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).
The design and cost reduction of a one-piece starting handle for the Wraith III model.
| Identifier | ExFiles\Box 148\5\ scan0149 | |
| Date | 13th March 1937 | |
| SECRET. 1260 To B.Y. Copy to Dr. Rm.{William Robotham - Chief Engineer} Mr. HPS.{Horace Percy Smith - Experimental Factory Mgr} E/PSN.1/MN.13.3.37. WRAITH III. One Piece Starting Handle to Reduce Cost. We send you herewith LeC.5563 of a one-piece starting handle for Wraith II. The factory cost of the Wraith II handle with 175% charges is 19.8/- and we consider that it should be possible to produce the new handle for about 5/-. The release spring has been deleted and the dogs are centred by an extension on the handle locating direct in the starting dog cap on the end of the crank, thus obviating the use of the Separate bearing carried on a pressing bolted to the wheelcase. The material of the dogs has been altered from 5% case hardening nickel to air hardening nickel chrome with the object of avoiding the chipping of the corners of the dogs which owing to their small size are hard right through. Note that the dogs have been strengthened by an alteration to the tooth angle. The starting dog cap has been made in two pieces so that the dogs only need to be made in nickel chrome steel. The handle has been made of drawn aluminium bar and no external machining is required. Tests which have been made on bending the tube indicate that no difficulty will be experienced if it is bent hot. The clearance at the front bearing has been increased and we estimate that there should be no difficulty in fitting the handle with the engine crankshaft centreline 1/4" out in any direction. We should be pleased if you would detail and instruct a sample handle to be made as soon as possible as we have yet to fix up a place to stow the handle under the bonnet. The alternative handle should not be detailed. We also have under consideration the trap in the shutters, instructions for which will be issued shortly. E/PSN. Att:LeC.5563. Print to Mx.{John H Maddocks - Chief Proving Officer}and HPS.{Horace Percy Smith - Experimental Factory Mgr} | ||