AU654476B2 - Valve - Google Patents

Description

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APPLICANT:

NUMBER:

FILING DATE: MILNES PTY. LIMITED PJ 9304/90 27/ 3/90 Form COMMONWEALTH OF AUSTRALIA The Patents Act 1952 COMPLETE SPECIFICATION FOR AN INVENTION ENTITLED:

VALVE

The following statement is a full description of this invention 1 including the best method of performing it known to me/us: -1- This invention relates to a valve and in particular to an improved valve for use in irrigation systems.

Crops such as cotton and rice are irrigated by a flood irrigation system which has pipes which are installed through the bank of an irrigation channel and, when the channel contains, these pipes normally terminate below the water level.

On the inner ends of the pipes, that is in a position normally under the water there is provided a flap valve which can be selectively used to close or uncover the end of the pipe and thus permit the water to flow to the area to be irrigated.

Conventionally the pipe end has fitted thereto a seat which presents an annular cylindrical face and which has means whereby the hinging .o arrangement for a flap valve can be connected.

Historically the seat and valve would be made of a metal and often on the valve there was simply a facing of a resilient rubber or rubber like material which provided the seal between the flap and the seat.

More recently there have been proposed seat and flap assemblies which are made of a synthetic plastics material and in these the seat is provided with an 0-ring or the like, which ring is located substantially within the flap valve, and which contacts the seat.

Whilst such valves are basically satisfactory they nevertheless have a number of problems in use.

The first of these is that where there is any deformation in the flap, and it is found that there can be such deformation as the stress in the flap -2- Milnes/85/Mar91 material is relieved whilst in situ then, because the O-ring is basically rigid, there can be a break down of the seal at least at certain positions around the periphery.

Secondly where any foreign material lodges between the flap and the seat, and it must be appreciated that irrigation water often carries such things as sticks and other floating objects, then the flap is basically held away from the seat and there tends to be a substantial failure in the valve closure.

It is the object of the present invention to provide a valve of this general type which overcomes or at least minimizes the previous difficulty.

The invention includes a valve having a valve seat in the form of an annular planar surface and a valve member in the form of a flap having a generally complementary annular planar surface and being pivotally mounted relative to the seat and movtable from a position where it is in contact with the S" seat to a position away therefrom, the valve member or the flap having a sealing member in the form of an annular resilient skirt directed inwardly towards the other member and outwardly relative to the axis thereof.

.o0 0 The valve member is preferably pivotally attached to an extension from the seat and the attachment also has an outwardly extending handle means to enable the flap to be moved away from or towards the seat.

Preferably when the valve member is closed there is access for liquid between the valve member and the skirt.

In order that the invention may be more readily understood reference will be made to the accompanying drawings, in which: -3- Milnes/85/Mar9l Fig. I is a side elevation of the valve of the invention; and Fig. 2 is an enlarged radial section through the valve of Fig. 1.

The valve may be made of any material but it is preferred that it be made of a high density plastics material and consists of two members, a valve seat 11 and a valve member The valve seat I11 is preferably annular and is adapted to be connected in a •water tight manner by adhesion or welding to a pipe 10 with which the valve is to be used.

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Directed outwardly, when the seat member is fitted, is an annular seat 13 which is substantially normal to the axis of the pipe.

It is preferred that the seat member 11 be provided with a pair of spaced

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outwardly extending lugs 14 which are adapted to receive a pivot pin 31 which will be described hereinafter.

The valve member 20 is substantially circular in form and presents an annular surface 22 which is adapted, when the valve is closed to move toward contact with the seat 13.

Located in this area there is an annular recess 24 which is formed in the face of the valve member at an acute angle directed outwardly from the axis of the valve member.

Located in this recess 24 tnere is a sealing member 23 which is in the form of an annular skirt of a resilient material.

When located, the free outer portion of this skirt is directed outwardly from the axis.

-4- Milnes/85/Mar91 The skirt may be a free fit within the recess 24 or may be held in position by screws or the like which enable replacement of the skirt.

The valve member also has a pair of lugs 25 extending outwardly therefrom.

The operating member 30 of the valve may preferably be made of a metal which is either inherently resistant to corrosion in the type of water in which the valve is to be used or is, for example, plastic dipped or otherwise coated, such as by galvanizing or anodizing.

°This handle has two arms 34 and 35 each of which has an aperture and is designed to be pivotally mounted by pins 31 and 32 to the lugs 14 on the seat and the lugs 25 on the valve member respectively.

