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).
Proposed modifications to the Wraith III Main Switch, RR.Sch.1077.
| Identifier | ExFiles\Box 168a\2\ img325 | |
| Date | 1st June 1937 | |
| To RHC{R. H. Coverley - Production Engineer}, Mr. [obscured] c.c. Rm{William Robotham - Chief Engineer}/Wst. [Handwritten] R.C. Please investigate 6139 BY/RD.6/B.1.6.37. Wraith III - Main Switch - RR.Sch.1077. Referring to RHC{R. H. Coverley - Production Engineer}/JS.{Mr Johnson's Secretary}6/MJ.8.5.37., and dealing with the points in the order stated :- (1) This .004 air gap is apparently a misunderstanding and our drawing and the test specification do not agree, but Rm{William Robotham - Chief Engineer}/Wst., has agreed to give us a large limit on this figure, and in this case, the fitting which is now done will be eliminated. (2) & (3) With regard to the deletion of the carbon contacts we believe an experimental switch has been made with solid copper contacts, and if Rm{William Robotham - Chief Engineer}/Wst., can assure us that it is satisfactory, then we can incorporate them in the revised design. There is no doubt that carbon contacts with laminated main contacts are the right thing, but may be too elaborate for the particular job in question. (4) We have no objection to the non-inductive resistance wire being wound on the core, and we suggest that RHC{R. H. Coverley - Production Engineer}/JS.{Mr Johnson's Secretary}, does a little experimenting with both methods in order to determine which is the more economical. (5) Copper will certainly have to be used if we delete the carbon contacts. If these modifications take place, the unit will become considerably smaller, and it may be possible to build it into the starter motor itself. BY/RD. | ||