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 from British Carbons regarding the grades and specifications of carbon brushes for dynamos.
| Identifier | ExFiles\Box 62\3\ scan0226 | |
| Date | 9th May 1931 | |
| X6066 TEL. 5225 & 3191. CODES: A.B.C. 5TH EDITION. LIEBER'S. British Carbons MANUFACTURERS OF CARBON BRUSHES FOR MOTORS & DYNAMOS. CAR DYNAMOS & STARTER BRUSHES, MAGNETO CARBONS. PROGRESS WORKS. CROWTHER STREET, BRADFORD, YORKS. PARTNERS: A.{Mr Adams} SOUTHERN. H.{Arthur M. Hanbury - Head Complaints} SAMPSON. W. HOLBREY. 9th May, 1931 Your Ref. Hs{Lord Ernest Hives - Chair}/CAPI/AD. Messrs Rolls-Royce, Ltd., DERBY. Dear Sirs, We are much obliged by your letter of the 6th inst. The Grade of Brushes which we sent to you as samples was our Grade B, which we have found to be very successful for Automobile Dynamos. We have pleasure in sending herewith, as requested, technical specification of same. In reference to concluding paragraph of your letter, we have been wondering whether you would like to try sets of Brushes in the same quality as we supply for all Fiat Dynamos, which is our Grade G.{Mr Griffiths - Chief Accountant / Mr Gnapp} This Grade has the distinction of being the first Electro-Graphitic Brush on the market. It is classed as a polishing Brush, as it contains a very slight amount of abrasive material. It is a particularly sweet-running Grade, and is practically sparkless under any load; being a pure natural Graphite it wears out more quickly than an Electro-Carbon [STAMPED: RECEIVED 11 MAY 1931] | ||