Patent GB-1156691-A (GB)
Title: Producing Wrought Metal Bar
IPC: B21B13/10
Filed: 1966-06-10
Abstract: 1,156,691. Rolling. REYNOLDS METAL CO. 10 June, 1966 [15 June, 1965], No. 26032/66. Heading B3M. [Also in Divisions B5 and C7] Metal bars of substantially uniform density throughout the section thereof are produced from metal particles, e.g. lead, zinc, nickel, copper, iron, magnesium, beryllium and aluminium particles preferably of greater than 200 mesh and alloys thereof by cold or hot compaction of the particles through a shar-shaped pass defined between a plurality of co-operating rollers to a preliminary shape constituted by a plurality of thin longitudinally and outwardly extending ribs which are subsequently compressed and inwardly deformed by passage through further roller passes to a final shape which does not include the ribs. In an integrated process (Fig. 1, not shown), centrifugally cast aluminium particles (100) are delivered from rail trucks (104) by a screw conveyer (106) to a pneumatic conveyer (107) for transfer through an electrostatic cleaner and air filter (108) to storage units (110) from whence the particles (100) are pneumatically conveyed and may be passed down a 60-foot vertical particle furnace (114), for heating to a temperature of between 450‹ F. and their incipient melting temperature of 1000‹ to 1200‹ F., prior to passage through a vertical tangential mill (118) which produces the section (120) of preliminary compacted shape from the ends of the ribs whereof insufficiently compacted metal is trimmed either by stationary cutters (238) (Fig. 7, not shown), positioned adjacent the rollers or by drawing through a trimming station (124) (Figs. 9 to 11, not shown), comprising a single adjustable multi-roller pass, the adjacent guide surfaces (308) whereof terminate in sharp co-operating cutting edges (310), before passage through a multi-stand mill (132) for compression of the ribs to form densified continuous rod (142) which is periodically cut by a shear (144) into lengths which are coiled and transferred, by hydraulic cylinder (152) actuated members, on to units (154) for transfer to an inclined gravity roller conveyer (156) for passage through an electric, oil, or gas-fired furnace (158), wherein the rod (142) is stress relieved at 350‹ to 450‹ F. for 35 minutes; the emergent rod (142) may immediately be drawn into wire. The vertical tangential compacting mill 118 comprises 3 pairs of opposed rolls 208 on parallel spindles 204, the conical peripheral roller sections whereof define satin-faced or ground compacting surfaces 210 forming a star-shaped pass 212 for the preliminary shape; the rolls 208 are all driven at the same speed by individual variable speed synchronous electric motors (226) (Fig. 2, not shown) and the pass is fed from an insulated and electrically heated hopper 242 provided with a triangular section adjustably mounted knife (252) (Fig. 5, not shown) over each roll 208; the rolls may be cooled by a coolant spray or by passage through water 262 in pressurized troughs 260 sealed to the rolls 208 by gaskets 264. The legs (214) of the star-shaped pass may alternatively terminate in closely spaced adjacent surfaces 236, Fig. 6, to form a thin projection of flash 121B or in abutting surfaces (236) (Fig. 8, not shown) which eliminate flash. In the roller trimming station, if used, the trimming rolls (306) are each driven by variable speed synchronous electric motors (320) and are adjustably mounted to compensate for sharpening of the roll cutting edge (310) and may be spray cooled. The rib compression mill (132) (Figs. 12 to 22, not shown) comprises a set of three guide rolls (400) and a plurality of three roll stands each of which may be driven at a different speed, via an adjustable gear-box (134) or by individual motor drive, and which successively inwardly crush alternate ribs and then crush the remaining ribs to a resultant circular section (408) which is then alternately deformed between a triangular and circular section by four successive roll passes, all of which maintain a constant cross-section and with succeeding roll stands of similar section being oriented at 60 degrees; four further roll stands of circular section produce a successively reduced section circular bar. In an alternative arrangement (Figs. 23-28, not shown), a plurality of two roll stands compresses each pair of opposed ribs in two successive stages to form a circular section. Particles of different alloys may be fed into the compacting mill 118 to produce various alloys or cladding affects or one or more solid metal wires, e.g. of high tensile steel, aluminium or copper, may be fed into the centre of pass 212. The outwardly extending ribs of the preliminary elongated shape may vary in thickness with the radius of the rib.