International Business Machines Corporation

Jeffrey H Paterra

Donald K Rex

Michael Clark Campbell

Kevin Dean Schoedinger

Randall David Mayo

Peter Alden Bayerle

Tuyen Van Pham

Loring C Bixler

James K Howes

Mohsen Marefat

Cathy J Senft

Martin J Brown, Jr

John L Breitenbach

System printer

User adjustment of an automatically established gap between a print head and a platen allows adjustment of print head gap relative to a set point by a simple key actuation operation which is preferably conducted during printing operation so that the user can directly observe the result of the adjustment. Storage of user defined adjustment values in non-volatile memory are correlated with measured thicknesses or tolerance ranges thereof and can be recalled after power off/power on cycles and/or after change of paper stocks in the printer. Adjustment limits are imposed to prevent printer damage and user adjustment can be carried out at higher resolution than automatic head gap setting. Graphical and fixed legend displays are preferably provided for confirmation of the adjustment and informing the operator of limits and operating limits and conditions of the gap adjustment.

Manual control/override for automatic forms thickness adjustment

A system for automatically adjusting the print head gap of an impact printer, particularly for paper stocks of differing thicknesses and multi-layer forms, provides for measurement of an absolute distance between an undeflected platen position and a home position of the print head. Paper stock thickness is measured by measuring the distance to the home position from a position of the print head when a predetermined force is exerted by the print head against the platen. Since a similar measurement is made when paper stock is not present in the printer and using the same force against the platen, platen flexure is removed as a source of error and a standardized force is available for compression of the paper stock during measurement. Improved accuracy is achieved at high speed while avoiding the use of position encoder/decoder arrangements. A wider range of manufacturing variations in printer geometry and rigidity can be accommodated with uniformly improved print quality.

Platen to print head gap adjustment arrangement

A printing device has paper feed devices upstream and downstream of a printing station. The downstream paper feed devices uses pairs of pressure feed rolls which frictionally feed the paper when received. A tapered guide channel positioned in side by side relation with the pair of feed rolls comprises a stationary guide plate and pivotable guide plate with guide surfaces designed to collapse any curl in the leading edge of single or multilayer paper. A spring maintains the pivoted guide plate in operating position with a predetermined spring force which opposes deflection by the leading edge of the paper but allow deflection due to paper generated forces exceeding the predetermined spring force.

Guide system for feed roll entry

Apparatus for selectively reinking an endless ribbon in that portion of the ribbon known as the ribbon print track. The ribbon print track is created in an endless ribbon by the repeated striking of the ribbon by a print mechanism thereby deforming the ribbon and depleting it of ink. Reinking the entire ribbon uses more ink than is necessary. Reinking only the print track extends the life of the ribbon by selectively using the available supply of ink. The apparatus achieves this result by use of an ink reservoir which supplies ink to a drive roller, which through a rotating pinching movement in cooperation with another roller, advances a ribbon into a stuffing cavity of an ink cartridge. The ink reservoir is rotatably mounted and formed to apply ink only to that portion of the drive roller which corresponds to the print track of the ribbon. The drive roller may be a composite of more than one roller in a stack of rollers and a single roller in the stack of rollers may receive the ink from the ink reservoir and transfer it to the ribbon print track.

Ribbon print track reinking with a roll system

A ribbon cartridge for an endless ribbon used in high speed printers, with increased reliability due to fewer parts, is constructed from a molded casing which is rectangular in shape into which are formed a post on which a cylindrical porous ink reservoir is mounted, a ribbon protector which isolates the ink reservoir from the ribbon in the stuffer box portion of the cartridge, and a forked bracket for mounting a shaft on which gears are mounted. A combination gear for driving a ribbon into the stuffer box and for re-inking the ribbon is mounted on a post and then rotatably mounted on the bracket formed into the housing and is inked by contact with the ink reservoir. An idler gear is rotatably mounted on a bracket which is pivoted from a socket molded into the socket wall and is spring biased into contact with the drive and transfer gear, which is turned by its extended shaft advance and ink the ribbon. As a result a simplified re-inking arrangement is achieved with the minimum of components. Also, by re-inking a central drive and transfer gear, only the print track of a ribbon is reinked thereby extending the re-inking life by conserving ink.

Ribbon cartridge with endless ribbon reinking mechanism

A paper handling system for a printer or copier has a forms feed tractor employing a sliding sprocket assembly and idler sprocket. The idler sprocket is mounted on the sliding sprocket assembly providing for adjusting the tension on the belt. The sliding sprocket assembly also has an inclined ramp thus providing a symmetric belt path.

Growing community of inventors

Charlotte, NC, United States of America

Jeffrey H Paterra