GB347715A - Improved apparatus for measuring and testing the physical properties of materials - Google Patents

Abstract

347,715. Testing physical qualities of materials. BRADLEY, H. and BRITISH BOOT, SHOE & ALLIED TRADES RESEARCH ASSOCIATION, 19, Bedford Square, London. Feb. 1, 1930, No. 3521. [Class 106 (ii).] Relates to apparatus for testing " patent " leather and other materials in which the specimen is clamped in an annular clamp and force applied to the material such force acting directly upon an elastically deformable member associated with a scale indicating the force applied, and consists in providing scales to indicate both force applied and the amount of " stretch " of the material. In the hand form shown in Figs. 1 and 2, the material to be tested is clamped between annular members 1 secured by screws 2. One member has a tubular extension 3 in which works a plunger formed of two tubes 7, 8 closed at one end and arranged to slide one in the other against the influence of a spring 9. Through the end of the tube 3 works a screw 5 attached to a thimble 4 working over the tube 3. A detachable head 14 rests on the plunger and is provided with an engaging part of spherical ellipsoidal or other true mathematical shape to engage the specimen. The tube 3 has a longitudinal slot 13 graduated at the edge and a curser 10 on the plunger works over the scale 11 so formed. A scale 12 upon which the load is read is also provided on the cursor. The edge of the thimble 4 is graduated to give subdivisions of the scale 11. In a modified form, Fig. 5, the clamp 16, 17 is similar to the above, while the end of the tube 18 is screwed to work over a screw 25 attached to the top end of two clamping members 24, gripping between them a diaphragm 22 upon which rests a rod 23 passing freely through the screw 25. Engaging the under side of the diaphragm is a screw 34 attached to one limb 35 of a U-shaped spring connected through levers to an indicating pointer. In the fan, the tube 18 is screwed down over the screw 25 to apply the stress to the specimen and the deflection of the diaphragm 22 is indicated by a pointer moving over a scale, a second pointer moved by the first giving the maximum indication. The thimble 39 is graduated around the edge to co-operate with a scale on the tube 19.