WO2006096892A1

WO2006096892A1 - Safety closure valve for fluid fuel operated appliances

Info

Publication number: WO2006096892A1
Application number: PCT/ZA2006/000026
Authority: WO
Inventors: Sidney Richard Hart
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-03-08
Filing date: 2006-02-20
Publication date: 2006-09-14
Anticipated expiration: 2007-09-08

Abstract

A safety closure valve comprises a body (1) having a fluid passage communicating between a fluid inlet (2, 22, 32) and a fluid outlet (3, 24, 33), a valve comprising a valve seat (16, 28, 39) and cooperating valve closure member (15, 27, 37) between the fluid inlet and fluid outlet, and a valve operating member movable between a normal terminal position in which the valve is open and a shut-off terminal position in which the valve is closed. The valve operating member is in the form of a loose weighty operating member (13, 25, 35) located within an enclosure (10, 23, 34) configured such that, in a normal operative orientation of the safety closure valve the valve closure member is in an open condition, and such that in an abnormal transverse orientation, the weighty operating member is in a shut-off terminal position in which its weight acts directly or indirectly on the valve closure member to urge it into engagement with the valve seat to close the valve.

Description

SAFETY CLOSURE VALVE FOR FLUID FUEL OPERATED APPLIANCES

FIELD OF THE INVENTION

This invention relates to a safety closure valve for fluid fuel operated appliances that employ a supply of liquid or gaseous fuel that operatively flows from a source thereof, typically a fuel tank, to a burner head or the like. More particularly, the invention relates to a safety closure valve for installation between a fuel supply tank and a burner head or the like in which the relevant appliance is freestanding and generally a portable appliance.

BACKGROUND TO THE INVENTION

Appliances of the general nature under consideration typically have a fuel tank that may stand on legs or a supporting foot or ring and to the top of which is fitted the appropriate burner that may be associated with a cooker (often referred to as a gas ring); a heater; an illuminating lamp or other types of appliances. Such appliances are usually portable in nature and therefore freestanding, in use. Typical of such fluid fuel fired appliances are paraffin or kerosene fired cookers and lamps; kerosene (paraffin) fired pressure stoves and lamps; and low pressure gas (LPG) or butane gas fired appliances such as stoves, lamps and heaters.

Such appliances are generally accompanied by the danger that, in the event that they are knocked over accidentally, they can start a destructive fire. In the case of liquid fuel fired appliances the liquid fuel can run out and become ignited by the already burning flame. In the case of gas fired appliances, the gas may continue to flow thereby supporting a flame that may come into contact with combustible items and, indeed, in the case of liquefied gas in a tank, liquid gas can be expelled through the burner thereby exacerbating the problem by spreading the flame some distance.

OBJECT OF THE INVENTION

It is an object of this invention to provide a safety closure valve that can be used to cut off the supply of fuel to an associated appliance in the event that it is knocked over.

SUMMARY OF THE INVENTION

In accordance with this invention there is provided a safety closure valve comprising a body having a fluid passage communicating between a fluid inlet and a fluid outlet, a valve comprising a valve seat and cooperating valve closure member between the fluid inlet and fluid outlet, and a valve operating member movable between a normal terminal position in which the valve is open and a shut-off terminal position in which the valve is closed, the safety closure valve being characterized in that the valve operating member is in the form of a loose weighty operating member located within an enclosure configured such that, in a normal operative orientation of the safety closure valve the valve closure member is in an open condition, and such that in an abnormal transverse orientation, the weighty operating member is in a shut- off terminal position in which its weight acts directly or indirectly on the valve closure member to urge it into engagement with the valve seat to close the valve.

Further features of the invention provide for the outlet to be located at an operatively upper end of the body in which case the valve closure member is preferably acted upon by gravity to maintain it in an open condition in the normal operative orientation; for the enclosure to be a cavity within the body; for the fluid inlet to be located at an operatively lower end of the body in which instance it is preferably coaxially with the outlet or, alternatively, at a position laterally offset in which case the passage through the valve may be by way of the cavity or may bypass the cavity conveniently above the cavity; for the inlet and outlet to be configured as a spigot and socket respectively for being received in, and for receiving, conventional screw threaded couplings provided on conventional fuel tanks and associated fittings having burners incorporated therein; and for the weighty operating member, that is preferably spherical in shape, to have a generally horizontal seat either in the form of a ring or squat conical surface for receiving it in a normal operative orientation of the closure valve and in which the closure member rests upon the weighty operating member and wherein the seat is configured to ensure that the weighty operating member either pivots around the seat or acts as a wedge when the body moves to a transverse orientation and in so doing urges the valve closure member into engagement with its valve seat.

