Description
Following is a sample of the information contained on this CD: BACKGROUND OF THE INVENTION (a) Technical Field of the Invention The present invention relates generally to steel rule dies. (b) Description of the Prior Art Steel rule dies are widely used to cut a variety of materials, e.g., cardboard and plastics, into a desired shape. Often, to form the steel rule dies, the steel rules were pressure inserted into slots which were located in a board of wood or other suitable material. During operation of the cutter, these steel rules often became loosened and ultimately disengaged, thereby necessitating costly and time consuming interruption of the cutting process as repairs were undertaken. Several attempts have been made to prevent this loosening of the steel rules in such steel rule dies. For example, U.S. Pat. No. 3,835,746, patented Sep. 17, 1974 by W. O. Young, Jr. et. al., provided a steel rule die in which the steel rule was inserted in a slot with its flat underside in direct contact with a backing plate. Removable resilient mounting means applied a spring force against the steel rule to hold the steel rule against a rigid support in the proper position. Removability of the resilient mounting means permitted ready replacement of any damaged steel rule. The resilient support had a spring which was secured thereto and which extended outwardly therefrom. The combined spring system was deformed by the steel rule upon insertion of the steel rule from above and continually applied a spring force against the steel rule to hold the steel in place. However, such deformation often led to mechanical failure of the retaining system as the steel rules were continuously replaced. U.S. Pat. No. 3,941,038, patented Mar. 2, 1976, by T. D. Bishop, disclosed a die cutting apparatus in which a cutting steel rule was supported in slots in a relatively massive support plate by using sinuous resilient elements and shims lying between walls of the slots in
