The invention is particularly although not exclusively concerned with improvements in filter valve mechanisms.

BACKGROUND OF THE INVENTION Water filtering systems for swimming pools, spas and the like employ a manually switchable multi-position valve assembly. Typically, the valve assembly is selectively switchable between filter, waste, close, backwash, recirculate and rinse positions.

Accordingly, it is customary to provide a simple Bourdon tube pressure gauge in fluid communication with the inlet side of the valve or filter assembly whereby an elevated pressure is indicative of a backpressure arising from accumulation of particulate material on the filter medium.

While generally effective for indicating the need to backwash the filter system, such an indicator system is inconvenient to use in that it is directly coupled to the valve body or filter tank which is usually positioned remotely from the swimming pool or spa, often in an enclosure. With the remote positioning of the backwash indicator, owners of swimming pools or spas do not monitor filter efficiency as often as they should. This results in extreme cycles in water condition between well filtered and poorly filtered water with excess consumption of pool chemicals required to rectify the growth of organisms in poorly filtered water. More importantly however continued operation of a filter pump under conditions of high pressure and low flow rates can cause serious physical damage to the filtration equipment.

Conventional filter valves also suffer a number of shortcomings.

Depending upon how the filtration system is installed, the pressure gauge may be located in a difficult to read position. The valve actuator comprises a relatively short handle with a wide flat surface with 90° angled side walls which is difficult to grasp and actuate against a very strong closure biassing spring.

Typically the actuator has a projection opposite the handle portion which locates the valve in a selected position with the projection located in one of several recesses in the top of the valve housing. Accumulation of dirt and leaves in these recesses makes actuation of the valve difficult due to increased friction between surfaces and premature wear in the actuator and/or the valve body. Moreover, accumulation of debris in the recesses can prevent full closure of the valve leading to inefficient filter operation, water loss and premature internal wear in valve seals.

Accordingly it is an aim of the present invention to provide one or more improvements in valve systems for swimming pool and spa filter devices to overcome or alleviate one or more of the abovementioned prior art disadvantages.

BRIEF DESCRIPTION OF THE INVENTION According to one aspect of the invention there is provided a filter pressure monitor for a swimming pool or spa filtration system, said monitor comprising :- a pressure sensing device in fluid communication with pressurised water from a filter pump; and, an alarm switch coupled to said pressure sensing device, said alarm switch, in use, being actuable, when a variance from a predetermined pressure range is detected, to actuate an alarm indicative of the need to clean said filtration system.

Suitably the alarm switch is actuated when a predetermined upper pressure limit is exceeded.

If required the alarm switch is actuated when a system pressure falls below a predetermined lower pressure limit.

Suitably the pressure sensing device includes an analogue or digital pressure display.

Preferably the pressure sensing device comprises a dial gauge.

If required the alarm switch may include a relatively moveable magnet and electric reed switch adapted for switching at a predetermined pressure.

The alarm may comprise an audible alarm.

Alternatively the alarm may comprise a visible alarm.

If required the alarm may comprise both audible and visible alarms.

The filter pressure monitor may include a direct electrical coupling between said alarm switch and said alarm.

Alternatively the filter pressure monitor may include a wireless coupling between said alarm switch and a remotely positioned alarm.

Suitably said alarm switch is located in a hollow recess in an actuating handle of a filter valve assembly.

Preferably an audible alarm is located in the actuating handle of said filter valve assembly.

A control circuit for the filter pressure monitor may also be incorporated into the actuating handle.

A removable electrical power source may be incorporated into the actuating handle if required.

If required any or all of said alarm, said monitor, said control circuit and/or a power source may be incorporated in said valve body or associated therewith.

Suitably the control circuit includes an on/off switch and, optionally, a test switch.

The alarm switch is preferably adjustable to a selected switch actuating pressure.

If required the alarm switch is adapted to detect and signal predetermined upper and lower pressure limits.

Preferably said pressure sensing device is coupled to an upper end portion of a hollow actuating stem extending between a valve head located in a valve body and said actuating handle.

According to another aspect of the invention there is provided a valve cover for an upper portion of a valve assembly for a swimming pool or spa filtration system, said cover being rotatable with a valve actuating handle and functioning in use to resist accumulation of debris in registration recesses locating said actuating handle in a selected valve operating position.

Suitably said actuating handle, when depressed against the restoring influence of a valve closure biassing spring, co-operates with engagement members on said cover to prevent distortion of said cover when said actuating handle is rotated.

An upright slotted aperture may be formed in the valve cover to accommodate the valve actuating handle extending therethrough.

Suitably upright projections are formed adjacent opposite sides of said slotted aperture for engagement with respective aligned slotted recesses in said actuating handle.

If required the upright projections may be formed on an inner surface of said cover.

Alternatively the upright projections are formed on an outer surface of said cover.

A shroud member may extend over the slotted aperture above the actuating handle for movement with said handle in an upright plane.

