Shadow mask support mechanism for a color television image tube

Claim 1

A mask support mechanism for a color television image tube including a rectangular shadow mask supported on a rectangular face panel, said mechanism comprising a first leaf spring, one distal end of said spring engaging a pin provided on the upper side of said rectangular face panel and providing a spring portion extending from a vertical center line toward one side only of said panel and secured at the other end to the outer surface of the side wall of a frame provided in said rectangular shadow mask, and a second and a third substantially identical leaf springs having ends engaging pins provided on the left and right sides of said panel, and each other end of said first, second and third springs being secured to the outer surface of the side wall of a frame provided in a rectangular shadow mask, a horizontal line connecting the spring portions of said second and third leaf springs being spaced from the horizontal center line of said face panel by a distance equal to one-fourth the shorter side length of the shadow mask frame, said shadow mask being resiliently supported at the inner side of said panel, the spring constant of said first leaf spring being selected to be 50 to 60 percent of those of the second and the third leaf springs and the spring deflection of the first leaf spring being determined to be small as compared with those of said second and third leaf springs, so that in the case of thermal expansion of the shadow mask the resultant force of the spring forces of said first, second and third leaf springs is substantially reduced.