Method and apparatus for monitoring the compression force of pelleting press rams

Abstract

A tablet compressing machine includes strain gauge sensors 5, 5' for monitoring the forces applied to piston rams 1, 2 by pressure rollers 3,4. The strain gauges are connected in a bridge circuit whose amplified output is fed to a mean value generator 15 and a logic control unit 9. The former generates a mean pressing force curve (A in FIG. 3) while the latter causes preset individual limit values for the pressing force signals (B, C in FIG. 3) to track fluctuations in the mean value curve, and compares the instantaneous pressing force signals with the individual limit values. Whenever these limit values are exceeded or fallen below the machine is disabled and the faulty ram is indicated on a display 14 by means of a sensor 7 which signals the ram being monitored. Means are also provided for disabling the machine whenever the mean value exceeds or falls below adjustable tolerance limits.

Dependencies are inferred from the claim text.