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).
Method for measuring high-speed steering wobbles using a chronograph and electrical contacts.
| Identifier | ExFiles\Box 29\1\ Scan234 | |
| Date | 22th July 1926 | |
| To R, from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} THE MEASUREMENT OF HIGH SPEED STEERING WOBBLES BY MEANS OF THE CHRONOGRAPH. High speed steering wobbles are a typical instance of a case where the chronograph can be used successfully to obtain information. An electrical contact is fixed on the pivot of the car so that when the wheel turns through an appreciable angle about the stub axle from its central position, an electrical circuit is completed. A second electrical contact is fixed to the wheel and is actuated once per wheel revolution. When a high speed wobble occurs, the contact on the pivot records the number of wobbles per second, the contact on the wheel the number of wheel revs. per second, and so the road speeds in m.p.h. The relation between the point on the record where the wobble occurs and the contact on the wheel gives direct indication of whether any particular factor on the wheel, such as out-of-balance, is in the same position at the same instant at any particular point in the cycle of the wobble. From the attached record it will be seen that the in and out motion of the wheel keeps substantially in step with its rotary motion. The amplitude of the wobble can be measured by arranging the electrical contact on the pivot to "make" when the wheel has turned through any required angle. Thus high speed wobbles under any conditions can more or less be compared for intensity. Contd. | ||