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Title:
SPRINKLER HEAD FLOW STOPPING TOOL
Document Type and Number:
WIPO Patent Application WO/2006/093418
Kind Code:
A1
Abstract:
A tool (1), including a plug arm (2) and a brace arm (3) pivotally connected to each other, at least one plug (4) located at one end of the plug arm (2), at least one brace (5) located at one end of the brace arm (3), and locking mechanism (10, 11), configured to lock the relative position of the plug arm (2) and brace arm (3) with respect to each other, the tool (1) being characterised in that the brace (5) is configured to engage with the sprinkler head to locate the plug (4) in an outlet of the same.

Inventors:
Van Weerden, Adrian Paul (5 Durham Street, Ngaruawahia, 2171, NZ)
Application Number:
PCT/NZ2006/000018
Publication Date:
September 08, 2006
Filing Date:
February 10, 2006
Export Citation:
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Assignee:
Van Weerden, Adrian Paul (5 Durham Street, Ngaruawahia, 2171, NZ)
International Classes:
A62C37/20; A62C35/60; A62C37/10
Attorney, Agent or Firm:
Wilson, Kathryn S. (Private Bag 3140, Level 12 KPMG Centre, 85 Alexandra Stree, Hamilton 2001, NZ)
Download PDF:
Claims:
WHAT I/WE CLAIM IS:
1. A tool, including: a plug arm and brace arm pivotally connected to each other, at least one plug located at one end of the plug arm, at least one brace located at one end of the brace arm, a locking mechanism configured to lock the relative position of the plug arm and brace arm with respect to one another, the tool being characterised in that the brace is configured to engage with a sprinkler head to locate the plug in an outlet of same.
2. A tool as claimed in claim 1 wherein the pivotal attachment of the plug arm and the brace arm to one another is configured to allow the engagement of the plug and brace respectively with the sprinkler head.
3. A tool as claimed in either claimi or claim 2 wherein the plug and brace of the tool are configured to interact with the water outlet and the frame of the sprinkler head respectively.
4. A tool as claimed in any one of claims 1 to 3 which includes a biasing portion which acts to bias the plug with respect to brace arm.
5. A tool as claimed in claim 4 wherein the bias is such that the plug and brace arms can be positioned within the sprinkler head when the tool is not in use.
6. A tool as claimed in any one of claims 1 to 5 wherein the plug is configured to substantially block the water outlet of the sprinkler head.
7. A tool as claimed in any one of claims 4 to 6 wherein the biasing portion is provided by a spring.
8. A tool as claimed in any one of claims 1 to 7 wherein the locking mechanism is provided by a screw rod which is attached to one arm and passes through an aperture in the other arm.
9. A tool as claimed in claim 8 wherein the spring fits over the screw rod.
10. A tool as claimed in any one of claims 1 to 9 wherein both arms contain at least one internal gusset.
11. A tool as claimed in claim 10 wherein the internal gussets are attached by a pin to provide the pivotal connection between the plug and brace arm.
12. A method for plugging an activated sprinkler head outlet which is releasing water, including the steps of: (a) positioning the tool within the sprinkler head frame, (b) activating the tool so that the plug and brace are secured against the outlet and frame respectively, the plug stopping the outflow of fluid from the outlet, and (c) locking the tool in position.
13. A tool substantially as herein described with reference to the accompanying drawings.
14. A method of plugging an activated sprinkler head outlet substantially as herein described with reference to the accompanying drawings.
Description:
SPRINKLER HEAD FLOW STOPPING TOOL

TECHNICAL FIELD

The present invention relates to a tool.

Specifically the tool is for use with a sprinkler system, for example a fire sprinkler system.

BACKGROUND ART

Fire sprinklers are one of the easiest and most effective methods for fighting the spread of fires in their early stages, and often result in the fire being extinguished before it can cause severe injury to people or significant damage to property.

Most buildings used for work or commercial purposes require fire sprinkler systems. These are often also present in private homes.

Fire sprinklers are most effective during the fire's initial flame growth stage. A properly selected sprinkler will detect the fire's heat, initiate alarm and begin suppression within moments after flames appear. In most instances sprinklers will control fire advancement within a few minutes of their activation. This will in turn result in significantly less damage than otherwise would happen without sprinklers.

