GB1481797A - Tabletting machines - Google Patents

Abstract

1481797 Tabletting machine MANESTY MACHINES Ltd 11 Nov 1974 [17 Nov 1973] 53494/73 Heading B5A Granular material from a hopper 160 is fed into dies 30 spaced around a rotary cylindrical die table 32 and compressed into a tablet in each die between a pair of punches 38, 40 individual to the die, the punch 40 being subsequently withdrawn and the punch 38 pushed through the die to eject the formed tablet. The punches are slidable in flanges 36, 34 of the table and moved radially with respect to the axis of rotation 14 of the table; the outer punches 38 are moved under the control or radial deflections of a flexible hoop 52 rotating with the table and which is constrained and guided by rollers 54, 56, 58 so as to assume a non-circular shape. The rollers 54 are adjustable radially of the table axis to vary the quantity of material fed into the dies and the roller 56 is radially adjustable to adjust the thickness of the tablets. The heads of punches 38 are held in engagement with the hoop by a spring ring 60. The heads 42 of the inner punches engage in a circular cam track formed between freely rotatable concentric circular parts 44, 46 the axes of which are offset from the axis 14. After die filling, the punches are brought to their extreme compressing positions at the roller 56 and the outer punches are brought to the tablet ejecting position at the roller 58 where tablets are received by a shoot. A tablet is thereby produced by each die during a single revolution of the table; by using additional flexible hoop deflectors or rollers more than one tablet per die for each revolution may be produced. The hopper feeds the material to a stationary framework including spaced vertical walls which, at their lower edges, have a radial clearance with the surface 24 of the die table against which the material is centrifugally held. Material is deflected over the dies to fill them, and scrapers, not shown, deflect excess material to an annular channel 84 of the table. Such excess is re-deflected by the feed framework to join further material supplied by the hopper. The table axis could extend vertically; the machine may comprise two tables rotating about a common axis.