In one preferred embodiment of the invention the valve closure member is a somewhat smaller diameter spherical body and the weighty operating member is a larger diameter spherical body. In another preferred embodiment of the invention the passage through the body bypasses the cavity and the valve closure member is an axially movable member coaxial with the outlet.

In order that the invention may be more fully understood different embodiments thereof will now be described with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:-

Figure 1 is a schematic sectional elevation of one embodiment of the invention in the operative orientation thereof; Figure 2 is a similar elevation of the same embodiment of the invention in a "knocked over" orientation in which the valve is closed;

Figure 3 illustrates a gas-fired cooker and associated fuel tank with the safety closure valve of this invention interposed between them;

Figure 4 is a schematic sectional elevation illustrating an application of the invention to a paraffin or kerosene fired pressure stove burner head;

Figure 5 is an exploded schematic elevation of an alternative arrangement suitable for a pressure stove burner head or the like; and,

Figure 6 is a detailed section of the safety closure valve illustrated in Figure 5.

DETAILED DESCRIPTION WITH REFERENCE TO THE DRAWINGS

In the embodiment of the invention illustrated in Figures 1 to 3 of the drawings, a safety closure valve comprises a body (1) that is typically of cylindrical shape having an axially orientated inlet (2) at the operatively lower end and a coaxial outlet (3) at the operatively upper end thereof. The inlet extends through an externally screw threaded spigot (4) complementary to a screw threaded socket (5) associated with a fuel tank (6) and the outlet extends through a complementary screw threaded socket (7) that is configured to receive the screw threaded spigot (8) of a gas cooker (9), as illustrated in Figure 3. The interior of the body is formed into a cavity (10) of generally right circular cylindrical shape and wherein the inlet (2) merges into the cavity by way of an enlarged diameter zone (11) that in turn enters the cavity by way of a circular seat (12). The circular seat is configured such that in the normal operating orientation of the valve that is illustrated in Figure 1 it is generally horizontal and receives a weighty operating member in the form of a large diameter metal sphere (13) that rests upon it. The circular seat has a set of circumferentially spaced notches (14) providing for flow of fuel past the surface of the large diameter sphere, in use, when it rests on the circular seat.

Resting on top of the large diameter sphere is a considerably smaller diameter metal sphere that forms a valve closure member (15) and that is held captive, although loosely in the normal operating orientation, within a truncated conical valve seat (16) communicating with the outlet.

The above arrangement is such that, in the normal operating orientation of the safety closure valve that is illustrated in Figure 1 , the liquid or gaseous fuel can enter through the inlet; pass the larger diameter metal sphere by way of the notches; pass through the cavity; through the gap between the valve closure member (15) and valve seat (16); and through the outlet (3).

However, in the event that the associated tank and appliance is knocked over with the consequence that the safety closure valve moves to a generally horizontal position that is illustrated in Figure 2, the large diameter metal sphere is acted upon by gravity and tends to "pivot" about the circular seat (12) that acts in the manner of the fulcrum. This moves the part of the surface of the large diameter metal sphere remote from the circular seat sideways and, in consequence of the "pivoting" action, towards the outlet. This in turn urges the valve closure member (15) into engagement with its associated valve seat (16). The arrangement is such that, as illustrated in Figure 2, the large diameter sphere is supported in a suspended position between the closure member and the circular seat so that the full weight of the large diameter sphere is exerted on the closure member detergent into firm contact with the valve seat. This effectively shuts off any further supply of fuel to the associated burner and, accordingly, effectively prevents fuel from escaping from the tank and causing a destructive fire.

The invention may be applied to many other different types of burners in many different ways. Simply by way of example, one application thereof to the burner head of a kerosene fired pressure stove is illustrated schematically in Figure 4. The only real difference in this case is that the body of the safety closure valve is incorporated into the body (18) of the burner head such that it receives vaporised kerosene from the usual pair of diametrically opposed passages (19) that extend downwards from the vaporisation chamber (20) located, in the normal way, at the top of the burner head (21).

The pair of passages (22) open into the safety closure valve cavity (23) at two diametrically opposite locations in the side of the cavity and the outlet (24) from the cavity either forms, or receives, the burner nipple.

