SAFETY TIMING CONTROL DEVICE OF GAS APPLIANCE

Abstract

A safety timing control device is provided for a gas appliance and includes an electromagnetic switch, a first timing controller, a second timing controller, a power converter, and an alarm unit. The electromagnetic switch includes an electromagnet, a return spring, a housing, a connection bar, and a plug. The first timing controller sets a predetermined period of operation of the gas appliance in order to control the supply of electrical power to the electromagnet, which in turn opens or closes a gas passage of the gas appliance to prevent a potential risk of explosion caused by undesired continuous supply of fuel to a flaming site of the gas passage or to prevent a potential risk of being poisoned by carbon monoxide generated by incomplete combustion of fuel gas in the gas appliance.

Description

FIELD OF THE INVENTION

The present invention relates to a safety timing control device of a gas appliance, and in particular to a safety timing control device of a gas appliance that uses an electromagnet to control a gas passage switch of the gas appliance.

BACKGROUND OF THE INVENTION

The progress of science and technology brings people the convenience of enjoying various resources, including fuel, electricity, and water, among which fuel gas is an indispensable type of the resources for modern living of human beings. Appliances that are operated on fuel gas, such as gas ranges and water heaters, receive fuel gas that is supplied through a piping system, allowing for easy and convenient use and operation of the gas appliances.

Although the gas appliances provide convenience and easiness of operation and use, they also carry potential risks. For example, when a user, who is using a gas range, is unexpectedly interfered and absent-mindedly leaves, totally forgetting the gas range is still cooking food, dry-burning may occur if the cooking is not stopped and continuously lasts for an excessively long period of tine. This may lead to a risk of explosion or fire.

Further, water heaters are operated on natural gas as an energy source. People prefer to have windows and doors shut down in cold days and they may unintentionally take a shower in an enclosed space. If the gas is not completely combusted in the water heater and carbon monoxide is produced and released, or the gas itself is released from the gas supply passage, a potential risk that the user is poisoned may occur.

Thus, to provide a gas safety control device and a carbon monoxide and gas leakage detector is an issue that needs to be overcome urgently.

SUMMARY OF THE INVENTION

In view of the above, the present invention provides a safety timing control device of a gas appliance, which comprises a timer that counts time so that when the operation of the gas appliance extends for a predetermined period of time, a supply of electrical power to the safety timing control device is cut off to block a gas passage of the gas appliance and thus cutting off the supply of fuel gas to a flaming site of the gas appliance.

The present invention discloses a safety timing control device of a gas appliance, which comprises a first timing controller, a second timing controller, a power converter, an electromagnetic switch, and an alarm unit. The electromagnetic switch comprises an electromagnet, a connection bar, a return spring, a housing, and a plug. The housing is mounted to an opening of a gas passage. The plug is received in the gas passage. The connection bar has a first end extending through the housing and coupled to a plug. The return spring is disposed around and encompasses the first end of the connection bar and is received in the housing. The connection bar has a second end that is movable by a magnetic force generated by the electromagnet. The first timing controller is operable to count a predetermined time period of operation of the gas appliance and is electrically connected to an electrical power supply unit. The second timing controller is electrically connected to the electromagnetic switch to count a time period of conduction-on of the electromagnetic switch. The power converter is electrically connected to the first timing controller and the second timing controller to convert and transfer electrical power supplied from the electrical power supply unit from the first timing controller to the second timing controller. The alarm unit is electrically connected to the first timing controller so that when the predetermined time period of operation of the gas appliance elapses, the first timing controller controls the alarm unit to issue an alarm signal. The electromagnetic switch is in a conduction-on condition during the predetermined time period of operation and the electromagnet generates a magnetic force that overcomes a return spring force of the return spring to attract and move the second end of the connection bar so as to open the gas passage. When the first timing controller reaches the predetermined time period of operation, the first timing controller cuts off the electrical connection with the electrical power supply unit to set the electromagnetic switch in a cut-off condition, where the magnetic force of the electromagnet varnishes and the plug is forced back by the return spring force of the return spring to close the gas passage.

Further, the safety timing control device further comprises a carbon monoxide and gas leakage detector, which is electrically connected to the first timing controller so that when the carbon monoxide and gas leakage detector detects gas leaking outside the gas passage or carbon monoxide generated by incomplete combustion of gas has a concentration exceeding a threshold, an electrical signal is generated and applied to the first timing controller to have the first timing controller cut off the electrical connection with the electrical power supply unit and establish a connection with the alarm unit to issue an alarm signal.

In summary, the present invention is applicable to general home environment and comprises a timer interface that is easy to operate so as to help the elders or young children to conveniently, easily, and efficiently set a desired operation time of the gas appliance in order to prevent potential risks caused by an undesired continuous supply of fuel gas to a flaming site of the gas appliance and to prevent the potential risk of poisoning caused by carbon monoxide generated through incomplete combustion of fuel gas by the gas appliance.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be apparent to those skilled in the art by reading the following description of preferred embodiments thereof with reference to the drawings, in which:

FIG. 1 is a schematic view illustrating a condition before electrical power is supplied to a safety timing control device of a gas appliance according to the present invention;

FIG. 2 is a schematic view illustrating an initial condition of supply of electrical power to the safety timing control device of the gas appliance according to the present invention;

FIG. 3 is a schematic view illustrating a condition of operation of the safety timing control device of the gas appliance according to the present invention;

FIG. 4 is a schematic view illustrating a condition where the operation of the safety timing control device of the gas appliance according to the present invention reaches a predetermined time period of operation;

FIG. 5 is a schematic view demonstrating an embodiment of a third timing controller of the safety timing control device of the gas appliance according to the present invention; and

