Abstract: An enclosure for housing electronic circuitry having a base and a cover with side walls includes a non-exposed fastening mechanism for securing, sealing, centering, and releasing the cover relative to the base. The fastening mechanism includes a ledge on the inside of a cover side wall and a restraining clip having a fixed leg mounted to the base and a flexible leg movable towards and away from the fixed leg and which engages the ledge when the cover is positioned on the base. A resilient gasket is fastened to the cover and positioned to seal the cover to the base and to be resiliently compressed when the cover is positioned on the base. The resilient compression of the gasket maintains the flexible leg in contact with the ledge to secure the cover to the base. The flexible leg also maintains the cover side wall away from the base. Several restraining clips are spaced apart on the base so that the flexible legs center the cover in at least one direction relative to the base.

Abstract: A thermal printer mechanism includes a print head assembly for locating a print head at a predetermined optimum position for printing or at a cleaning position and an adjustable guide path assembly for maintaining the center line of print stock aligned with the centerline of the print head for different widths of stock. The print head assembly includes a print head supported by a mounting bracket so that the head is maintained in a predetermined fixed position with respect to the platen shaft. A head force bracket sums the force from a pair of springs and applies it via a pivot shaft to the midpoint of the line of tangency of the print head with the platen roller so that the print head "floats" on the roller. The print head assembly can be pivoted from the printing position to a cleaning position by changing the positions of pins in a pair of camming slots.