Abstract: A magnetically mountable device for sensing deformation from loadings on machine members. The device includes a strain sensing transducer, brackets between which the transducer is supported, and magnetic bracket mounts which permit the transducer to be easily mounted on the machine member by virtue of magnetic attraction forces between the mounts and the force carrying member and yet be readily repositionable on the member so as to facilitate location of points of maximum stress concentrations during a working cycle of the machine.

Abstract: A piezoelectric transducer is positioned on a member of a power press subject to stress under dynamic conditions. A ball joint bracket means fixes and maintains the transducer on the member parallel with the direction of force and with the faces of the piezoelectric ceramic plate perpendicular thereto. The high voltage signal generated by the transducer is transmitted to a signal conditioning circuit and impressed upon the grid of a grid-controlled vacuum tube. If the conditioned signal is sufficient to overcome the biasing grid voltage, it activates an electric circuit for the performance of one or more functions, including stopping the power press in the case of an overload, counting the number of times the press is overloaded or the number of times a workpiece is produced, and measuring the press load during a work cycle.