Abstract: An automatic stop apparatus for use in combination with a cold-pilger mill to reduce the amount of tube scrap generated during a cold-pilgering operation includes a first control scheme for stopping the advancement of the pilger mill feed carriage and the operation of the mill's upper and lower pilger dies when the feed carriage pushing a tube through the pilger dies is a predetermined distance from the axis extending between the centers of the pair of pilger dies. The predetermined distance is selected to provide that facing end portions of the pushed and pusher tubes are positioned between the pilger dies.

Abstract: A metal tube induction annealing apparatus employs an induction heating enclosure having an elongated glass tube encircled by an electromagnetic coil of an induction heating system which provides an induction annealing chamber for receiving a hollow metal tube for undergoing annealing and an inert purge gas for bathing the tube during annealing. Cooling stages are located end-to-end downstream of the induction enclosure for progressively cooling the annealed tube. The inert purge gas is made to flow upstream in a direction opposite to the downstream direction of tube movement through the annealing chamber and cooling stages for accomplishing constant bathing or shielding of the exterior and interior wall surfaces of the tube and removal of heat by inert purge gas flowing through and out of the trailing end of the tube.

Abstract: A ferrous metal detector is used in conjunction with a ferrous metal mandrel of a pilger tooling set in a cold-pilgering machine to sense when the mandrel breaks during operation of the machine. The ferrous metal detector includes a transformer located adjacent to an end of the mandrel. The transformer has a primary winding and a secondary winding positioned along the path of tubing movement through the machine and sufficiently close to one another to be magnetically coupled together by a piece of the ferrous mandrel when located therebetween. The primary winding is excited by a suitable source with a constant predetermined signal which is transparent to non-ferrous metal of the tubing. Such signal couples a constant voltage in the secondary winding.

Abstract: An electrolytic etching apparatus employs a continuous stencil imprinted with a sequence of identification numbers and includes spaced spools and upper and lower electrodes defining an etching station located between the spools. The stencil extends between the spools and is moved by rotatably indexing the spools to position successive ones of the identification numbers over the lower electrode for etching on a successive one of the metal tubes. A wicking pad is draped over the lower electrode below the stencil and has one end extending into a reservoir of electrolyte also located below the stencil. The wicking pad draws up electrolyte by capillary action to provide a steady flow of the electrolyte to the portion of the wicking pad located directly below a portion of the stencil located at the etching station. The upper electrode is mounted for movement toward and away from the lower electrode and the wicking pad and stencil portions.

Abstract: Apparatus for detecting the level of a liquid. A metal-detecting proximity sensor is placed near a non-metallic, vertically-positioned guide shaft. A float is placed on the liquid. A tube has one end attached to the float and the other end insertably placed within the guide shaft. A piece of metal is placed within the tube. When the apparatus is used for determining when the level of the liquid reaches a predetermined value, the metal piece has a boundary which is located at the height of the proximity sensor only when the liquid level is at its predetermined value. When the apparatus is used for measuring the level of the liquid, the proximity sensor has an output signal proportional to the distance from itself to metal and the metal piece has an outer surface whose distance to the proximity sensor at the height of the proximity sensor, changes with changes in the liquid level.

Abstract: Apparatus for and method of clearing scrap from the opening of a workpiece in which a jet of fluid is directed over the opening, causing the scrap to be entrained in fluid streaming out of the opening to join the fluid jet. In a preferred embodiment of the invention, the fluid jet is pulsed in order to maximize its efficiency. In an alternative embodiment, a vacuum is used to collect the entrained scrap.

Abstract: A tube straightness checking apparatus includes a gauging mechanism disposed along a linear path and being operable to check the straightness of the tube as it is moved along the path past the mechanism. The gauging mechanism is operable to detect deviation of the tube from an imaginary centerline which is generally coincident with the linear path. The apparatus also includes linear hearing sets which guide a tube along the generally linear path past the gauging mechanism. Two embodiments of the gauging mechanism are disclosed. In the preferred embodiment, the gauging mechanism includes a gauge plate with a circular gauging orifice defined therein through which the tube passes as it is moved along the linear path. The gauge plate is electrically conductive and forms part of an electric circuit which is operable to provide an indication of an out-of-straightness condition upon the tube contacting the gauge plate as the tube moves along the linear path through the gauging orifice of the plate.