Sprinkler systems are essentially a series of water pipes which are supplied by a reliable water supply. At selected intervals along these pipes are independent, heat activated valves known as sprinkler heads. It is the sprinkler head which is responsible for water distribution onto the fire.

During the incipient fire stage, heat output is relatively low and unable to cause sprinkler operation. As the fire intensity increases, however, the sprinkler's sensing elements become exposed to elevated temperatures typically in excess of

57-107 0 C and they begin to deform. Assuming temperatures remain high, as they would during an increasing fire, the element will fatigue after an approximate 30 second to 4 minute period. This will release the sprinkler's seals allowing water to discharge onto the fire. In most situations less than 2 sprinklers are needed to suppress a fire. In fast growing fire scenarios such as a flammable liquid spill, up to 12 sprinklers may be required for control.

Additional actions may occur when sprinkler activation happens. These include initiation of building and/or fire department alarms, operation of supplemental water supply systems, shutdown of selected electrical and mechanical equipment closing of fire doors and dampers, and suspension of processes.

When fire fighters arrive they will verify that the system has contained the fire and, when satisfied, shut off the water flow and restore services. It is at this point that staff will normally be permitted to enter the damaged space and perform salvage duties.

A sprinkler head incorporates the spray nozzle which distributes water over a defined fire hazard area (typically 150-225 sq. ft.). Each sprinkler operates by actuation of its own temperature linkage. The typical sprinkler consists of a frame, thermal operated linkage, cap, orifice (or outlet), and a deflector. Styles of each component may vary but the basic principles of each remain the same. Fire sprinklers generally include the following features:

A frame, this provides the main structural component which holds the sprinkler together. The water supply pipe connects to the sprinkler at the base of the frame. The frame holds the thermal linkage and cap in place, and supports the deflector during discharge.

A thermal linkage, this controls water release. Under normal conditions the linkage holds a cap in place which prevents water flow through the sprinkler; however, as the link is exposed to heat it weakens and at a burst temperature releases the cap.

A cap, this provides the water tight seal which is located over the sprinkler water outlet. This component is held in place by the thermal linkage. Activation or breakage of the linkage causes the cap to fall from position and permit water flow.

A water orifice or outlet, this is usually a machined opening at the base of the sprinkler frame. It is from this opening which extinguishing water flows. Most water outlets are approximately 1/2 inch diameter with smaller bores available for residential applications and larger openings for higher hazard areas, buildings or factories.

A deflector, this is mounted on the frame opposite the outlet. The purpose of the deflector is to break up the water stream discharging from the outlet into a more efficient extinguishing pattern. Deflector styles determine how the sprinkler is mounted, by the angle of their tines.

Common sprinkler mounting styles are upright (mounted above the pipe), pendent (mounted below the pipe, i.e. under ceilings), and sidewall sprinklers which discharge water in a lateral position from a wall. The sprinkler must be mounted as designed to ensure proper action. Selection of a particular style is often dependent upon physical building constraints.

The most common form of fire sprinklers are sprinklers which are activated through the thermal linkage breaking, this requires the replacement of the sprinkler head with a new head incorporating an intact thermal linkage.

There are sprinkler systems which are configured to switch off the water supply once the fire has been extinguished and the room temperature has cooled to a

safe level, a bi-metallic snap disk on the sprinkler closes and water flow ceases. Should the fire reignite, the sprinkler will be reactivated. These are however very rarely used as they are inefficient.

Theoretically on/off sprinklers shut off reducing the quantity of water distributed, and resultant damage levels.

However, in practice an extended time period is required before room temperatures are sufficiently cooled to the sprinkler's shut off point. Frequently, fire emergency response forces will have arrived and will have closed sprinkler zone control valves, before the sprinkler's shut down feature has functioned, therefore decreasing their usability. A further disadvantage of on-off sprinklers is that they typically cost 8-10 times more than the average sprinkler.

Most sprinkler activations are localised with only one or two sprinkler heads being activated, often these in the same room or situated fairly close together.

