The present invention relates to a nozzle, preferably for extinguishing fire with water, more particularly a nozzle that can be adjusted from a position for emitting a jet stream to a position for emitting water fog, and that automatically returns to the fog position upon loss of water pressure or If the person operating the hose loses his grip on the nozzle.

A nozzle for extinguishing fire may be either a fixedly secured "water cannon" or a mouthpiece on a manually operated hose. Such nozzles are usually adjustable between a jet stream position and a fog position, depending upon the requirements of a given situation. Upon loss of water pressure, traditional nozzles will remain in their position unless a deliberate readjustment is made. When the pressure subsequently is turned on again and the nozzle is in the jet position, very dangerous situations may arise.

In the case of a hand-held hose, such a circumstance may lead to the hose operator losing control of the hose because of the sudden and powerful jet stream. The hose will then be flung about and may cause both injuries to people and damage to equipment until such time as the water pressure again is shut off, allowing the hose operator to regain control of the hose.

For fixedly secured, and possibly remotely controlled, water cannons, which are commonly used on, for example, helicopter decks of oil platforms and the like, a sudden release of such a water cannon, whether unintended or intentional, may cause havoc. Equipment lying in the path of the stream may be very seriously damaged by such a concentrated jet of water; personnel in the path of the jet stream will not only be injured by the water jet itself, but may also be thrown overboard thereby.

Fixedly secured water cannons are often remotely controlled, so that an operator can regulate both the direction of the stream and the stream characteristics. In such cases, remotely controlled motors make the adjustments between fog and jet stream positions. When water cannons are used, either in routine fire drills or in a fire situation in which the water cannon has been used in a jet position, the established routines show that the water cannon is readjusted to fog position in order to prevent the dangerous situations mentioned above.

However, in case of failure of the control system or of the routines, the water cannon might be left in its jet position, a situation which would not be discovered until the next time the water cannon is used. The operator has very few, if any, possibilities of checking the position of the water cannon before he actually observes the characteristics of the stream.

Nozzles which can be adjusted from fog to a jet stream position are well known in many variants, for example as shown in US patents 2,991,016 and 3,784,113.

A nozzle for automatic return to fog position is previously known. This nozzle, which is produced by Haisley Firetech Limited, has a cylinder disposed across the inner body of the nozzle and provided with a piston pressing a ball into engagement with a helical groove on the outer body of the nozzle. This nozzle has the following disadvantages: it has only one ball engaging with the helical groove; the direct pressure on the ball by the piston provides insufficient force for reliable locking; the geometrical relations make unwanted locking possible even when the pressure is removed; and the cylinder occupies a substantial part of the interior cross section of the nozzle, thereby disturbing the flow patterns of the nozzle and reducing its capacity. It has

also been shown in practice that this nozzle does not ensure reliable operation.

An object of the present invention is thus to provide a nozzle, preferably for fire extinguishing purposes, which can be adjusted between a jet stream and a fog position, and which upon loss of water pressure automatically assumes the fog position, at the same time as the disadvantages of the known nozzle are avoided.

This object is achieved by the present invention by means of a nozzle, preferably for the purpose of extinguishing fire, comprising an inner and an outer tubular body which can be rotated and longitudinally displaced in relation to each other, where one of the bodies has one or more helical grooves for engagement with corresponding engagement members on the other body, and where the nozzle is adapted to be adjusted between a jet stream position and a fog position in that the inner and the outer body are rotated in relation to each other and are thereby displaced in the longitudinal direction in relation to each other by the engagement between the helical groove and the engagement member, the nozzle being characterized in that two or more engagement members are adapted to be pressed into engagement with one of more helical grooves when fluid is discharged through the nozzle and to be disengaged when the fluid pressure in the nozzle falls below a predetermined level.

In terms of hand-held hoses there is also the additional danger that the person directing the hose may lose his grip on the nozzle so that the hose and the nozzle in an un¬ controlled manner will be flung about and constitute a hazard to the surroundings, as described above.

Accordingly, another object of the present invention is to provide a fire extinguishing nozzle which, in addition to automatically assuming fog position upon loss of water

pressure, also automatically assumes this position when the person guiding the hose loses his grip on the nozzle.

