GB2135428A

GB2135428A - Fluid flow control systems

Info

Publication number: GB2135428A
Application number: GB08302014A
Authority: GB
Inventors: Stephen Richard Heneker
Original assignee: Individual
Current assignee: Individual
Priority date: 1983-01-25
Filing date: 1983-01-25
Publication date: 1984-08-30
Also published as: GB8302014D0

Abstract

A water flow control system, for controlling the flow of water through a tap to dispense a desired volume of water, includes a dial 2, which is rotated to an angle indicative of a desired volume. Rotation of the dial 2 causes axial displacement of a rod 10, which displacement is transmitted against the biasing force of a spring 16 to an axially displaceable gearwheel 18. Rotation of a vane 26 located in the flow path through the tap is transmitted to the gear wheel 18. The gear wheel 18 carries a circumferentially extending cam surface 20. A cam follower 22, engaging the cam surface 20, trips a control valve 8, when sufficiently displaced by the cam surface 20. The control valve 8 when tripped initiates closure of the main valve of the tap. By varying the axial position of the gear wheel a greater or lesser rotation of the wheel is required before the control valve is tripped. In this way the volume of water dispensed by the tap is controlled. <IMAGE>

Description

SPECIFICATION Fluid flow control systems The present invention relates to fluid flow control systems.

Co-pending Patent Application No. 82/30022 describes a power assisted valve assembly in which the pressure of the mains water supply is used to assist the opening and closing of the valve. The assembly includes a valve member which is arranged with part of one surface to move into and out of contact with a vlave seat coupled to a mains water supply. A control chamber, which is also coupled to the mains water supply, is arranged to cover the opposite face of the valve member with water.

With water under mains pressure supplied to both faces of the valve member, the valve member is held against the valve seat because the surface area of the valve member covered with water from the chamber is greater than the surface area of the valve covered with water through the valve seat.

To enable the valve to open, the supply to the chamber from the water mains is cut off and water is drained from the chamber. The quantity of water drained will control the extent to which the valve member opens. To close the valve member, water from the mains is again supplied to the chamber.

An ON button controls the flow of water from the chamber while an OFF button controls the supply of water from the mains to the chamber, the flow control being effected through control valves.

The opening and closing of the above described valve assembly, while power-assisted, is opened and closed by manual operation.

According to the invention, there is provided a fluid flow control system for controlling the quantity of fluid flowing through a valve, rotary means rotatable at a rate proportional to the quantity of fluid flowing through the valve, means for transmitting the rotation of the rotary means to a rotary member actuation means responsive to the rotary member passing through a predetermined angular position to initiate closure of said valve.

According to the invention, there is further provided a liquid flow control system for controlling the volume of liquid flow through a valve comprising a rotary vane rotatable by the flow of liquid at a rate proportional to the volume rate of flow of liquid, a gear wheel, a gear train for transmitting the rotation of the vane to the gear wheel, support means for supporting the gear wheel for axial displacement, biasing means for biasing the gear wheel axially in one direction, abutment means for limiting the extent of displacement of said gear wheel by said biasing means, a circumferentially extending cam surface located on an end face of the gear wheel, a cam follower co-operable with said cam surface whereby rotation of said rotary vane is transmitted through the gear train, the gear wheel and said cam surface to displace the cam follower axially, and actuation means responsive to said cam follower reaching a pre-determined position to initiate closure of said valve.

According to the invention, there is still further provided a liquid flow control system for controlling the volume of liquid flowing through a valve, comprising a rotary vane rotatable in response to the flow of liquid through the valve at a rate proportional to the volume rate of flow, a gear wheel, a gear train for transmitting rotation of the rotary valve to the gear wheel, an abutment located on one end face of the gear wheel, radially spaced from the rotary axis of the gear wheel, actuation means arranged to be tripped by the abutment to initiate closure of said valve upon rotation of said gear wheel through an angle corresponding to u pre-determined flow indicated by the extent of rotation of said vane.

Fluid flow control systems embodying the invention will now be described by way of example with reference to the accompanying diagrammatic drawings in which: Figure 1 is a perspective view of a domestic pillar tap incorporating the fluid flow control system; Figure 2 is a fragmentary section through the fluid control system of the tap; Figure 3 is a plan view of the control system of Figure 2; Figure 4 is a perspective view of another fluid control system; Figure 5 shows a detail of the system of Figure 4; Figure 6 is a side elevation of yet another fluid control system; and Figure 7 is a fragmentary perspective view of the system of Figure 6.

The pillar tap shown in Figure 1 incorporates a valve assembly such as described in co-pending Patent Application No. 82/30022 and a fluid flow control system embodying the present invention.

The fluid flow control system when set will enable the tap to deliver discrete quantities of water; the quantity of water delivered being determined by the setting of the volume dial 1.