Water released from the sprinkler is required to bring any fire under control, preferably before it grows to a size which the sprinkler system is unable to control. Fire sprinklers are also often set off accidentally.

When the fire is extinguished the water continues to be released from the sprinkler system through the activated sprinkler head. Even after the fire department has turned off the water supply or main stop valves for the sprinkler system there is often still a large amount of water in the pipes which will continue to drain out of the activated sprinkler heads.

The extra water which flows out of the sprinkler head(s) once the fire has been extinguished or in the case of accidental sprinkler activations from the initial activation can cause a large amount of water damage to the premises.

Currently to prevent water damage once a fire has been extinguished or it has been determined that it was an accidental activation, buckets or other large containers are placed under the activated sprinkler heads to collect the water which is then manually removed from the building. Although this is an easy and practical method it does have a large number of disadvantages such as the labour required to remove the water from the premises. As the water is under quite high pressure the water flow is often quite fast which can lead to the buckets being easily filled and needing to be emptied or replaced. As the deflector acts to spray the water over a large area, it is often also difficult to collect all the water released.

Many corporate companies would also not have a large supply of containers which would be able to be used for this purpose.

There can also be a large loss of production or inconvenience during this time especially in sensitive areas such as dairy companies or multi storey offices or apartment blocks.

Sprinkler heads which have been activated by the breaking of the thermal linkage are generally repaired or replaced by the service provider for that particular system. The service provider is alerted through a pager/mobile phone that the system has operated. They are then required to attend the site of activation; the time that it takes the service provider to arrive can vary greatly, from approximately 30 minutes for a local activation, or up to 2 or 3 hours for a more remote activation. The service provider, or other qualified person will then unscrew and replace the activated or damaged sprinkler head(s).

If the fire service or emergency response team arrives and have assessed the situation and determined that the fire is out, or the activation was accidental they will generally isolate the sprinkler system to try to prevent further water damage. If the emergency response team are trained to replace a sprinkler head or heads

then they will wait for the service provider to arrive and unscrew and replace the activated or damaged sprinkler heads. This procedure often results in water being released for a significant amount of time which the system drains or the system can be isolated.

It would therefore be beneficial to building owners and fire or other emergency response team if a product was available which could overcome the above mentioned problems.

All references, including any patents or patent applications cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the references states what their authors assert, and the applicants reserve the right to challenge the accuracy and pertinency of the cited documents. It will be clearly understood that, although a number of prior art publications are referred to herein, this reference does not constitute an admission that any of these documents form part of the common general knowledge in the art, in New Zealand or in any other country.

It is acknowledged that the term 'comprise' may, under varying jurisdictions, be attributed with either an exclusive or an inclusive meaning. For the purpose of this specification, and unless otherwise noted, the term 'comprise' shall have an inclusive meaning - i.e. that it will be taken to mean an inclusion of not only the listed components it directly references, but also other non-specified components or elements. This rationale will also be used when the term 'comprised' or 'comprising' is used in relation to one or more steps in a method or process.

It is an object of the present invention to address the foregoing problems or at least to provide the public with a useful choice.

Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only.

DISCLOSURE OF INVENTION

According to one aspect of the present invention there is provided a tool, including:

a plug arm and brace arm pivotally connected to each other,

at least one plug located at one end of the plug arm,

at least one brace located at one end of the brace arm,

a locking mechanism configured to lock the relative position of the plug arm and brace arm with respect to one another,

the tool being characterised in that the brace is configured to engage with a sprinkler head to locate the plug in an outlet of same.

Throughout this specification the term plugging should be taken as meaning substantially filling or blocking the sprinkler outlet and thereby substantially stopping water flow through same. Similarly, the term plug should be taken as meaning the portion of the tool which substantially fills or blocks the sprinkler outlet when in the correct position.

Throughout this specification the term brace should be taken as meaning a device that keeps something steady or a strengthening or supporting piece or part. Specifically in relation to the tool of the present invention the term brace should be taken as meaning able to provide the bracing action required to position the plug against the sprinkler head outlet to block or plug the flow of water.

Throughout this specification the term pivotally should be taken as meaning a connection which is able to pivot around a defined point.

