Vacuum breaker

Abstract

A vacuum breaker is adopted for use on a water discharge end of a flush valve in a water supply piping system. It includes a valve which has a valve seat with a hollow section to house a plug. The plug is movable up and down under water pressure and a spring on the bottom to actuate flushing or stop flushing. The vacuum breaker further includes a coupling duct and a bushing housed in the coupling duct that is made from a flexible material. The coupling duct has a plurality of apertures near the top end. The outer wall of the bushing and the inner wall of the coupling duct form a gap therebetween. During flushing, the wall of the bushing is expanded outwards under water pressure to close the apertures to stop water overflow through the apertures. When the flushing stops, external air can enter through the apertures and the gap between the coupling duct and the bushing to balance the internal and external pressure and eliminate vacuum, and prevent back siphonage from occurring.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The invention relates to a vacuum breaker installed on a water discharge water end of a flush valve of toilet devices to eliminate vacuum in the flush valve through a plug which may return automatically and a flexible and deformable bushing and prevent sewage from counter flowing and contaminating clean water. [0003] 2. Description of the Prior Art [0004] Vacuum breaker is installed in a discharge tube of a flush valve to prevent back siphonage from occurring to the toilet or urinal that would result in counter flow to contaminate clean water. Conventional vacuum breakers such as those disclosed in U.S. Pat. Nos. 3,334,646 and 5,564,460 mainly have a flexible bushing with a discharge end temporarily open under the pressure of flushing water and closed after the flushing finishes. Moreover, the bushing wall will be expanded outwards during flushing to close air outlets of the water discharge tube to prevent water fro...

AI Technical Summary

Benefits of technology

[0005] The primary object of the present invention is to provide a vacuum breaker which has a rigid mechanism to actuate opening and closing of flushing to overcome the disadvantages occurred to the conventional vacuum breakers that cannot flush normally due to material fatigue.

[0006] Another object of the invention is to provide a vacuum breaker to eliminate the vacuum in the piping to prevent back siphonage from occurring.

[0008] By means of the construction set forth above, during flushing, the retaining ring on the lower side of the plug is moved downwards under water pressure to compress the spring. When the flush valve stops flushing, the elastic force of the spring pushes the plug upwards and the retaining ring seals the bottom end of the valve seat to prevent sewage in the toilet devices from counter flowing to the clean water. Moreover, during flushing, water passes through the bushing and forms a pressure on the wall of the bushing, and presses the flexible wall partly outwards to contact the inner wall of the coupling duct and seal the apertures of the coupling duct. Hence water does not over flow through the apertures. In addition, when flushing is stopped, water pressure on the wall of the bushing is absent, and outward deformation of the bushing does not take place, hence the apertures remain open, and external air can flow into the vacuum breaker through the apertures and the gap between the inner wall of the coupling duct and the outer wall of the bushing to balance the internal and external pressure of the vacuum breaker and eliminate the vacuum, and the back siphonage that might otherwise occur.

Problems solved by technology

However, when fatigues or damage occurs to the material after used for a period of time, response and control become not accurate, and sewage could counter flow through the not closely sealed bushing and contaminate drinking water.

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