Abstract: Slitter knives on a paper winder are moved to new positions by a bar to which the knife supports are coupled by means of a pin, carried on each support, and which engages in one of a number of holes equi-spaced along the bar. The bar is reciprocated so that the supports may be moved, in either direction, by successive increments equal to the hole pitch. The supports are moved in this manner until they each reach the nearest and most expedient hole to the new position. The bar is then moved one more pitch and as each support is determined to be at its new position its pin is withdrawn from the hole and it is clamped to stationary rails.Mounted on the bar opposite each hole is a switch arranged for operation by the pin, and connected to a central micro-processor which continuously monitors and controls movement of the knife supports.

Abstract: A number of values of a variable defining a program of operations are settable by means of three potentiometers, connected to a controlled apparatus, which control respectively the initial, final, and rate of change of the variable, each potentiometer having an associated plate one edge of which indicates the value set against a scale. The plate edges form a curve of a graph indicative of the program. In a modification a plurality of linear potentiometers are located at different positions along a scale showing stages in the program, the sliders of the potentiometers being used to set and also indicate the value of the variable at each stage.