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).
Technical analysis of spring plate and clip design, discussing forces, wear, and potential improvements.
| Identifier | ExFiles\Box 80\2\ scan0142 | |
| Date | 3rd May 1920 | |
| (2). DAL/CB3-5-20. chamfered edges, and are made so that the plates have the same curvature throughout. It is understood that the tendency to squeak is not nearly so pronounced as at present, and they, as a matter of fact, give very good service on 7CA. In view of this it is suggested that for immediate purposes we might slightly increase the width of the sheared end of the present leaves and possibly taper them slightly in elevation, and that with more correct manufacture than at present, the existing springs will be quite serviceable The material is in such a condition as to allow of these changes almost at once. We make out that the actions taking place on the clip are as follows:- (1). Two opposing forces tend to burst the clip putting tension in the bottom bolt and top bar. (2). Because these forces, though equal in moment, are not necessarily opposite, there is a moment tending to rotate the whole clip round. This is opposed by a moment between the corner of the clip and the holding-down stud, thus tending to break the latter. (3). When one wheel rises, the spring plates are twisted about an axis through their centre of area. If they fit the clip sideways the clip will be distorted, and therefore it appears as though the plate sides should be cylindrical. They are nearly so now. But it appears that if we had a spherical bolt to hold the clip, the opposing moment mentioned in (2) would not be available, or would be badly applied. This twisting also tends to hold up the centre holding-down bolt. Contd. | ||