This object is achieved by means of a nozzle of the above described type wherein, in addition, a release bolt having a narrowed-down portion is mounted in the flow path between the opening and the cylinder, so that the release bolt can be manually moved between two positions, one position in which a connection between the cylinder and the flow of fluid in the nozzle through the opening to the cylinder is established by means of the narrowed-down portion, the release bolt simultaneously closing off the drain aperture, and another position in which the release bolt prevents connection between the cylinder and the flow of fluid, leaving the drain aperture open.

The invention will now be explained with reference to the examples below and the enclosed drawings, where

Figure 1 shows a longitudinal section through a water nozzle according to the present invention, in a jet stream position.

Figure 2 shows a longitudinal section of the same nozzle in fog position.

Figure 3 shows a longitudinal section of another embodiment of the nozzle in which the nozzle is provided with a release handle shown in the pressed-in position.

Figure 4 shows a section of the device connected with the release handle, shown in the released position.

Figure 5 shows a longitudinal section of another nozzle according to the invention, in a jet stream position.

Figure 6 shows a longitudinal section of the same embodiment as Figure 5, in fog position.

The nozzles of the embodiments in all the drawings consist in principle of an outer 3 and an inner 2 approximately tubular body which are rotatable in relation to each other and can be longitudinally displaced in relation to each other. When the outer and the inner body 2,3 are rotated in relation to each other at the same time as the engagement members 15 of one of said bodies 2, 3 engage with helical groove(s) 19 on the other of bodies 2, 3, the bodies 2, 3 will then be displaced in relation to each other in the longitudinal direction according to essentially the same principle as used in known nozzles, for example nozzles for fire ex¬ tinguishing purposes.

The water enters in a known manner through the inlet 18 in the inlet base 1 from a water conduit system not shown. The inner cavity of the nozzle forms, as in known nozzles, a natural extension of the water conduit system through the inlet 18. The water then flows out of the nozzle between the deflector 6 and the throat 4. Depending upon the longitudi¬ nal positioning of the inner 2 and the outer 3 body relative to each other, the stream of water is either directed outward to the sprayer 31 on the spray ring 5 as shown in Figures 2 and 6 to produce fog, or held together by the straight sides of the interior surface of spray ring 5 and/or the outer body 3 as shown in Figures 1 and 5.

This principle of adjustment between fog and straight stream is well known from Inter alia the above mentioned U.S. patents.

The novelty of the present nozzle as shown in the drawings is that the engagement between the engagement member 15 and the helical groove 19 is terminated upon loss of fluid pressure from the conduit system, and that the inner and the outer body 2, 3 after being disengaged are moved by the return

spring 16 to those positions, relative to each other, that produce fog.

This is achieved in the embodiments of the present nozzle shown in the drawings in that the engagement member 15 consists of two or more balls which are positioned in ball ports 21 in the wall of either the outer or the inner body

2, 3 and which rest against the side formed by the cut 22 in the piston 7. The cut 22 forms an inclined plane which presses the ball 15 partly out of the ball port 21 when the piston 7 is moved forward by the fluid pressure in the nozzle through the opening 20, so that the ball is pressed against the wall of the other body 2,3 and engages with the helical groove 19 on the other body 2,3 when the bodies are rotated in relation to each other. Preferably, the axes of the piston 7 and the cylinder 23 are approximately parallel to the longitudinal axis of the nozzle.

Example 1

In the most preferred embodiment shown in Figures 1 and 2 the piston 7 is annular and is positioned in an annular cylinder 23 in the outer body 3. The outer body can consist of one part in which the cylinder 23 for instance is cast or turned, or it can be composed of two parts screwed together as shown in Figures 1-2, so that the annular cylinder is formed between these two parts which are screwed together.

When water flows through the nozzle, the piston 7 is pressed forward in the nozzle by the water pressure against the bottom of the piston through the opening 20. Around the periphery of the piston there are positioned at least two balls, each In its own ball port 21 in the interior wall of the outer body 3. These balls 15 are preferably positioned in the same plane, as shown in the drawings, but they can also be displaced in relation to each other in the longitudi¬ nal direction of the nozzle. If the balls 15, as shown here,

lie in the same plane, each ball is adapted for engagement with a helical groove 19 of its own, whereas two or more balls can be adapted for engagement with the same helical groove 19 if the balls are longitudinally displaced in relation to each other.

