A wire-drawing machine, suitable for use in-line with an enamelling machine, comprises a plurality of individual wire-drawing capstans mounted in individual bearings, at least one for each capstan. The capstans are arranged in a substantially planar rectangular array (comprising rows and columns of the capstans) with their axes aligned with the rows thereof. A series of parallel drive shafts, each serve all the capstans of one row or one column of the array. The capstans of one column are associated with a single wire line whereas the capstans of any one row are associated with a corresponding drawing stage for all the wires lines.

A plant for producing enameled wire using an inline process has, placed in order a wire pay-off system, a wire drawer, an annealer, an enameled dope coater, an enamel processing unit and an enameled wire take-up unit. The annealer and the dope coater are placed together in a single oven housing, which has a drying space, a curing space and a return shaft in which a circulating air blower, a heating unit and a catalyst are placed. The blower is responsible for producing a heated air current moving through the heating unit of the annealer and through the catalyst, the air current furthermore moving in the opposite direction to the direction of the wire through the curing space and the drying space. The wire makes its way through an annealing tube and the return shaft into waste gas pipe joined therewith and through a wire cooler, which is full of inert atmosphere as produced by a unit. After coming out of the wire cooler the wire is moved into the enamel dope coater from which it makes its way into the drying space and the curing space, it coming out of the curing space through a wire outlet and then makes its way into a wire cooler which is right next to the oven housing. From the wire cooler the wire makes its way to the wire take-up system, after being run through plant a number of times. The cooling air for the wire cooler is preheated by a heat exchanger before going into the curing space under gage pressure. Control of air circulation is undertaken by adjustment of the speed of the blower and adjustment of the door, while the temperatures for drying and baking are controlled by the waste gas door.

A continuous process for high speed fabrication of wire comprises the steps of directing wire through a first set of drawing dies to reduce the wire diameter to an intermediate diameter, applying a lubricant to the wire during the drawing process, annealing the intermediate diameter wire while it is still coated with some of the lubricant, controlling the tensile forces and elongation of the wire during the anneal, and drawing the annealed intermediate diameter wire to a desired final diameter in a second set of dies. The process is particularly well suited for fabricating fine copper wire having improved mechanical properties.

In a magnet wire fabrication process in which the drawing of wire is "in-line" with the enameling process, it is often a requirement that the drawing machines be supplied with electrical power from the utility grid rather than relying on an "in-house," closely regulated supply of electrical power. In such cases, during voltage dips on the grid, the drawing machine motors will slow down while the wires continue to be pulled from the drawing machine at the same speed as before. A wire accumulator is interposed between the drawing machines and the enameling oven to prevent breakage of wire by providing an accumulation of wire to be used in the event of such a voltage dip. The present invention discloses an apparatus for controlling the various channels of the accumulator so as to provide roughly equivalent amounts of wire in each channel so that the integrity of all channels during a power dip is assured. A central operator control station for effecting the desired control is disclosed. It comprises, among other things, a keyboard and a display for entering a desired wire gauge size to be drawn, and a signal processor for controlling the accumulator channels according to the commanded gauge size. A plurality of controllers for each channel are responsive to a speed command signal from a pulling capstan at the enameling end of the process. This signal is modified by a feedback signal derived from the accumulator channels so as to indicate the actual running speed of the various drawing machine motors and at the same time control the amount of wire accumulated in the various channels.

In a machine for reducing the cross-section of a number of wires by drawing each of them through a respective series of dies of decreasing diameter, a corresponding series of individual capstans is used for drawing each wire through its series of dies, and each one of several drive shafts supports at spaced positions along its length the capstans of a respective drawing stage of each series. Each capstan is driven by the shaft on which it is mounted, and the drive mechanism for the shafts can be adjusted, by presetting or otherwise, to give different peripheral speed ratios to the capstans, to suit different die sets and/or to compensate for wear. The capstans are mounted between bearings supporting the shafts, and the drive mechanism is located outside the bearing at the relevant end of the shaft. Preferably mechanism coupling adjacent shafts alternates between the two ends of the machine.