AU646546B2

AU646546B2 - Float valve shut off attachment

Info

Publication number: AU646546B2
Application number: AU11220/92A
Authority: AU
Inventors: Joseph Albert Johnson
Original assignee: Individual
Current assignee: Individual
Priority date: 1991-02-26
Filing date: 1992-02-25
Publication date: 1994-02-24
Anticipated expiration: 2012-02-25
Also published as: AU1122092A

Description

lg J 546

AUS"RALIA

Patents Act 1990 COMPLETE SPECIFICATION ror a Standard Patent

ORIGINAL

r TO BE COMPLETED BY APPLICANT Name of Applicant: Actual Inventor(s): Address for Service: JOSEPH ALBERT JOHNSON JOSEPH ALBERT JOHNSON o WRAY ASSOCIATES, Primary Industry House, 239 Terrace, Perth, Western Australia, 6000.

Adelaide Attorney code: WR Invention Title: "FLOAT VALVE SHUT OFF ATTACHMENT" Details of Associated Provisional Application: No: PK4837 The following statement is a full descripti-o of this invention, including the best method of performing it known to me:- 1 2 THIS INVENTION relates to a control for an actuator where said actuator is caused tc be active or inactive depending upon the presence of certain physical conditions, whereby on activation of the actuator, the physical conditions can be varied.

Throughout the specification the term actuator can be taken to include a fluid flow valve, a switch or any similar form of actuator which has an active and an inactive condition.

In one form the invention resides in an actuator control mechanism comprising a support, said support supporting a control arm and an actuator arm, each arm being pivotally supported from the support said support being adapted to be mounted to an actuator body accommodating an actuator and one end of the actuator arm extending from the support, such that the actuator arm is engageable with the actuator ":whereby the actuator arm is movable between a first eposition at which the actuator is rendered active and a Ssecond position at which the actuator is rendered inactive, the control arm extending from the support and adapted to be associated with a force generation means, the control arm being pivotally movable on the support between a first position and a second position, the control arm and actuator arm being interconnected by a resilient means providing a biasing force therebetween which when the control arm is in its first position biases the actuator arm to its first position and when the control arm is in its second position biases the actuator arm to its second position, the location of the pivot axes of the control arm and actuator arm on the support and the connection between the control arm and actuator arm by said resilient means being such that on the control arm and actuator arm being moved between the first and second positions and between 3 the second and first positions, the biasing force exerted by the resilient means increases to a maximum when the arms are intermediate their end positions on the support.

A particular example of an application of the invention relates to the operation of float control valves. Such valves are generally controlled by virtue of an arm which is pivotally supported towards one end from a valve body where the one end of the arm bears upon a valve member to effect the opening and closure of the valve while the other end is associated with a float which is supported in a body of liquid. The purpose of such valves is generally to control the level of the body of liquid on which the float is supported such that on the liquid level falling below a desired level the valve will be opened and on the liquid level rising above the predetermined level the valve will be closed. A difficulty with such an arrangement however arises from the feature that the movement of the one end of eoothe arm actuating the valve is in direct proportion to the oo4*** movement of the other end of the arm which results in a gradual openi.:'g and closing of the valve. As a result the 0 valve is actuated on relatively small movements of the o: level of the liquid. Where the valve is connected to a 00 source of liquid associated with a motor driven pump, small movements in the level of the liquid causes actuation of the valve, which can result in the motor being activated for short periods of time where liquid is delivered at Ssubstantially full pressure to the valve but it is only delivered from the valve in a restricted manner. This is not only an inefficient use of the motor driving the pump but also results in the motor being operated for short periods of time with a fairly high frequency. This can be also detrimental to the motor. Furthermore where the level of the liquid may be subject to wave action as a result of wind there can be some resultant movement of the valve member which again can cause undesirable repetitive short 4 term operation of the pump. Furthermore the maintenance of the liquid level at a predetermined level by utilisation of the valve often results in the condition where the valve is never allowed to be opened fully and it is only opened to a limited extent. In many cases the liquid being delivered to the valve is not in a pure state and may contain solid particles which can collect in the region of the valve. These accumulated particles may prevent complete closure of the valve if they are allowed to build up. The build up of these particles is exacerbated by the circumstance that the valve is never allowed to open fully which would enable clearance of the particles from the region of the valve.

While the above discussion has been made in relation to float operated liquid valves it can have equal application in other circumstances where valves are required to be opened to maintain a predetermined pressure or fluid flow .condition or in circumstances where an electric switch is required to be activated according to certain conditions and where control of those conditions can be measured by a force transmitting means such as a float, thermostat pressure sensor or the like.

It is an object of this present invention to at least partially overcome the difficulties which have been cited above.

In the case of a float operated liquid valve the inventic'A provides a means whereby the valve is caused to be opened to a substantial extent for a significant p riod of time and whereby the level of liquid is maintained in a predetermined range. In accordance with that example the actuator would take the fom of a valve and the force transmission means would take the form of a float supported by the body of liquid being monitored.