A control pin or pins 28 are fixedly secured to the inlet base 1, engage with the control groove 27 on the inner body 2 of the valve and prevent the inner body 2 from rotating in relation to the inlet base, but allow these to be displaced in relation to each other. The outer body 3 can be rotated in relation to the inlet base 1 and is prevented from being displaced in the longitudinal direction in relation to said base by a stop ring 42 secured to the inlet base 1, where a ball bearing 41 ensures that the outer body 3 can be easily rotated in relation to the inlet base.

When the outer body is rotated in relation to the inlet base without there being a fluid pressure in the nozzle, the balls 15 will rest in the ball ports 21 and the inner 2 and the outer 3 body will only rotate freely in relation to each other without a displacement in the longitudinal direction of the nozzle. The inner body 2 will then be pressed forward in the nozzle by the return spring 16 until it enters the position that provides fog. The inner body 2 is prevented from moving further forward than to the fog position by bumping against the back edge of the spray ring 5 which is secured to the outer body 3. This can naturally be achieved also by other means, for example by a separate stop ring.

When the water pressure is directed into the nozzle through the opening 20, the balls 15 are pressed into engagement with the helical groove(s) 19 as described above. By turning the outer body 3 in relation to the inlet base, the balls 15 will engage with the helical groove(s) 19, and a turn will cause the inner 2 and the outer 3 body to be displaced in relation to each other in the longitudinal direction so as to

achieve, in this manner, the adjustment of the stream as described above. The position providing a jet stream is obtained by pulling the inner body 2 backward in the nozzle, as shown in Figure 2.

When the water pressure in the nozzle is removed, the pressure against piston 7 ceases, piston 7 is pressed back by the piston spring 17, and the balls 15 are disengaged from the helical groove(s) 19, whereupon the inner body 2 is pressed back to the fog position by return spring 26 which is disposed between the inner and the outer body in order to press the inner body 2 into fog position.

Loss of water pressure may occur by intentional or uninten- tional shutting-off of water, but the fact that the nozzle returns to fog position prevents the unintentional occurrence of a hazardous jet stream when the water pressure returns.

Deflector 6, which together with the throat 4 defines the outlet orifice of the water, is mounted on a deflector support 9, which in the depicted nozzle has the form of a ring adapted for installation in the inner body 2 of the nozzle, and where the ring has radial supports for the stem

8. The deflector support 9 is mounted on the throat 4 which is secured to the inner body 2. The deflector 9 is secured to the stem 8 by any method, for example by their being screwed together. The distance marker 11 can be one or more rings or can be represented by a thicker portion of the stem

8. The length of the distance marker determines the distance between the deflector 6 and the throat 4 and thereby the capacity and stream characteristics of the nozzle.

The inner body 2 of the nozzle, the deflector support 9 and the throat 4 can of course be cast in one unit, but it is preferable to machine these parts separately and put them together as shown in the preferred embodiment. This makes

possible adjustments and adaptations of the nozzle, which are impossible with ready cast pieces.

The spray ring 5 is secured to the outer body of the nozzle. This outer body surrounds the inner body and can freely rotate and also be displaced in the longitudinal direction in relation to the inner body. O-rings 14 and a seal 25 prevent or minimize undesirable leakage in the nozzle. Spray ring 5 also prevents the inner body 2 from sliding out of the outer body 3.

A drain valve 32 having a valve ball 33 and a valve spring 34 contributes to a rapid fall in the pressure against piston 7 when the water pressure is removed. This drain valve is not necessary, but preferred. Particularly when a valve is mounted out of doors in an environment having variable temperature including frequent frost, it is desirable or even necessary that the valve and especially the cylinder 23 and the opening thereto, is completely emptied for water after use.

