WO2009091277A1

WO2009091277A1 - Locking-releasing head for a powder fire extinguisher

Info

Publication number: WO2009091277A1
Application number: PCT/RU2008/000020
Authority: WO
Inventors: Boris Konstantinovich Zuev
Original assignee: Obschestvo S Ogranichennoi Otvetstvennostyu 'nauchno-Proizvodstvenny Komplex 'bazalt'
Priority date: 2008-01-15
Filing date: 2008-01-15
Publication date: 2009-07-23

Abstract

The inventive locking-releasing head is designed for rechargeable powder fire extinguishers, from which the powder is released at positive pressure, and can be used as a primary means for extinguishing class A, B and C fires. The locking-releasing head comprises a body (1) provided with an axially displaceable hollow rod (8). A pressure indicator (11) is attached to one end of the rod and a flange (9) is formed on the other end thereof. A hollow elastic cylinder (19) which embraces the flange and the outer surface of the end section of the rod, thereby forming a valve (21), is arranged inside the hollow rod. The invention is characterised in that the end section of the rod (8) embraced by the wall of the elastic cylinder from outside has a diameter which is larger than the diameter of the middle section thereof and, in essence, is equal to the diameter of the smallest flow area of a seat, and the flange diameter is equal to 1.1-1.2 of the diameter of the smallest flow area of said seat. The inventive head exhibits the high technical-and-economic characteristics, ensures the high reliability of tightness of the valve and seat joint by preventing the valve rubber from flowing into clearances, that is substantial for the rechargeable fire extinguishers the tightness of which must be preserved for a long time.

Description

POWDER FIRE EXTINGUISHER LOCKING HEAD

Technical field

The invention relates to fire fighting equipment, namely, to the locking and starting heads of injection powder fire extinguishers, in which the fire extinguishing powder is ejected under excessive pressure, and may find application as a primary means of extinguishing fires of class A (solids), class B (liquid substances) , class C (gaseous substances), electrical installations under voltage up to 1000 V, as well as in automobile, railway and river transport.

State of the art

Known manual fire extinguisher according to SU 607576, containing a cylinder, a locking device with a spring-loaded valve having a rod, a pressure gauge and a siphon tube mounted in the neck under the valve. In this case, the siphon tube is freely installed in the neck of the cylinder for axial movement to contact the valve and has a travel stop and a piston mounted on its upper end, while the pressure gauge is located on the valve stem and is made in the form of a flag.

When the fire extinguisher is injected inside the cylinder, the pressure rises and the siphon tube connected with the piston rises up to the stop in the end surface of the valve, compressing the spring and raising the valve to a certain height. In this case, the cylinder is locked, and the flag, stopping opposite a certain risk on the scale, registers the pressure in the cylinder.

The disadvantages of the above devices include:

- the presence of a pair of "piston-cylinder" makes high demands on the accuracy and purity of manufacture of mating parts, which leads to an increase in the complexity of manufacturing;

- the movable piston seal is less reliable than the stationary one, which increases the likelihood of depressurization of the fire extinguisher during storage.

Also known is the locking-starting head for a powder fire extinguisher according to the patent US 2681707, comprising a housing with fastening elements to the tank a fire extinguisher, a handle connected to the housing, a shut-off device having a stem with a valve fixed to it, a control lever, a siphon tube, a pressure indicator and spray nozzles.

The above disadvantages are not resolved in this head.

Closest to the present invention is a locking and starting head according to patent RU 2205672, comprising a housing with fastening elements to a fire extinguisher tank, a handle connected to the housing, a locking device in the form of a hollow rod with a valve and pressure indicator fixed to it, a siphon tube and a spray nozzle.

A distinctive feature of the head is that in it the valve and indicator membrane are made in one piece in the form of an elastic hollow glass located inside the hollow stem. Moreover, the diameter of the stem flange on which the valve part formed by the edges of the walls of the glass is fixed is equal to the minimum diameter of the valve seat. The preservation of the shape of the elastic cup during the injection of the fire extinguisher is ensured by the fact that the membrane contacts the package of elastic indicator washers, and the outer side surfaces of the elastic cup repeat the inner contours of the rod in which it is located. In this design, the valve opening and closing is controlled by the direct action of the lever on the indicator connected to the valve through the stem and installed coaxially in the housing. The gap between the cylinder of the body and the side surface of the indicator is sealed with a rubber cuff, worn with an interference fit on the rod and pressed against the bottom of the indicator.

The disadvantage of this head is the insufficiently high reliability of the locking device when exposed to high pressure of compressed air located in the tank of the fire extinguisher. This is due to the presence of a significant gap between the minimum diameter of the valve seat and the outer diameter of the hollow stem, since to ensure the collection of the head, the diameter of the stem flange is equal to the minimum diameter of the valve seat. Thus, the locking surface of the valve under the influence of pressure flows into the specified gap, while it is strongly deformed, which can lead to destruction of the valve, followed by depressurization of the fire extinguisher. At the same time, the small difference in the diameters of the flange and the stem does not provide reliable fixation of the valve part on the stem.

