GB2368912A

GB2368912A - Water level sensor

Info

Publication number: GB2368912A
Application number: GB0027702A
Authority: GB
Inventors: Richard Brian John Harrison
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-11-13
Filing date: 2000-11-13
Publication date: 2002-05-15
Also published as: GB0027702D0

Abstract

A sensor assembly for sensing water level in a bath, the sensor assembly comprising <SL> <LI>a) a base (1) for mounting the assembly in a bath,<BR> b) an arm (4) projecting from the base,<BR> c) a float (5) carried on the arm and movable along the axial length thereof,<BR> d) a signal generator (15) for generating a visual or audio signal, and<BR> e) means for actuating the signal generator when the float has moved to a predetermined point along the arm. </SL>

Description

Water level sensor

This invention relates to water level sensors primarily but not exclusively for use in sensing water levels in baths.

Overflowing baths can cause major damage to the building in which they are situated. A number of devices have been proposed to attempt to deal with this problem by opening valves to allow excess water to pass to waste. One of the better designed examples of this is shown in W095/18896. This class of devices is not wholly satisfactory since with wear the device may leak leaving the user high and dry. Other less well designed devices may not be capable of disposing of the high volumes of water entering the bath.

According to the invention there is provided a sensor assembly for sensing water level in a bath, the sensor assembly comprising a) a base for mounting the assembly in a bath, b) an arm projecting from the base, c) a float carried on the arm and movable along the axial length thereof, d) a signal generator for generating a visual or audio signal, and e) means for actuating the signal generator when the float has moved to a predetermined point along the arm.

In some embodiments of the invention the float comprises a model of an object. The object can be

animate for example a duckling or a frog. In some embodiments of the invention the animate object is a duck and the visual or audio signal comprises an audio representation of a quack. Some embodiments of the invention further comprise a stop which the float abuts to actuate the signal generator. Some embodiments of the invention further comprise a stop which the float approaches to actuate the signal generator. In some embodiments of the invention each of the float and the stop carries a pair of contacts such that abutment of the float and the stop completes a electrical circuit actuating the signal generator. In some embodiments of the invention one of the float and stop has a switch mounted thereon which is actuated by abutment of the float and stop. One of the float and stop can carry a reed switch and the other of the stop and float can carry a magnet to actuate the reed switch.

In some embodiments of the invention one of the float and stop carries a Hall effect switch and the other of the stop and float carries a magnet to actuate the Hall effect switch.

Embodiments of the invention will be described by way of non-limiting example with reference to the accompanying figures of which Figure 1 is a sectional view of an embodiment; Figure 2 is a scrap sectional view of a support; and Figure 3 is a block diagram of a further embodiment.

The first embodiment comprises a dense base 1 for positioning the device on the bath floor. Desirably the base will comprise a plastics material to reduce the possibility of abrasion and damage of the bath or user. In the illustrated embodiment the base comprises a

piece of plastics material loaded with a dense material.

In the illustrated embodiment the base 1 is conical. Received in the base is arm 4. Arm 4 is again conveniently of plastics material but this is not essential and other materials for example stainless steel or aluminium could be used. Arm 4 could be moulded into base 1 Arm 4 could be a push fit in the base 1 or it could be screwed into base 1. Those skilled will be able to devise other ways of mounting the arm on the base. Arm 4 is rigid and of generally uniform cross section so that float 5 to be described hereinafter in more detail can slide up and down the arm. Arm 4 in the illustrated embodiment extends generally perpendicularly to the base but exact perpendicularity is not essential. The free end of the arm may be provided with a ball 2 to reduce the likelihood of

injury. Those skilled in the art will be able to devise other ways of reducing the likelihood of spiking injuries to those who may fall on the device of the invention.

Float 5 is provided. Float 5 is provided with a hole 6 through which arm 4 can extend allowing the float to move freely along the arm. Float 5 should be buoyant in water. Those skilled will have little difficulty in devising suitable materials for the construction of float 5. Examples include wood cork and hollow metal. In many cases plastics material which may or may not be hollow will be used.

In the illustrated embodiment the float 5 comprises a representation of a duck. It will be apparent that the invention is not so limited. Alternatives will be

discussed hereinafter by reference to other embodiments of the invention.

Stop 7 is provided on arm 4. In preferred embodiments of the invention stop 7 is movable along arm 4. As will become apparent this allows the depth of water sensed to be varied. In other embodiments of the invention stop 7 is fixed. Those skilled will have no difficulty in devising methods of providing stop 7 with means for being fixed and movable when desired. In the embodiment of Figure 1 stop 7 is provided with a resilient portion 10 which extends around the arm 4 gripping the arm and restricting accidental movement yet allowing the user to position the stop as desired. Those skilled in the art will have no difficulty in devising other ways of mounting the stop for example by providing the stop with a bush 11 which receives

the arm. Bush 11 is provided with a screw threaded portion into which is received screw threaded fastener 12 with tip 13 and head 14. Tightening the screw threaded fastener urges tip against the arm and causing the stop to be fixed relative to the arm. Arm 4 could be screw threaded and co-operate with a screw threaded stop. Desirably the float is completely removable from the arm (a reason for this will be given hereinafter) this could be achieved by making arm 4 removable from the base or the stop from the arm.

Float 5 co-operates with stop 7 so that when float 5 abuts stop 7 or reaches within a predetermined distance of stop 7 a signal is generated. Those skilled will have no difficulty in devising suitable ways of achieving this. In the embodiment of Figure 1 float 5 is provided with contacts 8. When contacts 8 abut

complementary contacts 9 of the stop a signal is generated as will be described hereinafter in more detail. In some embodiments of the invention as for example in that of figure 1 two spaced apart contacts are provided. Bath water has a degree of electrical conductivity. The degree of conductivity depends on many factors including the amount of some hardness inducing agents, the presence of bath salts or ionic surfactants. By spacing the contacts apart accidental actuation due to electricity being conducted by surface films can be reduced.

