Abstract: An air injection pipe assembly adapted for delivering atmospheric air to the exhaust manifold of vehicle engine comprises a manifold air tube having an inlet and a plurality of spaced outlets. An air inlet valve having an outlet pipe is snugly projected into the manifold air tube and crimped thereto. A plurality of irregularly shaped air injection tubes at their one ends project into the manifold air tube outlets respectively and are brazed thereto and a flair fitting is secured upon the other end of each of the air injection tubes adapted for projection into spaced openings of a vehicle exhaust manifold for securing thereto. The method of making an air injection tube comprises the steps of forming a manifold air tube into U-shape and assembling the outlet of an air valve into one end of the air tube and annularly crimping one end of the manifold tube around the outlet of the air valve.

Abstract: An electric bend head for bending tubes includes a frame mounting a gear box housing with a rotatable main shaft extending through the housing. A secondary shaft coaxial of the main shaft is journaled within the housing and projects therefrom. A rotatable worm gear within the housing is coaxially mounted upon the secondary shaft and a worm drive gear is journaled upon the housing and in mesh with the worm gear. A variable speed reversible electric motor upon the frame has a main drive shaft, and a transmission interconnects the drive shaft and the worm drive gear. A secondary drive plate is mounted the secondary shaft and a main drive plate is spaced from the secondary plate and mounted upon the main shaft. A bend die of semicircular shape, having an outwardly opening channel, is axially mounted upon the main plate.

Abstract: Apparatus for positioning the seam of a welded tube comprises a plunger rod of a diameter less than the tube having a first longitudinal axis supported and journaled upon its first axis for reciprocal and rotational movements. A radial knife edge projects from the plunger which is adapted for advancing on its axis into a welded tube having a seam rotatably supported upon the first axis. Successive rotation of the plunger causes the knife edge to operatively engage the seam and rotate the tube a predetermined angle, there being preset angular final seam position for the tube, the knife edge having a preset initial position clockwise ahead of the desired seam position. Rotation of the knife edge is counterclockwise.