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GB2199436A - Detection of fluid leakage - Google Patents

Detection of fluid leakage Download PDF

Info

Publication number
GB2199436A
GB2199436A GB08727968A GB8727968A GB2199436A GB 2199436 A GB2199436 A GB 2199436A GB 08727968 A GB08727968 A GB 08727968A GB 8727968 A GB8727968 A GB 8727968A GB 2199436 A GB2199436 A GB 2199436A
Authority
GB
United Kingdom
Prior art keywords
detector
liquid
water gathering
tracks
water
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
GB08727968A
Other versions
GB8727968D0 (en
Inventor
Douglas Sydney Knights
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
B & R Electrical Prod Ltd
Original Assignee
B & R Electrical Prod Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from GB868628513A external-priority patent/GB8628513D0/en
Priority claimed from GB878715600A external-priority patent/GB8715600D0/en
Application filed by B & R Electrical Prod Ltd filed Critical B & R Electrical Prod Ltd
Priority to GB08727968A priority Critical patent/GB2199436A/en
Publication of GB8727968D0 publication Critical patent/GB8727968D0/en
Publication of GB2199436A publication Critical patent/GB2199436A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • GPHYSICS
    • G01MEASURING; TESTING
    • G01MTESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
    • G01M3/00Investigating fluid-tightness of structures
    • G01M3/02Investigating fluid-tightness of structures by using fluid or vacuum
    • G01M3/04Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point
    • G01M3/16Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point using electric detection means
    • DTEXTILES; PAPER
    • D06TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
    • D06FLAUNDERING, DRYING, IRONING, PRESSING OR FOLDING TEXTILE ARTICLES
    • D06F39/00Details of washing machines not specific to a single type of machines covered by groups D06F9/00 - D06F27/00 
    • D06F39/08Liquid supply or discharge arrangements
    • D06F39/081Safety arrangements for preventing water damage

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Examining Or Testing Airtightness (AREA)

Abstract

Apparatus for detecting fluid leakage comprises a device 2 for detecting liquid by contact therewith and providing in consequence an electrical signal, and a water gathering member (10) extending over a predetermined area for conveying water to the detector whereby the detector device will detect leakage from the appliance from any point encompassed by the area of the member. Where space is limited the water gathering member may be an absorbant sheet and the detector may be provided on a PCB (100, Figs. 6 & 7 not shown). As shown, the water gathering member consists of a flexible plastic sheet 12 with a central ring portion for retaining the detecting device and corner flaps. Four rigid retaining rods are held rigidly between the ring and flaps so that the periphery of the sheet is higher than the central portion. The erected sheet may be mounted in an open frame member 20. <IMAGE>

