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 Hardy Spicer & Co. regarding a proposed change from 1300 to 1350 series splines and a discrepancy in Rockwell hardness tests.
| Identifier | ExFiles\Box 148\4\ scan0093 | |
| Date | 16th November 1938 | |
| 1262 HARDY SPICER & CO. LIMITED. TELEPHONE BIRCHFIELDS 4504-9. 6 LINES TELEGRAMS & CABLES AUTOJOINTS BIRMINGHAM CODE BENTLEY'S PHRAZE LONDON OFFICE 44-45 THOMAS STREET LONDON S.E.1 TELEPHONE HOP 0703 Manufacturers of HARDY SPICER UNIVERSAL JOINTS AND PROPELLER SHAFTS . GENUINE HARDY FLEXIBLE COUPLINGS . BRITISH BOUND BROOK OIL-LESS & COMPO OIL-RETAINING BEARINGS ALL COMMUNICATIONS TO BE ADDRESSED TO THE COMPANY Registered Office and Works BIRCH ROAD . WITTON BIRMINGHAM . 6 ENGLAND OUR REF JAD.MW YOUR REF Rm.{William Robotham - Chief Engineer}Gry.{Shadwell Grylls}7/MH{M. Huckerby} 16th November, 1938. Rolls Royce Limited. D E R B Y. Attention of Mr.Grylls, Dear Mr.Grylls, In dealing with the proposed change from the 1300 series to the 1350 series we can easily use the existing male spline because the diameter of a spline of 1350 is the same but in the 1350 series the teeth are longer. However, as this is a conversion and you have not so far experienced trouble with splines, we are proposing to use the splines from the shafts in stock so that the conversion will be made by removing the fixed joint and fitting in the 1350 in its place and fitting the 1350 sliding joint on to the existing splines. There is one other point and that is that we prefer the round flanges on account of the smoother operation but we realise the difficulty you are in regarding the frame. We have made an experiment with the size of hole 4 1/8" that exists in your steel sheet which, bent to the right curve, requires two slots of perhaps 1" wide, only 1/4" deep at the top and bottom of the hole. The joint can then be manoeuvred through this without doing any work on the remaining part of the hole. We are returning herewith two pieces of the journal which the writer brought away, which were alleged to read 55 Rockwell. We have re-tested these here and are not in agreement, the minimum reading being 59. An explanation of the difference would be either in the actual security of the device holding the piece or something like it. We are returning them herewith for your further check. -1- | ||