Print element mounting apparatus

Abstract

A print element mounting apparatus for attaching and removing a print disc to and from a selector shaft in a printing machine. The apparatus comprises a finger-grip cap which is fixed on the print disc and a coupling device carried by the print disc. The coupling device includes a generally circular shaped unitary flex member made from yieldable half-sections which are continually urged towards one another by a spring wrapped about the flex member. Each half-section includes a pair of pressure surfaces which are curved in complementary relation to form a biased opening at the central portion of the flex member. The selector shaft is fabricated to include tapered surfaces that operate in conjunction with the pressure surfaces to afford snap-action operation during interchange of the print disc accomplished through a push or a pull force axially applied to the cap. When the print disc is attached on the selector shaft, inward biasing tension from the spring causes the pressure surfaces to clamp about the selector shaft at a consistently accurate location for printing.