When the fluid flow control system is not set, the tap will operate in a normal power-assisted mode as previously described by operation of the ON and OFF buttons 4 and 6 respectively controlling ON and OFF control valves.

The fluid flow control system when set is arranged to trip and OFF control valve 8 (see Figure 2) of the valve assembly when a quantity of water corresponding to the quantity set by the dial 2 has been dispensed. As shown in Figure 2, the flow control system includes a dial 2 (shown diagrammaticaily) which is in screwthreaded engagement with the main body of the tap, the dial 2 carries a downwardly extending rod 10 which passes through an O-ring seal 12 into the inner body of the tap. The lower end of the rod 10 extends towards the upper face of a gear wheel 18 to make contact with the gear wheel 18 at a location radially spaced from its vertical rotary axis. The gear wheel 18 is supported on a shaft 14 for axial displacement along the shaft 14.A coiled spring 1 6 biases the gear wheel 1 8 upwardly to bear against the lower end of rod 10. Rotation of the dial 2 will thus cause axial displacement of itself and of the rod and so vary the axial position of the gear wheel 1 8.

One end of the spring 16 is secured to the gear wheel 18 and the other end of the spring is secured to the main body of the tap. In this way, when the gear wheel 1 8 is rotated from its initial angular position, it will be restored to its initial position upon release.

The gear wheel 1 8 has a circumferentially extending cam surface 20 extending about the axis of the shaft 14 and located at a greater radius, from the shaft axis than that at which the rod 10 is located.

A cam follower 22 engaging the cam surface 20 is coupled to the valve 8 by a coupling 24.

Rotation of the gear wheel 1 8 will thus effect displacement of the cam follower 22 which in turn through the coupling 24 will trip the valve 8 to initiate closure of the main valve member of the tap.

The rotation of the gear wheel 18 is effected by a multi-bladed rotary vane 26 (see Figure 3) located in the main flow path through the tap. The arrangement is such that the number of rotations which the vane 26 makes is proportional to the quantity of water passing the tap.

The vane 26 is mounted on a shaft 28 which carries a helical gear 30. A gear wheel 32 has a large gear 32a which meshes with the helical gear 30 and a small gear 32b.

An idler gear 34 meshes both with the small gear 32b and with the gear wheel 18.

The gear wheel 1 8 has a section 1 8a without teeth to enable the disengagement of the gear wheel 18 from the idler wheel 34.

In operation, when the dial is in its datum position, that is a position in which no specific volume of water is to be metered from the top, the rod 10, and therefore the gear wheel 18, are both located in their lowest positions. In this state, no degree of rotation of the gear wheel 1 8 will cause the cam surface 20 to displace the cam follower 24 sufficiently for the valve 8 to be tripped.

Thus, if the tap is turned ON and a flow of water commences, the vane 26 will turn and through the train of gears 32a, 32b and 34 will drive the gear wheel 18. As the gear wheel 1 8 approaches the completion of one revolution, the toothless section 1 8a of the gear wheel will come to face the idler wheel 34 and so become disengaged therefrom.

At this point, the gear wheel 1 8 will no longer rotate in response to further rotation of the vane 26. The vane 26 will thus continue to rotate until the tap is turned OFF. As soon as the tap is turned OFF, the spring 1 6 will cause the gear wheel 18 to re-engage the idler wheel 34 and return the gear wheel 1 8 to its initial angular position.

If now the dial 2 is rotated to a set mark representative of a desired volume of water, the rod 10 and therefore the gear wheel 18 will rise by an appropriate amount to render the action of the cam surface 20, through the cam follower 22, effective on the valve 8.

If the tap is now turned ON, the flow of water through the tap will again turn the vane 26 to commence rotation of the gear wheel 18. This time, however, during rotation of the gear wheel the cam surface through the cam follower 24 will trip the valve 8 after the preset volume of water has been dispensed and so shut the tap OFF.

When the flow of water from the tap has ceased, the spring 16 will return the gear wheel 1 8 back to its initial angular position.

Each time the tap is now turned ON, the same volume of water will be dispensed. To change the volume of water being dispensed, the dial is moved. This changes the angle through which the gear wheel 18 will rotate before the valve 8 is tripped. When the dial 2 is returned to its datum position, flow through the tap will no longer be metered.

It will be appreciated that, when the metering facility of the tap is not being used, the vane 26 and the gear wheels 32, 34 and 18 will all be rotated each occasion that the tap is turned ON, thereby ensuring continued free operation of the main moving parts of the system and reducing the risk of clogging.

In the system shown in Figure 6, the dial 2 of Figure 2 is arranged to be mounted on an annular body 40 with the screw-threaded portion of the dial 2 engaging the screw-thread 42 in a central through hole of the body 40. The body 40 is slidably mounted in the tap and a pin (not shown) rigid with the tap engages an axially extending slot 44 in the body to constrain the body against rotation.

