GB768593A - A method and means for passing tube blanks through step rolling mills - Google Patents

Abstract

768,593. Rolling tubes. AKTIEBOLAGET 8VENSKA METALLVERKEN. Marc 1955 [March 16, 1954], No. 7560/55. Class 83 (4). In a step-by-step tube rolling apparatus with reciprocating and oscillating rolls, 1, 2, Figs. 1, 4, the blanks are intermittently fed by a hammering operation. The blanks 58 to be rolled are supported on mandrels 45 projecting from a carriage E which is slidable into position along guides 31 under the action of double acting hydraulic cylinders 33. The carriage E has a framework 37 mounted on its forward end which runs on a supporting wheel 39 and has a number of guides 47 which support the mandrel but which have holes large enough for the passage of the tube blanks. For hammering the blanks a hammer member 50 is reciprocated in the frame 37 and has annular sections 54, Fig. 8, attached thereto which slide over the mandrels 45 and engage the ends of the blanks. The hammer has threaded grooves 51, 52 which engage coupled screw rods 48 running the length of the frame 37 and which are reciprocated to cause the hammering action by crossheads 79, Fig. 5, slidable between guides 81, 82 in the carriage E and reciprocated by a crank-shaft 71 and connecting rods 74. Rotation of the screw rods for feeding the hammer 50 progressively forward is obtained from a drum-like gear 85, engaging a gear 84, and having sufficient length to permit the gears to remain in engagement during the reciprocating motion. During each feeding operation the mandrel rods 45 are brought to the same longitudinal starting position and are released during the rolling operation by intermittently clamping and releasing the headed ends 108 of the mandrel within the carriage E. For this purpose a pair of cross-heads 103, 117, slidable between guides 105, 106 are reciprocated out of phase with each other from the crank-shaft 71 so that the headed ends 108 are clamped between the cross-heads during one part of the revolution only. The mandrel carriage E is adapted to be raised to an inclined position, Fig. 1, for feeding tube blanks 58 on to the mandrels from an inclined loading bridge C having a feeding device 29 adapted to push the required number of blanks 58 down a shoot 57 and over the mandrel rods 45. Specification 409,145, [Group VI], is referred to.