Shadow mask support structure including a plurality of bimetallic elements for each leaf spring

Claim 1

A shadow mask support mechanism for a color television picture tube including a plurality of mask supporters for supporting a shadow mask mounted on a frame adjacent a face panel; at least one of said mask supporters comprising deformable bimetallic means; said bimetallic means being disposed to displace said shadow mask in the direction of the television screen, said deformable bimetallic means having opposite end portions between which deformation occurs positioned in the direction of the length of said tube such that one end portion is secured to a wall of said shadow mask frame and the other end portion is secured to one end portion of a leaf spring, the longitudinal axis of said leaf spring extending substantially transversely of the axis extending between said opposite end portions of said bimetallic means, wherein the other end portion of said leaf spring engages a pin secured on the side wall of said face panel; said bimetallic means comprising first and second bimetallic members, said first bimetallic member, having a long axis which extends in the direction of the length of said tube, being disposed closer to said pin along the longitudinal axis of said spring then said second bimetallic member, the long axis of which extends substantially parallel to the axis of said first member, said first bimetallic member having a smaller relative thermal coefficient of expansion than said second bimetallic member, wherein said first bimetallic member, disposed closer to said pin along the longitudinal axis of said spring, deforms less than said second bimetallic member, and whereby twist imparted to said spring due to deformation of said bimetallic means is maintained substantially uniform along the length of said spring.