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).
Letter to Westinghouse seeking recommendations on the construction of magnet coils, comparing English and American methods.
| Identifier | ExFiles\Box 24\2\ Scan155 | |
| Date | 31th March 1921 | |
| OY3/G21321. X1109 March 31, 1921. Mr. R.G. Thompson, Westinghouse Electric & Mfg. Co., Springfield, Mass. My dear Mr. Thompson, X 1109 X 3331 X 3034 X 3428 I should be interested in receiving the courtesy of your recommendation for building up the magnet coils of our main switch and actuating box, prints of which we enclose herewith. As you already know, these coils are at present wound with double silk covered wire upon tubes and between end washers of paper, and after winding are impregnated with varnish by pressure and vacuum and then baked. This is a standard form of construction in England, but we understand that in this country the method of operation is different, and that it would be more usual to wind the coils of enamelled wire on a core tube and between washers of some non-hygroscopic substance such as Bakelite Micarta or Bakelite Dilecto. The coils could be covered with string after winding and then simply dipped in varnish and baked to fix the outside coils, but no attempt made to impregnate the coils. I should be glad of your opinion as to whether the second method, which we understood is the standard American practice, has any advantages over the first. Incidentally, I should also be glad to learn whether there is any danger of the varnish used on the outside dissolving the enamel on the outer coils. Thanking you for your courtesy in this matter, I remain. Yours truly, ROLLS-ROYCE OF AMERICA, Inc. Engineer. MO/G.{Mr Griffiths - Chief Accountant / Mr Gnapp} | ||