Abstract: A cassette containing a printing head removably installed in an ink jet printing machine. The cassette includes a housing which encloses the printing head in a protective manner when the cassette is removed from the machine and when the cassette is installed in the machine and the printing head is in an inoperative position. The head and housing are provided with locking elememts for securing the head in the housing when the cassette is to be removed.The machine includes a carriage for moving the printing head past a record carrier during printing operations, locking elements for locking the printing head onto the carriage when the cassette is installed in the machine, a receptacle for holding the housing in the machine, and a mechanism for releasing the locking elements when the printing head is in the inoperative position to permit removal of the cassette from the machine.

Abstract: A paper guiding device and operating method for use in an office writing machine, the device including a platen carried by a shaft and constituting a paper support, the platen shaft and platen being rotatable in a first direction for insertion of a paper sheet in the machine and in a second direction opposite to the first direction, a paper holding rail disposed adjacent the platen and carrying a plurality of pressure rollers which are pressed toward the platen, a rocker member supporting the rail and mounted to undergo pivotal movement about the axis of rotation of the platen shaft between a paper insertion position and a normal printing position; and a coupling member coupling the rocker member and platen such that rotation of the platen in the second direction effects pivotal movement of the rocker member into the paper insertion position for insertion of the leading edge of a paper sheet between the rollers and the platen and rotation of the platen in the first direction effects pivotal movement of the ro

Abstract: A tabulator apparatus for a typewriter whose carriage can be manually set to make carriage steps of different length corresponding to the width of types of different exchangeable type carriers. The apparatus includes a manually shiftable transmission connecting the tab carrier and the escapement member with the carriage so that the carriage can move in larger carriage steps relative to the tab carrier.