An elongated control member 46 extending parallel to the axis of the annular body 40 is slidably mounted on the outer surface of the annular body 40. A projection (hidden from view) on the control member 46 engages a circumferentially extending slot 48 in the body 40.

The body 40 has an annular collar 40a defining a part circumferentially extending slot 40b which is engaged by the upper end portion of the control member 46.

The control member has a cruciform recess 46a (see Figure 5) which is engaged by a peg rigid with the body of the tap or by a ball bearing 50 held captive by the body of the tap.

A spring 17 (see Figure 2) biases the dial and the annular body 40 upwardly within the tap body.

In operation, it will be appreciated that successive depression of the assembly of dial 2 and annular body 40 against the bias of the spring 17 will cause the ball 50 to enter alternate limbs of the cruciform recess 46a. Since one limb is longer than the other, it will be seen that upon release after each alternate depression the final position of the lower end of the rod 10 will be higher than that upon release after each intervening depression. In this way the assembly of dial and body can be used to set the tap into a manual operation mode or an automatic metering mode.

If the upper end of the control member is suitably marked and a datum mark provided in the upper end face of the annular body, the state of the tap can readily be determined by the operator.

The flow control system of Figures 6 and 7 is arranged to deliver a pre-set volume of liquid dialled by the user. When the tap is turned OFF, it will always return to its normal (non-automatic) mode of operation after dispensing the pre-set volume.

Therefore, unless the dial to indicate the desired volume is operated, the tap will always be found in its normal (non-automatic) configuration.

The act of dialling up a specified volume will automatically change the tap to its automatic configuration.

In the system of Figure 6, parts similar to those in Figure 2 are similarly referenced. In Figure 6, the gear 1 8 of Figure 2 is replaced by a gear 60 which is not axially slidable but is free to rotate.

The gear 60 carries a smaller coaxial gear 62 (see Figure 7). The lower end of the rod 1 0 carries a gear 64 which meshes with the gear 62. Thus, rotation of the dial 2 will cause the rotation of the gear 60.

A raised pawl 66 projecting from the upper face of the gear 60 is arranged to engage the cam follower 22. The coupling between the valve 8 and the cam follower 22 is pivoted at point 'a', and hinged at points 'b' and 'c'. Preferably the coupling is of polypropylene having living hinges at points 'b' and 'c'. The part of the coupling 24 between hinges 'b' and 'c' runs in a guide 70 to ensure that it moves in a predetermined manner.

The upper surface of gear 60 is provided with a radially extending slot 35 located between pawl 66 and the section of the gear with missing teeth.

Rotation of dial 2 to select a pre-determined volume of water to be delivered, rotates gear 60.

Assuming that the tap was in its normal (nonautomatic) configuration, than as gear 60 rotates (clockwise as illustrated), the cam follower 22 engages the slot 35.

Further rotation of the dial 2 will cause the cam follower to pivot about hinge 'c' and adopt the configuration shown in Figure 6.

The dial is further rotated until the desired volume to be delivered is indicated on the scale.

At this point valve 8 is open and free to move axially due to the lost motion built into the system, and is unrestrained by coupling 24. On depressing the 'ON' button, the tap opens. As soon as water flows through the tap the vane 26 begins to rotate thereby driving the gear train and rotating gear 60.

As this occurs, the dial 2 will also rotate, indicating to the user the volume of water yet to be delivered.

When the raised pawl 66 on gear 60 engages the cam follower 22, the section 'b-c' of the coupling lifts and when the lost motion of the system has been taken up, valve 8 is opened, thereby turning OFF the tap.

The valve 8 is now free to move as before, and the tap may now be used in its normal mode.

When next used in the normal mode of operation, the vane is driven and the gear train begins to rotate. When the idler gear 34 coincides with the section without teeth, the gear 60 is no longer driven, while the remainder of the gear train turns as described above, thereby reducing the risk of the system clogging.

To use the tap in its automatic mode, again the dial 2 is rotated as described above, and the gear 60 will again mesh with the idler gear 34.

The automatic dispensing of water can be interrupted at any time by operating the OFF button of the tap.

A stop (not shown) ensures that from its normal setting, the dial 2 can only be rotated in one direction to dial a volume.

For a given basic design of tap to be able to offer a number of different volume ranges to be delivered, a change in the pitch of the helical gear 30 with mating gear 32 will enable a good spread of ranged to be achieved.

For extreme differences in ranges of volume delivery, changes to the chamber in which the vane assembly rotates as well as changes to the selected gear ratios would be required. It will be appreciated that the gear train mechanism is immersed in the liquid that the tap is to deliver, thereby reducing sealing problems and providing some lubrication to the components.

The control and display elements to this system could, where appropriate, be electronic so as to provide, for example, servo-assisted dialling, and digital volume display as might be required for automatic coin-operated petrol pumps or other commercial liquid dispensing equipment.