This arrangement is such as to permit the valve member to come into contact with the valve seat about the total of the periphery thereof and to be effectively self adjusting into this position.

0 The arrangement of the valve member is such that it normally is directed into the irrigation channel and it is thus under thr water level of the channel when the channel is being used.

It is to be appreciated that irrigation channels need not be full of water through the whole of the irrigation systemn as there are normally gates whereby water is passed to channels only when the channel is used or is likely to be used.

When the valve is closed, as is shown in Figure 1 it will be seen that the water in the channel can enter behind the annular skirt and this provides a hydraulic pressure onto the free edge of the annular skirt and this acts to TMilnes/85/Mar9l1 hold the skirt in a sealing relationship with the valve seat.

We have found that even with only low water heads the seal provided is efficient.

When the valve is to be opened the handle member 30 is rotated about pivot 31 causing the valve member 20 to be rotated away from the valve seat and it is preferred that this rotation is such as to effectively move the valve member out of alignment with the water directly flowing into the pipe.

a* 0 When the valve is to be closed it is only necessary to rotate the handle •which will bring the valve member partially across the valve seat dnd if water is flowing there will be a positive action to move the valve member into position on the seat and once a seal is effected this will be maintained because of the hydraulic pressure on the outer surface of the skirt 23.

a Should there be any deformation of the members, particularly the valve member, the form of seal prcvided by the annular skirt 23 particularly in 0 association with the form of hingeing available will mean that a good seal is made by the valve.

It is not essential that any part of the valve member be located with line tolerances relative to the valve seat as the seal is made by the annular skirt 23 and this is of a length to take into account any variations in the spacing between the two members.

Further, should some obstruction, such as a twig or the like, be located between the valve seat and the valve member, then the valve member shall attempt to compensate fcr this both because of the length of the annular skirt and the pivotal connection.

-6- Mi lnes/85/Mar9 Whilst the valve will still leak, the area over which leaking occurs will be restricted as the valve seat will compensate itself overall, because of its pivotal connection at pivot 32 and the annular skirt will move into contact with the valve seat as soon as it is capable of doing so.

It will be clear that the annular skirt may equally be located in a recess provided around the periphery of the valve seat.

Should the annular skirt be damaged it will be appreciated that it is relatively straightforward to remove the damaged skirt from its recess and simply replace the skirt.

eo It will also be appreciated that the skirt does not have to be a tight fit in the recess as, again, the hydraulic pressure ~which causes the valve to close will also ensure that the skirt 4s held against the wall of its recess.

Whilst we have described herein one specific embodiment of the invention it is to be understood that variations and modifications in this can be made without departing from the spirit and scope thereof.

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Claims (12)

1. A valve having a valve seat in the form of an annular planar surface and a valve member in the form of a flap having a generally complementary annular planar surface and being pivotally mounted relative to the seat and moveable from a position where it is in contact with the seat to a position away therefrom, the valve member or the flap having a sealing member in the form of an annular resilient skirt directed towards the valve seat member and radially outward relative to the axis thereof. S

2. A valve as claimed in claim 1 wherein the valve member is pivotally mounted to an extension from the seat.

3. A valve as claimed in claim 2 wherein the extension is a lug or pair of lugs extending outwardly from the seat.

4. A valve as claimed in claim 3 wherein the valve member has an outwardly extending lug or pair of lugs co-planar with the lug(s) extending from the seat. e:*

5. A valve as claimed in claim 4 wherein the lug(s) on the valve member is/are below the centre line of the valve.

6. A valve as claimed in claim 4 or claim 5 wherein the pivotal connection is provided by a member which at one end is pivotally connected to the lug(s) associated with the seat and at the other end is pivotally connected to the lug(s) on the valve.

7. A valve as claimed in claim 6 wherein the member has two arms. II arms.

8. A valve as claimed in claim 7 wherein the member has a third arm which extends outwardly from the valve and provides an operating handle therefore.

9. A valve as claimed in any preceding claim wherein the skirt is located in a recess provided around the periphery of the valve seat.

A valve as claimed in claim 9 wherein the skirt is positively retained in the recess. iii!ii

11. A valve as claimed in either claim 9 or claim 10 wherein when the valve is closed, the outwardly extending portion of the skirt is held between the seat and the valve member and makes the seal therebetween.

12. A valve substantially as hereinbefore described with reference to the accompanying drawings. DATED this day of September, 1994 o MILNES PTY. LIMITED By its Patent Attorneys A. TATLOCK ASSOCIATES 7/