US Patent 7278371 Self-leveling wet/dry tube feeder

A wet/dry feeding device for the watering of live stock, primarily smaller animals, such as grower pigs, comprising a vacuum valve 1 with a diaphragm, water holding reservoir pans 4, water leveling tube 6, and double walled water feeding tube 5. The water level is automatically maintained within the reservoir pans 4 by an adjustable water feeding tube 5 which is placed into the water at a perpendicular angle to the water surface. At the top of the water feeding tube 5, a vacuum valve 1 with a diaphragm is located to allow water into the reservoir pans 4 until the water level enters the feeding tube sleeve, thereby activating the vacuum valve 1, and ceasing the flow of water.