| 摘要 |
<p>A vacuum cup control apparatus for applying and releasing vacuum in a vacuum cup includes a venturi passage for inducing a vacuum within the vacuum cup upon the flow of pressurized air therethrough. Another air flow passage extends through the housing for injecting a flow of air under pressure to the vacuum cup to relieve the vacuum therein. A sensor senses the vacuum level attained in the vacuum cup. A feedback signal is sent by the control apparatus to the external controller as an indication that a predetermined, selectable vacuum level has been achieved. The control apparatus is responsive to the sensor and signals from an external controller for applying vacuum to the vacuum cup until a predetermined vacuum level is attained in the vacuum cup. After the initial application of vacuum and prior to the injection of air under pressure to the vacuum cup, if the vacuum level within the vacuum cup decreases below the predetermined set level, the control apparatus will automatically reapply vacuum until the predetermined vacuum level is reached. A plurality of comparators, each provided with offset reference signal inputs, are responsive to the output of the sensor and generate a plurality of discrete vacuum select levels. A selector switch selects one of the comparator outputs to specify a predetermined vacuum level in the vacuum cup.</p> |
