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).
Test report on a rubber impregnated canvas disc, detailing torque versus relative movement.
| Identifier | ExFiles\Box 140\3\ scan0017 | |
| Date | 16th January 1925 | |
| The Sheffield Testing Works Ld. Telegraphic Address. TENSILE, SHEFFIELD Telephone No. 3871 (Central). M.{Mr Moon / Mr Moore} S REPORT No. 27853. BLONK STREET SHEFFIELD. 16th January 1925. The following are the results of a test applied to one "Rubber Impregnated Canvas Disc", received 6th January 1925, from Messrs. J.{Mr Johnson W.M.} & A.{Mr Adams} Hillman Limited. - SKETCH OF DISC. - Steel plates at each end of the 6 bolt holes. Each pair of plates being rivetted together with 4 rivets. - METHOD OF TESTING. - Two tools were made as shown in the sketch, and these were coupled together by the disc as when in use on, a motor car. The square shank of one of the tools was held in the testing machine, and a torque applied by means of the square shank on the other tool. It was found necessary to make the 3/4" dia: bolts of special steel, and Nickel Crome steel (heat treated to a tensile strength of 100 tons per square inch) was used for the tests. As the torque was gradually increased, the radial movement of one flange relative to the other flange was measured. Test No A.421. Disc marked:- HILLMAN PATENT 205086, HILLMAN DUDLEY TABLE DATA: Torque, in inch pounds | Relative movement between the two flanges in degrees. 168 | Zero 840 | 1 1680 | 1 3/4 2520 | 2 3/4 3360 | 4 4200 | 5 1/4 5040 | 6 3/4 5880 | 8 1/4 6720 | 9 1/2 7560 | 10 3/4 8400 | 11 3/4 10080 | 13 11760 | 14 1/2 13440 | 16 15120 | 17 16800 | 18 18480 | 18 3/4 20160 | 20 21840 | 20 3/4 23520 | 21 3/4 25200 | 22 3/4 26880 | 24 1/4 Remarks: The test was stopped when the torque had reached 26880 inch pounds (which at 1000 r.p.m. = 426 Horse power) as at this load the disc was so distorted as to allow the lugs of one flange to nearly touch the nuts on the bolts of the other flange. The disc showed no signs of fracture, but was permanently distorted after test and all the bolt holes in the disc showed signs of having elongated under stress. Messrs. J.{Mr Johnson W.M.} & A.{Mr Adams} Hillman Limited. | ||