In a preferred embodiment the pivotal attachment of the plug arm and the brace arm to one another allows the engagement of the plug and brace respectively with

the sprinkler head. This is important as it decreases the time required for the operator to position and lock the tool in position.

In a preferred embodiment the plug and brace of the tool will interact with the water outlet and the frame respectively.

The pivotal attachment between the brace and plug arms is such that it allows easy engagement of the tool in the sprinkler frame against the pressure of the wter discharging from the outlet of the sprinkler head.

Throughout this specification the term arm should be taken as meaning extensions from the tool which the operator can hold onto and use to operate same.

When a fire sprinkler is activated the water is released under pressure. The water pressure may vary greatly depending on the type of sprinkler system and use of same. The water pressure may vary from as low as 50 Kpa up to 600 Kpa. High risk systems may have an even higher water pressure.

In a preferred embodiment the tool and parts thereof are made out of a material which has the required strength to be used repeatedly in the expected water pressure. Examples of materials used may include: mild steel, stainless steel, or moulded plastic.

In one particularly preferred embodiment the tool may be made of stainless steel. Stainless steel provides the required strength to handle the water pressure and the positioning of the tool into an activated sprinkler head releasing same. Stainless steel also has the advantages that it does not rust and is very durable which allows for a long life span of the tool.

Throughout the rest of this specification the tool will be referred to as having two main configurations or positions. The first being an inactivated configuration wherein the tool is not in the correct position to plug a fire sprinkler head. The

second being an activated configuration wherein the plug and brace are in the correct position to plug the water outlet of a fire sprinkler head. It should be appreciated however, that the tool will have a range of movement between and extending from these two main positions.

In a preferred embodiment the tool may also include a biasing portion which acts between the plug and brace arm. The biasing may be in either the direction towards or away from the activated configuration wherein the outlet of the sprinkler head is plugged.

In one embodiment the bias may be provided so that when the plug and brace arms when in the inactive configuration, the tool is such that it can be positioned within the sprinkler head. For example, the brace and plug may be positioned close together to allow same to be inserted or positioned within the sprinkler head frame.

The plug and brace arms may then be manually squeezed or moved together by the operator, in the opposition direction to the biasing. This causes this brace arm to pivot around the pivoting point and move away from the plug on the plug arm.

Once the plug and brace are positioned in the correct activated position, blocking the flow of water from the fire sprinkler head, the locking mechanism may be activated to hold the plug and brace respectively in the activated position. Reference will herein be made to the tool having the biasing portion in this configuration.

Having the tool such that when it is in the inactive position the plug and brace are close together and when operated by squeezing the handles together they move further apart is preferred as it allows for the least amount of effort to be exerted by the operator. Due to the velocity of the water the least amount of action required in inserting the tool is to use one hand which is easily achieved with the bias

means in this embodiment.

Other configurations of the biasing means in relation to the plug and brace arms may also be utilized with the present invention, as long as same allows for the tool to have an inactive position, and an active position whereby the flow of water from an activated fire sprinkler can be blocked by positioning the tool in the sprinkler frame.

In a preferred embodiment the pivotal attachment between the brace and plug arm may allow the pivoting of the brace arm and brace in relation to the plug arm and plug, and shall be referred to as such herein. However this should not be seen as limiting, as the plug arm and plug may pivot in respect of the brace and brace arm. Having the brace arm (and therefore the brace) pivot is preferable as it allows for easier positioning of the plug in the correct position.

In a preferred embodiment the tool may be designed for use with a standard shaped fire sprinkler, specifically one which has an outlet and opposing same a frame and deflector portion. This provides two portions of the fire sprinkler head for the tool to act against. The plug will act against the water outlet while the brace will act against the opposing frame to hold the plug in the correct activated position.

In a preferred embodiment the plug and brace are shaped specifically to be able to fit inside most common fire sprinkler heads installed in current sprinkler systems.

In a preferred embodiment the plug may be any shape or size which is configured to fit into or substantially fill or block the water outlet of a particular sprinkler head.

As most fire sprinklers have a circular outlet preferably the plug is of a circular, domed shape. Having a domed shape allows one sized plug to interact with a range of fire sprinklers varying in the size of the water outlet.

