Patent ID: 8141576

Claim:
A float valve device, comprising: a housing having a cylindrical shape in general, wherein the housing is divided into a lower space and an upper space by a partition wall, and wherein the housing comprises (i) a ventilation pipe mounted to an outer wall of the upper space, for allowing the upper space to communicate with an exterior, (ii) an opening formed in the partition wall, (iii) a valve seat formed on a lower surface of the partition wall, (iv) and a communication hole formed in an outer wall of the lower space, for allowing the lower space to communicate with the exterior; a float which is arranged in the lower space of the housing so as to be vertically slidable and adapted to be raised by a liquid flowing in through the communication hole of the housing; a movable valve which is rockably supported on an upper portion of the float and which is adapted to abut the valve seat to close the opening when the float is raised to a predetermined height; and a retention frame which surrounds an outer periphery of the movable valve and which is attached to an outer periphery of the upper portion of the float to retain the movable valve and to allow the movable valve to ascend/descend by a predetermined distance and to incline with respect to the float, wherein the retention frame restricts an ascent/descent height of the of the movable valve with respect to the float, and a circumferentially uneven protrusion is formed on an abutment portion where the retention frame and the movable valve abut each other, wherein the protrusion is configured such that when the float descends in a valve-closed state, the retention frame and the movable valve first abut each other via the protrusion, and the protrusion imparts a lowering force to the movable valve, and wherein a height of the protrusion is set such that the retention frame and the movable valve abut each other solely via the protrusion even in a state in which the float is inclined to a maximum degree with respect to an axis of the valve seat.