Flow sensor device and associated vacuum holding system

A vacuum holding system including a source of vacuum pressure and a plurality of flow sensor devices, each flow sensor device having a connection to the vacuum pressure source and a connection to a plurality of suction cups associated therewith for holding respective articles, the vacuum cups being arranged in an array and having the source of vacuum pressure connected in flow communication therewith through the respective flow sensor device, the flow sensor devices being positioned intermediate the source of vacuum pressure and respective ones of the vacuum cups, each of the flow sensor devices comprising:

• a body portion having a main air flow passage therethrough, the main air flow passage including an upstream end connected to the respective vacuum cups and a downstream end connected to the source of vacuum pressure;
• a seating structure positioned within the main air flow passage including a seat portion located in communication with the downstream end thereof;
• a centering structure positioned within the main air flow passage upstream of the seating structure;
• a sealing member positioned within the main air flow passage between the seat portion of seating structure and the centering structure;
• a resilient member positioned within the main air flow passage between the sealing member and the seating structure, a portion of the resilient member contacting the sealing member and urging the sealing member into spaced relation to the set portion of the seating structure;
• each flow sensor device further comprising means for adjusting the closing flow set point to establish a desired flow cut off point including means for adjusting the positioned of the seating structure in the air flow passage and the distance between the seating structure and the centering structure to correspondingly adjust the rate of air flow through the main passage which will cause the sealing member to contact the seat portion of the seating structure so that;
• when leakage occurs between one of the suction cups and the article engaged thereby it will cause upstream to downstream air flow through the main flow passage to exert force on the sealing member to move the sealing member in a direction which opposes the urging of the resilient member and if a sufficient rate of air flow occurs through the main air flow passage the force exerted on the sealing member by the air flow will overcome the force of the resilient member and cause the sealing member to contact the seat portion of the seating structure in a sealing relationship such that air flow through the main air flow passage is substantially eliminated.