GB2235379A

GB2235379A - Hand operated fire extinguishers

Info

Publication number: GB2235379A
Application number: GB8919572A
Authority: GB
Inventors: G D Lee
Original assignee: Lifeline Fire & Safety Ltd
Current assignee: Lifeline Fire & Safety Ltd
Priority date: 1989-08-30
Filing date: 1989-08-30
Publication date: 1991-03-06
Also published as: GB8919572D0

Abstract

A modification to a fire extinguisher of the kind having, for operation of the extinguisher, a spring return handle grip 12 formed by fixed and movable arms (14, 16), wherein a coupling element (20) is so connected between the two arms (14, 16) as to maintain them in closed condition once they have been squeezed together, thereby to cause complete discharge of the extinguisher even though the squeeze on the handle grip 12 is released. <IMAGE>

Description

Hand Operated Fire Extinguishers This invention relates generally to hand operated fire extinguishers and in particular to hand operated fire extinguishers of the kind in which a valve for operating the extinguisher to cause it to discharge its contents is opened by squeezing together movable and fixed arms of a handle grip which forms part of a spring loaded valve operating mechanism, whereby the valve is closed to stop discharge of the extinguisher contents when the squeeze on the handle grip is relaxed to allow the two arms to move apart.

According to the invention, there is provided a modification of a hand operated fire extinguisher of the kind described, comprising a coupling element extending between the two arms, said coupling element being fixed to one arm and displaceably connected to the other arm in such a manner that, when the two arms are squeezed together, the coupling element is displaced relative to the one arm to a non-return position in which it holds the arms together when the squeeze on the handle grip is released, thereby to keep the valve open and cause the extinguisher fully to discharge its contents.

The invention is especially but not exclusively applicable to a fire extinguisher adapted for use in a racing car or other situation wherein, in the event of a fire or risk of fire, the handle grip is remotely operable through a cable connection to the two arms. In such a situation, when an emergency arises, it is required for a single short pull or tug on the cable to cause complete discharge of the contents of the extinguisher.

A preferred simple coupling element is a spring wire element formed at one end into a small transverse loop at which it is fixedly secured to one arm, preferably the movable arm, as by means of a rivet, and formed into a somewhat splayed U-formation at its other end, the U-formation being retained in an aperture in the other arm, preferably the fixed arm, with the major part of the formation projecting from the aperture towards the first (movable) arm.

With this arrangement, when the handle grip is squeezed, the coupling element moves with the movable arm to cause the U-formation to be displaced fully through the aperture to the side of the fixed arm remote from the movable arrn, the formation being compressed in passage through said aperture and expanding on emergence therefrom to prevent its return into the aperture, whereby said formation then acts as an abutment preventing return movement of the movable arm when the squeeze on the handle grip is relaxed.

The relevant part of a manually operable fire extinguisher in accordance with the invention is illustrated by way of example in the single figure of the accompanying drawing.

Referring to the drawing, the reference 10 generally indicates part of a valve and a valve operating mechanism for a hand operable fire extinguisher. This mechanism is wholly conventional, and includes a handle grip 12 which comprises a fixed arm 14 and a pivotted arm 16 which can be squeezed together to cause the valve to open and the extinguisher to discharge its contents. Typically, the arms 14 and 16 are of a U-shaped cross-section, as illustrated. Normally, when the' squeezeton the handle grip 12 is relaxed, the valve is closed under the action of the spring loading of the operating mechanism, accompanied by opening of the handle grip, and discharge is stopped.

There are situations, however, where it is desirable for a single short squeeze on the handle grip to be sufficient to cause complete discharge of the extinguisher. An example of such a situation is in a racing vehicle, where in an emergency the extinguisher is required to be remotely operable by a Bowden-type cable 18 to which the driver can apply a single short pull or tug at the end remote from the extinguisher.

In accordance with the invention, a coupling element 20 extends between the two arms 14 and 16 to prevent said arms from re-opening apart once the single short pull or tug has been applied to the cable 18, whereby the valve is held open and the extinguisher is caused to discharge the whole of its contents.

The coupling element 20 comprises a spring wire element bent into a small transverse circle 22 at one end, where it is fixedly secured, as by a rivet 24, to the movable arm 16.

