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).
Product leaflet describing the method of use and significance of the R.A.B.R.M. Hardness and Thickness Gauge for Rubber.
| Identifier | ExFiles\Box 93\1\ scan0165 | |
| Date | 27th June 1935 guessed | |
| 4 METHOD OF USE The methods of using the instrument for various purposes are outlined below; detailed instructions are supplied with each instrument. Hardness of Small Specimens or Large Sheets:—The gauge is first adjusted to read zero when the tip of the indenting ball is in the plane of the foot. Once this simple setting has been effected, no further adjustment is needed. The instrument is stood on the glass plate and the rubber sample is placed under the gauge with the foot resting on it; in the case of rubber sheets the glass plate is dispensed with and the instrument stood directly on the rubber. The 1 kg. weight is placed on the loading platform, carried on top of the gauge stem, and at the end of 30 seconds, during which the table is gently tapped, the reading is taken. (See Fig. 1). Hardness of Rubber-Covered Rollers:—The rods having been fixed in the appropriate pair of grooves and the zero of the instrument adjusted, the instrument is placed on the roller with the rods resting on its surface, and the hardness measurement made as above. (See Fig. 2). SECTIONAL DIAGRAM ILLUSTRATING PRINCIPLE OF R.A.B.R.M. THICKNESS GAUGE SCREW FOR ADJUSTING CONE TOE RING THICKNESS DISC TOE RUBBER RING SUPPORTING DISC Fig. 3. Thickness of Tensile Test Rings:— By adjustment of the screw in the upper disc the gauge is set so that when the 3-toed disc rests directly on the supporting disc, both the mm. and .01 mm. scales read zero. The ring is now rested on the supporting disc, and the 3-toed disc placed on top of it; the gauge then indicates directly the mean thickness of the ring at the three points where the toes rest. (See Figs. 3 and 5). Permanent Set:—The loading platform (Fig. 4) has a scale engraved round its edge for measuring the permanent set of standard Schopper rings after being broken or stretched and then cut open. The ring is so placed round the edge of the platform that one end is opposite the engraved arrow; the position of the other end on the scale then shows the percentage permanent set. GT 1125 THE R.A.B.R.M. HARDNESS AND THICKNESS GAUGE FOR RUBBER Designed by the Research Association of British Rubber Manufacturers (British Patents Nos. 324504 and 329629; U.S. Patent No. 1856306) Fig. 1. Hardness Testing of sheet or small samples. Fig. 2. Hardness testing of rubber-covered rollers. Hardness Testing—its Importance and Significance. Of all the mechanical properties of vulcanised rubber, hardness is the most rapidly and easily measured. Moreover, hardness tests have the advantage over most other forms of mechanical test, that they do not require the preparation of specially shaped test-pieces, and can be applied to finished rubber articles without damaging them. The hardness test has thus a very wide sphere of utility, being the ideal test for routine control of uniformity in manufactured products, as well as a useful test of the physical qualities of rubber for specification purposes. Recent work has shown, moreover, that the hardness test does more than furnish an arbitrary number by which a rubber can be characterised. Investigations made by the Research Association of British Rubber Manufacturers have demonstrated that the reading given by the ball indentation test is closely related to, and can be used to measure, the elastic modulus of rubber at small deformations, and can thus provide information which is important in specifying the properties of such rubber articles as tyres, solings, buffers, and shock- and vibration-absorbing devices, etc. The indentation hardness tester thus takes its place among the scientific instruments used to investigate the elastic properties of rubber for research or other purposes. SOLE MAKERS: GRIFFIN and TATLOCK Ltd LONDON Addresses: Kemble St.{Capt. P. R. Strong}, W.C.2. Telegrams: Gramme, Westcent. Telephones: Temple Bar 2621. GLASGOW 45 Renfrew St.{Capt. P. R. Strong}, C.2. Technical. Douglas 747. MANCHESTER 34 Gt. Ducie St.{Capt. P. R. Strong}, 3. Science. Blackfriars 6041. EDINBURGH 7 Teviot Place, 1. Science. 20626. LIVERPOOL 164 Brownlow Hill, 3. Physical. Royal 1934. Cables: Gramme, London. Codes: Private, A B C 6th Ed.{J. L. Edwards} and Bentley. CALCUTTA: P.O. Box 2136, B5 Clive Buildings. Telegrams: Aimil. Telephone: Cal.{Mr Calvert} 3304. AUSTRALIA: WYNYARD TRADING CO., Kembla Buildings, Margaret Street, Sydney. EGYPT: S. NARDELLIER, Sh. Ismail Pacha 9 (Garden City), Cairo. CHINA: HARVEY, MAIN & CO., LTD., 169 Yuen Ming Yuen Road, Shanghai. S. AFRICA: COOKE, TROUGHTON & SIMMS LTD., Geneva House, Loveday Street, Johannesburg; and at Capetown. BRAZIL: ADOLPHO BOTELHO, Rua São Pedro 183, Rio de Janeiro. All Prices are at British Warehouse. Prices including delivery abroad are quoted on application to any of our offices or agents. | ||