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).
Design, lubrication method, and advantages of a 'Kennedy Spring' model.
| Identifier | ExFiles\Box 154\1\ scan0007 | |
| Date | 24th December 1925 | |
| X.2628. To Hs.{Lord Ernest Hives - Chair} from E.{Mr Elliott - Chief Engineer} c. to CJ. DA.{Bernard Day - Chassis Design} RE. KENNEDY SPRING. We are sending you a model of the above which has been lent to us by the inventor. The spring bolt is drilled axially and also has a cross hole so that grease fed in from the greaser (form on the spring bolt unit) will pass into two grooves broached in the spring bolt holes. These grooves are in line with the length of the spring so as not to weaken the section in the middle of the leaves. The grooves also serve to engage snugs formed under the spring bolt head to prevent the latter from turning. Brass interleaving is provided having holes punched in along the length, and the necks between the holes reduced in thickness so that oil or grease may be forced from the spring bolt oilways along the length of the spring between all the working faces. The interleaving is definitely cut away to form a groove between the oilways and the nearest punched holes. Tabs are provided on the interleaves looking both upwards and downwards to engage the working leaves of the spring and maintain correct position. These tabs might be unnecessary as in any case spring clips would be required to enable the spring to take torque and to provide a sufficiently effective side control for the leaves. The advantages of this proposal are that there is only one lubrication point instead of four per spring, and it is not necessary to enclose the spring in a leather case along its length, although the protection of the shackles might require leather stockings on the ends. It would of course be necessary to provide a different method of feeding the grease at the centre to avoid damage from the bumpers, but there are a number of ways whereby the oilway could be brought out sideways to an Enots nipple. Mr. Royce has stated that he would like you to try out this method of spring lubrication at Derby. We are passing the model to DA.{Bernard Day - Chassis Design} for his inspection and opinion, after which we shall forward it to you. E.{Mr Elliott - Chief Engineer} | ||