GB1109238A - Tong caliper gauge - Google Patents

Abstract

1,109,238. Linear dimension gauge, electrical. BRITISH IRON & STEEL RESEARCH ASSOCIATION. July 26, 1966 [June 14, 1965], No.24969/65. Heading G1N. A linear dimension caliper gauge, e. g. for measuring hot steel billets of constant crosssection, has two arms 1, 2 Fig. 1 with a pair of strain gauges 10, 11 on each arm. One arm has two object engaging convex surfaces, Fig. 4, while the other arm has one, to ensure alignment of the gauge in a plane including the dimension to be measured. An adjustable stop 13, Fig. 3, may be provided to precisely locate the billet longitudinally of the arms. The spacing between the arms is adjustable by screws 7. The strain gauges are connected in a bridge circuit (not shown) having a centre zero meter, and it is arranged that the arms are parallel when a billet of the required dimension is inserted, the meter then indicating a null value. Any deviation from the desired dimension will then cause a deflection of the meter. When measuring the diagonal dimension of the billet the gauge is moved through a small angle around the billet and the true reading is the maximum value indicated which occurs when the arms are correctly aligned at the ends of the diagonal, as illustrated in Figs. 5, 6 (not shown). When measuring the dimension across the flats the gauge is similarly swept through an angle, but in this case it is the minimum value indicated which corresponds with correct alignment of the arms. To detect the maximum value the amplified bridge output is applied through a rectifier (16) Fig.7 (not shown) to a condenser 17, which is thus charged up to the peak voltage which is indicated on the meter. A switch is provided to discharge the condenser between readings. To reduce heat transfer the workpiece engaging surfaces are on hollow cylinders only the tips of which contact the arms, Fig.3. Each strain gauge may be on a steel strip which bridges a reduced portion of an arm, Figs. 8, 9 (not shown).