first end to the non-shaft end of the next adjacent crank, and
• c. a rotating link equal to twice the length of each crank and pivotally mounted at its center to the housing at a point in the plane of the shafts that is equidistant between each shaft and the next adjacent shaft, one end of said rotating link being pivotally connected to the second end of one of the floating links, and the other end of said rotating link being pivotally connected to the second end of the other floating link.