Academic Achievement and Efficiency of College of Agricultural and Life Sciences Students: A Multi-Year Study

A tool holder for a punching machine includes a housing attached to the frame of the machine for the purpose of accommodating a punch holder with a number of punches capable of actuation as required. The housing is essentially coaxial with the cutter slide of the machine. The punches are arranged with equal spacing around a pitch circle which is coaxial with the cutter slide and the housing, and eccentrically in relation to the cutter slide. Extending directly in line with each punch is a push-rod, which is supported in such a way as to permit its axial movement inside the housing in parallel with the common axis of the housing and the cutter slide. Each push-rod is so arranged as to be actuated by an impact heel capable of rotating relative to the housing about the axis of the latter. By transmitting the punching force from the cutter slide via the impact heel and the push-rod to the punch, the position of which has been adjusted by the relative rotation of the housing and the impact heel, the punch holder is relieved of eccentrically acting forces and is capable of accepting an increased number of punches in return for a corresponding increase in its diameter, without impairing the guiding of the punches.