5 The invention will be more fully understood in the light of the following description of one specific embodiment. The description is made with reference to the accompanying drawings of which:- Figure 1 is a schematic sectional view of the control mechanism according to the embodiment, the control mechanism maintains the valve in an OFF condition; and Figure 2 is a view corresponding to that of Figure 1 S.showing the control mechanism of the valve as held in the ON condition; Figure 3 is an isometric view of the embodiment; and Figures 4 and 5 illustrate alternative float arrangements for use with the embodiment.

The embodiment is directed for utilisation with a float controlled valve which can be used with reservoirs such as 0 stock troughs, water tanks and the like. The valve maintains the liquid level within the reservoir within a S.predetermined range whereby on the liquid level falling below a first predetermined level the valve will be opened and on the water level rising above a second predetermined level, which is higher than that of the first predetermined level, the valve will be closed.

The embodiment comprises a support 11 which comprises a pair of substantially parallel side plates helO together in spaced parallel relation. The plates support between themselves a control arm 12 and an actuator arm 13 which are pivotally supported about a first and second pivotal axes 14 and 15 respectively where the axes are located between the ends of the respective arms. The pivot axes 14 and 15 are each provided by a pivot pin which extends transversely between the side plates of the support 11.

One end 16 of the control arm 12 extends beyond the support I If 6 and is adapted to receive one end of a control rod 17 which supports a float 18 at its outer end. One end 19 of the actuator arm 13 extends outwardly from the support 11. The support 11 is adapted to be supportably received upon a valve body 20 by means of a support ring 21 provided on the base of the support 11 and which is adapted to be receivable around the valve body 20 to maintain the support 11 close relation to the valve body 20. When the support 11 is mounted to the valve body 11 the one end 19 of the actuator arm extends into the valve body to be engagable with the movable valve member 22 such that the valve member 22 is caused to be moved in the valve body 20 in accordance with the movement of the one end 19 of the actuator arm 13.

The actuator arm 13 is movable between a first position shown at Figure 1 at which the valve member 22 is maintained in the closed condition and a second position as shown at Figure 2 at which the valve member 22 is maintained in the open position. In addition the control arm 12 is movable between a first position at which the a float 18 is located at its uppermost position in the reservoir accommodating the body of liquid (as shown at Figure 1) and a second position at which the float 18 is located' at its lower-most level within the reservoir accommodating the body of liquid (as shown at Figure A pair of stops 23 and 24 are provided in the support 11 to be engaged by the control arm 12 to prevent movement of the control arm beyond the first and second position respectively.

To effect movement of the actuator arm 13 as a result of movement of the control arm 12 the other ends of both arms are interconnected such that on the control arm moving between the first and second position the actuator arm is also caused to be moved between the first and second position and on movement of the control arm between the 7 second and first position the actuator arm is also caused to be moved between the second and first position. The interconnection between the other ends of the arms 12 and 13 is effected by a resilient coil spring 25 which is in a state of compression when mounted between the arms such as to bias the other ends of the arms away from each other.

This biasing force however is at its maximum when the arms are intermediate their first and second positions.

Therefore in order for the control arm 12 to effect movement of the actuator arm from the first to the second position or alternatively from the second to the first position the force which is applied to the control arm must overcome the maximum biasing force which is exerted between the arms when the arms are at their intermediate position.

Furthermore on that maximum biasing force being overcome the movement of the control arm and thus the actuator arm Sfrom the first position to the second position and alternatively from the second position to the first •position, is rapid. The resultant effect of such is that on an appropriate force being applied to the control arm to S: effect its pivotal movement on the support against the resilient spring 25 it is moved rapidly to the other position and is not permitted to maintain an intermediate position. This results in the actuator arm rapidly moving between its end positions and not being permitted to reside at an intermediate position. As a result the valve is :oori caused to be either fully closed or substantially open.

The force which is transmitted to the actuator arm by the control arm is effected through the float 18 which is supported upon the surface of the body of liquid being monitored. On the level of liquid falling the float 18 will be prevented from falling correspondingly due to the biasing force which is applied between the other ends of the control arms 12 and the actuator arm 13 by the 8 resilient spring 25. The falling of the float will be as a result of the increased weight of the float, which results from the decreased support being provided by the liquid, overcoming the biasing force. On the force being required to support the weight of the float exceeding the biasing force provided by the resilient spring 25 the float arm will be caused to move to its lowermost position with respect to the support which will result in the valve being rendered or substantially open. The float will maintain its position within the body of water until the forces being applied to the control arm through the buoyancy of the float within the body of water exceed the maximum biasing force being provided between the other ends of the control arm 12 and actuator arm 13 by the biasing spring At such a time the float member will be caused to move to its upper most position within the reservoir causing the actuator to close the valve.

