Hunter Engineering Company

Curt Braun

Subbiah Sankaran

A continuous strip coating machine has top and bottom applicator rolls and a backup roll adjacent the top applicator roll. A lift roll to lift the strip of material and thus vary the angle of wrap of the strip about the bottom applicator roll is provided. The use of the lift roll in turn varies the pressure between the strip and the roll and thus the thickness of the coating applied to the strip bottom. Thickness may be measured indirectly by measuring pressure of the strip on the applicator roll. Thickness may also be measured directly. Oscillations of the strip in a drying oven may also be sensed and compensated for. Feedback control is used with the thickness measuring techniques to control the coating thickness by varying angle of wrap, relative speed between the applicator roll and strip, and/or nip pressure between the applicator roll and a transfer roll that transfers coating material to the applicator roll.

Strip coating machine with thickness control

An oven for drying and curing a film of paint, ink, or the like on a continuous strip of metal has a non-rectangular, and preferably oval, elongated oven chamber without sharp internal corners. By avoiding sharp corners in the oven, air flow is more uniform and deposits of condensed fumes are minimized. In some embodiments no internal bracing structure required. The absence of internal structure is permitted by the oven's walls, oval shaped in transverse cross section, which result a naturally self supporting structure. Cleaning nozzles may be provided for washing the inside of the oven without need for people to enter the oven.

Strip drying or curing oven

Thickness of metal sheet being cast is continuously controlled by passing a light beam through the gap between the casting machine rolls and measuring the amount of light passing through. The width of the gap is controlled in response to the measured light. To prevent interference in the hostile environment of a casting machine, the light is transmitted along an enclosed path and air is blown through the enclosed path into the roll gap. Both the thickness can be controlled in this way, and the profile can be controlled by axially shifting at least one of a pair of non-cylindrical work rolls.

Thickness control for a continuous caster

Heat treating apparatus for continuous painted strip, comprising an elongated, convective heating oven through which painted strip is passed while jets of hot gas are directed against the top and bottom surfaces of the strip to dry and cure the paint film. The strip is suspended from tension bridles at opposite ends of the oven, and hangs in a relatively flat catenary curve therefrom. Spaced longitudinally within the oven is a plurality of pairs of headers which are arranged to follow the catenary curve of the strip, each of said pairs comprising an upper header located above the strip and a lower header located below the strip. Each of the headers has a plurality of jet nozzles directed toward the strip, and duct means is provided for supplying hot gas to the headers so that the nozzles send jets of hot gas impinging against the strip. The static and dynamic pressure of the jets of hot gas cause the strip to float while still following the catenary curve that the strip takes when merely hanging by gravity from the bridles. However, when the strip is floated by the hot gas jets, all or most of the weight of the strip is carried by the gas, and tension in the strip is correspondingly reduced. Each of the headers is adjustable vertically so that it can be positioned to closely approximate the catenary curve of the strip, and also so that it can be moved closer to or further away from the strip so as to increase or decrease the amount of flotation.

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Riverside, CA, United States of America

Curt Braun