WO2009072682A1

WO2009072682A1 - A leakage sensor using sponge paper and a cutoff valve using that

Info

Publication number: WO2009072682A1
Application number: PCT/KR2007/006232
Authority: WO
Inventors: Byoung Hwan Choi
Original assignee: Byoung Hwan Choi
Priority date: 2007-12-04
Filing date: 2007-12-04
Publication date: 2009-06-11

Abstract

A leakage sensor using a sponge paper and a leakage cutoff device using the leakage sensor of the present invention are devices for detecting leakage of liquid such as water and oil, and for automatically blocking a liquid supply pipe to prevent progress of the leakage. A leakage sensor corresponding to an important component of the present invention is a sensor using a sponge paper and leakage sensor includes a case 110, two electrical terminals 120 attached to an upper plate of the case, and a cartridge 130. The leakage cutoff device using the leakage sensor includes an actuator 200 driven in response to a signal received from the leakage sensor, a rack 300 coupled to an axis of the actuator, a pinion 400 paired with the rack, and a valve 500 having an opening- shutting axis coupled to the pinion. The leakage sensor has a very simple structure using a sponge paper with high reliability. The leakage sensor may be manufactured in a small size and thus has advantages of low cost in addition to convenient management and establishment. Furthermore the leakage sensor may be repeatedly used by substituting only the used cartridge.

Description

A LEAKAGE SENSOR USING SPONGE PAPER AND A CUTOFF VALVE USING THAT

Technical Field

[1] The present invention relates to a leakage sensor and a leakage cutoff device, which are used as auxiliary devices for securing safe operation of apparatuses using liquid, such as a water purifier, a refrigerator, etc.

[2] A leakage sensor using a sponge paper and a leakage cutoff device including the leakage sensor of the present invention are devices capable of detecting leakage of liquid such as water, oil, etc, and capable of cutting off leakage by blocking a liquid supply pipe when leakage is detected.

[3]

Background Art

[4] A leakage cutoff device typically includes a leakage sensor and a cutoff valve for blocking a liquid supply pipe in response to a signal from the leakage sensor.

[5] Various types of the leakage cutoff devices have been developed and used, but such devices having electronic configuration are relatively complex and expensive.

[6] There is a relatively simple type of the leakage sensor adopting a paper-spring combination, such that a spring is attached to one end of a lever having a contact terminal, and another end of the lever, which is exposed out of case, is tied by a paper string, as illustrated in FIG. 1. If tension of the paper string is weakened due to moisture, the paper string is cut off by a restoring force of the spring and thus the contact terminal is electrically coupled to a signal line. Such leakage sensor adopting a paper-spring combination has a relatively simple structure but has degraded reliability since tension of the paper varies depending on environmental factors, particularly depending on humidity.

[7] The above-mentioned conventional leakage sensors have disadvantages of complex structure, poor reliability, and/or expensiveness. In addition, most of the conventional leakage sensors are disposable, and thus the leakage sensor must be replaced with a new one because the leakage sensor loses its own function after it is used once, thereby increasing inconvenience and maintenance cost.

[8] Nowadays a water purifier and a water heater/cooler, which are directly connected to a water pipe, are widely used in houses and offices. Also many refrigerators are directly coupled to a water pipe so as to immediately provide cool water or ice. Also such direct connections are adopted in oil boilers, oil stoves, etc.

[9] If leakage occurs in the apparatuses using liquid, it causes damage due to inundation as well as a loss due to leakage itself. Furthermore the leakage may result in catastrophe such as a fire by electrical short. [10]

Disclosure of Invention

Technical Problem

[11] As described above, a leakage sensor and a leakage cutoff device are important in apparatuses using liquid. The convention devices have poor reliability with complex structure, and thus they tend to malfunction frequently and maintenance thereof is difficult. Above all, the conventional devices are too expensive to be used in houses and offices.

[12] Accordingly a leakage sensor and a leakage cutoff device, which may be manufactured at low cost with simple structure and may be easily repaired and maintained, are required.

[13] A leakage sensor of the present invention has a very simple structure to be manufactured at low cost. The leakage sensor of the present invention has high reliability and may be used almost permanently by replacing simple components.

[14] A leakage cutoff device of the present invention operates in response to a signal from the leakage sensor and also has high reliability and simple structure to be manufactured at low cost.

