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).
Meeting notes on rear spring deflection, Packard-type suspension investigation, and turning circle calculations.
| Identifier | ExFiles\Box 100\1\ scan0093 | |
| Date | 25th February 1938 | |
| -2- Da{Bernard Day - Chassis Design}/DB.{Donald Bastow - Suspensions}3/N.25.2.38 Cont'd.{John DeLooze - Company Secretary} (4) Rear springs of the required static deflection have in the past been obtained merely by ordering from the spring maker. (5) Conference decision was to investigate design of Packard type suspension incorporating the following features:- Increased ground clearance. More room for spring and hence reduced spring stress. Girling or RR. brakes - the latter only if Girling could not be fitted in. Packard wheel movements for bump and rebound. Out of centre distance between pivot centre and wheel centre at road to be less than 2.25". Clearance for 5.00 - 16.00 rims and 7.000 section tyres. Wider brake drums of cast iron. Pressed steel bolt on wheels could be used if found necessary to accommodate the wider drum, otherwise an investigation into the possibility of spoking from one side only of the rim could be made. Front track to be 57.00". This investigation has been started. (6) Retention of 2.125" out of centre point at ground with provision for the 7.00" section tyre on 5.00" rim of B.50 implies reduction of the lock angle of the outside wheel from 32° to 28½° for the "standard" lock angle of inside wheel of 41°. This has the effect of increasing the turning circle diameter by an amount of 2 ft. to 4 ft. depending on the speed, the higher the speed the greater the increase in turning circle diameter, since the effect of taking the cross steering ball joints further away from the wheel is to reduce the lock angle of the outside wheel on a corner, and increased speed obviously throws more weight on to the outside wheel. The best turning circle for B.III with 41° lock on the inside wheel is 39 ft. diameter, and for B.50 with the same lock 40½ ft. (with 32° lock of outside wheel). Cont'd.{John DeLooze - Company Secretary} | ||