Abstract: A method and apparatus for adjusting the contact pressure of a thermal printhead against a platen roller. In response to the receipt of a control signal, a spring mechanism is activated to apply a torque against an arm attached to a shaft. Rotation of the shaft first brings the printhead into contact with a thermal medium which passes between the printhead and the platen roller. After the printhead contacts the thermal medium, further force applied through the spring selectively increases the torque which, in turn, increases the pressure of the printhead against the thermal medium. The pressure is adjustable as a function of the thermal medium, print speed, user darkness preference and other variables.

Abstract: A collet-clamp for retaining label supply rolls on a dispensing shaft. The collet has a plurality of fingers that can be tightened against the shaft when the clamp is moved axially toward the collet. The base of the collet supports a plurality of helical wedging surfaces that cooperate with annular segments formed on the axial hub of the clamp in order to cause the clamp to be brought closer to the collet when the clamp is twisted in a predetermined clamping direction with respect to the collet. The collet and clamp are assembled by bringing the annular segments of the clamp into cooperative engagement with the helical wedging surfaces of the collet by twisting the clamp with respect to the collet in the direction opposite the clamping direction prior to placing the collet-clamp fitting onto the shaft. While on the shaft the collet-clamp fitting cannot be disassembled.

Abstract: A method and apparatus for controlling the tension in a tape (16, 18) along a feed path between a reel (84, 112) and a processing station (20) is disclosed. A motor (146, 162) having a controllable torque is coupled to the reel. An advancement mechanism (22, 142) advances the tape through the processing station. Sensors (190, 192) produce signals proportional to the advancement of the tape through the processing station as well as the advance of the reel. These signals are compared to produce an indicia of the present operating radius of the tape on the reel, which is dependent upon the amount of tape wound upon the reel. With this indicia determined, empirically derived data can be consulted to determined the energization of the motor necessary to produce a torque that will compensate for the changing tape diameter on the reel, maintaining the tension in the tape substantially constant independent of the transfer of tape with respect to the reel.