[15]

Technical Solution

[16] A leakage sensor corresponding to an important component of the present invention uses a sponge paper (it may be referred to as a paper sponge, a compression sponge, a compression cellulose sponge, etc.). The leakage sensor includes, as illustrated in FIG. 2, a case 110, electrical terminals 120 attached to an upper plate of the case, and a cartridge 130 having a structure where a bottom plate 131 is attached to a sponge paper

132 and a metal plate 133 is attached on an upper surface of the sponge paper. [17] If the sponge paper 132 absorbs leaked liquid, the sponge paper 132 expands and thus leakage is detected since the electrical terminals 120 contacts with the metal plate

133 that is attached on the upper surface of the sponge paper.

[18] The leakage cutoff device using the leakage sensor includes an actuator 200 driven in response to a signal received from the leakage sensor, a rack 300 coupled to an axis of the actuator, a pinion 400 paired with the rack, a valve 500 having an opening-shutting axis coupled to the pinion, and a case 600 for containing the above components.

[19] If leakage is detected by the leakage sensor, the actuator 200 extends the rack coupled to the actuator to rotate the pinion coupled to the opening-shutting axis of the valve, thereby shutting the valve to block liquid supply. Advantageous Effects

[20] A leakage sensor of the present invention has a simple structure using a sponge paper to detect leakage of liquid and performs a reliable function.

[21] The leakage sensor may be manufactured in a small size and thus has advantages of low cost in addition to convenient management and establishment.

[22] The leakage sensor may be repeatedly used by substituting only the cartridge after it is used once, and thus maintenance cost may be reduced.

[23] A leakage cutoff device of the present invention has a very simple structure for reducing possibility of malfunction and manufacturing cost. Therefore, the leakage cutoff device may be adopted, at low cost, in water purifiers, refrigerators, heating apparatuses as oil stoves, etc. for houses and offices.

[24] By adopting the leakage cutoff device of the present invention, a loss due to leakage of water, oil, etc, damage due to inundation, and a fire by electrical short due to leakage may be prevented.

[25]

Brief Description of Drawings

[26] FIG. 1 illustrates a conventional leakage sensor.

[27] FIG. 2 illustrates a leakage sensor using a sponge paper of the present invention.

[28] FIG. 3 illustrates a latitudinal cross-sectional view of a leakage cutoff device of the present invention.

[29] FIG. 4 illustrates a longitudinal cross-sectional view of a leakage cutoff device of the present invention.

[30] FIG. 5 is a diagram illustrating connections in a leakage cutoff system.

[31] * Reference Numerals of Important Components

[32] 100: leakage sensor 110: case

[33] 120: electrical terminals 130: cartridge

[34] 131: bottom plate 132: sponge paper

[35] 133: metal plate 200: actuator

[36] 210: axis 300: rack

[37] 400: pinion 500: valve

[38] 510: opening- shutting axis 600: case

[39]

Best Mode for Carrying out the Invention

[40] A leakage sensor corresponding to an important component of the present invention is a sensor using a sponge paper (it may be referred to as a paper sponge, a compression sponge, a compression cellulose sponge, etc.), and its configuration is illustrated in FIG. 2. [41] Referring to FIG. 2, the leakage sensor 100 includes a case 110, two electrical terminals 120 attached to an upper plate of the case, and a cartridge 130.

[42] The case 110 may be manufactured using nonconducting material such as plastic, or by coating nonconducting material on conducting material. The case has a shape of a box, and all faces of the case have apertures 113 for providing penetration of liquid. The two electrical terminals 120, with being apart from each other by a predetermined distance, are attached to one face of the case. Respective signal lines are coupled to the electrical terminals.

[43] The cartridge 130 including the sponge paper is attached to the opposite face of the one face to which the electrical terminals 120 are attached. The cartridge includes a bottom plate 131 capable of being mounted on the face of the case 110, a sponge paper 132 fixed to the bottom plate, and a metal plate 133 attached on an upper surface of the sponge paper.

[44] The sponge paper 132 of the cartridge may be manufactured by pressing cellulose

(vegetable fiber) into a form of paper. One of sponge papers, which may be purchased on the market, can expand such that its thickness increases ten times if it absorbs water sufficiently.

[45] If liquid penetrates through the apertures of the case 110, the sponge paper 132 of the cartridge 130 absorbs the liquid and expands. When the sponge paper expands, the metal plate 133 attached on the sponge paper connects the electrical terminals 120 attached to the opposite face, thereby causing current to flow through a circuit. The electrical terminals 120 performs a function of informing incidence of leakage through the signal lines that are connected to an alarming light, an alarming bell, and/or a monitoring system.

