Compliant carriage plate adjustment method and apparatus for setting default printhead-to-media spacing in a printer

The apparatus, which adjusts and fixes a default printhead-to-media spacing (PPS) in a printer 10 with a frame 17 and a printhead-carrying carriage 20, includes a carriage rod 18 along which the carriage moves during printing, and a selectively adjustable and fixable compliant structure 26 which mounts the rod on the frame. The structure includes compliant substructures 28,30,32,34 which include portions both of a carriage plate 12 and one of frame components 14 or 16. The carriage plate has adjacent its four corners, displaced, out-of-plane, angular and resilient sheet metal strips, 12a1, 12a2, 12a3, 12a4 anchored through fasteners 36,38,40,42, respectively, to resilient cantilevered sheet metal tabs 14a, 14b, 16a, 16b, respectively formed in the frame components. In use, a screw (48, Fig.2) is turned to rotate a cam (44a), thus to drive upwardly on the underside of the carriage plate which shifts the elevation of the carriage rod vertically to achieve a desired PPS adjustment. The adjustment is both permitted and resisted by elastic compliant which exists in the sheet metal strips and tabs. The arrangement may be modified by replacing the compliant substructures by adjustable screw and compression coil-spring mechanisms (50,52,Fig.4) and tabs (58) and the cam by a screw adjustment mechanism (61) which includes a screw (62) which may be adjusted to shift the carriage plate upwards and downwardly against the compression springs and the tabs.