This invention relates to a breaker valve, more particularly to a valve to be inserted in a fluid pressure line, whereby the valve is operative on a 5. reduction of pressure on the pressure side of the valve to disconnect to prevent flow in either direction.

BACKGROUND OF THE INVENTION

In many industries and services, it is highly 10. desirable if not essential that where there is a sudden reduction in pressure or even a reduced pressure formed in a pressure line that some means be provided for preventing reverse flow into the main supply line on the pressure side of the breaker valve 15. in the event of there being some malfunction or the like on the pressure side.

This problem also occurs in the water reticul¬ ation systems, and if for example fertilizer and/or insecticide and/or pesticide is being distributed by connection to the water supply through a hose or the

5. like, or in some fixed reticulation system, where there may be a sudden main burst or the like on the pressure side, that this would cause a reduction in pressure between the main burst and the chemicals being distributed, that this reduction of pressure

10. which may even be below atmospheric pressure can draw back into the the mains reticulation system chemicals which are being added to the water supply. These chemicals can be very dangerous and poisonous and thus some means is required in order to prevent this back

15. flow.

Thus it is highly desirable if not even essential that even where the household gardener uses water pressure for spraying or the distribution of chemi¬ cals, that such a unit be incorporated but it is 20. considered to be essential in other installations of more commercial nature and in fixed installations.

BRIEF DESCRIPTION OF THE INVENTION

Thus there is provided according to the invention a breaker valve which is included in the pressure line 25. and operative so ^' that when the pressure reduces on the pressure line that the valve breaks and disconnects to thus completely isolate the equipment downstream of the breaker valve, there being then no connection between the two portions of the valve.

30. -BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a cross-sectional view of the valve in the disconnected mode,

Fig. 2 is a cross-sectional view of the valve connected for fluid flow.

DESCRIPTION OF THE PREFERRED EMBODIMENT

In a preferred form of the invention the breaker

5. valve 1 can include a main housing 2 having a hose coupling 3 for attachment of a hose 4 over a hose expander 5. The hose expander 5 has an enlarged portion 6 defining a shoulder 7.

The valve 1 includes a connecting piece 8 which 10. may be connected to a chemical dispenser (not shown), the connecting piece including an internal seal 9 against which a non-return valve 10 biassed by a spring 11 seats. The spring 11 bears at its outer end on the part of the body of the dispensing device to 15. which the connecting piece 8 is attached.

The connecting piece 8 is provided with a spigot 12 having a circumferential recess 13 into which catches 14 are adapted to engage to lock the connect¬ ing piece to the valve 1. The catches 14 are position- 20. ed within slots 15 formed in the end of a central housing 17 retained by a circlip 16 bearing on flange

20 of the housing 17.

The catches 14 can slide radially between a position shown in Fig. 1 and that shown in Fig. 2, the

25. inward movement being caused by the cam faces 18 of a thimble 19 which is slidable over the central housing

17. The thimble being cup shaped to engage the stem

21 and the enlarged portion 21 of the housing 17. A spring 23 is positioned between the interior of the

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thimble 19 and the shoulder forming the enlarged portion 22 of the central housing 17 to bias the thimble 19 toward the inlet end of the valve.

The stem 21 of the central housing 17 at its end 5. is provided with a plurality of radial slots 24 and the end abuts a wall 25 on the main housing 1.

A plunger 26 passes through the wall 25 and also the stem 21 of the central housing 17, the plunger 26 having a closed end 27 with a flange 28, O-ring 29 on

10. a seat 30 forming a cut-off valve. The plunger is formed with a plurality of radial webs 31 extending from the closed end 27, and at its outer end is formed by a hollow cylindrical portion 32, the webs 31 join¬ ing to the cylindrical portion 32 such that fluid can

15. pass between the webs and then through the cylindrical portion 32. A spring 33 acts between a shoulder 7 of the hose expander 5 and the flange 28 on the plunger to cause the cut-off valve to close by the O-ring 29 sealing on the wall 25 about the plunger.

