GB2609976A - A low-level indicator device for a portable water tank - Google Patents

Abstract

A portable water level indicator 10 includes a sensor 15 housed in an elongate housing 14. An extensible first section 21 has an end for contacting a base of a water tank T fig. 1 and is configured to set a depth of water level W fig. 1 that will trigger an alarm 13. An extensible second section 23 with an upper cap end 24 enables a total longitudinal length to be set in order for the end to be located within a restricted horizontal opening of the water tank which maintains the indicator in an upright position, fig. 1. The sensor 15 may be a float switch. The level indicator may comprise adjustable telescopic tubes.

Description

A low-level indicator device for a portable water tank

Technical field

The present invention relates to a low-level indicator device, e.g. an alarm, particularly for removable use with a portable water tank associated with a caravan or mobile home.

Background to the invention

It is common for a portable and refillable water supply to be located next to a caravan's static location. The water supply, often in the form of a rollable tank, is connected by tubing to the caravan's water utilities, e.g. kitchen/bathroom sink and shower, to supply water thereto. A pump is submerged to the bottom of the tank and automatically activated when a water service is opened, e.g. tap on a sink, to draw water from the tank.

Portable tanks are typically roto-moulded and basic in nature such that the water level can only be assessed by opening a cap and visually peering into the cavity of the tank itself. As such, it is very difficult for a user to assess how much water remains in an external tank. This is a particular problem when taking a shower which soon empties the portable water barrel.

The water may run out just as a user is covered in soap or the like.

A journey must then be made outside to check the water and take the tank for refilling. The immersible electric pump can also burn out if left to run dry. Constant physical water level checks are required unless the pitch has its own water faucet automatically topping up the container, and even these can fail.

Summary of the invention

In order to ameliorate the above problem, the present invention seeks to provide a portable water level indicator to alert a user that a tank has reached a minimum level. If necessary, the device can be adapted to different water tank volumes/heights.

In a broad aspect implementing the invention a low-level indicator device is defined according to claim 1.

A low water level alarm of the type described herein combines simple existing technology in a novel way. In an exemplary form, it is comprised of a telescopic tube system with an internal sensor, e.g. a float switch. Adjustable telescopic sections allow the user to set both a level at which the alarm is activated and the overall length of the tube so that it can be configured to engage within a filling hole at the uppermost portion of a water supply, e.g. a portable caravan water barrel, thus maintaining it in an upright position to ensure accuracy.

Since the float is located within a tube it cannot snag on the water pump or sides of the water barrel.

An alarm sounder is connectable to the sensor, e.g. via a plug-in cable which can be directed through a closed caravan window without compromising the window seal. In alternative forms the connection may be wireless. Preferably, the alarm circuit is configured to sound once only to minimise disruption and, thus, needs no 'mute' option. Preferably, the whole device may be powered by a minimal energy source, e.g. by two AA batteries, maintained within the alarm housing, distant from the sensor tube. A wireless version may require separate batteries for a radio transmitter at the sensor end.

Brief description of the drawings

Figure 1 illustrates a general view of a low-level water alarm according to the invention, in the context of being positioned in a water tank as may be located outside a caravan; and Figure 2 illustrates a more detailed view of the low-level water alarm.

Detailed description of the invention

The following description presents an exemplary embodiment and, together with the drawings, serves to explain principles of the invention. However, the scope of the invention is not intended to be limited to the precise details of the embodiments or exact adherence with all steps, since variations will be apparent to a skilled person and are deemed also to be covered by the description. Terms for components used herein should be given a broad interpretation that also encompasses equivalent functions and features. In some cases, several alternative terms (synonyms) for structural features have been provided but such terms are not intended to be exhaustive.

Descriptive terms should also be given the broadest possible interpretation; e.g. the term ''comprising" as used in this specification means "consisting at least in part of" such that interpreting each statement in this specification that includes the term "comprising", features other than that or those prefaced by the term may also be present. Related terms such as "comprise" and "comprises" are to be interpreted in the same manner. Directional terms such as "vertical", "horizontal", "up", "down", "upper" and "lower" may be used for convenience of explanation usually with reference to the illustrations and are not intended to be ultimately limiting if an equivalent function can be achieved with an alternative dimension and/or direction.