The objective of the invention is to increase the reliability of the locking device. Disclosure of invention

This problem is solved by the fact that in the shut-off and start-up head of a powder fire extinguisher, comprising a housing with a handle and fasteners to the fire extinguisher reservoir, a hollow rod coaxially mounted in the housing with the possibility of axial movement, a pressure indicator is attached to one end of it and a flange is formed at the other end , a valve covering the end of the stem with the specified flange, a seat formed by the housing, a control lever pivotally mounted on the housing with the possibility of acting on the stem, siphon tube, connected to the body and the spray nozzle according to the invention, the end part of the stem covered by the valve outside the middle part of the stem has an enlarged diameter substantially equal to the diameter of the minimum passage section of the seat, and the diameter of the flange is 1.1 to 1.2 times the diameter of the minimum passage section of the saddle.

Preferably, the non-contacting portion of the valve is enclosed in a thin-walled shell having at least one opening for communicating the submembrane and subvalvular cavities. It is desirable that said shell be fixed to the valve by crimping onto a return cone.

Advantageously, the valve is pressed against the seat by a spring installed in a siphon tube. In this case, the siphon tube may have an expanded part for accommodating a spring therein.

In addition, the housing can be made of two parts rigidly interconnected, one of which is a sleeve with fasteners to the fire extinguisher reservoir and to the siphon tube, and the saddle is formed by the wall of this sleeve. In this case, the housing parts are interconnected by contact welding.

The valve can be formed by covering the flange and the outer surface of the end part of the stem with a wall of a hollow elastic cup installed in the stem, the bottom of which is a pressure indicator membrane.

The design, in which the end part of the stem covered by the valve in comparison with the middle part of the stem has an enlarged diameter substantially equal to the diameter of the minimum bore, eliminates the annular gap between the minimum bore of the valve seat bore and the lateral surface adjacent to it in the closed position of the valve stock. The specified gap is within the tolerance for a movable landing. In this way, squeezing the elastic material of the valve into this gap under the influence of pressure is excluded, and the locking conical surface of the valve fits tightly in the seat with high reliability and durability of the joint sealing.

The diameter of the flange, which is 1.1 to 1.2 of the diameter of the minimum passage section of the seat, is selected, on the one hand, based on the condition of reliable fixation of the valve on it, and on the other hand, on the condition of maintaining the integrity and the necessary strength of the elastic material of the valve.

The presence of a thin-walled shell covering the non-contacting part of the valve prevents the valve from deforming in the radial direction, increasing the reliability of its fixation on the stem flange. At the same time, fixing the shell to the valve by crimping it onto the return cone ensures its reliable connection with the valve.

Brief Description of the Drawings

In FIG. 1 shows a trigger head of a powder fire extinguisher in accordance with the present invention, a sectional side view; in FIG. 2 shows a view A in FIG. one.

The best embodiment of the invention

The locking-starting head contains a housing 1 made by stamping from sheet metal in one piece with a handle 2. The lever 3 is connected to the housing 1 by means of a swivel 4. In the lower part of the housing there is a coaxial sleeve 5 attached, for example, by contact welding. An external thread 6 is formed on the outer surface of the sleeve 5 for screwing the locking and starting head into the opening of the fire extinguisher tank (not shown conditionally).

A saddle 7 having the shape of a truncated cone is stamped in the upper part of the sleeve 5.

In the housing 1 is installed a hollow rod 8, made with the possibility of axial movement. The walls of the lower part of the rod 8 are bent outward with the formation of the flange 9.

An indicator 11 is located in the upper diameter-enlarged portion of the stem 8 forming the cup 10, and the lever-gear mechanism 12 rotates arrows 13. The indicator 11 is fixed in the cup 10 of the rod 8 by crimping the edges of the cup 10 and then pressing the cap 14. Before by pressing the cap 14, the sealing ring 15 and the glass 16 are installed. The readings of the arrow 13 on the scale 17 (Fig. 2) are read through the window 18, made in the lever 3.

In the cavity of the rod 8, repeating its internal contours, an elastic cup 19 is located, the bottom of which is the membrane 20 of the indicator 11, and the edges 8, worn on the flange 9 of the rod 8 and covering its lower extended part, are a valve 21. Outside the rod 8, in contact with the cup 10, a sleeve 22 is inserted that seals the movable connection of the rod 8 to the housing 1 during operation of the fire extinguisher.

Between the bottom plate of the indicator 11 and the membrane 20 of the elastic cup 19, an elastic washer 23 is mounted kinematically connected with the two-arm lever 24 of the indicator 11.

To prevent deformation of the valve 21, its part, which is not in contact with the seat, is enclosed in a ferrule 25, which is fixed to the indicated part of the valve by compression on the inverse cone.

It should be noted that the operations of forming the flange 9, putting on the valve 21 and installing the holder 25 are carried out at the assembly stage, when the rod 8, pre-assembled with the indicator 11, an elastic washer 23, glass 16 and cap 14, is installed in the housing 1 with the rear end position.

Such an assembly is possible if the diameter of the lower expanded part of the stem 8 does not exceed the minimum diameter of the seat 7, since the assembly is carried out in the direction from top to bottom.