Motor control for regulating the stream may advantageously be installed in this embodiment. A motor (not shown) can then be used to rotate the outer body 3 in relation to the inlet base 1. Such an installation will be very simple since the outer ring moves only in a circular motion and not in the longitudinal direction. Such a motorized control may advantageously be supplied by an electric or hydraulic motor or actuator mounted on the inlet base 1 or in a location which remains rigid in relation thereto, and where a toothed wheel of the motor/actuator drives a toothed ring on the outer body 3. If the nozzle is to be manually controlled, it will be desirable that a handle be mounted on the outer body 3 in order to facilitate rotation.

Example 2

The embodiment of this example is shown in Figures 3 and 4, which show a special adaptation of the present nozzle for use on hand-held hoses. In addition to the functional aspects that have been described with regard to the em- bodiment of Example 1, shown in Figures 1 and 2, the nozzle is here provided with a release device comprising a release handle 35 having a release lever 36, a release bolt 37 with a return spring 39, and a narrowed-down portion 40, said release device being positioned in the release cylinder 41. When the nozzle is not held by hand or the release lever 36 is not pressed in against the release handle 35, the release bolt 37 shuts off the water flow through opening 20 into the cylinder 23. When the release handle 35 and thereby the release bolt 37 is pressed in, water can flow through the opening 20, across the narrowed-down portion 40 and into the cylinder 23, allowing the nozzle to be adjusted as described above. If the operator lets go of the handle, the release bolt is retracted so that water is prevented from passing through, at the same time as the water in the cylinder 20 is drained by means of the drain opening 38. The balls 15 will therefore be disengaged from the helical groove 19 so that the valve enters the fog position as described above when the water pressure is removed from the valve.

Accordingly, this embodiment is suitable for hand-held hoses. A hose having such a nozzle will be less dangerous than a traditional nozzle by being in a fog position when the water pressure returns after a loss thereof, ensuring that the hose is not knocked out of the hands of the person holding it, and by being automatically returned to the least dangerous position, the fog position, when the hose is lost or is out of control.

It may be desirable for ease of handling that a handle or grip ring is mounted on the outer body 3.

Example 3

Figures 5 and 6 show another embodiment which differs from those described above in Examples 1 and 2 primarily in that the inlet base 1 is fixedly mounted on the inner body 2 of the nozzle, and in that each of the balls 15 is installed in its own cylinder-shaped piston 7 which has a cut-out portion and is positioned in the inner portion 2 of the nozzle. This solution Includes at least two pistons 7 in their individual cylinders 23, each piston having its own piston spring. This solution entails that the outer body 3 both can be rotated and move axially in relation to the inner body 2 and the inlet base 1.

The deflector 6, which together with the throat 4 defines the discharge orifice of the water, is mounted on the deflector support 9. The deflector support 9 is held in place by the throat 4 which is screwed into the inner body 2. The deflector 9 is fixedly secured to the stem 8, which runs through the deflector support, and the deflector is secured to the stem 8 by deflector screw nuts 10.

The distance marker 11 may be composed of one or more rings that can be positioned either as shown in the drawings or between the deflector 6 and the deflector support 9. In this manner the stream characteristics of the nozzle can be adapted to requirements and water pressure.

The inlet base 1, the inner body 2, the deflector support 9 and the throat 4 can obviously be molded in a unit, but it is preferred to machine these parts separately and assemble them as shown in the drawings. This assembled unit, or the main part of the nozzle, constitutes also in the preferred embodiment an assembled unit the parts of which are fixedly mounted in relation to each other, for example by being screwed together as suggested in the drawings.

The outer body of the nozzle is composed of an adjustment ring 3, whereon a handle 13 on a handle support 12, and a spray ring are mounted. The outer body surrounds the inner body 2 and can freely be rotated and also displaced in the longitudinal direction in relation to the other body 2. The O-rings 14 and the seal 25 prevent or minimize undesirable leakage In the nozzle.

The return spring 16 presses the outer body 3 in the direction of the inlet base 1, or the position that provides fog. Without water pressure in the nozzle, a rotation of the outer body 3 will not lead to any longitudinal dis¬ placement of the outer and the inner body in relation to each other. The return spring can be any type of elastic member, but it is preferred to use a helical spring as shown in the drawings, or a helical wave spring.

