Abstract: A quick release locking device is provided for adjustably securing a circular tool carrier head about a shaft of a rotary die cutting mechanism in which a cylindrical cam has the camming face of the cylinder undercut and filled with a deformable non-compressible plastic substance to increase the resiliency of the camming face.

Abstract: A capacitor detector device for detecting a change of capacitance in a protected zone, which device comprises an antenna element adapted to be mounted in spaced relationship with a grounded element to define the protected zone between the elements and having a nominal capacitance therebetween, which capacitance is changed upon intrusion of an object to be detected. The device includes an oscillator means for pumping, at a preselected frequency, the grounded element with respect to an internal floating ground of the device, means for connecting the antenna to the floating ground of the device whereby the antenna is capacitively coupled to the pumped ground element and means for detecting changes in the capacitive coupling of selected amounts between the antenna element and the pumped grounded element.