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).
Letter from Borg & Beck discussing the Servo type over-center clutch pedal spring and the associated patent situation in the USA.
| Identifier | ExFiles\Box 147\1\ scan0267 | |
| Date | 24th August 1937 | |
| Handwritten (top): By - This appears to give us a clear run in U.S.A. What about this Country Rm{William Robotham - Chief Engineer} BORG & BECK CLUTCH THE STANDARD REG. U.S. PAT. OFF. BORG & BECK DIVISION OF BORG-WARNER CORPORATION Manufacturers of Automotive Clutches Handwritten: 1247 6558 SO. MENARD AVE. CHICAGO - ILLINOIS Tuesday August 24, 1937 Handwritten: Seen by Rm{William Robotham - Chief Engineer} on a Dodge (who fit B+B clutch) Handwritten (Left margin): Patents By NW{N. Walker - Patents} If no patent in U.S.A. we should exploit? we have to be safe we could tag on By Mr. W. A.{Mr Adams} Robotham Rolls-Royce Limited Derby, England Dear Mr. Robotham: It was very kind of you to write us in July regarding your short visit with us in Chicago and we want you to know that we fully enjoyed meeting you and discussing mutual problems, and also hope that you will not overlook us on any future visits to this Country. With further regard to the Servo type clutch pedal spring you have probably gathered from my telegram of August 13 that the patent situation is somewhat indefinite and we are not yet able to give you additional information. As you know, the general type of this over-center spring is very old having been used in a great many different forms; probably the best known in this Country being the door stop by means of which a door is normally kept closed by the spring, but when the door is opened wider than usual the spring goes over-center and holds it open. Last year, this type spring was incorporated in all Oldsmobile cars, but the layout was such that it served the purpose of a hold-back spring on the pedal when clutch was fully engaged, but did not give any appreciable amount of assistance in releasing the clutch. We then took the same type spring and experimented with various installations and found that pedal pressure could be greatly reduced. Of course, Olds have filed patent application on this device as applied to an automobile and General Motors is unwilling to discuss their claims to us and our Patent Department feels that since the broad idea of an over-center spring is old, and also since there are several other types of springs, or combination spring and cam movements, patented as applied to clutch pedals, that it would not be advisable for us to try to cover our contribution which is really more of an analysis. After Oldsmobile came out with this spring in their 1937 cars a number of other manufacturers have experimented with similar installations and particularly at Nash, Studebaker and Chrysler we have given them the benefit of our experience with the result that Nash have adopted Servo springs in the latter part of their 1937 models and will continue to use in the '38 cars. Chrysler and Studebaker have not yet definitely decided to incorporate the spring in their 1938 models as they may possibly use vacuum shifting devices, but the experimental work with both of these customers has been quite satisfactory and all these people have expressed the opinion that they would not regard the patent situation on this device with any fear. | ||