20. A pressure chamber 34 is provided between the wall 25 and the thimble 19, the slots 24 communicating fluid into the chamber. A cup washer 35 seals the chamber and the cup washer 35 and the thimble 10 thus act as an annular piston. A sealing ring 36 surrounds

25. the tubular portion 32 and is adapted to seal against the thimble wall 37 and the end of the connecting piece 8 when it is inserted into the housing.

In the disconnected condition as shown in Fig. 1 the spring 33 forces the O-ring 29 to close the cut- 30. off valve by sealing on the wall 25 and thus no fluid

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can flow from the hose 4, any pressure in the hose acting on the end of the plunger to thus assist in closing the cut-off valve.

The connecting piece 8, when no fluid pressure is 5. applied to the inlet, cannot be connected, for spring 23 moves thimble 19 to the catch release position as shown in Fig. 1, and hence the catches 14 will not engage in the recess 13 of the connecting piece 8. The connecting piece when inserted engages the end of the 10. plunger 26 and moves the plunger to open the cut off valve by moving the O-ring 29 away from its seat, and when no supply of fluid is present the connecting piece cannot be locked in position.

However when the hose 4 is connected to a supply

15. of fluid under pressure, and with the connecting piece

8 not inserted, the fluid flow is prevented by the cut-off valve from flowing through the valve. When the connecting piece 8 is inserted, the spigot 12 engages the end of the plunger 26 moves the plunger to

20. open the valve by moving the O-ring 29 to leave its seat. The fluid pressure then is applied through the slots 24 to the cup washer 35 to move the thimble to force the catches 15 into the recess 12 to lock the connecting piece in position. The fluid then flows

25. opening the non-return valve 7.

On the occurrence of a reduction in pressure in the upstream side of the valve, there is a reduction of pressure in the chamber 34 so that spring 23 causes the thimble to move to disengage the catches. Spring 30. 33 causes the plunger 26 to move to disengage the connecting piece, whereby the valve 7 will close.

Thus the valve breaks into two pieces, and valve 7 closes to prevent back flow therethrough. If there is a reduction in pressure below atmospheric pressure the plunger would move to open the back flow valve to 5. allow air to flow back through the hose. However due to the fact that the connecting piece is disconnected no contaminating fluid can flow back through into the valve housing.

When pressure is applied to the pressure chamber, 10. this acts on the thimble and forces the thimble against Its biassing spring so that the thimble main¬ tains the catches in the locking position and fluid can then flow around the plunger and out the outlet of the connecting piece.

15. If in the event of there being a reduction of pressure on the pressure disc of the breaker valve, the pressure in the pressure chamber is reduced, thus allowing the thimble to move backwardly and when this occurs the thimble passes the position of the catches

20. allowing these to move out of the recess. The catches and recess are so designed that when the thimble passes the catch position, that the ejecting spring acting on the plunger will cause the connecting piece to be ejected completely from the body.

25. The cut-off valve in the body in this position is closed or if there is a reduced pressure on what is normally the pressure side of the system, that the cut-off valve is adapted to open and allow the air to enter into the system this air entering without taking

30. any contaminating fluid with the air.

It will be seen that to connect the breaker valve, a positive action must be taken to insert the connecting piece into the valve body, this only being retained in position when fluid pressure is applied to

5. the unit. Thus it will be seen that the unit is designed to be used only when it is particularly desirable and/or it is. required that the unit be used for the particular circumstances, and it will not be readily possible for unauthorized people such as child-

10. ren to connect the chemical dispensing device to the pressure system unless the positive steps and actions have to be taken to insert the connecting piece into the body and to have it retained in position by the fluid pressure flow.

15. While catches are utilized as the detent means, it will be realized that other forms of catches or detent balls can be used.

While the invention has been particularly designed for the addition of agricultural chemicals or

20. the like or other detergents to be dispensed by water pressure from the reticulated water supply, it is to be realized that the invention can be utilized in many aspects of industry and commerce and services and that the invention is not particularly limited to its use

25. on water supply, but can be utilized on any fluid pressure line, or whether it be of liquid or gaseous nature.