Abstract: A feedback position control system and method of extracting feedback phase or position information therefrom. A resolver or similar device such as an inductosyn is connected to each movable member of a machine tool such that the phase of the resolver output signal is indicative of the displacement of each movable member about its respective axis. The stator windings of the resolver are excited with reference and quadrature signals to generate a periodically varying output signal. The zero crossings of the output signal are monitored and the digital count in a reference counter (C.sub.A and C.sub.B) corresponding to the times of zero crossing are stored. The scaled sum of the counts C.sub.A and C.sub.B is determinative of the phase of the output signal relative to the reference signal.

Abstract: A flotation garment employs first and second sheets of a thermoplastic film bonded face to face along a rectilinear grid work of seams forming a spaced array of mutually isolated air cells, so that the garment will not substantially lose its buoyancy when a portion of the cells are punctured. The bonded seams are perforated at selected points to enable adequate ventilation.

Abstract: A shear machine having a blade for cutting successive increments of material from flat sheet work stock has a cutting zone guarded by a curtain of light. Photosensitive means actuates a brake to stop blade motion if an object extends through the light curtain towards the cutting zone. Hold-down mechanism is operated by a lever or the like situated outside of the guarded region to enable the final portion of a sheet of work stock to be manually held in place at the cutting zone without penetrating the light curtain. The plane of the light curtain inclines towards the front of the shear machine enabling the hold-down mechanism control lever or the like to be situated on the machine above the cutting zone where it may be reached without interception of the light curtain by the operator.