GB1279950A - Rotary tabletting machines - Google Patents

Abstract

1279950 Feeding rotary tabletting machines MANESTY MACHINES Ltd 14 July 1969 [25 July 1968] 28185/71 Heading B5A In a continuous rotary turret tabletting machine wherein a plurality of hardened metal dies 23, each containing a lower punch 24, are provided around a horizontal table 21 of the rotary turret 12, and corresponding aligned upper punches 27 are provided in a horizontal turret flange 26, at last part of the particulate tabletting material is fed to the dies from an annular enclosed space 34 which is defined, within the circle of dies 23, between the turret flange 26 and the table 21, and from which the particulate tabletting material rotating with the turret 12 is deflected over and into the dies 23 by a stationary deflector comprising a tongue 53 and an attached plate 52 inclined towards the table 21 in the direction of rotation thereof. The outer boundary of the space 34 is defined by a stationary wall 35 comprising spaced apart strips 36 and 37, between which locate nylon scrapers 41, 42 which are respectively spring urged against the underside of the flange 26 and the upper face of the table 21, the wall 35 being relieved in the lower part thereof along an arcuate extent at 50 where the upper part is attached to a feed housing 45 which feeds material to the space 34 and which is also provided with a feed opening 49 extending over a number of dies 23 to feed material thereto. In the described embodiment, wherein two moulding cycles are performed for each 360 degrees rotation of the table, there is provided a diametrically opposed pair of feed housings 45, and two diametrically opposed pairs of opposed pressure rolls 32, 33, which respectively actuate the upper and lower plungers 27, 24 for a final moulding compression of the material, the plungers 27, 24 otherwise being guided by camtracks 29, 28 so that, on the approach to a feed housing 45, the upper and lower plungers 27, 24 are raised respectively to clear the housing 45 and to locate the moulded tablet level with the table upper surface for deflection by a deflector 54 into a shoot 55. During passage beneath the deflector plate 52 the lower punch 24 is moved downwards and then, when the die 23 communicates directly with the opening 49, is slightly upwardly displaced prior to material being cleared from the surface of the dies 23 by scrapers 57, 58 in the housing 45. After leaving the housing 45, the powder in the dies 23 is precompressed between the punches 27, 24, prior to the final compression applied from the rolls 32, 33. It is stated that the space 34 may be provided with outwardly projecting vanes to assist movement of the material therein with the turret 12. The turret 12 is rotated by the engagement of an interior gear-ring 20 thereof by a gear 19 which is driven, via a worm gear 17, from a motor 13.