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).
Modifications to the Phantom III brake system.
| Identifier | ExFiles\Box 92\4\ scan0332 | |
| Date | 10th May 1937 | |
| AFM{Anthony F. Martindale} Have we fitted this document? File Dr. C:L.Ds.Jnr.{Charles L. Jenner} HPS.{Horace Percy Smith - Experimental Factory Mgr}FMS/Cy. E/HDY.{William Hardy}2/HP.10.5.37. Phantom III Brakes. 306 We send herewith N.Sch.5141 showing modifications to remedy the trouble complained of in Rm{William Robotham - Chief Engineer}/GWH.{George W. Hancock - Head Chateauroux}/24.3.37 that the hand and foot brake shoes interfere with one another due to the clearance between them being insufficient to allow for the spreading of the friction linings. The suggestions we now show have been made by RHC{R. H. Coverley - Production Engineer}/Cy and are referred to in RHC{R. H. Coverley - Production Engineer}/Cy.2/1S.29.4.37. The principal alteration is that the foot brake shoe is moved towards the dust guard .075. The designed clearance between the shoes becomes .150 instead of .075. The toggles are offset at the cam end and to permit of this the cam operating lever must be set sideways. If there are many existing levers they can be bent but we prefer that a new forging is made with increased width as shown. A new forging is required for the boss at the heel of the shoe as this now has an extension to give more rigidity to the lateral control of the shoe. We show rivets for securing the shoe to the boss as it is now thought that as stretching has to be done even with bolts, the use of riveting may only mean that the amount of stretching is increased somewhat. We show the shoe pull off spring at the toe end changed over to the opposite side from the spring at the heel end, which is unaltered. It is necessary to slightly shorten the coils of the pull off spring to clear the spring to the cam lever. The pin in the shoe for the toe pull off spring is now the same as for the lever pull off spring. if it is found to project too much for convenient riveting over, we suggest reducing as required and reducing the boss on the cam lever to agree. The pin at the junction of the toggle link and the shoe has been modified to reduce cost. p/umv | ||