Abstract: A pen plotter employs a cable-driven carriage which carries the writing pen and includes a pen-lift mechanism. A shifting idler pulley system located at one side of the plotter returns a pair of drive cables from the opposite side of the carriage to a rotatable drive drum located on the opposite side. The idler pulleys are shiftable equally and in opposite directions toward and away from the pen carriage. One cable is connected to the carriage by being tensively trained about a pen-lift mechanism drive wheel on the carriage. Shifting the idler pulleys causes said drive wheel to rotate without affecting the lateral position of the pen carriage and, therefore, the shifter mechanism independently controls the up/down motion of the writing pen. One drive cable, therefore, accomplishes the functions of both pen carriage movement and writing pen up/down motion control.

Abstract: A manipulator for expendable immersion devices is provided with a spring loaded distal end to absorb mechanical shock when the immersion device is mounted on the manipulator and the manipulator is provided with a mechanical stop to eliminate the possibility of mechanical damage to the immersion device.

Abstract: A hot stylus using a mandrel of soft material having good heat conductivity and good electrical conductivity is used to carry heat to the writing end of the mandrel. That end fits in an aperture of a jewel bearing surface which rides on the heat sensitive paper. The mandrel is soldered in a groove along a thermistor having a positive temperature coefficient. The mandrel also provides one electrical connection to the thermistor. The other electrical connection is by way of a foil contact soldered to an opposite face of the thermistor. That assembly is potted and assembled on a circuit board which provides the electrical leads from the stylus body to which the foil is soldered and from the mandrel itself.