Abstract: A thermal demand printer for printing on media is a novel system which includes a case structure including a hinged cover panel, easily removable guide structures and media hanger, and a single central support wall to which the various components are attached. The printer includes a power supply circuit for receiving power from an external source and conditioning it for operation of the printer. An input device is provided for receiving command signals related to the operation of the printer. A control circuit for processing the command signals and generating corresponding control signals for controlling the operation of the printer and a printhead assembly for processing the control signals and generating corresponding control signals for controlling the operation of the printer are mounted in the case structure and coupled to the input device and the power supply circuit. The printhead assembly includes a printhead support structure which controls the printhead.

Abstract: A demand printer for printing on media includes a ribbon take-up spindle for accumulating spent printing ribbon and facilitating removal of the spent ribbon from the spindle. The spindle has a surface with a protrusion bore formed therethrough. At least one protruding segment extends through the protrusion bore. The protruding segment controllably projects away from the spindle surface for maintaining a space between a portion of the spindle surface and the spent ribbon accumulated on the spindle. A biasing structure is operatively associated with the spindle and the protruding segment for controllably biasedly directing the protruding segment through the protrusion bore in the spindle. A retracting structure is provided for controllably compressing and expanding the biasing means to controllably move the protruding segment through the protrusion bore.

Abstract: A dental handpiece assembly equipped with an improved latch mechanism for detachably connecting a motor section to a straight or angular handpiece section. The latch includes a ring disposed between the two sections, the ring having an outer surface which is substantially flush with the casings of the respective sections when the parts are assembled and the ring is in its normal latching position. Unlatching is accomplished by displacing the entire ring in a transverse direction, by finger pressure applied at any point along a semi-circumferential area of the ring's outer surface, to shift an arcuate rib out of engagement with the neck portion of the other section of the assembly.