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).
Evaluating the Buckley Patent Adjustable Tappets.
| Identifier | ExFiles\Box 158\4\ scan0023 | |
| Date | 20th March 1935 | |
| W/S - Db.{Donald Bastow - Suspensions} C. to Wor{Arthur Wormald - General Works Manager}: + 1157 Hs{Lord Ernest Hives - Chair}/Smth.19/KW.20.3.35. The Buckley Patent Adjustable Tappets. Re Db.{Donald Bastow - Suspensions}21/JL.18.3.35. We have examined the drawing of this device and have come to the conclusion that :- (1) It does not provide any automatic adjustment of tappet clearance. (2) It would be noisier than normal valve gear. (3) It would aggravate the wear of the bottom tappet. Our reasons for these conclusions are as under :- (1) At the commencement of the valve opening operation the valve will not move until the inner spring washer is choc-a-bloc, since the outer spring washer is stronger than the inner. The distances through which the bottom tappet would move before this occurred would depend on the amount of wear and stretch which had taken place in the valve gear. The device does not therefore provide an automatic adjustment to maintain a constant equivalent tappet clearance. (2) Until one of the spring washers is choc-a-bloc, the controlling force on the valve is the difference of the spring washer loadings. This would be quite inadequate to provide the necessary accelerations and decelerations of the valve and noise would occur as the spring washers became choc-a-bloc or as the cotters clashed against the end of the slots. Similarly the closing toe of the cam would be quite ineffective in reducing the noise as the valve seated. (3) Practically the whole of the valve spring loading is continually applied to the cam follower, which would cause rapid wear of this part. There are many other criticisms which concern the assembly and durability of the device. Hs{Lord Ernest Hives - Chair}/Smth. | ||