Description

Detection of fluid leakage This invention relates to the detection of leakage of fluids, especially in confined spaces.
In particular. this invention relates to apparatus for detecting water leakage from an appliance, particularly though not exclusively domestic appliances such as washing machines.
Domestic washing machines are particularly prone to water leakage and such leakages can quickly develop so as to cause flooding. It is therefore important to detect such leakages at an early stage. Since the areas in which leakage may occur will not normally be immediately visible to a person using the appliance, it is known to provide a detector device which is situated in a position in which leakage is most likely to occur so that should leakage occur, drops of water falling on the device will close an electrical circuit whereby to generate an alarm signal and/or automatically switch off the appliance.
The disadvantage with such an arrangement is that a leak from another area in which leakage is less likely to occur will not be detected.
In order to overcome or at least reduce this problem the present invention provides apparatus for detecting leakage of liquids comprising a device for detecting liquid by contact therewith and providing in consequence an electrical signal, and a water gathering member extending over a predetermined area for conveying water to the detector whereby the detector device will detect leakage from the appliance from any point encompassed by the area of said member.
In use the pater gathering member may be placed underneath the base of an appliance. Thus by providin~ a water gathering member which zill collect liquid leaking from any point of the appliance encompassed by the area of the member. a single detector device will detect water leakage from a large area.
According to one embodiment of the invention the water gathering member comprises a flexible member which can be rolled up, e.g. as a tube, for ease of transport and packing. As preferred, the member comprises a sheet of flexible material, such as plastics, with spoke members which extend from the point at which the detector dexice is located to the periphery of the flexible member. The water gathering member may be erected by locating rigid spokes or rods between the water gathering point and between suitable locating members such as flaps on the edge of the material of the member so as to provide the required degree of tension for erecting the member in desired configuration. Alternatively the water gathering member is moulded such that when unrolled, it slopes to a central point. Such arrangement is useful where space is limited.
Frequently the amount of available space beneath an appliance within which to place detection apparatus is extremely limited and it is therefore desirable for the apparatus to be as flat as possible so that it occupies the minimum possible depth. Thus, in a preferred embodiment of the invention the water gathering member is a pad or sheet of absorbent material and the invention further provides a detection device comprising a two contact liquid detector adapted to be of low height. Any material which will allow water to travel through it may be used as the water gathering member. Readily available household materials may be used, such as newspaper, blotting paper and paper towelling, thus reducing the cost of the overall detection system.
The detection device of the present invention comprises a device for detecting liquid by contact therewith comprising a planor member having a major surface carrying electrically conductive tracks for placing against an absorbent member whereby the presence of liquid in the absorbent member will cause a short circuit between the tracks.
Preferred embodiments of the invention will now be described by way of example only and with reference to the accompanying drawings wherein: Figure 1 is a schematic view of the detection device according to a first embodiment of the invention located under a washing machine; Figure 2 is a perspective view of a liquid detector employed in the present invention Figure 3 is a view of the water gathering member in an erected configuration; Figure 4 is a view of the erected water gathering member mounted on a base; Figure 5 is a circuit diagram of a liquid detector employed in the present invention connected to a control circuit.
Figure 6 is a bottom plan view of an alternative liquid detector; and Figure 7 shows a section through the liquid detector of Figure 1 along the line A-A'.
Referring now to Figures 1 to 4, a liquid detector device 2 is mounted at a central point in a water gathering member 10, the water gathering member comprising a rectangular plastics flexible sheet 12 having a meter ring portion 13 located about the central point and flaps 14 at the four corners of sheet 12. Four rigid retaining rods 16 of plastics or metallic materials are dimensioned so as to be held rigidly between ring 12 and flaps 14 whereby with the four rods inserted, the water gathering member is erected in a rectangular configuration with the periphery of the plastics member substantially higher than the central point so that water or other liquid falling on to the pater gathering member will run dozen the central point. This arrangement is shown in Figure 1.
In order to mount the water gathering member beneath an appliance, a base member may be provided comprising a rectangular open frame member 20 on which the edge of the water gathering member 10 is mounted.
As shown in Figure 1 the device is mounted beneath a washing machine 22 and may be seen to cover substantially the whole area beneath the appliance so that water leakage from any point beneath the appliance will be detected.
The method of assembly of the appliance is as follows.
Firstly the fabric member 12 is unrolled from a tubular contiguration and the detection device is mounted in the centre by screwing the retaining bolt 2 into ring portion The The rigid spoke members 10 extend from the retaining portion 13 to the flaps 14 at the corner of the flexible sheet 12 whereby to form the flexible sheet into a rigid water gathering member 10.