Figure 4 illustrates, in addition, a slight variation to the seat for the large diameter sphere (25) in that the sphere is supported on a squat truncated conical surface (26) having a cone angle selected so that the desired movement of the small diameter valve closure member (27) into engagement with its cooperating valve seat (28) is achieved when the valve is moved from its normal operating position to a transverse position.

In use, the embodiment of the invention illustrated in Figure 4 operates exactly as described above to close off the outlet as may become necessary and thereby interrupt the flow of vaporised kerosene to the outlet (24). A further alternative arrangement is illustrated in Figures 5 and 6 in which the passage (30) through the body (31) communicates between a pair of diametrically opposite inlets (32) and an axial outlet (33) all of which are located operatively above a cavity (34) containing a large diameter steel sphere (35). In this instance the valve closure member (36) is an axially movable plunger type having a truncated conical sealing surface (37) at its operatively upper end and a lower end (38) that extend into the cavity to cooperate directly with the large diameter sphere in the same manner as is described above.

The truncated conical sealing surface (37) is in cooperating relationship relative to a circular valve seat (39) such that under normal operating conditions the valve is open and when the valve is moved to a generally horizontal condition, the weight of the large diameter sphere acts on the lower end (38) of the valve closure member to cause the valve to close.

This arrangement is particularly convenient for manufacture purposes as it lends itself to press fitting a closure (40) having the circular seat (41) for supporting the large diameter sphere in order to form the cavity and to press fitting the body (31) to a burner head (41) (see Figure 5).

It will be understood that numerous variations may be made to the embodiments of the invention described above without departing from the scope hereof.

Claims

CLAIMS:

1. A safety closure valve comprising a body (1) having a fluid passage communicating between a fluid inlet (2, 22, 32) and a fluid outlet (3, 24, 33), a valve comprising a valve seat (16, 28, 39) and cooperating valve closure member (15, 27, 37) between the fluid inlet and fluid outlet, and a valve operating member movable between a normal terminal position in which the valve is open and a shut-off terminal position in which the valve is closed, the safety closure valve being characterized in that the valve operating member is in the form of a loose weighty operating member (13, 25, 35) located within an enclosure (10, 23, 34) configured such that, in a normal operative orientation of the safety closure valve the valve closure member is in an open condition, and such that in an abnormal transverse orientation, the weighty operating member is in a shut-off terminal position in which its weight acts directly or indirectly on the valve closure member to urge it into engagement with the valve seat to close the valve.

2. A safety closure valve as claimed in claim 1 in which the outlet is located at an operatively upper end of the body.

3. A safety closure valve as claimed in claim 2 in which the valve closure member is acted upon by gravity to maintain it in an open condition in the normal operative orientation.

4. A safety closure valve as claimed in any one of the preceding claims in which the enclosure is a cavity within the body.

5. A safety closure valve as claimed in any one of the preceding claims in which the fluid inlet (2, 22) is located in an operatively lower region of the body in which instance the passage passes through the enclosure and forms part thereof.

6. A safety closure valve as claimed in any one of claims 1 to 4 in which the fluid inlet (22, 32) is at a position laterally offset in which case the passage through the valve may be by way of the enclosure or may bypass the enclosure above the cavity.

7. A safety closure valve as claimed in any one of the preceding claims in which the inlet and outlet are configured as a spigot (4) and socket

(7) respectively for being received in, and for receiving, conventional screw threaded couplings (5, 8) provided on conventional fuel tanks (6) and associated fittings (9, 21, 41) having burners incorporated therein.

8. A safety closure valve as claimed in any one of the preceding claims in which the loose weighty operating member is spherical in shape and a generally horizontal seat either in the form of a ring (12, 41) or squat conical surface (26) is provided for supporting it in a normal operative orientation of the closure valve and wherein the closure member rests upon the weighty operating member and wherein the seat is configured to ensure that the weighty operating member either pivots around the seat or acts as a wedge when the body moves to a transverse orientation so as to operatively urge the valve closure member into engagement with its valve seat.

9. A safety closure valve as claimed in any one of the preceding claims in which the valve closure member is a somewhat smaller diameter spherical body (15, 27) and the weighty operating member is a larger diameter spherical body (13, 25).

10. A safety closure valve as claimed in any one of claims 1 to 8 in which the valve closure member (36) is an axially movable member coaxial with the outlet (33).