Abstract: An automatic water supply device for animals or plants, which uses a siphon tube for transferring a batch of water from a vessel having a float-valve type water inlet control device to a tray. The water transferring operation of the siphon tube is triggered by the water head applied to the siphon's outlet end and by the water received in the tray being reduced by a predetermined amount due to reduction of water level in the tray. The inlet tube portion of the siphon tube located in the internal space of the vessel has a diverged open end having an opening area which is substantially larger than that of the outlet tube portion of the siphon tube.

Abstract: An automatic water supply system used for raising domestic animals such as cattle, horses, poultry and so on and especially for pigs. Instead of a water flow control device such as a valve, float or the like provided in a self supply water trough, a flow control container is used which is communicated through a water supply pipe to a common water storage tank, placed at an elevated position inaccessible to a pig or the other animals and includes a float, a valve and a siphon which may ensure the automatic and positive supply of water into the trough as the water level in the trough is lowered by an animal drinking therefrom. Therefore the unnecessary supply of water caused by the undesired engagement of the mouth of an animal with the water flow control device in the trough mischieviously, and/or the stopping up of the drain with remaining food particles may be completely eliminated.