GB641961A - Improvements in and relating to rotary mould table presses for moulding tablets and the like from material in powder form - Google Patents

Abstract

641,961. Rotary mould-table machines. COURTOY, C. E. June 24, 1947, No. 16701. [Class 87 (ii)] Material to be moulded is fed by gravity from a hopper 1 on to the surface of a rotating table 2 having a number of circularly disposed mould cavities. The material is compressed in the cavities by upper and lower plungers 8, 9 working in guides in the rotating turret 3 to which the mould table is secured. Movement of the plungers 8 is derived from a cam groove in a member 10. Upper and lower pressure rollers 11, 15 act on the plungers at the compressing station. The turret is rotated by a worm-wheel 5 and worm 6. The lower compression roller 15 is rotatably mounted in a member 16 slidable vertically in the machine frame and cushioned, to limit the maximum pressure that may be applied to the moulding material, by a pneumatic-hydraulic device comprising compressed air in a cylinder 26 acting, through liquid 27, on the base of a piston 24 in a cylinder 25. The piston bears against a collar 20 on one end of a lever 18 pivoted at 19 and bearing at an intermediate point on a pivot 17 at the lower end of the member 16. The air pressure is adjustable. In a modification, the piston 24 is open at the lower end and contains air and thus itself acts as the vessel 26 which is dispensed with. The air pressure in the piston is variable. A stop 21 adjustable by screw-and-worm mechanism 22, 23 limits the upward movement of the roller 15. The position of the lower plungers 9 at the loading station may be varied by adjustable segments 13 moved by screw mechanism 14. In a further modification the lever 18 is dispensed with, in which case the piston 24 bears directly against the pivot 17.