Abstract: A shaft assembly, including a main shaft, is used with a postage meter of the type including a base supporting the main shaft. A printhead is mounted to the outer end of the main shaft so the main shaft and printhead rotate together. The main shaft has a flat surface against which a number of elongate value rods are mounted parallel to the main shaft axis. The outer ends of the value rods are coupled to the printhead to operate the printing elements of the printhead. The inner ends of the value rods are connected to stepper motor drives, mounted to the base, to move the value rods axially. Bearings, mounted to the main shaft, radially position the main shaft relative to the base. At least one of the bearings is fixed to a chosen axial position along the main shaft so that such bearing, when mounted to the base, also axially positions the main shaft relative to the base.

Abstract: A postage meter stepper motor module for use in a postage meter of the type having a base supporting a rotatable main shaft to which a printhead is mounted. The main shaft has a number of value rods mounted to it. The outer ends of the value rods are coupled to the printhead so movement of the value rods parallel to the main shaft axis changes the chosen value print character at the printhead. The stepper motor module includes a stepper motor frame mounted to the base at a chosen position relative to the main shaft. A stepper motor is mounted to the stepper motor frame. A yoke couples the stepper motor to a chosen axial position along one of the value rods through a coupler ring. The coupler ring and yoke allow the value rod to rotate freely about the main shaft while maintaining the axial position determined by the stepper motor. The stepper motor and yoke are coupled by a rack and pinion arrangement to translate the rotary motion of the stepper motor to the linear motion of the yoke.

Abstract: A printhead assembly is used with a postage meter of the type having a base supporting a main shaft and a stepper motor drive. The stepper motor drive positions value rods carried by the main shaft according to the value of the postage to be printed. The printhead assembly includes a value module mounted to an outer end of the main shaft so to rotate with the shaft. A dater/slogan module is also mounted to the outer end of the main shaft assembly and is positioned or indexed, such as using guide pins, to the value module. The components are housed within an enclosure including a separate printhead cover assembly. The printhead cover assembly includes an opening through which the field service personnel has access to the dater/slogan module to allow the them to remove the dater/slogan module, such as for maintenance or repair, without affecting the security of the meter.

Abstract: A modular universal postage meter includes a base to which stepper motor modules and a drive shaft assembly are mounted to predetermined positions relative to the base. The drive shaft has a bifurcated printhead, including a secure value module and a field service accessible and removable dater/slogan module, mounted to its outer end. The stepper motors are coupled to the value module of the printhead through a number of value rods mounted to and parallel with the shaft assembly. The value rods can move parallel to the axis of the main shaft. Rings surround the shaft engage respective value rods and are themselves axially positioned by yokes coupled to the stepper motors. Since the stepper motor modules are registered to the base, they can be moved and replaced with minimal adjustments and realignment since the shaft assembly is likewise registered to a predetermined position relative to the base. Thus the base acts as a reference for the stepper motor modules, the shaft assembly and the printhead.