| 摘要 |
A vacuum cup control apparatus for applying and releasing vacuum in a vacuum cup engaging a workpiece includes a housing having a venturi passage for inducing a vacuum within the vacuum cup upon the flow of air through the venturi passage. A one-way check valve in the passage seals the vacuum in the vacuum cup upon cessation of air flow through the venturi passage. Another air flow passage extends through the housing to a control port on the housing for injecting a flow of air under pressure to the vacuum cup to relieve the vacuum therein. A sensor mounted in the housing 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 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. The control apparatus also injects air under pressure to the vacuum cup to relieve the vacuum in response to a signal from the external controller. 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 reapply vacuum until the predetermined vacuum level is reached.
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