Abstract: Apparatus for printing any line of characters comprises printing wheels on a common shaft, the wheels on the shaft together defining a printing line over a hammer. Each printing wheel is rotated by a respective stepping motor through a respective setting wheel. An aligner bar is inserted into notches in the wheels, prior to printing, to verify the alignment of the characters in printing position. The stepping motors are bi-directional and take the shortest path from a preceding printing position to the next printing position. The pulsing frequency may be ramped to give a higher stepping rate in the intermediate portion of each printing wheel movement.

Abstract: This invention is concerned with the high speed printing of a line of text on a sheet in very accurate registration with an edge of the sheet or another feature (for example an existing print line) on the sheet. The sheet is fed without preregistration on to a track (10, FIG. 1) which passes the printing station (20). A detector (16) adjacent the track senses the arrival of the edge or some other feature of the sheet and a printing control means (14) responsive to the detector signal initiates the firing of the printing hammer (22) when the print line reaches the printing station, a registered operation being thereby effected without stopping the sheet. The detector signal may start the operation of a counter (70, FIG.

Abstract: A stitching assembly for stitching together sheets of paper, card and similar materials comprises a frame carrying a number of stitching machines each of which includes a stitching head and a clinch block connected together so that each stitching head and its associated clinch block are movable along the frame as a unit. A code bar assembly which is mounted on the frame includes a number of code bars and co-operating means on the stitching machines and the code bars which co-operate to locate the stitching machines at positions along the frame determined by the spacing of the co-operating means along the code bar. The spacing of the co-operating means on each of the code bars is different and the code bar assembly includes means to move the code bars to enable each one of them to be associated with the co-operating means on the stitching machine.

Abstract: In apparatus for conveying successive stacks of sheets to a station at which an operation is to be performed on the stack, the sheets are advanced by pushing elements (14) to the station, at which a resilient finger (17) projects through a slot (16) in the track. The finger (17) aligns the leading edges of the sheets in the stack. When the stack of sheets is to be advanced, a slide (20) retracts. The finger (17) is pivotally mounted on the slide and its upper inclined edge engages the bottom rear corner of the slot when the slide is retracted, causing the finger to sink below the track until the slide is returned in time for the alignment of the next stack.

Abstract: To print on each of a number of sheets, the sheets are advanced, preferably in underlapped form, up to registering stops. When a sheet has been registered at the stops, suction is applied to an underlying conveyor, the stops are withdrawn and the sheet is advanced in steps to a printing station, the sheet being held in register by suction during this advancement. Printing takes place while the sheet is stationary and still held in register, between steps of movement. Suction may be switched on and off at the registering station by means of a movable perforated switch plate, the perforations of which are aligned, in a first position of the switch plate, with suction-conveying perforations in another plate or belt; in a second position of the switch plate its perforations are misaligned with the perforations in the other plate or belt, preventing the application of suction to an overlying sheet.