| 摘要 |
947,710. Making thermocouples; wire. ENGELHARD INDUSTRIES Inc. May 16, 1960 [Aug. 28, 1959], No. 17249/60. Addition to 849,431. Heading B3A. [Also in Division H1] A thermocouple comprises one element of a platinum alloy, e.g. platinum with rhodium, iridium, or ruthenium, in the form of a solid wire, together with a second element of wire of the type described in the parent Specification i.e. of platinum in the form of a platinum tube 6, Fig. 3, filled with a core 4 of a compacted partially fused bundle of platinum wires 5. The composite wire is produced by casting a bar of chemically pure platinum, swaging it to ¢ in. diameter, and cutting into two 6 in. lengths, one length being swaged to 0.2 in. diameter chemically cleaned and then drawn to 0.02 in. diameter, being cleaned at 0.07 and 0.02 in. diameter. The wire then being cut into 6¢ in. lengths and about 100 of the lengths inserted into a ¢ in. diameter hole drilled through the second ¢ in. diameter length of platinum. The composite tube being swaged to a 10% reduction in diameter, chemically cleaned, and heat treated for sixteen hours at 1400‹ C. in hydrogen. The tube then being hot swaged to 0.3 in. diameter, cold swaged to 0.07 in. and drawn to 0.02 in. being chemically cleaned at 0.3, 0.2 and 0.07 in. diameter. The composite wire finally being welded to the end of a platinum-10% rhodium wire to form the thermocouple. The composite wire is said to inhibit grain growth throughout the wire cross-section and give substantially greater tensile strength than conventional solid wire. |
