Abstract: A tube bending apparatus is provided for placing a plurality of bends in an elongated tube. The apparatus includes a position sensor for sensing at least one location on the tube for assessing the accuracy of the bends placed therein. The apparatus further includes a programmable bender having a bend die and a clamp die for securely engaging the tube and bending the tube through a selected degree of curvature. A collet assembly is operative to axially and rotationally position the tube for each sequential bend. A pressure die boost and a collet assembly are provided for exerting axial pressure on the tube to urge the tube into the bend. The amount of axial force is programmed and selectively controllable in response to sensed operating conditions. A lubricated mandrel is programmably operative to be placed inside the tube. The movement of the mandrel is programmable and the flow of lubrication therethrough is both programmable and condition responsive.

Abstract: A bending apparatus is provided for rectangular tubes. The apparatus comprises a bending die, a wiper die, a clamp die, a pressure die and a mandrel. The clamp die and pressure die are provided with tongues which are engageable in corresponding grooves in the bending and wiper dies. The tongues and the clamping and pressure surfaces of the respective dies are dimensioned to enable the rectangular tube to be bent about either of its two axes by placing the tube on either of the opposed sides of the respective tongues. The tongue of the pressure die is movable to facilitate the tangential advancement of the pressure die under the action of a booster for urging the tubing into the bend. The mandrel includes a plurality of movable blocks. A plurality of springs interconnect the blocks to facilitate alignment. The blocks are mounted to a replaceable head which can be removed and replaced when worn. The mandrel includes channels for lubrication.

Abstract: A precision bending apparatus is provided for precisely bending tubes. The precision bending apparatus includes a preprogrammed bender for placing a selected sequence of bends in the tube. The apparatus further includes a position sensing means for sensing the precise position of locations on the bent portion of the tube. A control means is in communication with both the position sensing means and the bender, and is operative to alter the program of the bender based on data sensed by the position sensing means.

Abstract: Double walled tubing, a method and apparatus for producing the same are disclosed. First and second metal tubes of substantially identical diameters are selected. One end of the second tube is expanded, and the first tube is pushed into the second tube. By mounting the first tube on a mandrel having a mandrel ball with an outer diameter which approximates the inner diameter of the first tube, any creases in the first tube caused by the insertion will be removed by the mandrel ball upon withdrawing the mandrel from the first tube.

Abstract: Double walled tubing, a method and apparatus for producing the same are disclosed. First and second metal tubes of substantially identical diameters are selected. One end of the second tube is expanded, and the first tube is pushed into the second tube. By mounting the first tube on a mandrel having a mandrel ball with an outer diameter which approximates the inner diameter of the first tube, any creases in the first tube caused by the insertion will be removed by the mandrel ball upon withdrawing the mandrel from the first tube.