Can detection and switch mechanism for can filling apparatus

摘要

A filling apparatus for metal containers has a rotatable bowl carrying filling syrup or other fluid with a plurality of filling valves arranged on the bowl bottom around its periphery to fill empty containers moved into traveling engagement with each valve. A control cam manipulates each valve in a repeating sequence through close, vacuum, fill and vent positions. A switching cam follower tracking the control cam and a cooperating switch activate the valving sequence if a can is present at a particular filling valve and de-activate the sequence if a can is not present. A pneumatic cylinder actuated by series connected proximity sensors for metal objects, such as cans, manipulates the cooperating switch to direct the switching cam follower for each filler valve into one control cam tracking mode if an empty can is in place below the filler valve or into a second valve closing mode if a can is not present. One sensor detects filler valve position and the other sensor detects presence of a can by a change in the inductance of the sensor produced electric field. Concurrence of sensor outputs manipulates the cooperating switch.