Convertible apparatus for heat treating materials

A convertible heating system for use in a process line for heat treating a continuous sheet material as the continuous sheet material is advanced along the heating system, wherein the process line includes an entry section for supplying untreated continuous sheet material to the convertible heating system and an exit section for receiving the treated continuous sheet material from the convertible heating system, said convertible heating system comprising:

• a housing having an input end for receiving the continuous sheet material to be heat treated and an output end and defining a path along which the material is operatively advanced through the housing from the input end to the output end, said housing, enclosing a plurality of heating sections disposed serially along the path;
• a convertible section of said plural heating sections comprising confrontingly opposed first and second heaters disposed on respectively opposite sides of said path for directing heated air from said heaters toward opposed faces of the continuous sheet material as the continuous sheet material is advanced along the path in said housing, said second heater being positionally fixed in said housing and said first heater being movable substantially transverse to said path between a first position predeterminately spaced from said second heater for applying a first heat treatment to the continuous sheet material and a second position more remote from the second heater than said predeterminate spacing of said first position for applying a second heat treatment to the continuous sheet material;
• and
• a heater lifting device connected to said first heater and selectively operable to move said first heater between said first and second positions of the first heater for converting said heating system between first and second heat treatment configurations for applying said first and second heat treatments to the continuous sheet material;
• said second heater comprising means for directing a stream of heated air substantially upwardly onto one of the opposed faces of the continuous sheet material so as to support the continuous sheet material on the stream of heated air in a substantially horizontal orientation through said convertible section in said first position of the first heater for applying said first heat treatment to the continuous sheet material, and for directing the stream of heated air substantially upwardly onto the one of the opposed faces of the continuous sheet material without supporting the continuous sheet material on the stream of heated air and thereby permitting the sheet material to assume a catenary sag through said adjustable section in said second position of the first heater for applying said second heat treatment to the unsupported continuous sheet material.