Abstract: A paster roller is provided for use on high speed web handling equipment of the type having a support upon which a feed roll and a new roll are mounted. Variable torque brakes associated with each roll exhibit a substantially constant coefficient of friction at all web speeds. Apparatus for splicing the web from the feed roll onto the web from the new roll is provided including a uniquely designed paster roller having a deflectable outer surface with annular grooves situated therein. The brakes each include a brake caliper assembly for use in conjunction with the rotatable shaft upon which the roll is mounted which has a disc member associated therewith. The assembly includes a housing having a bore therein. A port provides a fluid connection between the extension of the housing and the bore. A cylindrical puck member is at least partially received within the bore.

Abstract: Solvents evaporated from ink solutions in the drying sections of a multi-station printing press are converted into harmless gases by heating in an oxidation chamber. The amount of energy required to maintain the oxidation temperature is substantially reduced by preheating the exhaust by passing same through a previously heated bed of ceramic heat exchanger elements prior to introduction into the oxidation chamber. At high solvent concentration levels, preheating to the ignition temperature may result in excess heat of combustion being generated which is detrimental to the oxidation chamber structure. In order to regulate the heat generated, a portion of the heat exchanger bed is bypassed by a regulated amount of exhaust. Alternatively, the solvent concentration level of the exhaust can be lowered by mixing same with the floor sweep exhaust (of substantially lower solvent concentration) in regulated proportions in order to control the amount of heat of combustion generated during preheating.

Abstract: The LEL (Lower Explosive Limit) control includes a gas analyzer normally connected to receive sample gas from the evaporation enclosure of a press dryer section and which, during calibration, is sequentially connected to first analyze solvent free gas and then gas having a known solvent content. Situated with the analyzer is a detector the resistance of which changes in proportion to the temperature within the flame cell of the analyzer. The detector forms a portion of a bridge circuit, which also includes a potentiometer. The output of the bridge is amplified, compared to a selected reference voltage and a signal representing the difference therebetween is processed. The processed signal is combined with a signal representing the web speed to form a resultant signal to control a pneumatically operated damper in the enclosure exhaust conduit. Automatic calibration of the system is initiated periodically and takes place in two phases.

Abstract: A variable torque core brake exhibiting a constant coefficient of friction at all web speeds is regulated in accordance with the position of a dancer roller to maintain web tension at a constant level. Steady state changes in web tension caused by the gradual reduction of the diameter of the feed roll as web is removed therefrom are compensated for by electronically generating a signal representative of the effective diameter of the feed roll and varying the torque on the brake associated with the core of the feed roll in accordance with the signal so as to maintain a dancer roller at a substantially constant position. Transient changes in web tension are compensated for by sensing dancer roller displacement and generating a signal proportional thereto. The signal is processed by taking the derivative thereto and combining the proportional and derivative signals. The combined signal is then utilized to vary the brake torque.