Automatic leak test machine for canister production lines - has differential pressure diaphragm operating electric contact reject control

摘要

The canister leak test machine consists of rotating shaft (7) driven by a motor via belt and pulley. A second belt drives the feed and take-off conveyor which handles the containers and transports them to and from the test device. The shaft has radial assemblies (1) whose arms carry air-lines and electric control cables from rotating pneumatic couplings and slip rings in the shaft hub (71) to the leak detector at the outer end of the radial arms. A pneumatic spring-loaded piston (24) holds the container with its open and against a flat plate having an air-tight seal (14). Cam operated valves put the canister (18) under pneumatic pressure. This pressure is maintained by a reservoir (11) and any change of pressure caused by a leaking can is detected by a differential-pressure diaphragm (16) which operates an electric contact. This signal is used to control the machine so that the faulty canister is rejected from the production line conveyor.