US Patent 10518988 Safety mechanism for use with a drum unloader

An apparatus for forcing a viscous material to flow from a storage container. This apparatus having a follower plate configured to be inserted into an open-end of the storage container; a sealing element located around the outer periphery of the follower plate; a pump assembly that includes a pump, an air motor, and a pipe in fluid communication with the follower plate; a support stand comprising a base, a crossbar; and two or more cylinders and rods; one or more control systems; and a safety mechanism configured to reversibly allow or prevent the air pressure from being supplied to the air motor depending upon the position of the follower plate either outside or inside the storage container. The sealing element is configured to provide a leak-proof seal with the storage container when the follower plate is located inside the storage container.