24-02-2017, 12:07 PM
A system for controlling the sequence and duration of the operating steps in processes such as vulcanization of a tire is capable of operating under two basic modes or parameters. In one mode, the operative steps are dictated by elapsed real time, while in the other mode, the operation can be dictated by equivalent healing factors elapsed. The desired length of each step or curing, either in time or in curing equivalents, is set in an input program medium. In time mode, the time-generating circuits provide an output proportional to the elapsed time, the output of which is shown in a counter and compares electrically with the information in the input program means. When a match occurs, the time generating circuits and screens are reset and the input program means directs the tire vulcanization press to perform the next sequential function. Also described is a circuitry which is capable of performing secondary functions such as extending the length of a stage, as required. If it is desired to operate in the equivalent curing mode, a signal proportional to the curing equivalents elapsed is developed by an equivalent curing generating circuit which performs the digital integration of the Arrhenius function. The input for curing equivalent generator circuits may be a signal proportional to the temperature of the tire developed by internal thermocouples or it may be a signal which is directly proportional to the Arrhenius function generated by a thermistor sensor.
