GB726562A - Improved method of and means for cold-working steel bars to improve their strength - Google Patents

Abstract

726,562. Altering physical structure. TENTOR STEEL CO., Ltd. Feb. 25, 1953 [March 29, 1952], No. 5245/53. Class 83 (4). Twisting and stretching.-A method for improving the strength of steel bars, especially re-inforcing steel, by cold working by twisting or stretching or both during which the bar is held between two gripping devices is characterized in that the steel bar or bars wound around each other is or are, in the intervals between the cold-working, intermittently conveyed in the longitudinal direction to the treatment zone section, the bar or bars being conveyed to said zone through or along the one gripping device and being removed also in the longitudinal direction from said zone through or along the other gripping device. Steel bars welded together into long lengths and coiled on a drum 3 pass through straightening rolls 4 to a fixed stock 5 carrying a pneumatic or hydraulic gripping device 6 with adjustable jaws and through ring supports 7 to feed rolls 8 and thence to a sliding stock 9 having a rotatable grip 10 and then on to shears 12. After the cold working the bar is cut and feed rolls 13 convey the bar to adjustable automatic shears 14, 15 and 16 which cut the bar into predetermined lengths which fall into storage compartments 17, 18, 19 and 20. In operation, when the grippers 6 and 10 have gripped the bar the stock 9 is moved by chain or screw drive or by hydraulic means, to stretch the bar and either before, after or simultaneously with the stretching the grippers 10 are rotated by a motor 22 and belt drive 23 to twist the bar. After the stretching and twisting operation the grippers are opened and the feed rolls 8 push the cold worked steel through the stock 9 and pull fresh bar from the drum 3 into the machine. When the stock 9 has returned to its starting position the shears 12 cut the cold-worked bar which is then conveyed by the rolls 13 to the shears 14, 15 and 16 and cut into lengths. The drum 3 may be rotatable on two axes at right angles to each other and if desired instead of shearing the cold worked bar into lengths it may be coiled on a take-up drum similar to the drum 3.