GB610011A - Method and press for compacting metallic powder - Google Patents

Abstract

610,011. Moulding metal compacts. AMERICAN ELECTRO METAL CORPORATION. Aug. 11, 1944, No. 15391. Convention date, Sept. 1, 1943. [Class 87(ii)] A method of pressing a loose fill of metallic powder into a compact having a shape including portions (e.g., A and B, Fig. 6) whose thicknessses, measured in the direction of pressing, differ considerably, the ratio of the thicknesses of uncompressed fill to the thicknesses of compact equalling the ratio of the density of the compact to the density of the fill, is characterized by the steps, carried out simultaneously, of compressing the fill portions individually, unyieldingly and in the same compression ratio. A telescopic punch may be used. From the dimensions of the finished compact 51 and a known compression ratio, the dimensions of the mould cavity 60 to be filled with metal powder are calculated. In Fig. 5 the powder is shown in the process of compression. The lower telescopic punch comprises the independent plungers 66, 67 which are actuated by the cams 70, 71 by means of pins 76, 77 and 80, 81 engaging in opposite grooves 78, 79 and 82, 83. The upper plungers 68, 69 are actuated in the same manner by the cams 73, 74, the two cam shafts 72, 75 being driven in synchronism. The grooves in the cams are so designed that the punches start from their original positions, Fig. 4, and reach their final positions, Fig. 6, simultaneously. After this final position has been reached the upper punch is withdrawn completely from the mould and the plungers 68. 69 returned to their original positions, Fig. 4. Meanwhile, plunger 67 is driven further upwardly to eject the compact, the plunger 66 remaining in its final position during this operation. The lower plungers are then returned to their starting positions. Instead of cams or eccentrics, individual hydraulic, geared electric motor &c. drives may be used to operate the plungers through levers. A single compression method may be used with a stationary bottom to the mould and a single telescopic punch such as 68, 69. Alternatively the bottom punch may be telescopic and the upper punch formed from a single plunger in the usual manner. Compacts suitable for use (after sintering) as rotors in electric (impulse) generators may be made.