A workstation at a packaging machine with a tool having an upper part (2) and a lower part (3) whereby at least one of said parts (3) is driven with a stroke-type movement and a compressive force is exerted via said tool onto a workpiece (4) in the working position, and said tool has a spring arrangement (26), the prestress and deflection path of which can be adjusted. A device (25) for measuring the compressive force on the workpiece (4) in the working position is provided and so located in the area of the upper and/or lower part (2 and/or 3) of the tool that it is loaded by the compressive force in the working position.

A press control system monitors and is responsive to the loads associated with individual die stations in a progressive die. The system detects chipped, dull, or excessively loaded portions of the progressive die and provides automatic quality monitoring of the parts produced by the press. The system provides a display of press load as a function of time scaled by the speed of the press. The press load as a function of time is automatically analyzed to determine and display the number of die stations and the peak loads associated with each die station in the progressive die. The peak loads are compared to limit values that depend in part on the past history of the press in order to monitor the condition of the progressive die and if necessary to shut down the press. The number and quality of parts produced by the press are also determined from the peak loads. Gradual wear of the die is monitored to determined when sharpening is required. To detect anomalies at any phase in the press cycle, the press load is compared between successive cycles. A master/slave computer system is disclosed for monitoring and controlling multiple presses.

This disclosure concerns an apparatus and methods for reproducing compaction and ejection events in a plurality of press machines. Each press machine has at least one die opening wherein a compound is placed to be compressed at least once between upper and lower punches sliding inside the said die whereupon the compressed compound is ejected from the die cavity. The apparatus and methods ensure that the plurality of compression and ejection events have the same exact speed, profile curvature, and pressure or force as on any pre-specified press machine by matching the timing and geometrical path of the punch movements as well as the depth of fill of the die. The linear speed of the punches is matched by a computer controlling the programmable motor of the die carrier. The path protiles of the punches are matched mechanically by means of interchangeable rollers and cams with the predefined geometry. The pressure or forces of the matching events are controlled and adjusted by means of the positioning of the lower punch in the die.

An apparatus for reproducing compaction and ejection events in a plurality of press machines is disclosed. Each press machine has at least one die opening wherein a compound is placed to be compressed at least once between upper and lower punches sliding inside the said die whereupon the compressed compound is ejected from the die cavity. The apparatus and methods ensure that the plurality of compression and ejection events have the same exact speed, profile curvature, and pressure or force as on any pre-specified press machine by matching the timing and geometrical path of the punch movements as well as the depth of fill of the die. The linear speed of the punches is matched by a computer controlling the programmable motor of the die carrier. The path profiles of the punches are matched mechanically by means of interchangeable rollers and cams with the predefined geometry. The pressure or forces of the matching events are controlled and adjusted by means of the positioning of the lower punch in the die.

Compression forces (F) in a rotary tablet compressing machine (40) are monitored and controlled to provide enhanced accuracy in determining peak compression value and continuous validation of a compression waveform. The compression waveform is repetitively sampled under computer control at a sampling frequency that is many times the frequency of the compression events. The samples are stored in a computer memory (26) until at least one complete compression event is recorded. Identification of beginning and ending samples of an individual tablet compression event are obtained from the waveform itself by locating minimum amplitude samples, or by use of a separate signal that is derived from a transducer which is responsive to the angular position of a rotating turret. Stored samples representing the compression waveform as time and amplitude data are passed to a processor (23) that statistically fits the data to an equation form which represents the ideal shape of a compression event. If the quality of the data fit falls below a preset value, the tablet associated with that coefficient is subsequently rejected by a mechanism that is activated by the computer (26), which records the event as a waveform error. A counter (25), having a user selectable maximum threshold, is incremented each time a tablet is rejected from the same punch pair as a result of a waveform error. If the maximum count threshold is reached, then the tablet compressing machine (40) is stopped by the computer (26) and a message identifying the faulty punch pair is displayed.