As shown in Figure 2, the liquid detector is constructed as a bolt having a threaded portion 3 and a head portion 4 which has a recess b at its top in which a suitable liquid detector S is located. This liquid detector may comprise a capacitive arrangement or alternately may comprise electrically conductive probe members which are short circuited together when liquid gathers in the head of the bolt. Thus when liquid covers the head of the bolt, an appropriate electrical signal is generated by the liquid detector.
Referring to Figure 5 there is shown a circuit diagram of the liquid detector connected in a control circuit, the liquid detector 2 comprising electrically conductive probes 30 connected to a voltage dividing network R1. R2, with capacitances Cl, C3 provided to absorb transients which could otherwise cause inadvertent switching of the control circuit. An integrated circuit 32 of type MAN 602 CPA is provided to transform a mains voltage provided from lines L. N via a transformer TXl to suitable DC levels V- and V+.
When water is present at the detector probes, the probes are short circuited together and hence a voltage level which is sensed at the input V SENSE of the integrated circuit 32 changes, and the change is detected by the integrated circuit to provide an output signal on output OUV to switch on a driver transistor TRI to energise a light emitting diode 40 which provides a light signal across a light coupling to a light sensitive thyristor 42, thereby to switch on the thyristor and energise a relay 44 to open relay contacts 46 in the live conductor of the mains supply, whereby to switch off the power supply to the washing machine.
The circuitry shown in Figure 5 is conveniently mounted in a mains supply plug for the appliance or in an adaptor socket for the plug. The solenoid 44 is normally provided in a washing machine control system and therefore is conveniently used as part of the control circuit of the present invention.
Modification may be envisaged, for example the detector device may be formed as a member with a nut for receiving a bolt member whereby the detector device is bolted to the central part of the water gathering member. The detector device may be mounted above,. or below the water gathering member and where mounted above, it may be of a small height for applications where space beneath the appliance is restricted.
For appliances with little or no clearance beneath the appliance, the appliance may be raised in height so that the water gathering member according to the invention may be positioned beneath the appliance.
In an alternative arrangement where space is limited, the detector device may be formed as a sheet member of absorbent material so that water falling thereon is absorbed by the absorbent material whereby to change the electrical conductivity of the material so that electrodes connected at appropriate points to the material will detect the change in electrical conductivity and thereupon generate an electrical alarm signal. emp1csing a circuit shown in Figure 5.
A second embodiment of apparatus according to the invention will now be described with reference to Figures 6 and 7. These figures illustrate a detector device comprising a two-contact liquid detector connected to an electric circuit for providing an alarm signal and/or a signal disconnecting the appliance when leakage is detected. Figure 6 shows a two-contact liquid detector formed of a double-sided through circuit board (PCB).
The PCB 10 has two conductive tracks 102 and 103 printed on one surface thereof. Each of the printed tracks has a connecting wire 104 soldered thereto on the opposite surface of the PCB. The surface carrying the tracks is left free of connections so as to enable the liquid detector to seat flat against a mating surface.
As Figure 7 shows, the PCB is mounted in a housing 10o which covers the first face of the PCB and the soldered junctions with connecting wires 104. The wires 104 are provided with an insulating sleeve, pass through a side wall of the housing 10, and the electrical circuit forming part of the detector device. Within the housing 106 weights 105 are provided resting on the PCB to promote firm seating of the liquid detector 1 to the mating surface.
In use, the detector device may be connected to a control circuit of an appliance of the type shown in Figure 5. The wires 104 are connected to the voltage dividing network R1, R2. The circuit operates to swith off the power supply to the appliance when there is a short circuit between tracks 102 and 103 caused by the presence of water.
The preferred method of use for the detector device shown in Figures 6 and 7 is in conjunction with absorbent material. Suitable absorbent material, e.g. sheets of newspaper, is to be placed underneath the chosen appliance so as to cover the whole area, or a chosen area of possible leakage. The PCB 100 is to be placed on the absorbent material with the surface carrying tracks facing downward.
Should a leakage or spillage occur (either of a slow nature, or continuous flow) then the absorbent material will become soaked with liquid. The area of saturated absorbent material will grow until it reaches the PCB 100.
When the area of saturated absorbent material reaches printed tracks 102 and 103 it will provide an electrical path between the tracks and will thus actuate trip coil 44 of the electrical circuit leading to the automatic disconnection of mains power from the appliance. When used in connection with a washing machine a detector device according to the invention may be arranged to close solenoid values in the washing machine, when a leak is detected, to prevent further water from being supplied to the machine.
It is further preferred when using the detector device of Figures 6 and 7 in conjunctions with absorbent material to position the liquid detector 1 centrally on the absorbent material so as to be in the path of travel of liquid from any part of the absorbent material.

