Technical Field

This invention relates to a closure. More specifically, but not exclusively, this invention relates to a high-speed closure for use in suppressing combustive situations at an early stage.

Introduction and Background to the Invention

The use of flame detectors and automatically actuating systems is known in the fire-fighting industry. These systems work on a principle whereby a sensor gives a signal to an actuator, which then opens a valve closure, releasing fire suppression agent from a pressurized vessel into the localized area of the flame to extinguish it. One system in particular operates by knocking out a pin, which then allows a sealing collar to fall downwards, thus allowing the propellant and pressurized agent to escape.

Such valve closures are usually reusable to save costs. A disadvantage of such reusable valve closures is that they are prone to leakage and/or failure as the mechanism for the release of these valve closures may damage the opening mechanism. This is especially the case where the opening mechanism is not of a robust design. In addition, such closures may be opened, accidentally or otherwise, by tampering with the valve closure from the outside.

A last disadvantage is that the design of a positively acting valve closure which may be activated within the shortest possible time (normally in the order of milliseconds) may be complex, which allows for a certain amount of risk when the valves are reset.

Object of the Invention It is an object of this invention to provide a dispensing arrangement that at least partially alleviates the disadvantages mentioned, or offers an alternative to other prior art.

Disclosure of the Invention According to the invention a dispensing arrangement suitable for a pressurized container that contains a pressurized fire suppression agent, is provided comprising a housing having a flow passage for the flow of fire suppression agent; a closure member movable between a closed position wherein the pressurized fire suppression agent is prevented from flowing through the flow passage, and an open position in which the fire suppression agent is allowed to flow through the flow passage; and a securing means movable between a secured position in which the securing means secures the closure member in its closed position, and a released position in which the securing means releases the closure member, enabling it to move to its open position, the securing means being adapted to be actuated from its secured position to its released position by pressurized actuation fluid.

The dispensing arrangement may further include an actuation means to release the pressurized actuation fluid, thereby causing the holding member to move towards the released position.

The actuation means may include a sensor adapted to detect heat or a flash of light of a particular wavelength from an explosion.

The closure member may be in the form of a piston or shuttle movable within the flow passage so that in it's closed position it closes an outlet port in the flow passage and in its open position the outlet port is unobstructed to permit the discharge of fire suppression agent.

The dispensing arrangement may further include a distribution compartment from which the pressurized fire suppression agent may be routed to a plurality of locations. The securing means may comprise an engaging member adapted to engage the closure member in its closed position in the flow passage; and an actuating member movable between an un-actuated position in which the engaging member is engaged with the closure member, thereby preventing movement of the closure member, and an actuated position in which the engaging member is released from their locking position and allowing movement of the closure member.

The actuating member may be located within an annular slot on the housing.

The actuating member may be sealed against the sides of the annular slot by means of O-rings on the inside surface and outside surface of the actuating member.

The flow passage may be in the form of a cylindrical bore.

The closure member may be in the form of a piston movable within the cylindrical bore.

The actuating member may be an annular collar configured and dimensioned to move in a sliding fashion along the cylindrical bore. The annular collar member may have an annular channel along its inner surface for receiving the engaging member when the collar member is in its actuated position.

The cylindrical bore may have an aperture for receiving the engaging member.

The engaging members may be configured and dimensioned to protrude inwardly through the apertures in the walls the cylindrical bore when the annular collar is in the un-actuated position.

The engaging members may be configured and dimensioned so as not to protrude into the cylindrical bore when the annular collar is in the actuated position and the engaging members have been received into the annular channel, thereby allowing the closure member to be ejected from the cylindrical bore.

The piston may have a piston seal means to enable the piston to seal the cylindrical bore closed when the piston is in the closed position.

The securing means may comprise a plurality of engaging members.

The cylindrical bore may have a plurality of apertures for receiving the engaging members. The engaging members may be spherical balls. The engaging members may be spherical metal balls. The piston seal means may preferably be an O-ring seal.

A source of pressurized actuation fluid for release by the actuation means may be provided by the pressurized container or from another source. The dispensing arrangement may further include a failsafe flow passage between the source of pressurized actuation fluid and the annular slot. The failsafe flow passage may be blocked by a plug. The failsafe flow passage may be through the piston. The plugs may be composed of material having a low melting point, so that if the actuation means fails, the increased heat from a fire or explosion will cause the plug to melt, thereby allowing the release of pressurized fire suppression agent. In a preferred embodiment, the plug will be made of lead or a lead alloy.

The failsafe plugs may be composed of a temperature sensitive glass bulb that ruptures at a predetermined temperature.

The plug may be a pressure release valve rated to a predetermined pressure, so that if an increase in heat causes the pressure of the pressurized actuating fluid to increase, the pressure release valve will release the excess pressure, thereby causing actuation of the dispensing arrangement.

These and other features of the invention are described in more detail below.

Specific Embodiment of the Invention

An embodiment of the invention is described below purely as an example thereof and without limiting the scope of the invention with reference to the accompanying drawings, wherein:

Figure 1 is an exploded perspective view of a dispensing arrangement according to the invention, as it would be assembled;

Figure 2 is a cross section of a dispensing arrangement according to the invention in the closed before it is actuated;

Figure 3 is an exploded perspective view of a dispensing arrangement according to the invention during actuation;

Figure 4 is a cross-sectional view of a dispensing arrangement according to the invention after actuation; and

Figure 5 schematic diagram setting out the dispensing arrangement in an embodiment showing how the sensor and actuation valve would be connected with a source of actuation fluid such as a compressed air cylinder.

