GB394609A - Improvements in and connected with elongation gauges for use when testing materials in tension - Google Patents

Abstract

394,609. Gauges. HOUNSFIELD, L. H., 3, Durrington Park Road, Wimbledon, London. Jan. 30, 1933, No. 2826. [Class 106 (ii).] A gauge for measuring the percentage increase in gauge length of tensile test pieces after they have been pulled comprises a cradle or trough for carrying the test piece, abutments on the trough to engage the ends of the test piece, one being adjustable to a fixed position and the other being movable with an index lever travelling over a scale, and means for adjusting the relative positions of the trough and lever in accordance with the gauge length of the test piece. As shown, a trough 1 carries abutments 12, 18 having vertical faces to engage a test piece. The abutment 18 is adjustably secured to the trough by a screw 19, nut 21, and spring 22, the screw extending through a slot 20 in the trough. The abutment 12 is slidable on the trough and is frictionally held by a plate 13 extending over its sides; it carries screwed pins 15, 16 respectively engaging an index lever 9 and carrying a spring 17 engaging the lever. The trough is secured to a saddle 2, adjustable on a slide 4, and having a cover 3 and fixing screw 5. The slide 4 carries the pivot 8 for the lever 9, and also a scale 10, and is graduated so that it may be set, relatively to index marks 6 on the saddle 2, in accordance with the known gauge length of the test-piece, or in accordance with a distinguishing number applied to the test-piece and varying with such length. The abutments are set up so that, when the test piece, before being pulled, is between them, the reading on the scale 10 is zero. After the piece has been pulled, it, or the assembled piece if it has been broken, is again placed between the abutments, the necessary adjustment being applied only to the abutment 12; the percentage extension is then read from the scale 10.