Air vent

Claim 1

A float-type air vent, such as used as an air vent valve for cold water, hot water and the like, comprising a valve body, said valve body defining a hollow chamber having an upwardly extending central axis, said valve body having a top portion extending across the upper end of said hollow chamber, an upwardly extending side portion extending downwardly from said top portion and laterally enclosing said hollow chamber, and a bottom portion extending downwardly from said side portion and forming an inlet to said hollow chamber extending about the central axis of said hollow chamber, a float valve housed and guided freely movable within said hollow chamber and prevented from downward displacement therefrom by said bottom portion, a seat member positioned in the upper part of said side portion of said valve body and spaced laterally from the central axis of said hollow chamber, said valve seat member having a connecting passage therethrough communicating between the hollow chamber in said valve body and the exterior of said valve body and the axis of said passage defining an acute angle with the central axis of said hollow chamber, and a valve seat mounted in said valve seat member extending about said connecting passage at the interior surface of said valve body, said float is spherical and comprises two semi-spherical shells secured together along a circumferentially extending seam which extends substantially normally of the upright axis of the hollow chamber and the radius of said float being greater than the dimension along the central axis of said hollow chamber between the inside surface of the top portion of said valve body and the plane extending normally to the central axis and passing through the lowermost point of the inlet to the connecting passage so that the seam of said float body is located in a plane spaced below the lower end of said valve seat, said two semi-spherical shells each having a different thickness with the thicker said shell being located below the thinner said shell so that the center of gravity of said float is located on the central axis of the lower one of said shells below the horizontally extending seam thereof, said top portion having an opening therethrough extending along the central axis of said hollow chamber, an operating rod extending through the opening in said top portion along the central axis of said hollow chamber in such a manner that the lower end of said rod projects into said hollow chamber, and a cap screwed onto the outer surface of said top portion of said valve body and having an opening therein through which the upper end of said operating rod projects upwardly and is arranged so that said cap cooperates with said operating rod and the upper end of said operating rod is exposed exteriorly of said valve body and by adjusting the screw connection of said cap to said top portion of said valve body, the position of the lower end of said operating rod within said hollow chamber can be selectively established for positioning said float at said valve seat for closing off said connecting passage extending through said valve seat member, and the upper end of said operating rod is accessible on the exterior of said valve body for manually displacing said float from said valve seat.