BRIEF DESCRIPTION OF THE DRAWINGS In order that the various aspects of the invention may be more fully understood and put into practical effect, reference will now be made to preferred embodiments described in the accompanying drawings in which:- FIG 1 shows a part sectioned side elevation of the upper portion of a valve assembly 1 for a swimming pool or spa filter.

An upper housing portion 2 comprising an inlet plenum chamber 3, an inlet port 4 and a mounting flange 5 is secured by mounting bolts 6 to the mounting flange 7 of a lower valve body 8 incorporating a distribution plenum chamber (not shown) of conventional configuration.

Located within inlet plenum chamber 3 is a valve member 9 having a valve stem 10 and a valve head 11. Valve head 11 is urged by compression spring 12 into contact with a valve seat (not shown) comprising a plurality of separate apertures with which an aperture (not shown) in valve head 11 may be selectively aligned to perform the various functions of the distribution valve including filtering, cleaning etc. The configuration and functionality of the distribution valve is well known and forms no part of the present invention.

Valve stem 10 protrudes sealingly through an aperture (not shown) in the top wall 13 of upper housing portion 2 and is pivotally connected via pivot pin 14 to an inner portion 15 of actuating handle 16. Inner portion 15 of actuating handle 16 includes a locating projection 17 which locates in circumferentially spaced, radially directed locating apertures 18 in a recessed aperture 19 in top wall 13, the locating apertures 18 serving to align the aperture (not shown) in valve head 11 with one of the apertures (not shown)

in distribution plenum chamber 8.

When actuating handle 16 is pushed downwardly at its free outer end, cam portion 20 on the inner portion 15 of handle 16 urges valve stem 10 upwardly and thus lifts valve head 11 out of sealing engagement with the valve seat (not shown) on the upper surface of distribution plenum chamber 8. With the valve head 11 in an elevated position, locating projection 17 is also elevated above locating aperture 18 thereby permitting rotation of the actuating handle 16 to register a selected valve position. During rotation with compression spring 12 under compression, frictional engagement between cam portion 20 and the base 21 of recess19 is minimised by a bearing plate 22 of low friction material.

A pressure gauge 23 of the Bourdon tube type is mounted on hollow valve stem 10 in fluid communication with the interior of inlet plenum chamber 3 via an aperture 24 in the wall of valve stem 10.

A transparent plastics cover 25 is rotatably coupled to upper housing portion 2 by a tongue and groove type connection having inwardly directing projections 26 which are secured in a circumferential groove 13a formed about top wall 13. Actuating handle 16 extends through a vertical slotted aperture 27 in the wall of cover 25 to permit pivotal movement about pivot pin 14.

On opposite sides of slotted aperture 27 are inwardly directed projections 28 which engage with slotted guide members 29 formed on each side of handle 16. Alternatively projections 28 could be formed on handle 16 to engage with slotted guide members associated with the cover 25. It readily will be apparent to a skilled addressee that the projections and guide members may be formed externally of cover 25. When the remote free end of handle 16 is depressed to release projection 17 from a particular valve

aperture registration position, guide members 29 engage with projections 28 to prevent distortion of the relatively flexible cover 25 when handle 16 is rotated whereby the cover 25 rotates with handle 16 by engagement with a respective side edge of slotted aperture 27.

Even in its simplest form as shown in FIG 1, these aspects of the invention offer substantial improvements over prior art filter valve assemblies.

Positioning of the pressure gauge on top of the valve assembly makes it easier to read than a valve positioned in a side wall of inlet plenum chamber 3 as it is easily viewable from 360. Moreover, the provision of a transparent plastics cover provides weatherproof protection for the pressure gauge 23 and electrical connections thereto (described later) for increased longevity. The cover 25 also prevents ingress of debris into recesses 17 and 19 which could interfere with easy operation of the valve.

If required, the top portion 30 of transparent plastics cover 25 could be formed as a magnifying lens to enable easy reading of the pressure gauge dial or read out. In addition actuating handle 16 is longer than a conventional valve handle and includes an ergonomically designed end knob 31 which together with greater leverage permits easy valve operation.

FIG 2 is a top plan view through A-A of the embodiment of FIG 1 and shows more clearly the interaction between actuating handle 16 and transparent cover 25.

As previously described, when valve handle 16 is depressed guide members 29 engage projections 28 in slots 29a on either side to prevent flexing of the lower portions of cover 25 in opposite tangential directions on each side of aperture 27 wherein engagement between projections 26 and retaining groove 13a is retained thereby allowing cover 25 to rotate freely

with handle 16.

FIG 3 shows one form of pressure monitoring system.

Pressure gauge has a small permanent magnet 40 attached to the indicator needle 41 and at lest one magnetically actuable reed switch 42 electrically coupled via conductors 43,44 to a control circuit (not shown).

Reed switch 42 is secured to the body of the pressure gauge at a position representing a maximum pressure indicative of the need to clean the filter medium by backwashing or the like. When the indicator needle 41 approaches the predetermined maximum pressure setting, the magnet 40 actuates reed switch 42 to close the circuit between conductors 43 and 44 to activate an alarm as described later.