The description herein refers to an embodiments with a particular combinations of features, however, it is envisaged that further combinations and cross-combinations of compatible features may be possible. Indeed, isolated features may function independently as an invention from other features and not necessarily require implementation as a complete combination.

Figure 1 outlines an example of a low-level water indicator device 10 in use, i.e. as installed into a portable water tank T having a submersible pump P located under a water level W and connected to a caravan-side power source and water receiving plug (not visible) via conduits C. Of the pair of conduits C, one carries water from the tank T and one houses an electrical cable powering the pump P. Tank T has at least one filling opening H and H that facilitate filling of the tank. The tank may be oriented in an upright position as pictured, or on its side where it may be configured for rolling along a ground surface.

The device 10 comprises three tubular sections, detailed with reference to Figure 2 below. An electric cable 11 exits from an uppermost end of device 10, proximate a cap on opening F1 and is directed to pass through an aperture into the living space of the caravan, e.g. via a window that may be closed with the seal pressed against the relatively thin wire of cable 11. Cable section 12 denotes an indeterminate length where it passes through a window, door or other opening. At its distal end cable 11 plugs into an alerting unit 13, e.g. an alarm/sounder. In the "wired" form illustrated, a power supply is maintained at the sounder end so that it is not required to be submerged in a sealed enclosure or close to water at the tank end.

Referring to Figure 2, device 10 is principally comprised of three telescopic tubular sections that configure the device into a total length that extends between a bottom of the water tank and a filling opening. A main/central elongate body section 14 is generally tubular with an opaque wall and houses a float switch 15 proximate its lowermost end 16. Float switch 15 is of a generally known type and includes a moving/floating ring 17 slidably mounted on a shaft 18. The shaft 18 is threaded (and may be longitudinally adjustable) into a fixed boss/plug 19 installed a short way into body 14 from end 16 via interference fit or gluing, etc. A magnetic switch operates depending on the position of ring 17 relative to shaft 18. For example, ring 17 is less dense than water and configured to float in a raised position (not illustrated) when the water level W is above it. When the water level drops below switch 15 and ring 17 falls to a lower position (as illustrated) a magnetic/electric connection between ring 17 and shaft 18 is changed. Such a state is detected at the alarm unit 13 via wire 11. For simplicity it is envisaged that a binary open/closed float switch is the preferred solution in the present invention.

In the illustrated form, since sensor 15 is housed within main tube 14, and not exposed (e.g. compared to a floating ring outside and located around tube 14 which could act as supporting shaft 18), neither the pump P nor its components can interfere with operation. It is also protected from mechanical damage.

At least one bore 20, through boss 19, enables fluid to pass through and flood the internal chamber of tube 14. Without this relief mechanism a sealed headspace would prevent the external water level from affecting float 17.

At a lowermost section of the device, a clear tube 21 is telescopically attached to main body 14, i.e. as a sleeve in an interference fit. Tube 21 may be slidably adjusted along a longitudinal axis A of the device in order that the alarm's water detection level may be set. A transparent material allows the distal end 16 of tube 14 to be seen which is proximate to the sensor. It will be apparent that the further a distal, tank-bottom-contacting, end 22 of tube 21 is from main body end 16 (and switch 15), the "deeper" the water remaining will be when the alarm will trigger. In a "deep" configuration the alarm will sound earlier compared to a short distance between ends 16 and 21 which may correspond to when the tank is almost empty.

It will be apparent that a distance setting adjustment may be achieved by another mechanism than telescopic tubes. Indeed, any adjustable extending member may provide an engaging/contact surface/foot to set how far the sensor is maintained from the base of the tank.

