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).
Preliminary examination of an American Bosch ignition coil and distributor fitted to a chassis in America.
| Identifier | ExFiles\Box 61b\4\ scan0100 | |
| Date | 25th October 1926 | |
| EFC. WB.{Mr Brazier/Mr Bell}108. 25.10.26. COPY. X.4275. AMERICAN BOSCH IGNITION COIL AND DISTRIBUTOR AS FITTED TO RR.CHASSIS IN AMERICA. PRELIMINARY EXAMINATION. This unit as received consisted of two ignition coils and two distributors mounted side by side on an aluminium casting, the drive for both being taken from an intermediate gear wheel secured to the main driving shaft. For convenience the main features of interest, from a preliminary examination, are tabulated below:- (1) Contact breaker lever insulated and screw earthed. (2) Contact points flat. (3) Contact lever spring has small rating and large set, the load on the points being 1 lb.2 oz. (4) The condenser is soldered to the case and is also connected with a minimum of joints to the lever. (5) Contact points are offset from the line of the cam profile. (6) Distributor has sparking points of brass and they are inserted flush with the distributor head moulding, the H.T. distributing rotor being moulded with a cowl which covers the contact breaker unit. (7) Unique cam design, the cam sliding freely on the driving spindle and coupled direct to the governor weights on the automatic advance mechanism, being secured to the main shaft by a spring ring. (8) Long plain bearing (cast iron) supports the whole drive, and is wick lubricated. The whole unit is compact and finished off remarkably well, everything being easily detachable, and designed evidently with a view to providing the minimum amount of attention. Battery ignition is almost universal | ||