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).
Mr. Royce's suggestion for a taper reamer design.
| Identifier | WestWitteringFiles\E\June1920\ Scan18 | |
| Date | 14th June 1920 | |
| To WS. from E.{Mr Elliott - Chief Engineer} Copy to C.J. " WOR.{Arthur Wormald - General Works Manager} " BY.{R.W. Bailey - Chief Engineer} " EFC. ORIGINAL X.4143 RE TAPER REAMER. RECEIVED In accordance with Mr. Royce's wishes I send you as follows, a suggestion which he has made for a taper reamer. The idea is to use a reamer with flutes having a quick left hand spiral threaded with a slow right hand thread. The objects in view are to limit the rate of feed to a predetermined amount so that the reamer cannot be jammed, and to break up the cut. The form of hole produced would be stepped thus - the number of steps per inch being the same as the number of threads per inch. It is not entirely correct to speak of the reamer as threaded, as the teeth or lands on each lip would require to be backed off. Mr. Royce suggests using four flutes for .5" diameter with the lips a little unevenly spaced to avoid chattering. The teeth on any one lip should be level with the teeth on any other lip, and they will constitute a four start thread; thus each collar of the stepped taper hole will be attacked simultaneously by four cutting edges, and any excessive end pressure applied to the reamer will be carried by the lands bearing on the end surfaces produced by the teeth themselves in the taper hole. The spiral on the teeth should be equivalent to that of a single thread of 100 per inch. The teeth should be of the Sellers form made with parallel tops, as per sketch. The width of the tops should be at least greater than the pitch of the thread divided by the number of lips on the reamer, so that each tooth will take a cut wide enough for the rate of feed, and will not cut itself in. (Contd.) | ||