With reference to the drawings, a dispensing arrangement is generally indicated by reference numeral 10.

A dispensing arrangement 10 suitable for a pressurized container 12 that contains a pressurized fire suppression agent 14, is provided comprising a housing 16 having a flow passage 18 for the flow of fire suppression agent 14; a closure member, in the form of a piston 20, movable between a closed position wherein the pressurized fire suppression agent 14 is held contained within the pressurized container 12, and an open position in which the fire suppression agent 14 is released from the pressurized container 12. A cylindrical bore 26, which extends through the housing 16, defines the flow passage 18, and the piston 20 seals against the inner wall of the cylindrical bore 26 by means of an CD- ring seal 30 located around the piston 20. The piston 20 also has a circumferential slot 34 around its outer surface. The cylindrical bore 26 has a plurality of radially spaced circular apertures 32 through it.

The dispensing arrangement 10 further comprises a securing means. The securing means is comprised of a plurality of engaging members in the form of steel balls 22; and an actuating member in the form of an annular collar 24. The annular collar 24 has an inner diameter that is slightly larger than the outer diameter of the cylindrical bore 26, allowing the annular collar 24 to slide along the cylindrical bore 26 between a secured position as shown in Figure 1 , and a released position as shown in Figure 2. The annular collar 24 also has an annular channel 28 on its inner surface, located towards the top of the annular collar 24.

The annular collar24 is located within an annular slot 36 formed between the cylindrical bore 26 and the housing 16. The annular member forms a seal against the sides of the annular slot 36 by means of collar O-rings 38.

The housing 16 incorporates an actuation flow passage 40 through it. The actuation flow passage 40 is connected to an actuation means. The actuation means comprises a sensor 100 for detecting a fire or detonation, such as a heat sensor or a sensor adapted to sense light of a particular wavelength, a source of pressurized actuation fluid such as a compressed air cylinder 110 as well as an actuation valve 120 for allowing flow of the pressurized actuation fluid through the actuation flow passage 40 in response to the detection of an event by the sensor 100.

In use, the sensor 100 will detect an event such as a flash or heat above a predetermined level, and will open the actuation valve 120, which will allow pressurized actuation fluid to flow through the actuation flow passage 40 into the annular slot 36. The increased pressure within the annular slot 36 will cause the annular collar 24 to move from its secured position to its released position.

When the annular collar 24 is in its secured position as shown in Figure 1 , the steel balls 22, which are received into the apertures 32, abut against the portion of the inside surface of the annular collar 24 beneath the annular channel 28. It is envisaged that the annular collar 24 can have a circumferential indentation 39 around its inner surface at the level that the steel balls 22 abut the inner surface of the annular collar. The force of the steel balls 22 against the circumferential indentation would serve to hold the weight of the annular collar 24 up.

In this position, the steel balls 22 protrude through the apertures 32 into the flow passage 18. The steel balls 22 protrude into the circumferential slot 34 in the piston 20, preventing the piston 20 from moving downwards under the pressure of the pressurized fire suppression agent 14.

When the annular collar 24 moves downwards into its released position as shown in Figure 2, the annular channel 28 is aligned with the apertures 32 in the cylindrical bore 26. The steel balls 22 are pushed outwardly by the piston 20, so that the balls 22 are received into the annular channel 28. In this position, the steel balls do not protrude through the apertures 32 into the flow passage 18, and do not act as an obstruction to the movement of the piston 20 through the flow passage 18 any longer.

The piston is then ejected from the flow passage into the bottom of a distribution compartment 42, thus releasing the flow of pressurized fire suppression agent 14. The distribution compartment 42 has a plurality of openings 44 in its sidewalls, through which the pressurized fire suppression agent 14 may be routed to various locations where it will be most effectively deployed. The conical shape of the top of the piston 20 will act to deflect the flow of pressurized fire suppression agent 14 into the openings 44.

It is envisaged that the source of pressurized actuation fluid may be the pressurized fire suppression agent 14 itself.

It is further envisaged that the dispensing arrangement 10 may be made failsafe by including a failsafe flow passage 46 between the source of pressurized actuation fluid and the annular slot 36. The failsafe flow passage is blocked by a plug 48. It is envisaged that the plug 48 will be made of lead or lead alloys, and will melt at raised temperatures caused by a fire or explosion. Should the actuation means fail, the raised temperatures caused by a fire or explosion will cause the plug 48 to at least partially melt, thus allowing flow of the pressurized actuating fluid into the annular slot 36, causing the release of the pressurized fire suppression agent 14.

The failsafe flow passage 46 could alternately be through the piston 20, as a form of direct release of the pressurized fire suppression agent 14.

Many embodiments and variations are possible without departing from the spirit or scope of the invention as set out in the consistory clauses above. For example, the failsafe flow passage 46 may be an aperture in the cylindrical bore 26 between the pressurized flow suppression agent 14 and the annular slot 36, or the failsafe flow passage may be between an independent source of pressurized actuation fluid and the annular slot. Further, the plug 48 may alternately be a shattering glass plug known in the art, which is rated to a specific temperature or pressure. The plug 48 can alternately be a pressure release valve rated to a predetermined pressure, so that if an increase in heat causes the pressure of the pressurized actuating fluid to increase, the pressure release valve will release the excess pressure, thereby causing actuation of the dispensing arrangement.