Abstract: A pierced hollow rolled by obliquely positioned conical or barrel-shaped rolls, is held against excessive ovality by driven guide sheaves or disks acting in combination with guide bars downstream for controlling the rate of radial widening of the hollow. Oblique positions of the axes of the disks permits them to be of larger diameter.

Abstract: A mandrel rod with or without rolled tubes thereon is held by four guide structures, two arranged above and two below with respect to the axis of rolling, and each being arranged on a lever, these levers are arranged in pairs to both sides of the rolling axis, and they are particularly interconnected and connected to a common drive to permit common radial retraction of the guide structure; these guide structures have basically three different positions, one of full retraction permitting a mandrel rod with rolled tubes thereon to be removed by lifting while simultaneously a fresh mandrel rod is placed into the rolling axis from below; in a second position of the guide structures they engage a mandrel rod in the rolling axis, and in the third position they form-fittingly engage a hollow on the mandrel rod in the rolling axis.

Abstract: A traction device for buffering tubes including a reversibly driven sprocket and two guide members, each member being pivotably adjustable about a horizontal axis to change its orientation for orienting the chain in different directions vis-a-vis the sprocket wheel.

Abstract: Pipes are moved transversely from one roller track to another one through two, bidirectional devices which in one example have a stationary and an up and down reciprocating member with shoes constructed to provide alternatingly downwardly inclined surfaces. Up and down movement results from pneumatic operation of an inflatable tube. The opposite direction of movement is provided for by a second up and down moving member with oppositely oriented roll-off surfaces.