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).
Procedure for testing servo efficiency using an apparatus with two spring balances.
| Identifier | ExFiles\Box 178\1\ img096 | |
| Date | 9th July 1924 | |
| TESTING THE SERVO EFFICIENCY. Apparatus for testing the efficiency of the servo can easily be fitted up to work either on the car or on the Gearbox testing rig. It is probably preferable to do the test before mounting the box in the car as any fault is then more easily rectified. The apparatus consists of two maximum reading spring balances, one which reads the pull operating the servo and the other reads the pull from the servo. Prints are attached showing the method of setting up on either the gearbox testing rig or on the car. Drawings of the spring balances used can be obtained. To make the test when the apparatus is mounted on the car it is only necessary to brake in the ordinary way and read the pull registered in each of the spring balances. For convenience we take the load registered in spring balance 'B' and divided by the load in balance 'A' as the ratio for comparing the output of servos. This ratio should come within the limits given on the attached drawing. Attached also are curves which show the proportion of braking effort going to the front and the total braking for variations in the servo output. (contd). | ||