Abstract: A dot matrix shuttle printer and/or a module therefore uses print wires of different lengths so as to achieve desired close packing of individual print wire actuators and correspondingly close wire-to-wire spacing of the print wires. To help maintain synchronization between the operation of all print wires, the longer ones include hollow sections so as to cause all the print wires to have substantially equal mass in spite of their differing lengths. The longer print wires include a hollow tube of stainless steel. A tip of wear resistant material is fixedly inserted at one end of the tube to effect impact printing.

Abstract: The present invention provides a bi-directional drive printer actuator with position feedback control and methods of operation to optimize the performance of impact type printers. By monitoring the position of the print wire, a forward input power pulse can be varied as to magnitude and duration to maintain a desired predetermined velocity of the print wire up until the time of impact. Further, by monitoring position feedback signals generated as the print wire returns to an at-rest position, a reverse input power pulse and forward input power pulse can be modulated for magnitude and duration to maintain a desired rearward velocity of the print wire, and bring the print wire to an at-rest position with a minimum of rebound off a back stop.

Abstract: A solenoid-type print wire actuator includes a unitary one-piece bobbin formed of a magnetically permeable material and having two axially spaced-apart annular grooves in the outer surface thereof. An electromagnetic coil is wound on the bobbin. A dumbbell-shaped armature is disposed coaxially within the bobbin and is connected to the print wire for axial movement thereof, the armature having two cylindrical piston portions respectively disposed adjacent to the bobbin grooves. The ends of the bobbin are respectively supported in bores in the leg portions of a U-shaped member, the leg portions being interconnected by another piece to form a frame of magnetically permeable material to define a flux path.

Abstract: An apparatus for determining the temperature of railroad car wheel journals (i.e., "hotbox" detector) includes a sensor including a pyroelectric cell responsive to infrared radiation signals, which are focused onto the cell, to output voltage signals as a function of the radiation signals inputted thereto. The sensor exhibits a nonlinear gain response to different frequencies of input signals and compensation is provided by coupling the output of the sensor to a differentiating circuit which has a similar but relatively negative gain response. The output of the differentiating circuit is a substantial voltage replica of the infrared input signal and this voltage signal may be applied to a suitable utilization device such as one which records journal temperature and/or provides a suitable alarm when a sensed journal temperature exceeds a predetermined value.