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).
The testing and operation of the Humphrey Sandburg clutch fitted to a Lea-Francis car.
| Identifier | ExFiles\Box 6\2\ 02-page013 | |
| Date | 15th January 1927 | |
| S/W. Hs.{Lord Ernest Hives - Chair} Copy to:- PM. HUMPHREY SANDBURG CLUTCH. I was given the opportunity this morning to test the working of the above clutch fitted to a Lea, Francis car and found its action most interesting. You will be aware of this clutch which I believe so far it has been proposed to fit to one of the gears of each pair in the gear box, but in this car it was fitted to the transmission immediately behind the gear box, the gear box being of normal construction. A single clutch only was fitted driving ahead and as this would give no reverse drive a separate control was fitted for reverse of the nature of a dog clutch, which supressed the action of the Humphrey clutch. Certainly for gear changing under any conditions, the operation of this clutch enables a change to be made up or down quite silently. The operation is as follows:- On wishing to change gear, either up or down, the accelerator pedal is released and the main engine clutch is put full out. There is a speed indicator driven off the primary shaft of the gear box which under these circumstances, owing to its small inertia and the damping of the gear-oil very rapidly comes to rest. As soon as it is at rest the gear lever is quickly moved to the new position desired and the accelerator pedal again depressed. The engine accelerates until it reaches the car speed, the car having been free wheeling up to this point when the drive is taken up without any appreciable shock. I am sure you would be interested in the operation of this device and I have arranged to see a Buick car some day next week which is fitted with it in a more developed form. Perhaps you would like to see this and test it yourself, or would wish one of your assistants to do so. If so, would you kindly let me know. CWB. | ||