Publication: The Electrical Engineer
New York, NY, United States
H. W. JOHNS MANUFACTURING CO.
We are in receipt of the June catalogue of electrical materials issued by the H. W. Johns Manufacturing Company, in which they call particular attention to their new electric street car heater. The heater Is durable In construction and economical In operation. The wires are not liable to oxidation, as they are protected from the atmosphere by a covering of asbestos which also forms a complete electrical Insulation for them.
The wire after being wound with an asbestos thread is woven into cloth with an asbestos warp. A piece of this cloth containing a required amount of wire is fastened with fireproof insulating cement to a sheet of asbestos millboard, which forms its support. The whole Is then covered in a case of perforated steel plate which is japanned with an insulating compound.
These heaters admit a free circulation of air through and under the perforated plate, the latter being arranged so that the back of the heater is half an Inch in front of the panels below the seat. The heaters are controlled by a knife switch which can be adjusted to give three degrees of heat.
|Keywords:||H. W. Johns Manufacturing Company|
|Date completed:||January 17, 2011 by: Elton Gish;|