Flame-retardant wire and cable (US Patent 3,576,940, 1971)

John G. Stone, George S. Buetiner and Christian A. Alm received US Patent No. 3,576,940 on May 4, 1971, filed December 3, 1968.

The patent's abstract:

An electrical conductor or cable, capable of maintaining electrical integrity when exposed to open flame temperatures of 1000* F. without propagating a fire or resulting in falling burning particles or generating large volumes of smoke. The conductor or cable of this invention is comprised of a metallic conductor or plurality of conductors covered by a layer of primary insulation. Such conductors are then covered by a layer of silicone rubber which is, in turn, covered by a layer of glass fiber. The layer of glass fiber may then be covered by another layer of silicone rubber which is, in turn, covered by a layer of braided asbestos impregnated with an intumescent material. In the alternative, the second layer of silicone rubber may be covered by an asbestos tape which is then covered by a layer of elastomeric material having fire-retardant properties.

Where it was listed

• Asbestos, July 1971, in its patents department (the year's issues)