When water pressure is put on the nozzle, water will flow into the opening 20 and press the piston 7 in, thereby pressing the ball out of the conical cut 22 in the piston 7 through an aperture/port in the inlet base 1 so that the ball will be able to engage with the helical groove 19 on the adjustment ring 3. By rotating the inner body with the outer body 3, the inner and the outer body will be longitudi- nally displaced in relation to each other in that the balls 15 move along the helical groove 19, thus giving the outer body a helical motion in relation to the inner body.

Upon loss of water pressure, the piston 7 is pressed back by the moment which, in conjunction with the piston spring 17, presses the ball 15 against the conical surface 22, so that the ball 15 falls back into the cut in the piston, and out of its engagement with the outer body 3. The outer body 3 will therefore be pressed by the return spring 16 back in the direction of the inlet base 1, and the nozzle returns to the fog position.

It is preferred that the ball 15 rests against the conical cut 22 in the piston 7 the whole time. At a correct selection of the ball size, the angle of the ball port 21 in relation to the main part, the angle of inclination of the conical cut in the piston 7, and the positioning of this cut so that the ball, even when engaged with the helical groove, rests against the conical cut 22 of the piston 7, the piston 7 will, upon loss of water pressure, be pressed back toward the opening 20 merely be the pressure of the ball against the conical cut in the piston, so that piston spring 17 is not strictly necessary. However, it is preferred to have such a spring as a safeguard.

In order for all the balls 15 to be able to engage with the helical groove 19 at the same time, the positioning of the ball port and the conical cut 22 must be adapted to the pitch angle of the helical groove 19. Normally the ball ports 21 will therefore be displaced in relation to each other in the longitudinal direction of the nozzle, and the pistons 7 will have different positions for the conical cut 22. Air vents 24 prevent the build-up of overpressure or underpressure in the cylindrical cavity 23 which will prevent movement of the piston 7. Simultaneous engagement of all balls 15 can also be obtained by having a plurality of helical grooves 19, each of which is adapted for engagement with one ball 15.

The cylindrical cavity 23 of the piston 7 is bored in the main body 2 and the axes of the cavity 23 and the piston 7 run approximately parallel to the longitudinal axis of the nozzle. The opening 20 is preferably at that end of the cylindrical cavity 23 which is closest to the inlet base 1 and thus the inlet to the nozzle. The water pressure will therefore create a pressure against the piston 7 and press it forward in the longitudinal direction of the nozzle, whereby the ball is pressed out of the conical cut 22 through the ball port 21 and into engagement with the helical groove

19. It will also be possible to have the opening 20 at that end of the cylindrical cavity 23 which faces away from the connection piece 1, and turn the cylinder 7 around. In this solution the piston will move contrary to the direction of water flow in the nozzle, creating more unfavorable and uncertain pressure conditions, and this solution is therefore less advantageous than the first solution.

The nozzle can be operated either by manual rotation of the handle 13 or by a toothed wheel of a (not shown) regulation motor engaging with the toothed wheel of the adjustment ring 13.

The section depicted in Figures 5 and 6 shows a piston 7 and a ball 15, but it is preferred that there would be dis¬ tributed two or more such pistons 7, mounted in cylinders 23 in the inner body 2 at approximately equal intervals around the circumference of the inner body 2. By using two or more pistons 7, reliable operation of the nozzle is ensured even at a failure of one of the piston/ball assemblies, and no oblique load will occur in the nozzle. It has proved preferable to use 2 to 7 piston/ball assemblies, depending upon the size of the nozzle. More pistons will increase the complexity and production cost of the nozzle. A particular- ly preferred compromise between cost and reliable operation is a nozzle having three piston/ball assemblies spaced at equal intervals around the circumference of the inner body 2.

To ensure that such fire extinguishing nozzles are reliable in all situations and as maintenance free as possible, it is preferred to coat all interior and exterior surfaces with a coating which reduces the friction between the parts and in addition prevents the formation of a surface layer that can cause a failure in the functioning of the nozzle. Especially preferred is a nickel-teflon coating, preferably of the type Magnaplate from General Magnaplate Corp.

The nozzles shown are all intended for fire extinguishing purposes and are preferably used for water, water/foam mixtures or water having other additives, but the principle can naturally also be applied to other fluids and for other poroses.