The lever 3 is pivotally connected to the housing 1 (Fig. 1) and locked in its initial position by a pin 26 (Fig. 2). The lever 3 is made by stamping and has a U-shaped cross-section. The side walls of the lever 3 cover the handle 2 of the housing 1 (Fig. 1), and they are made inwardly bent protrusions 27 to prevent the lever 3 from disconnecting.

A siphon tube 28 is installed in the lower part of the head by means of, for example, a two-way thread 29. A spring 30 is installed between the rod 8 and the siphon tube 28, which compresses the valve to the seat. In the side of the housing 1, an opening 31 is made with an internal thread 32 in which the spray nozzles 33 are installed (Fig. 1).

To seal the joint between the sleeve 5 and the tank of the fire extinguisher, a rubber ring 34 is installed in the groove of the sleeve (Fig. 1).

The head works as follows. When extinguishing the fire, the check 26 is removed, releasing the lever 3. After removing the checks 26, the bent ends 27 of the lever 3, covering the handle 2 of the housing 1, prevent the lever 3 from disengaging from the housing 1 and, thus, its loss in case of emergency handling of the fire extinguisher.

When you press the lever 3, he, overcoming the pressure force of compressed air and the resistance of the spring 30, through the cap 14 and the stem 8 moves the valve 21, opening the passage for the powder. Fire extinguishing powder under the action of excessive pressure in the tank of the fire extinguisher through a siphon tube 28, the gap between the valve 21 and the seat 7 and the spray nozzles 33 is thrown into the zone of the fire.

During the injection of the fire extinguisher, its storage in official circulation and when extinguishing the fire, the arrow 13 of indicator 11 shows the pressure in the tank on a scale 17 (Fig. 2). In this case, the position of the arrow 13 against risks “14” corresponds to the state of the inflated fire extinguisher. Monitoring the indications of the indicator 11 can be carried out directly during operation with a fire extinguisher, looking from above through the window 18 in the lever.

The movement of the arrow 13 in the direction of increasing pressure is as follows.

The pressure force of the compressed air pumped into the reservoir is perceived by the membrane 20 of the elastic cup 19 (Fig. 1) and transmitted to the elastic washer 23, which, when deformed, acts on the two-arm lever 24.

The two-armed lever 24 (Fig. 1) converts the deformation (movement) of the washer 23 into a rotation of the gear sector, which rotates the tribe on the axis on which arrow 13 is mounted (Fig. 2). Simultaneously with the rotation of the arrow, a spiral spring is connected, connected with the tribe. When the specified pressure is reached, the arrow 13 and the entire mechanical system are in this position throughout the entire storage period.

In the process of using a fire extinguisher as a fire extinguishing agent, the pressure in the tank drops and arrow 13 (Fig. 2) makes a return stroke under the action of a spiral spring.

When the arrow 13 reaches a zero value on the scale 17, the entire mechanical indicator system returns to its original position, and the valve 21 sits in the seat 7 under the action of the spring 30.

In the head corresponding to the present invention, along with high technical and economic indicators, high sealing reliability is achieved the joint of the valve with the seat due to the elimination of the flow of rubber of the valve into the gaps, which is very important for injection fire extinguishers, the tightness of which must be maintained for a long time.

Claims

CLAIM

1. The locking and starting head of the powder fire extinguisher, comprising a housing with a handle and fasteners to the tank of the fire extinguisher; a hollow rod coaxially mounted in the housing with the possibility of axial movement, a pressure indicator is attached to one end of the rod, and a flange is formed at the other end; a valve covering the end of the stem with the specified flange; saddle formed by the body; a control lever pivotally mounted on the housing with the possibility of impact on the rod; siphon tube connected to the housing; and spray nozzles, characterized in that the end portion of the stem covered by the valve, compared to the middle portion of the stem, has an enlarged diameter substantially equal to the diameter of the minimum passage section of the seat, and the diameter of the flange is 1.1 to 1.2 times the diameter of the minimum passage section of the seat .

2. The locking-starting head according to claim 1, characterized in that the non-contacting part of the valve is enclosed in a thin-walled shell having at least one opening for communicating the submembrane and subvalvular cavities.

3. The locking-starting head according to claim 2, characterized in that the casing is fixed to the valve by compression on the return cone.

4. Lock-trigger head according to any one of paragraphs. 1 - 3, characterized in that the valve is pressed against the seat by a spring installed in a siphon tube.

5. The locking-starting head according to claim 4, characterized in that the siphon tube has an expanded part for accommodating a spring therein.

6. The locking-starting head according to claim 1, characterized in that the housing is made of two parts rigidly interconnected, one of which is a sleeve with fastening elements to the fire extinguisher tank and to the siphon tube, while the saddle is formed by the wall of this sleeve.

7. The locking-starting head according to claim 6, characterized in that the housing parts are interconnected by contact welding.

8. The locking-starting head according to claim 1, characterized in that a hollow elastic cup is installed in the stem, the bottom of which is a pressure indicator membrane, and from the opposite end the wall of the elastic cup covers the flange and the outer surface of the stem end portion with the formation of a valve.