Abstract: A thermography machine to be subject in use to periods of waiting for supplies of sheets to be processed is provided with a control system whereby at any time the conditions of a normal "run" mode of operation can be switched to or from operations in a "standby" mode, with retention of a high heating chamber temperature in readiness for processing sheets yet with important reductions of heat losses from the heating chamber, so reduced infusion of heat into the ambient workshop air, and decreases of power consumption and of wear and deterioration in the driving of the conveyors and several other components of the machine. Heating chamber temperature and wattage output of the heaters are controlled over a wide range of A.C. supply line voltages in both modes of operation by supplying current to the heaters from a thermocouple heat control coupled with a proportional voltage control.

Abstract: Raised printing is produced on a printed sheet by applying thermography powder to a top printed surface of the sheet while printed areas on such top surface are tacky, such that the powder adheres to such printed areas and is thereafter melted in a heating section. The heating section comprises an upper heater, a lower heater, and a conveyor for conveying the sheet between the upper and lower heaters such that the upper heater heats the sheet from above while the lower heater heats the sheet from below, to melt and expand the powder.

Abstract: A system is provided for intermittently processing successive definite lengths of flexible sheet material in continuous web form, e.g., tractor-fed computer printout paper, with nearly tensionless transport of the web through web feeding operations, cyclical web processing and driving operations, and web delivery operations, that are not speed-interdependent. For each processing cycle, with the web extended without slack through an upstream lead to a processing station where a certain length of the web is positioned to be next processed, an excess length of loose web is fed into that lead, typically forming a loop in it; then the certain web length is processed and driven forward a distance shorter than the length of loose web; and then web is retracted from the upstream lead to remove the residual loose web and leave a next certain web length in position to be processed.

Abstract: A thermography apparatus includes a wire mesh conveyor belt for conveying sheets through a heating zone in which a resin is heated and melted. A plurality of inserts is mounted on the belt for supporting the sheets. Each of the inserts comprises an elongate strip, the strip including an edge integrally formed with a plurality of pointed projections. A widest cross-section of the insert is sized to permit the insert to be inserted laterally into a lateral opening in the belt with the projections thereof lying in the plane of the belt and then rotated 90.degree. to a position wherein the projections extend beyond the plane of the belt to support the sheets. Provided at each end of the strip is a pair of bendable tabs which can be crimped around a wire portion of the belt to anchor the strip to the belt. Since the sheets are supported only by pointed projections, thermography printing can be performed on both sides of the sheets with little risk of the ink being smeared.

Abstract: A slitter feeds paper sheets one-at-a-time from a stack onto an alignment table and against a guide surface. A quick and accurate adjustment for the guide surface enables the orientation of the guide surface and thus of the sheets to be adjusted. The sheets are fed to a cutter and are cut into segments. The cutters include radially overlapping cutting edges which are freely separable, against a spring-bias, to accommodate the simultaneous passage of more than one sheet. The cut segments are discharged onto conveyor assemblies and fanned-out in divergent directions for collection. The conveyor assemblies support the segments along laterally spaced lines and frictionally engage the segments with a drive belt intermediate the lines of support. A quick-release clutch enables the drive to the sheet feeding mechanism to be interrupted.