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 Adamant Engineering Company discussing the specifications and efficiency of L7 Marles Steering gears.
| Identifier | ExFiles\Box 28\3\ Scan034 | |
| Date | 1st November 1934 | |
| Telegrams: "ADAMANT, Phone, Luton." CONTRACTORS TO H.M. ADMIRALTY, WAR OFFICE & AIR MINISTRY. Telephone: LUTON 1818 (2 LINES). ADAMANT ENGINEERING COMPANY, LIMITED (Incorporating J.{Mr Johnson W.M.} C. TREADGOLD & SONS. Established 1878.) Engineers and Founders. SPECIALISTS in the DESIGN and MANUFACTURE of HIGH PRECISION TOOLS, JIGS, FIXTURES, etc. SPECIAL MACHINES, SPECIAL MACHINE TOOLS and ACCURATE PRODUCTION WORK. SOLE MANUFACTURERS and SALES AGENTS for the MARLES and MARLES-WELLER STEERING GEARS. Directors: S. CARLTON SMITH, A.M.I.Mech.E., M.I.P.E. F.{Mr Friese} G.{Mr Griffiths - Chief Accountant / Mr Gnapp} MATRAVERS, M.A. (CANTAB), A.M.I.Mech.E., A.M.I.E.E., M.I.A.E., M.I.P.E. O.{Mr Oldham} CARLTON SMITH, M.A. (CANTAB), F.I.S.A., M.I.P.E., Secretary. ALFRED SLATTER, M.I.E.E. J.{Mr Johnson W.M.} W. HAZEL, F.I.S.A. Your Ref: Hs{Lord Ernest Hives - Chair}/Hdy.{William Hardy}5/MJ Our Ref. PGM/AGS/CB. Head Offices, Works and Design Dept.: DALLOW ROAD, LUTON. 1st. November, 1934. Messrs. Rolls-Royce Ltd., Experimental Department, DERBY. Dear Sirs, For the attention of Mr. Hardy. We are in receipt of your favor of the 31st October reference as above, this letter being in connection with the L7 Marles Steering, a sample of which we had the pleasure of supplying to you some time ago. As regards the question of increasing the drop arm movement in these gears, we are afraid that it would be a very difficult matter to do this, as it would involve the diameter and length of the cam, as also the steering box casting. We can, however, supply you with a Cam giving the same 65° rockershaft movement and taking 3 1/4 turns to effect this, this latter number of turns being in fact one of our standard gear ratios which we fit in this steering. If you will be good enough to return the gear to us we will fit the lower ratio cam in the place of the one already fitted, this new ratio naturally involving a lower helix angle. As regards the efficiency of the gear, the average gear, with the ratio already supplied in the box, when run in reaches a figure of approximately 72 to 75%. It certainly will not reach the figure of 85 to 90%, as the design of the gear is such to deliberately cut the efficiency down, as we find this is the highest efficiency which is practicable with the ordinary lay out of steering linkage. - 1 - | ||