Throughout this specification the term domed should be taken as meaning a rounded exterior surface with a circular, elliptical or polygonal base.

In a preferred embodiment the plug may be configured to block the most common sprinkler outlet sizes. Common sprinkler outlet sizes range from 10 mm to 20 mm. This may be via a domed plug which can fit a range of outlet sizes, or interchangeable plugs with differing dome sizes to cover the range of common outlet sizes. However, this should not be seen as limiting, as the plug may be configured to block either smaller or larger sprinkler outlets.

The radius of the plug is crucial to the operation of the tool as it fills the sprinkler head outlet when positioned correctly. In a preferred embodiment the radius of the plug allows it to fill a standard water outlet. In an alternative embodiment the plug may be of a larger or smaller size configured to fit into and prevent water flow through a specific sized outlet, which varies from the standard.

In a preferred embodiment the tool may be shaped so that the operator can operate same from below the fire sprinkler which has been activated.

As most fire sprinkler heads are located on the ceiling, the easiest and most direct route to apply the tool is from substantially below the fire sprinkler, and herein the operator shall be referred to as being positioned below the sprinkler head when operating the tool. However, this should not be seen as limiting as the operator may also be positioned off to one side of same.

Therefore in order to be able to place the plug and brace against the required perspective portions of the sprinkler head the arms are preferably angled so that when the operator is positioned substantially below the sprinkler head the plug and brace may be positioned substantially horizontal to the sprinkler outlet and frame respectively.

It is also preferable that the arms are sufficiently long to enable the user or operator to easily position the tool within the sprinkler head even with a high water pressure flow through same and activate same to plug the outlet of the sprinkler head.

In a preferred embodiment the entire tool may have a total length of approximately 30cm. However, this should not be seen as limiting as a device with longer or shorter handles may be used depending on the place of use and likely people to be using the same. For example in a building with high ceilings it may be worth having a device with longer arms which can be utilised by a person standing on the ground rather than having to have that person climb up onto a desk/chair or ladder.

In a preferred embodiment the arms of the tool may be laser cut out of the stainless steel or other material to obtain the required shapes which are then folded to provide the specified angles to provide the pivoting and correct positioning of the plug and brace. This also allows the tool to be easily assembled.

In a preferred embodiment the plug is made from stainless steel, plastic, rubber in order to provide a water tight connection with the sprinkler outlet when the apparatus is activated and in position. However, this should not be seen as limiting as any other material may be utilized if it is capable of forming a substantially water tight seal against the sprinkler head outlet when biased against same.

In a preferred embodiment the plug may be manufactured separately and attached to the plug arm, and shall be referred to as such herein. Having a detachable plug means that same can be easily replaced, or changed to a different sized plug if required. However, this should not be seen as limiting as the plug may also be manufactured as an integral part of the plug arm.

In a preferred embodiment the plug may be secured to the plug arm using a counter sunk screw. This means that the plug may be changed depending on the size of the sprinkler outlet. However this attachment means should not be seen as limiting as other methods of attaching the plug to the plug arm may be utilised, for example via gluing or welding.

In a preferred embodiment the biasing portion is provided via a spring, and shall be referred to as such herein. However, this should not be seen as limited as one skilled in the art would realize that a range of biasing portions may be used with the present invention, and how same would be used.

In a preferred embodiment the spring may be positioned between the brace and plug arms. This means that when not in use the biasing means pushes outwards on the plug and brace arms resulting in the plug and brace being close together and capable of being positioned within a sprinkler frame. When the arms are squeezed or moved towards each other this is against the biasing means. However, this configuration should not be seen as limiting as it may be possible to have the biasing means in other configurations such as on one side of the plug or brace arm.

In a preferred embodiment the locking mechanism is provided via a screw rod which is attached to one arm and passes through an aperture in the other arm. The position of the arms may then be locked via movement of a star wheel to hold the arms the required distance apart. Variations on this may also be used in conjunction with the present invention. Again, this should not be seen as limiting as one skilled in the art would be aware that other locking mechanisms could be used in conjunction with the present invention, and how same would be used.