The systems described are particularly suitable in water taps which may be incorporated in commercial or domestic installations, but they are equally appropriate to the delivery of other fluids such as chemicals and petroleum products.

in connection with the delivery of water, the systems described may assist the consumer in water conservation by limiting the volume used for any particular purpose, or giving the consumer a better idea of the quantity of water required for different needs.

It should be noted that the flow control systems described can form the sole means of controlling the tap, without the normal operation option, and this could be used in commercial applications.

Additionally a tap or valve could incorporate the automatic volume delivery feature only, set to deliver a specified volume without the variable setting feature. Such a device might be used in public lavatories, ships, aircraft and even spacecraft where the prevention of water wastage is important.

In such an application, the tap would require one button only, all other functions being automatic, thus providing a simple low cost tap that delivers a known preset volume of water each time it is operated.

Claims

1. A fluid flow control system for controlling the quantity of fluid flowing through a valve, rotary means rotatable at a rate proportional to the quantity of fluid flowing through the valve, means for transmitting the rotation of the rotary means to a rotary member, actuation means responsive to the rotary member passing through a predetermined angular position to initiate closure of said valve.

2. A system, according to claim 1, including adjustment means for varying the pre-determined angular position of the rotary member at which sais actuation means will initiate closure of said valve.

3. A system, according to claim 2, wherein said adjustment means comprises means for adjusting the angular position of the rotary member prior to the valve being opened.

4. A system, according to claim 2, wherein said rotary member is axially displaceable along its rotary axis and carries a circumferentially extending cam surface on one end face, wherein said actuation means comprises a cam follower co-operating with said cam surface, said cam follower acting to initiate closure of said valve when displaced by the cam surface of said rotary member beyond a pre-determined axial position, and wherein the adjustment means comprises means for adjusting the axial position of the rotary member

5. A system, according to any preceding claim, wherein said rotary means comprises a rotary vane arranged to be located in the flow stream of fluid passing through said valve.

6. A system, according to any preceding claim, including means for decoupling the rotary member from the rotary means when the rotary member reaches a second pre-determined angular position.

7. A system, according to any preceding claim, wherein the actuation means includes a control valve for controlling said first mentioned valve.

8. A system, according to any preceding claim, including means for inhibiting operation of said actuation means by said rotary member.

9. A liquid flow control system for controlling the volume of liquid flow through a valve comprising a rotary vane rotatable by the flow of liquid at a rate proportional to the volume rate of flow of liquid, a gear wheel, a gear train for transmitting the rotation of the vane to the gear wheel, support means for supporting the gear wheel for axial displacement, biasing means for biasing the gear wheel axially in one direction, abutment means for limiting the extent of displacement of said gear wheel by said biasing means, a circumferentially extending cam surface located on an end face of the gear wheel, a cam follower co-operable with said cam surface whereby rotation of said rotary vane is transmitted through the gear train, the gear wheel and said cam surface to displace the cam follower axially, and actuation means responsive to said cam follower reaching a pre-determined position to initiate closure of said valve.

10. A system, according to claim 9, including adjustment means for adjusting the location of said abutment means to vary the angle through which the gear wheel must rotate before the cam follower reaches said predetermined position, thereby to vary the volume of liquid dispensed from the valve.

11. A system, according to claim 10, wherein the adjustment means is operable to displace the gear wheel axially to such an extent that said cam follower does not reach said pre-determined position irrespective of the extent to which the gear wheel is rotated.

12. A liquid flow control system for controlling the volume of liquid flowing through a valve comprising a rotary vane rotatable in response to the flow of liquid through the valve at a rate proportional to the volume rate of flow, a gear wheel, a gear train for transmitting rotation of the rotary vane to the gear wheel, an abutment located on one end face of the gear wheel, radially spaced from the rotary axis of the gear wheel, actuation means arranged to be tripped by the abutment to initiate closure of said valve upon rotation of said gear wheel through an angle corresponding to a pre-determined flow indicated by the extent of rotation of said vane.

1 3. A system, according to claim 12, including adjustment means for pre-setting the initial angular position of the gear wheel prior to the vane being rotated by said flow whereby to vary the volume of liquid dispensed by said valve.

14. A system, according to any one of claims 9 to 1 3 wherein said gear wheel has a toothless section to enable the gear wheel to be de-coupled from the gear train after rotation of the gear wheel to its maximum extent.

1 5. A liquid flow control system substantially as hereinbefore described with reference to Figures 1 to 3 of the accompanying drawings.

1 6. A liquid flow control system substantially as hereinbefore described with reference to Figures 1 to 3 as modified by Figures 4 and 5 of the accompanying drawings.

17. A liquid flow control system substantially as hereinbefore described with reference to Figures 6 and 7 of the accompanying drawings.