DE732183C - Process for the production of electrical heating resistors - Google Patents

Description

Process for the production of electrical heating resistors It is known electrical heating resistors by pressing one on one. Mandrel coiled Manufacture wire spool, with on the mandrel: an insulating intermediate layer Asbestos, mica or the like. Is arranged. To avoid mutual displacement of the turns «ground them to the base by means of an adhesive or through a 'made by wrapping protective cover held.

The invention now proposes: a simple manufacturing process, in which special interlayers, thickeners and the like are unnecessary. This new process consists in that first the wound on a mandrel, mutually non-touching windings by passing an 'electrical Stromes provided in a known manner with a gapless insulating oxide skin whereupon the turns are made strong by pressure in the axial direction of the mandrel are pressed together and still during the compression by passing through heated by an electric current and then cooled. Because of this Heating and subsequent cooling, through which the material of the heat resistance is hardened to a certain extent, a resilient holding together, the coils: is achieved, so that the turns are subsequently formed into a flat band by pressing rollers or the like can be rolled or pressed.

It is advisable to use a strong one again after the flattening or rolling Current passed through the wire for a longer period of time in order to obtain a permanent oxide layer.

To explain the method according to the invention, the individual Operations shown in Figs. I to 7.

Alb. i shows the winding of a wire i on a linen mandrel 2 .. The individual turns are arranged at a certain distance from one another; so they do not touch. A current is sent through the heating wire i, so that the wire is coated in a known manner with an insulating oxide layer. The wire coil (Fig. A) is then pressed together by suitable pre-bake 3 or the like until the individual turns lie against one another. While the coil is still held in a compressed state, its strong current is passed through it, causing the coil to heat up. Subsequently, the coil is cooled, whereby a hardening of the wire occurs, so to speak, which has the consequence that the individual turns remain resiliently cohesive. The coil is then flattened according to the operations shown in Figs. 3 to 5. The finished heating resistor is shown in two views in Figs. 6 and 7.

Claims (1)

PATENT CLAIMS: i. Process for the production of electrical heating resistors endlessly by flattening a wire spool wound on a mandrel, characterized in that d, ate the turns that were initially not in contact with one another Passing through an electric current for the purpose of forming a gapless Oxydiiaut isolated in a known manner and then on the same non-conductive spike in the Axial direction of the same pressed together forcefully and during this compression by passing through a corresponding electric current and the following Cooling down to achieve a resilient cohesion between the individual turns hardened, so to speak, and then between. Press rollers or the like of any desired supplementary cross-section rolled into an endless flat strip with a maximum thickness of two wire gauges will. z. Method according to claim i. characterized in that after the flat pressing or rolling the oxide-skinned wire coil flat again a strong current for the purpose of forming a cunning protective oxide layer through the wire for a longer period of time is passed through.