Patent ID: 6782787
Filing Date: 2004-08-31
Classification: B21D,Y10T

Abstract:
A punch tool comprising a punch element comprising a punch having a lower punch tip, and a punch driver element having an upper surface adapted to be engaged by the ram of a punch press in a punching operation, said elements being axially aligned and threaded together to enable axial adjustment of the length of the combined punch driver and punch element in response to relative rotation of said elements, one of said elements including, adjacent its periphery and spaced from its axis, a latch movable along an axis parallel to the axis of said elements between an upper, locked position preventing relative rotation of said elements and a lower, unlocked position permitting relative rotation of said elements, and a spring having a predetermined spring constant and urging said latch into its upper, locked position, said latch having a sufficiently low mass and said spring having a sufficiently great spring constant as to prevent said latch from unintentional movement into its unlocked position in response to striking of the punch driver element by a punch press ram during a punching operation, said puch element including a punch guide having a bore through which said punch axially moves in a punching operation, and wherein said punch guide includes an upper peripheral portion having a housing receiving said latch and spring and an upper rim, said punch driver element including a locking disc positioned beneath said upper rim of said punch guide, said disc having a plurality of circumferentially spaced grooves in its outer periphery receptive of said latch when the latter is in its upper, locked position to prevent rotation of said punch driver element with respect to said punch guide.