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).
Road spring prices and manufacturing methods for the Phantom I and Phantom II.
| Identifier | ExFiles\Box 16\7\ Scan197 | |
| Date | 19th October 1929 | |
| Copy. To Wor.{Arthur Wormald - General Works Manager} from RHC.{R. H. Coverley - Production Engineer} RE ROAD SPRING PRICES AND MANUFACTURING METHODS. With reference to the conference you intend to call early next week to discuss the spring costs and manufacturing methods, we outline below some points for discussion. The Phantom II price which we have recommended in our recent report on visit to Firth's, shews an increase over Phantom I. of 50%. The reason for this is the increased amount of machining called for in our latest spring specification. We do not consider that any appreciable reduction in price can be obtained by further investigation of present operation methods and general handling of springs by Firth's, our only hope of reducing this figure is to review the present manufacturing requirements. We do, however, understand that in order to arrive at certain price reduction, it has been decided to delete grinding on all spring leaves except the main leaves, but we doubt that any cut in price will be effected by this alteration. We discussed this point with Mr. Fawcett and he considered that distortion of plates would be such during the bending operation, that fitting times would be increased, and absorb the reduction in price brought about by the deletion of grinding plates. This distortion is due to skin tension of rolled material which in the case of ground plates is removed. Phantom I Road Springs were built up with rolled material which has .006" concavity on each side, consequently there was less risk of leaves distorting during bending operation, chiefly owing to the slight variance in section. If distortion did take place, it was provided for by the concavity referred to. Very little difficulty is experienced, and the time taken for the setting and fitting up of springs with this material is greatly reduced. Therefore, the most hopeful solution and one which would bring about the greatest reduction in price would be to revert to this type of spring leves, maintaining the present main plate machined all over, with the improved lubricating scheme and cadmium plating, and the fitting of anchor plates to spring leaves before cadmium plating, which will reduce the fitting cost for spring clips. There is another question which will arise and that is the price of replace springs to customers:- contd: | ||