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 Hoffmann Manufacturing Co. Ltd. detailing alterations to bearing specifications.
| Identifier | ExFiles\Box 153\1\ scan0077 | |
| Date | 12th October 1937 | |
| HOFFMANN Registered Trade Mark TELEPHONE: 3151 (Five Lines) TELEGRAMS: HOFFMANN, CHELMSFORD CODES USED: A.B.C. 5TH EDITION, BENTLEY PHRASE, BENTLEY 2ND PHRASE, MARCONI AND WESTERN UNION 5 LETTER. BRANCHES: LONDON, BIRMINGHAM, MANCHESTER, LEEDS, GLASGOW. AGENTS IN PRINCIPAL COUNTRIES THROUGHOUT THE WORLD. BALL-AND-ROLLER-BEARINGS STEEL-BALLS-AND-ROLLERS THE HOFFMANN MANUFACTURING Co. LTD. CONTRACTORS TO THE ADMIRALTY, WAR OFFICE AND INDIA OFFICE. CHELMSFORD. Handwritten: 1300 MESSRS. ROLLS-ROYCE LTD. DERBY. October 12th. 1937. YOUR REF. Rm{William Robotham - Chief Engineer}/FJH.{Fred J. Hardy - Chief Dev. Engineer}2/MH.{M. Huckerby} IN YOUR REPLY PLEASE QUOTE OUR REF. CHS/AMB.101934. Handwritten: FJH.{Fred J. Hardy - Chief Dev. Engineer} Dear Sirs, FOR THE ATTENTION OF MR. F.J. HARDY. We were very pleased to learn from your letter of the 7th. instant that your tests on the batch of steering rollers, Hoffmann Bearing No. N.2784, were satisfactory and we can go ahead along these lines. We are accordingly altering our drawings, and for your information are itemising the changes we are making in each bearing. Hoffmann Bearing No. N.2784, Your Part No. F.61471. Increase Outer Track to 1.233". Handwritten: 1.2270 0.006 " Diametric Slackness to .0025". " Faces of Distance Piece to 0.75" diameter. Harden Distance Piece. Hoffmann Bearing No. N.2891, Your Part No. F.89447. Increase Outer Track to 1.5366". Handwritten: 1.5276 0.009 " Diametric Slackness to .0031". Hoffmann Bearing No. N.2904, Your Part No. F.89670. Increase Outer Track to 1.3659". Handwritten: 1.3609 0.005 " Diametric Slackness to .003". Hoffmann Bearing No. N.2790, Your Part No. FW.911. The three bearings you ordered of this size have already been despatched with the existing dimensions, but for future orders we propose to increase the Outer Track to 1.3659", and the Diametric Slackness to .003". Handwritten: 1.3609 0.005 We have not yet received the six bearings you have found with too much pre-load, but immediately they arrive we will examine | ||