At an uppermost section of the device, a further tubular element 23 is telescopically attached to main body 14. In the illustrated form the telescoping upper element 23 sits within main body 14, but a location outside using the same dimension as lower section 21, is possible.

By slidably adjusting how far this upper element 23 extends from the main body 14, the total length of the device from an upper end 24 to the lowermost point 22 is determined. Upper end 24 is comprised of a cap which encloses cable 11. In the illustrated form, cable 11 is fixedly attached to cap 24 so that the cable within the device has enough slack to extend to a maximum length, but not beyond.

As above, it will be apparent that a distance setting adjustment may be achieved by another mechanism than telescopic tubes. Indeed, any adjustable extending member may provide an engaging/contact surface/head to set the total length, e.g. concertina-type wall may be pulled to extend and retract the adjustable lengths.

In use, as seen in Figure 1, the cap 24 is intended to be arranged within a fixed structure of the tank, e.g. at the lip of a threaded flange of the barrel's horizontal screw cap, restricting lateral movement. When set to a maximum height that will fit within the tank the device is thus held upright so retains its accuracy for sensing water level.

Also as seen in Figure 1, the device sits alongside the pump P and its conduits C and does not obstruct it.

It is likely that a user will set the relative lengths of the device only once, soon after purchase, by following instructions, since a water tank is a long lasting product of unchanging dimensions (to set the total length) and the user will learn how much warning of low water level they would like to have from the device.

By way of example, a typical water tank T has a capacity of 40 litres which can be emptied after a four-minute shower. A user may wish to have a one-minute warning while the tank remains one quarter full, in which case the lower tube may be extended to a distance to maintain the switch 15 one quarter distance of the internal tank height from its bottom. The illustrated example shows a depth of about one fifth of the total tank capacity. When the water level W drains to height 16, the alarm will sound.

As mentioned, it is strongly recommended that the alarm sounder unit 13 is situated within a caravan. This is for protection from the elements and so as not to disturb other campers.

The slender, flexible cable 11 may be run from the device sensor through a convenient window and plugged into unit 13 via a socket 25. Caravan window seals are usually spongy enough to allow the window to be locked shut with the cable in place. A wireless version is also possible, e.g. that communicates via a radio frequency between the sensor when activated and an alert means within the caravan.

The alert unit 13 may be configured (or re-configured) so that, after the alarm sounds it auto cancels, to avoid the need to manually override what might become an irritating reminder.

The control circuit may be relatively simple to achieve the functionality described above. More sophisticated functions may be included if required.

In the wired version, the electrical supply may be provided by two AA batteries, i.e. a very low voltage. Main materials are preferably WRAS approved for use in potable water or for food grade requirement applications. It is recommended that the immersed part of the device is cleaned regularly with an anti-bacterial solution and rinsed before use along with the water barrel and pump.

The device described above will not automatically prevent a water pump from burning out if it is left to run dry for too long. The alarm may not always be heard or acted upon, particularly, if the caravan pipework leaks and the occupant is not present to become aware that the water level has dropped unexpectedly. In one form the device/unit 13 may be connected to a kill switch (e.g. via the caravan's internal wiring) that prevents the pump being energised when the alarm has triggered an audio and/or visual alert, or on a timer to automatically shut down the pump after a specified time period. Such an approach would enable a user to have advanced warning that the pump was about to shut down, and give time to finish a task like rinsing during dish washing or in a shower.

By way of summary, a portable water level indicator is described herein that includes a sensor housed in an elongate housing, dimensioned to fit inside a water tank. An extensible first section has an end for contacting a base of the water tank and is configured to set a depth of water level that will trigger an alarm. An extensible second section with an upper cap end enables a total longitudinal length to be set in order to be located within a restricted horizontal opening of the water tank, minimising lateral movement and maintaining the indicator in an upright position.

The invention presents the following advantages and features: 1. Provides a low-level water alarm, e.g. as embodied by a telescopic sensor tube of three distinct sections.

2. The float switch housing remains in a fixed position within the centre section of the telescopic body.

3. Adjustment for depth is achieved by altering the length of the lower tube section with respect to the main/central section that houses the float switch.

