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).
Magnetically controlled bypass valve for a shock damper system.
| Identifier | ExFiles\Box 105\3\ scan0236 | |
| Date | 7th March 1932 | |
| X5820 For Files. Hs.{Lord Ernest Hives - Chair}552 MAGNETICALLY CONTROLLED BYPASS VALVE. SHOCK DAMPER. In the original scheme - Hs.{Lord Ernest Hives - Chair}427, each damper required individual operation, also it was necessary to stop the car each time it was desired to either open or close the leaks. Later, "André" dashboard controls were adapted, one control operating the front and another the rear damper leaks. With this method of operation however, the time element is so large that it is possible to overrun a rough section of a road before the valves can be closed. Also the driver's attention is partially diverted from the road during the operation. The magnetically operated bypass valve overcomes both the above failings, since all four dampers can be operated by one switch, or if preferred, two switches, one for the front, and another for the rear pair of dampers. An experimental model adaptable to 20/25HP rear dampers was tried on the test rig, and diagrams taken of high pressure or rebound pressures, with 1" and 4" ball pin movements. With a .062" diameter bypass, air gaps, or valve lifts, of .030" and .050" were tested. The diagrams show that from a mechanical point of view there is not a great deal to choose between .030" and .050" air gaps, whilst from an electrical point of view the .030" gap has a distinct advantage, since it permits the use of a higher initial return spring load, thus allowing higher ball pin loads to be used without affecting the bypass valve. Alternatively, for the same stable ball pin loads as were used for these tests (i.e. 140/140 lb) it may be possible to reduce the size of the solenoid, and incidentally the current consumption. During these tests the opening of the valve was controlled solely by the solenoid, the bypass valve being lifted without the assistance of any internal damping pressure. By utilizing some of the pressure in the main cylinders it may be possible to reduce the size of the coil, - incidentally the consumption - whilst still maintaining a return spring load sufficiently high to close the valve against the maximum internal pressure produced by the required ball pin loads. | ||