GB538803A - Improvements in or relating to method of and apparatus for spreading powdered material in a mold - Google Patents

Abstract

538,803. Moulding powdered materials. WELLMAN CO., S. K. Feb. 15, 1940, No. 2927. Convention date, March 1, 1939. Class 87 (ii) Powdered material, particularly metal powder, is uniformly distributed within a mould by introducing the entire charge into the mould, moving a spreader over and in contact with the charge supporting surface until the entire charge has been churned and mixed and then continuing to move the spreader against the charge while gradually separating it from the surface of the mould. Fig. 1, shows a hand apparatus in which a spreader blade 20 secured to a stem 5 guided within a barrel 2 and adjustable therein by a screw operable by a hand wheel 17. The barrel 2 is carried by a support 1 and is surrounded by a sleeve 19. In use, the charge is introduced into the mould cavity 27 and the blade 20 is lowered to contact with the surface of the mould or of a bottom plate 28a. By means of the sleeve 19 and a knob 23 the device is manipulated to advance the blade along each of the mould walls in succession, while in contact with the bottom surface, until the whole charge has been stirred, after which the hand wheel 17 is turned to raise the blade slightly and a further circuit is made, this process being repeated until the blade is clear of the powder. Fig. 5 shows a machine comprising a turntable 48 supporting mould members 88, 87 which are centred by a pin 50 and annular plate 89 ; a blade 47, fitting the mould cavity, is adjustably secured to an arm 43 carried by a stem 38 adapted to be raised and lowered by rack gear operable by a hand wheel 42 and also adapted to be raised automatically through a crank mechanism comprising a crank disc 65 furnished with an adjustable crank pin connected by a link 68 to a link 70 pivoted at 71 to the framework, the link 68 being also connected by a link 72 to a clamp 74 adapted to be secured to the stem 38 by a screw 75. The crank disc 65 is driven from a motor 57 through a friction clutch and is furnished with stops adapted to engage a fixed stop pin to limit its movement to about 90 degrees. In operation, with the clamp 74 free. the turntable 48 is set in rotation, the mould is charged with powder and the blade 47 is lowered to contact with the plate 89 ; the crank disc 65 is then turned backward until the stop engages the stop pin, the clamp 74 is tightened and the motor 57 started. After the crank has moved through its allotted angle, clamp 74 is released and the blade is raised out of the mould cavity by operating handwheel 42. A separator 91 is lowered into the mould cavity and the process is repeated. When a desired number of layers have been spread, the pin 50 is lowered by means of a lever 51 and the mould assembly is slid off the table 48 and transferred to a press. The blade may be stationary and the mould moved up and down, or the blade may be arranged to rotate within a stationary mould. Specification 537,870 is referred to.