The other end of the coupling element 20 is preformed into a somewhat splayed U-formation 26, which is engaged into and retained within an aperture 28 in the fixed arm 14, with the major part of the formation projecting from the aperture towards the movable arm.

In use, when the extinguisher is operated by a pull or tug on the cable 18, which squeezes the arms of the handle grip together, the coupling element 20 moves with the movable arm 16 to which it is fixed, whereby the U-formation 26 is displaced through the aperture 28, being compressed in passage through the aperture but expanding on emergence on the side of the fixed arm 14 remote from the movable arm, so that it is then not able to re-enter the aperture. As a result, even though the cable is no longer being pulled and the valve operating mechanism would tend to restore under its spring loading, the U-formation acts as an abutment preventing the arms 14 and 16 from opening apart, whereby the valve is held open and the extinguisher is caused fully to discharge.

It will be clear that, in order to ensure that the valve remains fully open, i.e. the arms remain held closed together, the dimensions of the spring wire coupling element 20, and in particular the dimensions of the U-formation 26, are appropriately matched to the stroke of the movable arm 16 when squeezed towards the fixed arm 14.

Various modifications of the above-described and illustrated arrangement are possible within the scope of the invention.

Claims

1. In a hand operated fire extinguisher of the kind in which a valve for operating the extinguisher to cause it to discharge its contents is opened by squeezing together movable and fixed arms of a handle grip which forms part of a spring loaded valve operating mechanism, whereby the valve is closed to stop discharge of the extinguisher contents when the squeeze on the handle grip is relaxed to allow the two arms to move apart, the modification which comprises a coupling element extending between the two arms, said coupling element being fixed to one arm and displaceably connected to the other arm in such a manner that, when the two arms are squeezed together, the coupling element is displaced relative to said other arm to a nonreturn position in which-it holds the arms together when the squeeze on the handle grip is released, thereby to keep the valve open and cause the extinguisher fully to discharge its contents.

2. A fire extinguisher according to claim 1, wherein the handle grip is remotely operable through a cable connection to the two arms.

3. A fire extinguisher according to claim 1 or claim 2, wherein the coupling element is a spring wire element formed at one end into a small transverse loop at which it is fixedly secured to one arm and formed into a somewhat splayed U-formation at its other end, the U-formation being retained in an aperture in the other arm with the major part of the formation projecting from the aperture towards the first arm.

4. A fire extinguisher according to claim 1 or claim 2 or claim 3, wherein the coupling element is fixed to the movable arm and displaceably connected to the fixed arm.

5. A fire extinguisher according to claim 4 when appendant to claim 3, wherein the coupling element is rivetted to the movable arm.

6. A fire extinguisher of the kind described, modified in the manner hereinbefore described with reference to the accompanying drawings.

7. A method of modifying a hand operated fire extinguisher of the kind in which a valve for operating the extinguisher to cause it to discharge its contents is opened by squeezing together movable and fixed arms of a handle grip which forms part of a spring loaded valve operating mechanism, whereby the valve is closed to stop discharge of ,the extinguisher contents when the squeeze on the handle grip is relaxed to allow the two arms to move apart, according to which a coupling element is connected to extend between the two arms, said coupling element being fixed to one arm and displaceably connected to the other arm in such a manner that, when the two arms are squeezed together, the coupling element is displaced relative to the one arm to a nonreturn position in which it holds the arms together when the squeeze on the handle grip is released, thereby to keep the valve open and cause the extinguisher fully to discharge its contents.

8. 'A method according to claim 7, according to which the coupling element is a spring wire element formed at one end into a small transverse loop at which it is fixedly secured to one arm and formed into a somewhat splayed U-formation at its other end, the U-formation being retained in an aperture in the other arm with the major part of the formation projecting from the aperture towards the first (movable) arm, so that when the handle grip is squeezed the coupling element moves with the movable arm to cause the U-formation to be displaced fully through the aperture to the side of the fixed arm remote from the movable arm, the formation being compressed in passage through said aperture and expanding on emergence therefrom to prevent its return into the aperture, whereby said formation then acts as an abutment preventing return movement of the movable arm when the squeeze on the handle grip is relaxed.

9. A method of modifying a fire extinguisher of the kind described, substantially as hereinbefore described.