GB677234A - An improved machine for briquetting powdered metal - Google Patents

Abstract

677,234. Hydraulic machines. HALLER, J. Oct. 20, 1948 [Oct. 20, 1947], No. 27266/48. Class 69 (ii) [Also in Group V] A bush is moulded from powdered metal, e.g. bronze, in a die between upper pressing plungers 29, 31 and lower pressing plungers 24, 26. A core 28 forms the bore of the bush. Movement of a lever 277 of a valve 244, see Fig. 20 (not shown) allows pressure fluid from a pipe 267 to act on a piston 60 to move a feed shoe 47 over the die. When the die is filled with material from the shoe, the lever 277 is moved to a reverse position to retract the shoe. A valve 245 is then actuated to cause a piston 93 and the plunger 29 to move downwards. When the plunger 29 reaches the surface 51 of the die table 18, the valve 245 is moved to a neutral position, holding the plunger 29 in this position. A valve 243 is then actuated to raise the core 28 above the surface 51. This valve is then moved to its neutral position. A valve 241 is actuated to raise a piston 161 and the plunger 26. When the plunger 26 has moved through about half its stroke, see Fig. 14 (not shown), the valve 241 is moved to its neutral position. Valves 245, 246 are then actuated to force the plungers 29, 31 downwards the plunger 31 telescoping with the core 28. The distance these plungers move downwards is adjusted depending upon the dimensions of the bush which are desired. The valve 241 is then actuated to cause the plunger 26 to finally compress the material. The upper plungers are then raised by reversing the valves 245, 246. Valves 242, 241 are actuated to cause the plungers 24, 26 to move upwards simultaneously, and the valve 243 is reversed to lower the core 28. When the plunger 24 reaches the surface 51, the valve 242 is moved to its neutral position, and the plunger 26 is allowed to continue its upward movement to eject the moulded bush. The plungers 24, 26 are then returned to their starting positions. The plungers and core may be moved in different sequences and to different positions from those of the previous operation to form bushes of the forms shown in Figs. 34 and 35 (not shown) by the operations shown in Figs. 21 to 33 (not shown). The distances through which the various plungers move may be controlled by (a) stops, (b) limiting the distance to which the pistons can move in the cylinders or (c) providing scales and pointers on the plungers. The levers of the valves may be moved manually, but, preferably to make the machine fully automatic, they are operated by solenoids which are energised by limit switches operated by arms projecting from the various plungers.