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).
Confidential internal memorandum discussing the patent implications of using a plate clutch for a servo mechanism, compared to Hispano and Renault designs.
| Identifier | ExFiles\Box 22\1\ Scan183 | |
| Date | 23th June 1924 | |
| 4214 To BY.{R.W. Bailey - Chief Engineer} and Mr. Claremont. From R.{Sir Henry Royce} c. to CJ. BJ. RG.{Mr Rowledge} DA.{Bernard Day - Chassis Design} E.{Mr Elliott - Chief Engineer} Hs.{Lord Ernest Hives - Chair} SECRET. RL/M23.6.24. E.{Mr Elliott - Chief Engineer} A.{Mr Adams} C. PLATE CLUTCH FOR SERVO. X.1013. RE. RENAULT. X.9910 X.4214 I cannot see that the substituting of the well known plate clutch and spiral key operation for the shoe type of clutch in the Hispano combination constituted an invention, and would enable Renault to escape Hispano or give them a master patent to prevent anyone else using a plate clutch (single or multiple) in a servo combination which was not the same as theirs or Hispano (This applies to both plate clutch and spiral yet operating device.) In our adopted scheme we do not use the same combination as Renault. Renault is exactly Hispano with other well known parts. Our description would not follow Renault. We do not use spiral keys, but face cams. These do not transmit the torque to the servo but from one lever to another. Again, supposing when Hispano (Y) patented their combination the plate clutch was not invented, but was subsequently invented by a person X, could Renault look at X's patent, and rush off and protect its use in Y's combination, and so prevent the original inventor X, using his own invention (patented) on his friend Y's combination of mechanism constituting a machine or device. (Built any complete machine you like, complex or simple, and then apply my argument, and I do not think Renault would stand.) I say that substituting a known mechanism for another does not constitute an invention any more than in this case another form of free-wheel would. Renault functions exactly as Hispano. The RR. brake scheme is different. It has no free-wheel, the foot force does not go to the servo, but from one lever on to another, on the back brakes only. RR. had I believeplate clutch servo drawn for semi-servo system, and about their Works( but not published) long before the date of Renault's patent. Our detail functioning is patentable. If necessary we could make our plate clutch double flat cone. | ||