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).
Gap measurements for an automatic main switch and auxiliary switch.
| Identifier | ExFiles\Box 64\3\ scan0012 | |
| Date | 9th October 1924 | |
| X.8650 EFC. X.8650. AUTOMATIC SWITCH. E.A.C.II. Following our conversation and the suggestion by you to increase the length of the poles on the above switch, to reduce the gap, - below we give you a list of the gaps as should be produced by the parts made to drawing :- MAIN SWITCH. Position. Gap on Core Stop. Copper Gap. Carbon Gap. Off. .070 .108 .100 Carbon in contact. .025 .025 - Copper in contact. - - - Laminated Brush deflected. .012 AUXILIARY SWITCH. Position. Gap on Upper Contact. Gap at Armature Coil. Gap on Lower Contact. Gap at Carbons. Off. - .093 .071 - Carbons in contact. .016 .077 .043 - On. .040 .053 - .054 You will notice on the Main Switch the Gap on Core Stop distance is .070, whereas in your specification of test of the present standard Main Switch the distance called for is .078. There is a difference, however, in the Armature Stop which on the standard switch is .025 thick, and on this new Automatic Switch is .050. In view of this point, we shall hold up the producing of the poles in the Works, whilst you are testing out the suggestion of a Distance Washer underneath the pole and coil to raise same. It might be advisable to hand a copy of these gaps to Mr. Coverley for him to check by as he builds, and we send an extra copy herewith for that purpose. BY/RD. | ||