Jeffrey mine insulator and pin

Malleable Iron Pins for Mine Feeder System.

The Jeffrey Manufacturing Company, Columbus, Ohio, is marketing an insulating support for feed wires in mines. The pin is made in halves of malleable iron, threaded for a glass insulator at one end and barbed at the other, it is driven into position in the roof.

Malleable Iron Insulated Pin.

The insulator is cupped and the pin has a hollow centre, allowing for drainage and preventing the collection of moisture on the feed wire.