This invention relates to a linearly adjustable support mechanism in general, and more specifically to an apertured adjustment disc which provides a plurality of incremental linear, vertical adjustments, with no horizontal component, to raise and lower a supported member. This device has particular significance in a printing environment to align an ink or toner applicator member, such as a magnetic ink brush, with respect to a recording head or recording medium to insure that the magnetic brush will be parallel to the surface of the recording head or recording medium, to prevent the occurrence of a print intensity gradient in one instance or apply a uniform coating to the recording member in the other instance.

A printer is provided which has an openable front panel. This front panel is opened to load printing paper into a paper tray which is invisibly located behind the front panel. The paper tray is provided in a mechanical sub-chassis movably disposed within a mechanical main chassis of the printer. The sub-chassis is laterally slidable relative to the main chassis via a pair of guide rails and is rotatable to open the front panel via a pair of arm plate to expose the paper tray outside of the printer body. The arm plates are attached to a drive shaft supported by the main chassis so as to allow slight relative displacement therebetween to cancel assembly error. According to rotation of the drive shaft, the both arm plates swing synchronously.

The resolution of an image that is produced by a graphic recorder is related to the rate that recording paper passes through a recording zone and the sweep rate is related to the rate at which a scanning electrode contacts the recording paper. According to the present invention, both the sweep rate and the resolution are simultaneously coordinated through the use of a ratchet wheel and pawl that are interconnected between the scanning electrode and feed rolls. The ratchet wheel is indexed through the movement of the scanning electrode and as the scanning electrode makes a sweep, the feed rolls are indexed by successive or multiply successive teeth in the ratchet wheel. An anti-backlash device is associated with the ratchet wheel to prevent the ratchet wheel and the feed rolls from reversing themselves during operation of the recorder.

A cartridge for supplying a record medium to a strip chart recorder and method of using the same therewith. A pivoting member of the cartridge is engaged with a support member of the mechanism; the cartridge is pivoted about the support member into an operative position in the mechanism; and the cartridge is releasably secured against disengagement from the operative position.