In a preferred embodiment the screw rod of the locking mechanism has the compression spring providing bias fitted over same.

In a preferred embodiment both arms contain at least one internal gusset, on the internal angle of the arm which are then fixed together via a pin to provide the pivotal connection between the plug and brace arm.

Throughout this specification the term gusset should be taken as meaning a bracket or other portion which strengthens as angle of a structure or device.

In preferred embodiments the gussets may be designed to provide the least area of resistance from the flow of water hitting same, this also keeps the size and weight of same to a minimum to allow the tool to be easy operated. However the gussets must also providing sufficient strength to the pivoting attachment of the plug and brace arms.

According to a further aspect of the present invention there is providing a method for plugging an activated sprinkler head outlet which is releasing water, including the steps of:

(a) positioning the tool within the sprinkler head frame,

(b) activating the tool so that the plug and brace are secured against the outlet and frame respectively, the plug stopping the outflow of fluid from the outlet, and

(c) locking the tool in position.

Once the tool is in position it can be left until the water has been turned off and either the remaining water drained from the system through the sprinkler valve room or from a specific drain point in the system, or it is drained from the sprinkler pipe work in a controlled manner through the activated sprinkler head(s) once containers to collect the water have been found and placed in position. The tool can then be removed from the sprinkler head. The sprinkler head is then replaced ready for any future fires.

The tool as described herein can be beneficial in isolating or restoring the sprinkler system. Once the fire has been extinguished or it has been determined that the sprinkler head(s) had been accidentally activated the tool can be used to plug the sprinkler outlet to stop any further water flow or damage from same. This also allows the sprinkler system to be partially reinstated and operations to continue until the service provider or other qualified person arrives to replace the activated sprinkler head(s).

The tool can be easily and quickly placed in position to stop the flow of water within a few seconds.

The tool may also in some situations be used to unscrew the activated, damaged or plugged sprinkler head.

There are a significant number of advantages to the tool as shown in the present application, these include the following:

• The tool is quick and easy to use.

• The tool can be used once a fire has been extinguished or when it has been determined that there was accidental activation of same to prevent extra water from emptying out into the building, this prevents an increased water damage and potential maintenance or redecorating costs.

• This apparatus also allows the sprinkler system to be reinstated back to full working status with less down time of waiting for a service person to attend the site to repair damaged sprinklers. For example in a factory situation where the sprinkler system is crucial to the normal operation of the factory, the sprinkler system can be reinstated in the sprinkler valve room back up to full working pressure before replacement of the

sprinkler heads. This may be via the following: the fire service installing/positioning the tool in the activated sprinkler head(s) and not isolating the system in the sprinkler valve room, the system if not isolated will automatically fill to the town/city main pressure, or if boosted by a pump will fill to the highest pressure of the boost pump.

The system can then be reinstated through the automatic calling system and factory operation can be continued.

• A further example of this may be a dairy company wherein the activated sprinkler system must shut down the drier operation till the fire system is repaired. This can cost huge amounts of money and the possibility of wasting product due to the inability to use it especially at a time they call the flush.

BRIEF DESCRIPTION OF DRAWINGS

Further aspects of the present invention will become apparent from the following description which is given by way of example only and with reference to the accompanying drawings in which:

Figure 1 shows a side on schematic of the tool according to one embodiment of the present invention;

Figure 2 shows a perspective view of the tool according to one embodiment of the present invention,

Figure 3 A and B show a schematic of the plug arm of the tool according to one embodiment of the present invention,

Figure 4a & b shows a schematic of the brace arm of the tool according to one embodiment of the present invention,

Figure 5a & b shows a schematic of the gussets according to one embodiment of the present invention.

BEST MODES FOR CARRYING OUT THE INVENTION

Figure 1 shows a side on schematic of the tool according to one embodiment of the present invention.

Figure 1 shows a tool generally indicated by (1 ).

The tool (1 ) incorporates a plug arm (2) and a brace arm (3).

The plug arm (2) incorporates a plug (4) which is of a domed shape of a size which fits into and fills the outlet of a sprinkler head.