The effect of the control mechanism valve is such that when S• the valve is opened it is opened to a substantial extent and when it is caused to be moved to close it is rapidly closed. As a result the collection of any debris or solid particles in the region of the valve will be substantially cleared as a result of the substantial opening of the valve. Furthermore where the liquid is delivered to the valve through a motor driven pump the utilisation of the motor is maximised in that there is a substantial delivery of liquid from the valve member. Furthermore since the liquid levels at which the valve member is closed and opened are spaced from each other the activation of the pump would be for an extended period of time sufficient to allow for the raising of the liquid level from the position at which the valve is opened to a position whi'.h the valve is closed.

i ~If desired the pivot axis for the control arm can be varied /7 X in its position on the control arm to vary the spacing 9 between the liquid levels at which the valve is closed and opened.

It should be appreciated that the embodiment in its utilisation need not be restricted to the particular from of float operated valve described in relation to the embodiment where the float 18 is mounted directly to the arm 17.

If desired and as shown at Figure 4 the control rod 17 may be spaced above or below the level of liquid and support a float through a further arm where the float is able to slide along the further arm between a pair of stops.

9 In addition according to another form as shown at Figure the float may be supported from the control rod by a flexible member such as a piece of rope, chain, string or the like where the control arm is located within the body of liquid and a weight is mounted at the end of the control rod. On the level of liquid falling below a predetermined level the degree of support provided to the control rod by the float decreases until the degree of force required to support the weight exceeds the biasing force exerted on the control arm and the actuator arm is moved to cause the opening of the valve. On the liquid level being raised the upward movement of the float will be restricted until such time as the buoyancy of the float overcomes the biasing on the control arm.

It should be appreciated that tie scope of the present invention need not be limited to the particular scope of the embodiment described above and in.particular need not be limited to the particular application of the embodiment.

Claims

1. An actuator control mechanism comprising a support, said support supporting a control arm and an actuator arm, each arm being pivotally supported from the support, said support being adapted to be mounted to an actuator body accommodating an actuator and one end of the actuator arm extending froit the support such that the actuator arm is engagable with the actuator whereby the actua-cor arm is movable between a first position at which the actuator is rendered active and a second position at which the actuator is rendered inactive, the control arm extending from the support auid adapted to be associated with a force generation means, the control arm being pivotally movable on the support between a first position and a second position, the control arm and actuator arm being interconnected by a resilient means providing a biasing force therebetween which when the control arm is in its first position biases the actuator arm to its first position and when the control arm is in its second position biases the actuator arm to its second position, the V' location of the pivot axes of the control arm and actuator arm on the support and the connection between the control arm and actuator arm by said resilient means being such i that on the control arm and actuator arm being moved between the first and second positions anld between the second and first positions, the biasinr force exerted by the resilient means increases to a-maximum when the arms are intermediate their end positions on the support.

2. An actuator control mechanism as claimed at claim 1 wherein the resilient means comprises a spring

3. An actuator control mechanism as claimed at claim 2 wherein the spring is in a state of compression. 11

4. An actuator control mechanism as claimed at any one of the preceding claims wherein the support comprises a pair of parallel members and said control arm and actuator arm are pivotally supported between the members.

An actuator control mechanism as claimed at any one of the preceding claims wherein the location of the pivot axis for the control arm can be selected from a plurality of positions along the control arm.

6. An actuator control mechanism as claimed at any one of the preceding claims wherein the actuator comprises a liquid valve. .0

7. An actuator control mechanism as claimed at claim 6 I wherein the force generation means comprises a float and said actuator control is intended to be located such that the float is supported on the surface of a body of liquid. a. S

8. An actuator control mechanism substantially as herein described with reference to the accompanying drawings. DATED this ELEVENTH day of NOVEMBER 1993. 5S55* 0 JOSEPH ALBERT JOHNSON Applicant Wray Associates Perth, Western Australia, Patent Attorneys for the Applicant ABSTRACT An actuator control mechanism comprising a support, said support supporting a control arm and an actuator arm, each arm being pivotally supported from the support, said support being adapted to be mounted to an actuator body accommodating an actuator and one end of the actuator arm extending from the support such that the actuator arm is engageable with the actuator whereby the actuator arm is movable between a first position at which the actuator is rendered active and a second position at which the actuator is rendered inactive, one end of the control arm extending from the support and adapted to be associated with a force generation means, the control arm being pivotally movable too$ on the support between a first position and a second IOt position, the control arm and actuator arm being interconnected by a resilient means providing a biasing •force therebetween which when the control arm is in its S"first position biases the actuator arm to its first *SSSS* S"position and when the control arm is in its second position biases the actuator arm to its second position, the *location of the pivot axes of the control arm and actuator •arm on the support and the connection between the control S.arm and actuator arm by said resilient means being such that on the control arm and actuator arm being moved between the first and second positions and between the second and first positions, the biasing force exerted by the resilient means increases to a maximum when the arms are intermediate their end positions on the support.