Claims (12)

  1. CLAIM##:
    CLAIn5s: 1. Apparatus for detecting leakage of liquids comprising a device for detecting liquid by contact therewith and providing in consequence an electrical signal. and a water gathering member extending over a predetermined area for conveying water to the detector whereby the detector device will detect leakage from the appliance from any point encompassed by the area of said member.
  2. 2. Apparatus as claimed in claim 1 in which the water gathering member is so shaped that liquid gathered by the member will run under the force of gravity to a point at which the detector device is located.
  3. Apparatus as claimed in claim 1 or 2 in which the water gathering member comprises a flexible member which can be rolled up when not in use.
  4. 4. Apparatus as claimed in 1, 2 or 3 in which the water gathering member is moulded so as to slope towards a point at which the detector is located.
  5. Apparatus as claimed in claim 1, 2 or 3 in which the water gathering member comprises a sheet of flexible material having spoke members which extend from the point at which the detector device is located to the periphery of the flexible member.
  6. 6. Apparatus as claimed in claim 1 in which the water gathering member comprises a sheet or pad of absorbent material.
  7. 7. Apparatus as claimed in claim 6 in which the device for detecting liquid comprises a planor member having a major surface carrying electrically conductive tracks which surface is positioned against the absorbent material whereby the presence c liquid in the material will cause a short circuit between the tracks.
  8. 8. A device for detecting liquid by contact therewith comprising a planor member having a major surface carrying electrica#lly conductive tracks for placing against an absorbent member whereby the presence of liquid in the absorbent member will cause a short circuit between the tracks.
  9. 9. A device as claimed in claim S in which the device comprises a through printed circuit board having the tracks printed on one of its major surfaces and connecting wires soldered thereto on its opposite major surface.
  10. 10. A device as claimed in claim 8 or 9 in which the planor member is protected by a housing which leaves the major surface carrying the tracks exposed.
  11. 11. Apparatus for detecting leakage of liquids substantially as hereinbefore described with reference to the accompanying drawings.
  12. 12. A liquid detection device substantially as hereinbefore described with reference to Figures 6 and 7 of the accompanying drawings.
GB08727968A 1986-11-28 1987-11-30 Detection of fluid leakage Withdrawn GB2199436A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB08727968A GB2199436A (en) 1986-11-28 1987-11-30 Detection of fluid leakage

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
GB868628513A GB8628513D0 (en) 1986-11-28 1986-11-28 Water leakage detection
GB878715600A GB8715600D0 (en) 1987-07-02 1987-07-02 Detection of fluid leakage
GB08727968A GB2199436A (en) 1986-11-28 1987-11-30 Detection of fluid leakage

Publications (2)

Publication Number Publication Date
GB8727968D0 GB8727968D0 (en) 1988-01-06
GB2199436A true GB2199436A (en) 1988-07-06

Family

ID=27263224

Family Applications (1)

Application Number Title Priority Date Filing Date
GB08727968A Withdrawn GB2199436A (en) 1986-11-28 1987-11-30 Detection of fluid leakage

Country Status (1)

Country Link
GB (1) GB2199436A (en)

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2266396A (en) * 1992-04-21 1993-10-27 Michael John Shackell Leak detector
GB2272553A (en) * 1992-11-13 1994-05-18 O Dea Francis Joseph Apparatus for controlling flooding from a water using appliance
WO1998054559A1 (en) * 1997-05-27 1998-12-03 Apv Fluid Handling Horsens A/S Fluid leakage detector
GB2348033A (en) * 1999-03-16 2000-09-20 Nicholas George Foggin Water leakage warning device
GB2355564A (en) * 1999-08-03 2001-04-25 Anthony Terence Goode Washing machine leak or flood alarm
GB2369912A (en) * 2000-09-09 2002-06-12 Bw Technologies Ltd Leak detection
GB2377995A (en) * 2001-05-11 2003-01-29 Nicholas Julian Orchard Water detection device with co-planar electrodes
EP1762652A1 (en) * 2005-09-09 2007-03-14 I.R.C.A. S.p.a. Industria Resistenze Corazzate e Affini Safety device for dishwashers and washing machines
DE102012103504A1 (en) * 2012-04-20 2013-10-24 B. Braun Avitum Ag Device for extracorporeal blood treatment with leakage sensor
US8679326B2 (en) 2007-12-20 2014-03-25 Gambro Lundia Ab Medical apparatus for extracorporeal treatment
ES2556403R1 (en) * 2014-07-14 2016-01-29 José Manuel ARES ESTEVE FLOOD SENSOR FOR A LEG OR SOIL SUPPORT
DE102015105609A1 (en) * 2015-04-13 2016-10-13 Wittenstein Ag Sensor, drive component with sensor, drive with drive component and evaluation method
WO2019014162A1 (en) * 2017-07-11 2019-01-17 Fresenius Medical Care Holdings, Inc. Fluid leak detection in a dialysis machine
US11808664B1 (en) * 2023-05-15 2023-11-07 Corey Ryhorski Moisture-detecting water source shutoff device

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3696357A (en) * 1970-04-15 1972-10-03 Bernard W Kilgore Enuresis prevention training device
GB1294001A (en) * 1969-09-02 1972-10-25 Gerard Francis Wittgenstein Safety installation for preventing pollution by pipelines
US3770002A (en) * 1971-11-01 1973-11-06 L Brown Automatic water shut-off system
US4020478A (en) * 1975-09-18 1977-04-26 Hatfield Edward S Moisture detecting device
GB1489971A (en) * 1974-02-01 1977-10-26 Husqvarna Ab Device for protection against flooding
GB1545353A (en) * 1976-09-14 1979-05-10 Seb Sa Apparatus driven by an electric motor and incorporating a safety switch
US4502044A (en) * 1982-05-19 1985-02-26 Farris James R Moisture alarm system
GB2186722A (en) * 1986-02-17 1987-08-19 John Arthur Webb Detecting leakage of liquid from machines

