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).
Proposal for a suggested sheet metal body stiffener for a 20 HP vehicle.
| Identifier | ExFiles\Box 41\3\ Scan373 | |
| Date | 29th September 1923 | |
| To BY.{R.W. Bailey - Chief Engineer} from Da.{Bernard Day - Chassis Design} c. to CJ. LHS.{Lord Herbert Scott} HS.{Lord Ernest Hives - Chair} X.3730 Dal/M29.9.23. GE. SUGGESTED BODY STIFFENER - 20 HP. X.3730 We send herewith N.sch.1461. shewing a sheet metal channel for stiffening the bottom runner of the body, two of which we would like Derby to make up for us as soon as possible. At first we propose to mount the body on four brackets (two either side) positioned as shewn. Taking the maximum body load of 2000 lbs. as somewhat uniformly distributed along these channels supported in this fashion the deflection at the centre is just under .060". Since the value of E.{Mr Elliott - Chief Engineer} for wood is only one eighteenth that of steel the wooden runner adds very little stiffness to the entire section and can be thinned down to as small a dimension as the coachbuilders can permit of for constructional reasons. The body is bolted directly to the brackets at the rear but on the forward brackets it rests on rubber blocks being held down by a coachbolt and spring. We think this spring should give a load of about 100 lbs. but suggest that this is a matter for experiment. By so mounting the body we relieve it of all the deflections of the main frame, which the road continually varies. The second advantage we gain is that the body is only rigid attached to the chassis at the extreme rear end as remote as possible from the centre of engine vibrations. This is an advantage over the Daimler system. The weight of each channel is about 16 lbs. The amount of weight saved by the reduced number of brackets, lighter runners, and lighter ironing of the body will quite compensate for this. In any case the added weight will not exceed the weight of tie-bars if they were fitted. Lastly we would point out that this scheme would enable bodies to be lifted on and off the chassis without breaking their backs, of which there is always considerable danger. If Derby will kindly proceed to make these pieces we will take the matter up in a few days with Sales and the coach-builders, and endeavour to find a car on which these can be lifted. This car should preferably be a cabriolet. We believe Messrs. Barkers would be pleased to fit up the pieces on a car for us. In any case we will let you know what you should do with the parts. Please send LHS.{Lord Herbert Scott} a print of the drawing. DA.{Bernard Day - Chassis Design} | ||