| 摘要 |
<p>HEATED LIQUID SYSTEM INTERLOCK A motor drive for a hot melt adhesive pump is maintained in an inoperative condition until the adhesive has heated sufficiently to permit free operation of the motor. The adhesive is received in a container supported upon a heater which is activated to heat the container and the adhesive therein. The output of a proportional control for the heater, which is responsive to the container temperature, is monitored. The output of the proportional control, when the container temperature in near a set point temperature indicative of a desired heated condition for the adhesive, is an intermittent signal. In one form of the invention, the intermittent signal is electrically integrated to produce an interlock release. pulse permitting operation of the motor. In a second form of the invention, a thermal relay is-coupled to a source of electrical power through a switching circuit, which permits power to be coupled to the thermal relay during the intermittent off times of the heater. The thermal relay thermally integrates the intermittent power coupled thereto and produces an interlock release signal to permit operation of the motor.</p> |
