From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Insulating materials, an American Bosch Induction Coil, and distributors.
| Identifier | ExFiles\Box 24\2\ Scan127 | |
| Date | 5th April 1921 | |
| COPY. X.1109 Oy2 - G5421. April 5, 1921. Hs{Lord Ernest Hives - Chair} RECEIVED MAY 9 1921 E4S / 7JA Mr.Claude Johnson, Managing Director, Rolls-Royce Ltd., London, England. Attention . Mr. F.H.Royce and Works Committee. Dear Sir, X.1109 Re Insulating Material. X 2434 X 3513 Replying to Mr.Royce's memo E4/G18/3/21 which has just come to hand. We are arranging to interview the representative of the Bakelite Company at an early date as Mr.Royce requests. X.4275 American Bosch Induction Coil. With regard to the American Bosch induction coil, this consists of a laminated core of low hysteresis iron inside a fiber tube. The primary is wound with enamel wire with varnished linen between the layers, and the secondary of enamel wire with varnished paper between the layers. The enamel used on the wire is Tung enamel, of Chinese origin, made from cotton seed, we believe. It has high elasticity and dielectric strength and maintains these qualities indefinitely. The coil is jacketed about the middle with a copper plated jacket of low hysteresis iron, which extends to within about ¼" of each end of the coil, the magnetic gap formed between the ends of the core and jacket being sufficient for a quick magnetic break. The black tube surrounding the coil is Bakelite Micarta, and the end moldings are of Bakelite. The ballast resistance is wound on a porcelain spool mounted on an asbestos washer. The coil is not impregnated, but is taped and varnished on the outside. The coils have been tested under a spray of brine and under all sorts of conditions of heat and moisture. X.800 Distributors. Bakelite cannot be safely used for the tracks of the rubbing type of distributors or for the post carrying the H.T.collecting | ||