Modifications to the Wraith II rear brakes based on experience with the first car.
| Identifier | ExFiles\Box 7\7\ X 606 Brakes-page043 | |
| Date | 1st March 1937 | |
| SECRET. AFM {Anthony F. Martindale} Parthen 606 BY: C.W. Br. {T. E. Bellringer - Repair Manager} Fm. HPS. {Horace Percy Smith - Experimental Factory Mgr} Wraith II Rear Brakes. We send herewith N.Sch.5044 showing modifications which have been suggested as the result of experience with the first car. The principal modifications are as follows:- (1) Shoe pull off springs of increased resilience are provided. The two springs are alike and their fixings are also now alike. (2) The shoes have raised bosses as required for riveting of the hollow rivets. (3) Brake rope jaws and hexagon headed bolts to the new standards are shown. An economy is made by the provision of only three fitting bolts for securing the brake carrier plates to the flange on the axle. These bolts are .250 diameter. The remaining seven bolts are .312 dia. in .3437 holes. (4) The brake camshaft is to have .025 endwise clearance, that is .0125 each side of the designed position. We are prepared to accept a carrier plate variation which may reduce the clearance almost to nothing or increase the clearance to a total of .050. We think that if necessary this can be increased beyond .050, but we consider this is a reasonable allowance for manufacturing variation. (5) The adjustment levers are modified so that the pin in the fork, and therefore the adjustment pieces can be removed more readily. The adjustment rod is now made from square bar. (6) The eye of the camshaft lever for the brake rope fork is not bushed but must now be hardened. This lever is already hardened for needle roller bearings elsewhere. (7) The oil spout on the aluminium carrier plate projects less from the plate in order to enable the brake rope | ||
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).