Abstract: An automatic control mechanism for the thickness of an ink layer on a duplicator cylinder employs a sensing roller mounted for movement along a path which extends both peripherally and radially of the cylinder where the ink is to be measured and thus the drag on the ink pulls the cylinder to an equilibrium position where it just maintains sufficient contact with the layer of ink to be subject to that drag whereas any further movement will move it radially away from the ink layer to lose contact. The pivoting support for the sensing roller engages a switch when an extreme position is attained and this provides an "enough ink" signal.An adjustable biasing mechanism enables the position of the sensing roller to be additionally subject to a biasing selective manually by the operator to control ink layer thickness and another adjustment in response to the speed of rotation of the duplicator.

Abstract: The disclosure relates to a stencil duplicator having a loading device in the form of a pair of guide members which are mounted for movement between a first position in which they define a slot into which a stencil can readily be inserted to attain a predetermined position and a second position in which they define a narrower slot and hold the stencil heading strip close to the surface of the rotatable ink screen of the duplicator and in the path of movement of mounting pins carried by the stencil mounting bar on the ink screen so that when the pins next pass the guide members they enter holes in the stiff heading strip of the stencil and drag the stencil through the slot and onto the surface of the ink screen without any need to stop the machine.Preferably the guide members present elongate edge portions which are undulated to define recesses, through which in the second position of the guide members the pins may pass, and fingers between said recesses to hold the stencil heading strip adjacent each recess.