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).
Proposals for rear road springs for the Goshawk II.
| Identifier | ExFiles\Box 49\3\ Scan020 | |
| Date | 25th January 1921 | |
| H.{Arthur M. Hanbury - Head Complaints} R.{Sir Henry Royce} 285A. (100 T) (S. H.{Arthur M. Hanbury - Head Complaints} 159, 11-8-20) G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 9200 X 426 To R from DA.{Bernard Day - Chassis Design} (Struck through) To EN. Copy to EFC. DA{Bernard Day - Chassis Design}3/CB25-1-21. (Stamp: RECEIVED) (Handwritten in stamp: EFC X426 JAN 26 1922) RE REAR ROAD SPRINGS - GOSHAWK II. We send herewith a print of "N" Scheme 727 showing the proposals for rear road springs. The blades are graded in such a way that the bending moments, are proportional to the modulus of section on each blade, and so the stress should be constant except for any effect due to the encastrement in the middle of the spring, which we are investigating now, but which is a long job to get through. We propose to send these springs to the makers, and if they wish to vary them, to let them do so until we are able to tell them exactly what to do. The clips are those Messrs Woodheads have recently been working on, and appear to make a neat job, and do not break on the bumping rig as do the present clips. We have kept an average stress within 100,000 lbs per square inch with a stress in the master leaf of 91,000. the latter being obtained by limiting the free camber to 1.5". We have drawn the biggest spring but we think that the body loads are on the high side, and that as a matter of fact, the heaviest of these springs will practically never be used. (London specify 10 cwt for six seater covered body on 40/50). The springs, are, of course, rather heavy on account of the great number of blades which is necessary in order to keep the stress down. This is because the curvature is very high The method of grading the overhang has the effect of giving a concave | ||