BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a gas shut-off valve assembly, and more particularly, a seismically activated gas shut-off valve.

Description of Prior Art and Related Information

Earthquakes frequently occur daily, and are almost ubiquitous in some areas, with individuals in those areas barely stopping their routines unless the magnitude of shaking is significant. Some earthquakes are unnoticed because they are too weak or occur in remote areas of the world. However, even small earthquakes, if located close enough to densely populated areas (for example, urban or heavily populated suburbs), can cause significant damage to foundations and utility lines running underground. In particular, gas flow lines can be extremely dangerous when seismic activity is enough to crack a line. The escaping gas can leak and trigger a chain reaction of explosions if it comes into contact with enough heat.

Various methods to shut off gas flow in conduits and pipelines in response to earthquake vibrations are known in the art. These methods generally share the common features of placing a gas valve in a section of a gas pipeline, maintaining the gas valve in an initial open position.

A conventional gas valve requires a person to manually rotate a handle which is connected to a disc inside the flow passage. The disc is by default always in the flow and when open, usually has some surface area obstructing the passage and the gas flow therethrough. When closed, the disc is rotated on an axis orthogonal to the gas flow until the flat face of the disc is perpendicular to the flow and the disc edges are abutting the gas line walls.

As can be seen, there is a need to improve on the efficiency of current gas shut-off valves which may restrict gas flow even when the valve is normally open.

BRIEF SUMMARY OF THE INVENTION

In one aspect, a seismically activated gas shut-off valve assembly is disclosed. The gas shut-off valve assembly comprises a gas flow passageway defined by a conduit wall; a port in the gas flow passageway; a platform positioned above the gas flow passageway; a door positioned below the platform; a retention mechanism retaining the door in a first position, wherein the door first position is perpendicular to the port in the gas flow passageway and normally open permitting gas to flow through the passageway; and a weight positioned in equilibrium on the platform, wherein, in response to a seismic vibration above a threshold level, the weight is displaced from equilibrium off the platform and onto the door positioned below the platform, wherein an impact from the weight on the door disengages the door from the retention mechanism, releasing the door to move about a horizontal axis and into a second position parallel to the port and sealing the port putting the valve assembly into a closed state, preventing gas flowing through the passageway.

In another aspect, a seismically activated gas shut-off valve assembly, comprises a gas flow passageway defined by a conduit wall; a port in the gas flow passageway; a platform positioned above the gas flow passageway; a door positioned below the platform; a retention mechanism retaining the door in a first position and outside an inner diameter of the conduit wall, wherein the door first position is perpendicular to the port in the gas flow passageway and normally open permitting gas to flow through the passageway; and a weight positioned in on the platform, wherein, in response to a seismic vibration above a threshold level, the weight is displaced off a front edge of the platform and onto the door positioned below the platform, wherein an impact from the weight on the door disengages the door from the retention mechanism, releasing the door to move about a horizontal axis and into a second position into the gas flow passageway sealing the port and putting the valve assembly into a closed state, preventing gas flowing through the passageway.

In yet another aspect, a seismically activated gas shut-off valve assembly comprises a gas flow passageway defined by a conduit wall; a platform positioned above the gas flow passageway; a well in the top surface of the platform; a door positioned below the platform; a retention mechanism retaining the door in a first position, wherein the door first position is normally open permitting gas to flow through the passageway; and a weight positioned in the well of the platform, wherein, in response to a seismic vibration above a threshold level, the weight is displaced from the well and off the platform and onto the door positioned below the platform, wherein an impact from the weight on the door disengages the door from the retention mechanism, releasing the door to move into a second, closed position, preventing gas flowing through the passageway.

