Abstract: A tool assembly for forming internal threads on the interior surfaces of tubular structures which comprises a substantially cylindrical tool holder defining circumferentially about one end thereof, a plurality of disc-shaped forming edges, said tool holder adapted for rotational contact with a tubular workpiece, a rotating means located in operative contact with said tool holder, said rotating means situated for longitudinal reciprocation along an inclined track, a workpiece securement means comprising opposed clamps or the like located on a base structure and adapted to secure said workpiece in axial alignment with said tool holder, and a track comprising paired track members or rails associated with said workpiece securement means, wherein said securement means and said track are inclined with respect to the horizontal whereby said workpiece is apically situated with respect to said track to enable said tool holder to traverse the interior of said workpiece while moving on said track.

Abstract: The present invention comprises (1) a heat source, (2) a heat pipe, and (3) a thermal transformer in thermal contact with said heat pipe and proximately disposed to said heat source, whereby a uniform heat transfer from said heat source to a heating system is obtained. The thermal transformer includes (1) a container, (2) a working fluid and its vapor which are essentially in equillibrium, (3) evaporating surfaces depending from the internal surfaces of the transformer that are wetted with the working fluid and that are proximate to the heat source, and (4) condensing surfaces depending from the exterior of those areas of said heat pipe that are in thermal contact with said transformer.