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1294001A (en) * 1969-09-02 1972-10-25 Gerard Francis Wittgenstein Safety installation for preventing pollution by pipelines
US3696357A (en) * 1970-04-15 1972-10-03 Bernard W Kilgore Enuresis prevention training device
US3770002A (en) * 1971-11-01 1973-11-06 L Brown Automatic water shut-off system
GB1489971A (en) * 1974-02-01 1977-10-26 Husqvarna Ab Device for protection against flooding
US4020478A (en) * 1975-09-18 1977-04-26 Hatfield Edward S Moisture detecting device
GB1545353A (en) * 1976-09-14 1979-05-10 Seb Sa Apparatus driven by an electric motor and incorporating a safety switch
US4502044A (en) * 1982-05-19 1985-02-26 Farris James R Moisture alarm system
GB2186722A (en) * 1986-02-17 1987-08-19 John Arthur Webb Detecting leakage of liquid from machines

Cited By (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2266396A (en) * 1992-04-21 1993-10-27 Michael John Shackell Leak detector
GB2272553A (en) * 1992-11-13 1994-05-18 O Dea Francis Joseph Apparatus for controlling flooding from a water using appliance
GB2272553B (en) * 1992-11-13 1996-06-12 O Dea Francis Joseph Means for detecting water leakages from appliances
WO1998054559A1 (en) * 1997-05-27 1998-12-03 Apv Fluid Handling Horsens A/S Fluid leakage detector
GB2348033A (en) * 1999-03-16 2000-09-20 Nicholas George Foggin Water leakage warning device
GB2355564A (en) * 1999-08-03 2001-04-25 Anthony Terence Goode Washing machine leak or flood alarm
GB2369912A (en) * 2000-09-09 2002-06-12 Bw Technologies Ltd Leak detection
GB2369912B (en) * 2000-09-09 2004-12-15 Bw Technologies Ltd Leak detection apparatus
GB2377995A (en) * 2001-05-11 2003-01-29 Nicholas Julian Orchard Water detection device with co-planar electrodes
EP1762652A1 (en) * 2005-09-09 2007-03-14 I.R.C.A. S.p.a. Industria Resistenze Corazzate e Affini Safety device for dishwashers and washing machines
US8679326B2 (en) 2007-12-20 2014-03-25 Gambro Lundia Ab Medical apparatus for extracorporeal treatment
DE102012103504A1 (en) * 2012-04-20 2013-10-24 B. Braun Avitum Ag Device for extracorporeal blood treatment with leakage sensor
US10071194B2 (en) 2012-04-20 2018-09-11 B. Braun Avitum Ag Device for extra-corporal blood treatment with leakage sensor
ES2556403R1 (en) * 2014-07-14 2016-01-29 José Manuel ARES ESTEVE FLOOD SENSOR FOR A LEG OR SOIL SUPPORT
DE102015105609A1 (en) * 2015-04-13 2016-10-13 Wittenstein Ag Sensor, drive component with sensor, drive with drive component and evaluation method
JP2016200597A (en) * 2015-04-13 2016-12-01 ヴィッテンシュタイン アーゲー Sensor, driver component with sensor, driver with driver component, and method for determination
WO2019014162A1 (en) * 2017-07-11 2019-01-17 Fresenius Medical Care Holdings, Inc. Fluid leak detection in a dialysis machine
CN110869068A (en) * 2017-07-11 2020-03-06 费森尤斯医疗保健控股公司 Fluid leak detection in dialysis machines
US10682455B2 (en) 2017-07-11 2020-06-16 Fresenius Medical Care Holdings, Inc. Fluid leak detection in a dialysis machine
US10888649B2 (en) 2017-07-11 2021-01-12 Fresenius Medical Care Holdings, Inc. Fluid leak detection in a dialysis machine
US11808664B1 (en) * 2023-05-15 2023-11-07 Corey Ryhorski Moisture-detecting water source shutoff device

Also Published As

Publication number Publication date
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WAP Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1)