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 Borg & Beck concerning clutch flywheel spigotting and bolt hole dimensions.
| Identifier | ExFiles\Box 129\2\ scan0014 | |
| Date | 25th January 1935 | |
| [Handwritten top center: GRY{Shadwell Grylls} X2200] Telegrams BORGANBECK, LEAMINGTON SPA. Telephone LEAMINGTON SPA 1550. BORG & BECK COMPANY LTD. MANUFACTURERS OF CLUTCHES. Registered Office BROCK HOUSE, LANGHAM STREET, LONDON, W. 1. WORKS: Tachbrook Road, LEAMINGTON SPA, Warwickshire. Directors E.{Mr Elliott - Chief Engineer} B. BOUGHTON. W. EMMOTT. D.{John DeLooze - Company Secretary} T. BROCK. Your Ref Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls}9/KW Exptl.Dept. Our Ref TS/HTB/EA 25th January, 1935. Messrs. Rolls-Royce Ltd., DERBY. [Signature] Dear Sirs, We beg to acknowledge with thanks your letter of the 22nd inst., and we are pleased to note that the sample 11" clutch recently supplied to you, and also the 10" clutches supplied to you some little time ago, are functioning satisfactorily. With reference to the various points mentioned in your letter would advise that it is not usual for this type of clutch to be spigotted into the flywheel at the cover flange, and as you will appreciate this automatically does away with the advantage of a flat face flywheel which is an aid in manufacture and particularly in regard to the efficient grinding of the flywheel friction face. We could, of course, arrange to machine the cover flange to a dimension suitable to your goodselves and embodying usual Newall limits should you so desire, but we feel that this is rather unnecessary inasmuch as the bolt holes are definitely line reamed to the following dimensions - 10" clutch, six holes - .376/.3775" 11" clutch, eight holes - .376/.378" Would advise that these holes are reamed into position from a fixture located in the slots in the clutch cover and which carries the pressure plate so that you will appreciate that the major portion of the clutch is at all times running true in relation to the slots in the cover and the retaining bolt holes. Final inspection of the cover is carried out in regard to the bolt holes both for size and chordal dimensions, the latter being within .001". [Handwritten in left margin: THIS SEEMS O.K.] | ||