Apparatus for producing tablets

Claim 1

In a tablet press for producing tablets from particulate material and which tablet press comprises, (a) a die plate having a bore for receiving particulate material; (b) an adjustable dosing device for feeding a metered amount of particulate material into the bore for forming each tablet; (c) upper ad lower rams reciprocable together in a compression stroke in the bore to compress the particulate material into a tablet and having a preset separation of the rams at the end of this compression stroke which preset separation determines the thickness of the tablet formed; (d) means for measuring the compression pressure existing at the end of the compression stroke of the rams; (e) means for comparing said measured pressure with preselected upper and lower pressure limits and for generating a pressure error signal if said limits are exceeded by the measured pressure; and (f) adjustment means responsive to said pressure error signal for varying the amount of particulate material fed to the bore by the dosing device until the measured pressure on subsequent compression strokes falls within the preselected upper and lower limits, the improvement comprising: means for sampling and weighing the tablets produced at spaced time intervals; means for comparing the weight of each tablet so sampled to preselected upper and lower weight limits and for generating a weight error signal if said weight limits are exceeded; and, means responsive to the weight error signal for varying the preset separation of the rams at the end of the compression stroke and/or the preselected upper and lower pressure limits until the weight of further sampled tablets falls within the preselected weight limits.