The brace arm (3) contains a brace portion (5) which engages with the frame of the sprinkler head in order to position and hold the plug in place.

The plug arm (2) and brace arm (3) are pivotally attached by a pivot pin (6).

The plug arm (2) also incorporates an internal gusset (7), this is located substantially in the middle of the width of the plug arm (2) and fits through a corresponding slot on the brace arm (3).

The brace arm (3) contains two internal gussets (8) which are positioned on either side of the slot through which the gusset (7) from the plug arm (2) is positioned.

The pivoting pin (6) is attached through (7) and (8) in order to connect the plug arm (2) and brace arm (3) and provide a pivoting connection between same.

The tool also includes a biasing portion (not shown in detail but location of same is shown) (9) which biases the plug arm and brace arm away from one another, keeping the apparatus in the open position when not in use.

In this example the biasing portion is a compression spring.

The arms may be locked in the closed position by a locking mechanism, in this case incorporating a threaded screw (10) and star wheel (11). As the plug arm (2) and the brace arm (3) are pushed together the plug (4) and bracing portion (5) are moved apart into the closed position. The locking device (10) and (11) can then be activated to hold the apparatus in this closed position.

In the example shown the tool has a number of holes in the plug and brace arm, these are only for aesthetic value and to minimize the weight of the tool.

Figure 2 shows a perspective view of the tool, showing the same features as in Figure 1 using the same numbers.

Figure 3A shows a schematic of the plug arm (2) from a side angle. In one preferred embodiment the straight portion of the plug arm (12) is approximately 230 to 240 mm in length, the is then a first angled portion (13) which is approximately 45 mm long (internal edge) and is at an angle of 140° (14) to the straight portion (12). At a further 130° (15) angle to the first angled portion (13) is the plug holding portion (16), onto which the plug (17) is attached.

Figure 3B shows a schematic of the plug arm (2) from a front angle, showing the lengths of the various portions. The plug arm has a total length (18) of 307 mm, the straight portion (12) has a length of 237 mm, the first angled portion (13) has a length of 45 mm, and the plug holding portion (16) has a length of 25 mm.

The preferred width of portions (12) and (13) is 25 mm, the plug holding portion (16) is preferable indented to a width of 17 mm. The decrease in width of the plug holding portion (16) is essential in that it allows the plug holding portion to be placed within the frame of a standard sprinkler head.

The preferred thickness of the plug arm (2) is 5 mm.

Figure 4A shows a schematic of the brace arm (3) from a side angle. In one preferred embodiment the straight portion of the brace arm (19) is approximately 130 to 140 mm in length, there is then a first angled portion (20) which is approximately 110 to 115 mm long (internal edge) and is at an angle of 150° (21) to the straight portion (19). At a further 105° (22) angle to the first angled portion (19) is a second angled portion (23). The second angled portion (23) is approximately 40 mm long. At a further 140-150° angle (24) to the second angled portion (23) is the bracing portion (24) which acts to brace against the sprinkler head frame to hold the plug in position.

Figure 4B shows a schematic of the brace arm (3) from a front angle, showing the lengths of the various portions. The brace arm has a total length (25) of 307 mm, the straight portion (26) has a length of 132 mm, the first angled portion (27) has a length of 112 mm, the second angled portion (28) has a length of 40 mm and the brace portion (29) has a length of 25 mm.

The preferred width of portions (26), (27) and (28) is 25 mm, the brace portion (29) is preferable indented to a width of 12 mm. The decrease in width of the brace portion (29) is essential in that it allows the plug holding portion to be placed within the frame of a standard sprinkler head.

The preferred thickness of the plug arm (3) is 5 mm.

Figure 4B also shows an aperature (30), through which the outer gusset from the plug arm (number 7 Figure 1) passes in order to attach to the inner gussets attached to the brace arm and provide a pivoting attachment between the plug and brace arms.

Figure 5 shows the general shapes of the outer (31) and inner (32) gussets.

The angles and lengths given above allow the tool to be positioned into sprinkler heads that have partially recessed escutcheon plates in ceilings. The angles allow for easy insertion of the tool in these circumstances.

The length of the plug and brace arm may be easily varied.

Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope of the claims.