Heating arrangement for revolving bodies whose diameter varies during production thereof by build-up welding

Claim 1

Heating apparatus for a revolving workpiece of increasing diameter having a generally cylindrical configuration defining a generally horizontal axis of revolution wherein said workpiece is produced by build up of welding material thereon during a welding process comprising: an assemblage of heating elements located alongside said workpiece and confined to within a geometrical sector bounded by a pair of radii extending through said horizontal axis of revolution perpendicularly thereto; said heating elements being generally arranged to extend in the vicinity of a circular arc of said geometrical sector; said heating elements including a first plurality of heating elements arranged generally centrally of said sector on said circular arc and a second plurality of heating elements divided into two groups each located circumferentially on opposite sides of said first plurality of heating elements; said first and said second plurality of heating elements being movable relative to each other in directions extending radially generally perpendicularly to said horizontal axis of revolution whereby said first plurality of heating elements may be moved closer to said workpiece than said second plurality of heating elements during the initial stages of said build up of welding material when said diameter of said workpiece is relatively smaller; and undercarriage means upon which said first and second plurality of heating elements are mounted for moving said heating elements together relative to said workpiece perpendicularly to said axis of revolution toward and away from said workpiece; said first and second plurality of heating elements being thereby movable relative to each other toward and away from said workpiece to enable control of the heat energy imparted to said workpiece in dependence upon the degree of the increase in the diameter thereof.