It is not essential that electricity passes through the float and stop. For example one of the stop and float could be provided with a microswitch which could be actuated by the other of the float and stop abutting it.

Physical contact between the float and the stop are not essential. Those skilled in the art will have no difficulty in devising cheap and effective ways of achieving this.

Examples include providing one of the float and the stop with a reed switch or a Hall effect switch and the other of the stop and float with a magnet. These arrangements may be preferred since they are not affected by the variable conductivity of bath water. In some cases the switch will then be actuated without physical contact between the float and the stop. Those skilled will be able to devise other methods of achieving this result.

Actuation of the signal generator 15 by abutment to or proximity with the float and stop causes a signal to be generated. In some embodiments of the invention this

is simply an audio or visual signal such as an alarm buzzer or lights. In other embodiments of the invention more distinctive signals are generated. For example in the embodiment of figure 1 signal generator 15 could generate a duck quacking sound alternatively or additionally the duck's eyes could light or flash.

The skilled worker will have no difficulty in generating duck quacking sounds. The use of such a sound has a number of useful benefits. First duck quacks are fairly unusual sounds in most domestic environments. If the sound is heard it will likely impinge on a user's conciouness fairly quickly.

Secondly the novelty value of a quacking duck my encourage an otherwise reluctant bather to bathe so as to hear the quacking sound.

As previously explained in some embodiments of the invention the float is removable from the rest of the device. This allows the float to be removed and used as bath toy when not being used to sense water depth.

A large number of modifications will suggest themselves to the skilled. In particular it is not essential that the float be in the form of a duck. An alternative could be a frog. Once again the distinctive and penetrating croak of a frog provides a good warning. It is not essential that water loving animals or animals at all be used as floats. For example the float could be in the form of a ship and the penetrating and distinctive sound of a ship's klaxon or foghorn used. Of course it is not essential that the float be in the form of an object having any connection with water be used.

The float could for example be in the form of whatever characters or objects which are the latest subject of cult interest.

In the embodiment of figure 1 the signal generator is carried within the float 5. A power supply for example a small battery 200 is provided with the float. In some embodiments of the invention the battery 200 is sealed within the float and replacement is not possible. This is advantageous in that there is less likelihood of water ingress with consequent disruption. The float will however be of limited life as a component of the sensor arrangement. However once the battery 200 is exhausted the float need not be discarded but can be used as a toy in or out of the bath. In some embodiments of the invention the float is provided with a switch 201 for connecting the battery to the

sound generator. The switch may be a press switch and may be actuated by squeezing the float if the float is made of resilient material. It may be desirable to provide an indication that the sound generator is powered such as lights in the eyes of animate objects.

In other embodiments of the invention the signal generator is not included within the float but rather is associated with the stop.

In many embodiments of the invention the signal generator is local to the sensor assembly. It is however within the scope to have a repeater unit 300 repeating the signal at a distant location. This distant location may be the only location at which the signal is detectable by unaided humans. For example signal generator 301 may generate a low power radio signal

which is transmitted to repeater unit 300 which may be in another room. Repeater unit 300 produces a signal, for example visual or aural, in response to the output from the signal generator 301.

While described by reference to a bath it will be apparent to the skilled that the invention could be used in sinks.

Those skilled in the art will have no difficulty in devising modifications. In particular it will be apparent to the skilled that float 5 need not be prevented from moving beyond the point at which the signal generator is actuated. This could be achieved by, for example, providing the arm with a magnetised portion and the float with a Hall effect switch. As the

Hall effect switch approaches the magnet the switch is actuated but the float can continue to rise. It is clear that in this embodiment there is not a stop. In this arrangement it would be desirable to toggle the signal generator since otherwise as the float moved further up the arm the Hall effect switch would no longer detect the magnet field and the signal generator would switch off.

Claims

1. A sensor assembly for sensing water level in a bath, the sensor assembly comprising a) a base for mounting the assembly in a bath, b) an arm projecting from the base, c) a float carried on the arm and movable along the axial length thereof, d) a signal generator for generating a visual or audio signal, and e) means for actuating the signal generator when the float has moved to a predetermined point along the arm.

2. A sensor assembly as claimed in claim 1 wherein the float comprises a model of an object.

3. A sensor assembly as claimed in claim 2 wherein the object is animate.

4. A sensor assembly as claimed in claim 3 wherein the animate object comprises a duckling or a frog.

5. A sensor assembly as claimed in claim 4 wherein the animate object is a duck and the visual or audio signal comprises an audio representation of a quack.

6. A sensor assembly as claimed in claim 1 further comprising a stop which the float abuts to actuate the signal generator.

7. A sensor assembly as claimed in claim 1 further comprising a stop which the float approaches to actuate the signal generator.

8. A sensor assembly as claimed in claim 6 wherein each of the float and the stop carries a pair of contacts such that abutment of the float and the stop

completes a electrical circuit actuating the signal generator.

9. A sensor assembly as claimed in claim 6 wherein one of the float and stop has a switch mounted thereon which is actuated by abutment of the float and stop.

10. A sensor assembly as claimed in claim 7 wherein one of the float and stop carries a reed switch and the other of the stop and float carries a magnet to actuate the reed switch.

11. A sensor assembly as claimed in claim 7 wherein one of the float and stop carries a Hall effect switch and the other of the stop and float carries a magnet to actuate the Hall effect switch.

12. A sensor assembly substantially as described herein by reference to any one or more of the accompanying figures