4. The uppermost tubular section is slidable in order to further adjust the overall length relative to a tank height into which the device is placed.

5. The device is dimensioned to fit through a rollable barrel! water container filling hole and reside therein without protruding, and thus allow the open hole to receive a cap closure and/or a pump cover fitted over it to keep out contamination. The total diameter is most preferably less than three centimetres.

6. The tube sections are held upright by its adjusted length and by location within the diameter of the filling hole section, or an equivalent fixed structure, to maintain measurement accuracy.

7. The three sections preferably have no threads and hold their last adjusted position by interference fit. However, a threaded or ratchet-type solution may be employed to achieve adjustability along a longitudinal axis.

8. The lowermost tube section (relative to insertion into the tank) is preferably transparent to facilitate depth setting by being able to see the float's height in relation to the distal end of the bottom section.

9. Furthermore, the lowermost section is preferably comprised of a relatively soft plastic to prevent skidding on the bottom of the barrel or damage to the pump.

10. The device is entirely portable and preferably of lightweight, nontoxic plastic.

11. A standard immersible electric caravan water pump with its cable and pipe is easily accommodated within a water container directly alongside the level indicator of the invention. A future iteration may be integrated with a water pump, i.e. such that both a pump and integral low-level indicator provide a combined solution.

12. The alarm sounder (and/or visual alert device) is located remotely from the water sensing tube assembly and is connected via a waterproof cable and plug which can be disconnected. A wireless transmitter may also be used to trigger the alarm. Maintaining the alert cues within the living space will minimise disturbance to others on a campsite and generally outside of the caravan.

13. In one form, the alarm is configured to emit a sequence of audible warning tones once only, to alert the occupant to low water level. In this way it minimises disturbance/irritation to a user or others and does not require muting because shut off is automatic.

14. The device is usually reset by refilling the water container after an alert has issued, but will not re sound if the water level has gone and/or continues to go beyond the minimum set level.

Claims (13)

1. Claims 1. A portable water level indicator comprised of: a sensor for detecting a presence or absence of water; an elongate housing for housing the sensor; an extensible first end for contacting a base of a water tank; an extensible second end for locating against a fixed structure of the water tank; wherein a total longitudinal length of the elongate housing may be set by virtue of the first and/or second extensible ends.
2. 2. The indicator of claim 1, wherein the sensor is located proximate or toward the first end and, in use, a depth at which the sensor detects water can be set by adjusting the extensible first end relative to the sensor.
3. 3. The indicator of any preceding claim, wherein the extensible first end comprises a first extensible portion slidably attached to the elongate housing.
4. 4. The indicator of claim 3, wherein the first extensible portion includes a transparent wall such that a location of the sensor can be determined.
5. 5. The indicator of claim 3 or 4, wherein the extensible second end comprises a second extensible portion slidably attached to the elongate housing.
6. 6. The indicator of claim 5, wherein the first extensible portion and/or second extensible portion are comprised of tubes arranged telescopically relative to the elongate housing.
7. 7. The indicator of any preceding claim, wherein the sensor is a float switch, optionally threaded into an apertured boss set into the elongate housing.
8. 8. The indicator of any preceding claim, further comprising a remotely located alarm unit in communication with the sensor and configured to activate an audio and/or visual alert when the sensor detects a presence or absence of water.
9. 9. The indicator of claim 8, wherein communication between the indicator and alarm unit comprises a wire, optionally connected via a removable plug in socket connection.
10. 10. The indicator of claim 8, wherein communication between the indicator and alarm unit is a wireless connection.
11. 11. The indicator of any preceding claim 8 to 10, wherein the alarm unit is configured to sound an alert once only for a short time period.
12. 12. The indicator of any preceding claim 8 to 11, wherein the alarm unit is configured to activate a kill switch, after a specified time period, associated with an electric pump of the water tank.
13. 13. The indicator of any preceding claim, in combination with a water pump.