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).
Technical specifications for the Wraith II rear brakes.
| Identifier | ExFiles\Box 7\7\ X 606 Brakes-page012 | |
| Date | 7th July 1930 | |
| trout (crossed out) Martindale 606 By-Rev.Ho.3/54 Ha/Em. F.W.R. E/HDT.1/HP.7.7.30. Wraith II - Rear Brakes. We send herewith H.Sch.462D which shows the above. The drums are of aluminium with cast iron liners 12" inside diameter. The liner is retained in place by eight pieces dovetailed in the liner and riveted to the drum. The inner disc on the wire wheel must be shaped to give clearance for the rivets. A single pair of aluminium shoes 2.375 wide is provided for each wheel to serve for both foot and hand brakes. They are not provided with anti-squeak shoes. The lining thickness is .375 and the amount of wear provided for at the centre of the shoe is .1875. The cam radius is .4375 and the rope lever radius 6.0. The leverage between the cam and the brake rope is, therefore, 13.7 to 1. The rear brake rope eye is .5" below the centre line of the top leaf of the rear spring. A rubber faced "off" stop is provided at the suggestion of the Experimental Department to avoid a clank when the brakes are released. There is no stop for the camshaft in the "on" direction, but the amount of rotation that can be given to the camshaft is limited, particularly as with the combined hand and foot brake shoes the rear equaliser is to have stops to restrict the equalisation movement. The brake drums are secured to the hubs by parallel fitting bolts retained in place by a stop ring, so that the drums can be removed without removing the hubs. One bolt is displaced to fix the relative position of drum and hub. | ||