[46] As described above, the leakage sensor has a very simple structure and may be manufactured so that all of width, length and height of the leakage sensor are within one centimeter. The leakage sensor may be recycled by substituting the used sponge paper that has been expanded by absorbing liquid. For convenience of recycle, one face 111 of the case 110 may be opened and closed.

[47] The sponge paper can expand by absorbing sufficient amount of liquid such as water, and thus malfunction may be prevented since it does not expand due to moisture in atmosphere.

[48] Referring to FIG. 3 illustrating a latitudinal cross-sectional view of a leakage cutoff device, the leakage cutoff device using the leakage sensor includes an actuator 200 driven in response to a signal received from the leakage sensor, a rack 300 coupled to an axis of the actuator, a pinion 400 paired with the rack, a valve 500 having an opening- shutting axis coupled to the pinion, and a case 600 for containing and fixing the above components. [49] The actuator 200 is driven electrically, and may be an actuator of a small size such that the axis 210 is pushed out when electrical power is provided. Such an actuator may include a solenoid, and actuators of various types may be available on the market. For example, a test button 220 may be established on the actuator.

[50] If electrical power is provided to the actuator 200 when the leakage sensor detects liquid, the solenoid in the actuator 200 is activated to push out the axis 210.

[51] In case that the leakage cutoff device is coupled to a small pipe of a water purifier in houses, the leakage sensor may be used directly as a driving switch of the actuator 200. In contrast, if the leakage cutoff device is coupled to a big pipe for industrial use or architectural use, a big valve driven by a high power is required and thus a large actuator for high power is required. In this case, it is desirable to activate an additional driving switch of the actuator using the leakage sensor and to drive the actuator by power provided through the switch.

[52] The rack 300 has a shape of a rod on which gear-teeth are formed and the rack 300 is coupled to the axis 210 of the actuator 200. The rack and the axis of the actuator may be coupled to each other through flange connection, screw connection, coupling connection, etc.

[53] Referring to FIG. 4 illustrating a longitudinal cross-sectional view of a leakage cutoff device, the pinion 400 paired with and coupled to the rack is coupled with the valve 500 such that an opening- shutting axis 510 of the valve is inserted into the pinion.

[54] An entrance portion and an exit portion of the valve are established respectively to a liquid supply pipe.

[55] The valve 500 in the leakage cutoff device may be any types of valves that open/shut a water path by rotating the opening-shutting axis 510. Typically a handle is coupled to the opening- shutting axis 510 of the valve, but the pinion 400 is coupled instead of the handle in the leakage cutoff device of the present invention. Wedges may be inserted between the axis aperture of the pinion and the opening-shutting axis to prevent the axis from idling.

[56] One unit may be formed such that the actuator, the rack and the pinion are built in a single case and the valve is fixed on an outer surface of the case.

[57] Operation of the leakage cutoff device of the present invention may be described as follows.

[58] As illustrated in FIG. 5, if electrical power is applied to the actuator 200 directly by the leakage sensor 100 or indirectly through a driving switch of the actuator when leakage is detected by the leakage sensor 100, the actuator operates to push out the axis so that the rack 300 coupled to the axis performs a straight-line motion. With the straight- line motion of the rack 300, the pinion 400 coupled to the rack performs a rotational motion so that the opening- shutting axis 510 of the valve 500 established at the water supply pipe is rotated by the pinion. As a result, the valve opened during normal times is shut to prevent progress of the leakage. [59]

Industrial Applicability

[60] The leakage sensor and the leakage cutoff device of the present invention may be used as safety devices for detecting leakage of liquid and cutting off the leakage in arbitrary apparatuses using liquid such as a water purifier, a refrigerator, an oil stove, etc.

Claims

[1] A leakage sensor comprising: a case (110) having a shape of a rectangular parallelepiped box formed of nonconducting plastic, all faces of the case having apertures for providing liquid paths, a first face of the case having a mounting projection; two electrical terminals (120) attached to a second face of the case, the second face being opposite to the first face, the two electrical terminals being coupled to respective signal lines and being apart from each other by a predetermined distance; and a cartridge including a bottom plate mounted on the mounting projection of the first face, a sponge paper attached to the bottom plate, and a metal plate attached on an upper surface of the sponge paper.

[2] A leakage cutoff device comprising: a leakage sensor (100) of claim 1; an actuator (200) driven in response to a signal received from the leakage sensor; a rack (300) coupled to and extended from an axis of the actuator; a pinion (400) paired with the rack; and a valve (500) attached to a liquid supply pipe, an opening-shutting axis of the valve being coupled to the pinion.