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).
Tests and proposed improvements for internal support for side spare wheel carriers.
| Identifier | ExFiles\Box 179\2\ img091 | |
| Date | 13th March 1931 | |
| ORIGINAL From Hs{Lord Ernest Hives - Chair}/Les.{Ivan A. Leslie} To R.{Sir Henry Royce} DA{Bernard Day - Chassis Design}/EV.{Ivan Evernden - coachwork} Hs{Lord Ernest Hives - Chair}/Les.3/MA.30.13.31. X/600 x5b00 INTERNAL SUPPORT FOR SIDE SPARE WHEEL CARRIERS. 25 HP. N.S.3358 effected a large reduction of the movement of the side spare wheels on the bumper chassis. On the road this scheme is not rigid enough. By applying a force of 45 lbs at the top of the wheel we have measured the deflections of the various parts on the bumper chassis. 4% of the deflection takes place in the carrier brackets themselves. As these brackets have previously given satisfaction, we have investigated the movement of the frame relative to the dash. When the stiffness in the frame is bolted to the dash as shown on N.S.3358 as an alternative, no advantage is gained by the diagonal tubes. Fig.1 show the alterations made to reduce the frame movement by 60%. The brackets themselves now have a greater deflection than the frame. We shall try this improvement on the road in the immediate future. The external connection between the dash and the frame marked Y on Fig.1 reduces the frame movement by 29%. We have taken similar deflection test with the Derby scheme R.R.Sch.124. This is no better than N.S.3358 a large deflection was found between the bottom of the dash and the top of the frame. This would be eliminated by bracket Y in Fig. 1. Also a local frame deflection was found between the bottom bolt of the carrier bracket and the lower outside edge of the frame. This would be reduced by distance pieces to fill in the box section. F.2. No scheme has been tried on the road for F.2. The only scheme we have for F.2. that could be used for production is R.R.Sch.138. This is similar to R.R.Sch.124. From deflection tests this is no better than the experimental sch. to Rt.6819 and Rt.6954, which we previously reported to be satisfactory on the bumper chassis. We have only one F.2. car with side spare wheel carriers, and this car is now being connected to diamond engine mounting, R.R.Sch.138 is being fitted to this car. | ||