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).
Description of the contact breaker, auto-advance mechanism, and distributor assembly.
| Identifier | WestWitteringFiles\U\August1930-November1930\ Scan137 | |
| Date | 20th October 1930 guessed | |
| -3- By removing two screws the whole contact breaker unit can be detached leaving the cam and the auto-advance mechanism in position. A long plain bearing, grease cap lubricated, supports the distributor spindle. The cam is hollow and filled with oil soaked felt. The automatic advance is of particularly simple construction. Two spring loaded masses formed of sheet iron sectors each pivoted at one end move outward under the action of centrifugal force. An extension of the iron sector at the pivot end presses upon and moves along the curved surface of an oval shaped pressing secured to the cam. The cam is therefore advanced relative to the drive when the sectors move outward and the motion is apparently kept proportional to "v" by the radius of the point of contact of the force varying due to the sector extension arm moving along the curved surface of the oval cam disc. The H.T. rotor is a small bakelite moulding with a nickel "brush", the contact between the H.T. terminal on the distributor head being secured by a light spring riveted to the rotor, bearing on a fixed carbon in the head. The H.T. distributor head has brass inserts for the H.T. distributing electrodes, these inserts being carried through the moulding and fitted with spikes on the top. The H.T. wires are located in moulded grooves at the top of the head and contact made by these spikes | ||