Typically a pressure increase in the fluid circuit between a filter pump and a filter is due to progressive blockage of the filter medium causing a backpressure in the line. As the empirical maximum desired operating pressure valve may vary from installation to installation depending on pump power, filter medium, filter volume etc, it is desirable to readily change the pressure gauge reading at which the alarm control circuit is actuated. This can be achieved by a plurality of circumferentially spaced reed switch fixing points on the gauge body or associated housing parts or alternatively the reed switch may be secured to the transparent plastics cover which is rotatably secured for the gauge body. In this manner, the desired alarm actuation pressure may be set simply by effecting relative rotation between the gauge body and the gauge cover to align the reed switch with a selected pressure value indicated on the gauge dial 45.

During the filtration cycle of a swimming pool, it is not uncommon for a skimmer box filter to become clogged with leaves or other debris to the extent that water flow on the suction side of the filter pump is restricted or

even prevented allowing the filter pump to run dry. This can cause serious damage to the pump due to overheating and otherwise interfere with normal pool water filtration.

Blockage of a skimmer box filter or other suction line filter can be determined by reduction of line pressure below a desired minimum value for a particular system. By adding a second reed switch 46 as shown in FIG 3, the operation of the pool or spa filter may be adapted to operate between predetermined maximum and minimum values and provide an alarm signal for a pressure condition outside that range to indicate that attention is required to the main filter system or the skimmer box filter.

If required, the system may include discernibly different alarm signals to indicate high pressure or low pressure to indicate the specific nature of attention required. The alarm may comprise one or more audible signals, one or more visual signals or combination thereof.

FIG 4 shows a side elevational part sectioned view of a particularly preferred embodiment of the invention.

As shown pressure gauge 23 is mounted in valve stem 10 for sealed relative rotation therewith. A fluidic seal is achieved by an O-ring 50 located in a groove 51 in gauge nipple 52 and rotation is permitted by a grub screw 53 which locates in a groove 54 also in gauge nipple 52.

Pressure limit switches 42,46 are electrically coupled to a control circuit 55 located within the hollow interior of handle 16 by conductors 43,44.

Also, located within the hollow interior of handle 16 are an activating switch 56, a replaceable dry cell 57 and an audible alarm 58 such as a buzzer or the like. Suitably switch 56 is movable between on and off positions and may also include a test position to test the condition of the battery by a single buzzer tone to indicate an active battery. Alternatively,

the control circuit may include a voltage measuring circuit to activate differing audible signals indicative of low battery life.

The pressure gauge 23 and its associated electrical connections is located within weatherproof cover 25 and switch 56, control circuit 55, battery 57 and audible alarm 58 are also securely weatherproofed within the hollow interior of handle 16 thus leading to reliable electrical circuitry.

It readily will be apparent to a person skilled in the art that many modifications and variations may be made to the various aspects of the invention without departing from the spirit and scope thereof.

For example any form of pressure sensing device may be employed such as a miniature strain gauge which provides an electrical signal proportional to pressure detected. Such a device could be coupled to a digital readout. As a signal proportional to pressure can be detected, the apparatus may be calibrated to provide a warning signal as a maximum or minimum pressure is approached. This warning signal may comprise a tone of differing pitch, amplitude or frequency and/or a visible signal of differing colours or a flashing signal.

In other modifications, the audible alarm 58 may be replaced with a low power radio transmitter adapted to actuate an audible and/or visible signal within an adjacent building such as a house. If required, the radio transmitter may be adapted to activate an autodial modem to send a pool filter status report by telephone line to a remotely located swimming pool or spa maintenance service.

In yet another modification, the pressure gauge may comprise a generally hemispherical graduated dial indicator rotatable relative to a fixed curved pointer to permit easy reading of pressure values. The graduations may simply comprise coloured segments indicating satisfactory or

unsatisfactory operating pressures in addition to or as an alternative to empirical values.

In yet another embodiment of the invention a conventional valve arrangement may be modified to provide a filter pressure alarm by removing the pressure gauge from the filter body and replacing it with a signaling gauge or pressure sensor as described generally above. A simple magnetic reed switch gauge may be coupled to a weatherproof housing enclosing the control circuit, on-off switch, battery and audible alarm, the housing being mechanically secured to the valve body or to a convenient adjacent structure.

In a still further embodiment of the invention, that portion of slotted aperture 27 as shown in FIG 1 may include one or more shroud members to seal the aperture against the ingress of debris. A shroud member attached to handle 16 may cover the upper opening and a spring biased lower shroud member may telescope into the recessed inner region of the handle when depressed.

Throughout this specification and claims which follow, unless the context requires otherwise, the word"comprise", and variations such as "comprises"or"comprising", will be understood to imply the inclusion of a stated integer or group of integers or steps but not the exclusion of any other integer or group of integers.