FIGS. 6A and 6B are schematic views illustrating an operation of a carbon monoxide and gas leakage detector of the safety timing control device of the gas appliance according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to the drawings and in particular to to FIG. 1, a schematic view is given to illustrate a condition before electrical power is supplied to a safety timing control device of a gas appliance according to the present invention. The safety timing control device 1 of the gas appliance according to the present invention comprises a first timing controller T1, a second timing controller T2, an electromagnetic switch M, a power converter C, and an alarm unit B. The electromagnetic switch M comprises a plug M1, an electromagnet M2, a return spring M3, a housing M4, and a connection bar M5. The housing M4 is mounted to an opening formed in a gas passage G. The plug M1 is arranged in the gas passage G. The connection bar M5 has a first end M51 that extends through the housing M4 and is coupled to the plug M1. The return spring M3 is arranged around and encompasses the first end M51 of the connection bar M5 and is received and disposed in the housing M4. The connection bar M5 has a second end M52 that is movable by a magnetic force generated by the electromagnet M2. The first timing controller T1 is operable to count a predetermined time period of operation of the gas appliance and is electrically connected to an electrical power supply unit V. The second timing controller T2 is electrically connected to the electromagnetic switch M to count a time period of conduction-on of the electromagnetic switch M. The power converter C is electrically connected to the first timing controller T1 and the second timing controller T2 to convert and transfer the electrical power that is supplied from the electrical power supply unit V from the first timing controller T1 to the second timing controller T2. The alarm unit B is electrically connected to the first timing controller T1 in such a way that when the operation of the gas appliance reaches the predetermined time period, the first timing controller T1 controls the alarm unit B to issue an alarm signal.

The electromagnetic switch M is kept in a conduction-on condition within the predetermined time period of operation and the electromagnet M2 generates a magnetic force that overcomes a return spring force of the return spring M3 to attract the second end M52 of the connection bar M5 in such a way that the gas passage G is kept open. When the first timing controller T1 reaches the predetermined period of time of operation, the first timing controller T1 cuts off the electrical connection with the electrical power supply unit V so that the electromagnetic switch M is put into a cut-off condition and the magnetic force of the electromagnet M2 varnishes so that the plug M1 is driven by the return spring force of the return spring M3 back to close the gas passage G. Further, the electromagnet M2 comprises a recess formed therein so that when the electromagnetic switch M is in the conduction-on condition, the magnetic force generated by the electromagnet M2 drives the connection bar M5 to move, at least partly, into the recess and the plug M1 that is coupled to the connection bar M5 moves in unison therewith to open the gas passage G; and when the electromagnetic switch M is in the cut-off condition, the connection bar M5 is caused to move outward of the recess and the plug M1 of the connection bar M5 is moved in unison therewith to close the gas passage G.

The safety timing control device 1 according to the present invention is applicable to a gas appliance, such as a gas range and a water heater. When operating and using the gas appliance, a user may make a setting in advance according to a desired time period of operation. F or example, when using the gas range to cook food, the user may first operate the first timing controller T1 to set an activation time period of the gas range, meaning setting the time period of cooking food with the gas range. Similarly, when the safety timing control device 1 is used with a water heater, the time period of operation of the water heater can be set according to the need of the user. In an embodiment of the present invention, the first timing controller T1 is provided with an interface composed of a keypad of numeric buttons and allows for setting of time in a “stepless” manner with an available setting for the maximum time period of operation being for example 90 minutes.

Referring to FIGS. 2-4, schematic views are given to respectively illustrate an initial condition of supply of electrical power to the safety timing control device of the gas appliance according to the present invention, a condition of operation of the safety timing control device of the gas appliance according to the present invention, and a condition where the operation of the safety timing control device of the gas appliance according to the present invention reaches a predetermined time period of operation. The present invention uses the electromagnet M2, which when energized, generates a magnetic force, to control opening and closing of the gas passage G. The operation principle is that the electromagnet M2 is not a permanent magnet and the electromagnet M2 generates the magnetic force only when energized and loses the magnetic force when de-energized. Thus, with the first timing controller T1 of the safety timing control device 1 being electrically connected to the electrical power supply unit V, the electromagnet M2 may selectively generates a magnetic force that overcomes the return spring force of the return spring M3 to attract and move upward the connection bar M5. Since the first end M51 of the connection bar M5 is coupled to the plug M1, when the connection bar M5 is magnetically attracted and moved upwards, the plug M1 is moved in unison with the connection bar M5 and is also attracted upward thereby opening the gas passage G. When de-energized, the electromagnet M2 loses the magnetic force and the return spring force of the return spring M3 forces the plug M1 back a position of closing the gas passage G. The connection bar M5 is formed of or comprises a magnetically attractable material in order to be attracted by the electromagnet M2 when the magnetic force is generated through energization. Further, in an embodiment of the present invention, the connection bar M5 is arranged in a range of magnetic attraction of the magnetic force generated by the electromagnet M2 when it is energized so that the connection bar M5 is magnetically attracted and movable thereby.

When the first timing controller Ti of the safety timing control device 1 is activated and starts counting time, the electrical power supplied from the electrical power supply unit V is converted and transferred by the power converter C to the second timing controller T2 and is further transferred through the second timing controller T2 to the electromagnet M2 of the electromagnetic switch M. Then, the second timing controller T2 counts the time period of conduction-on of the electromagnetic switch M and selection is made among windings according to the time period of conduction-on. More specifically, the safety timing control device 1 comprises a first winding L1 and a second winding L2, which are arranged around and encompass the electromagnet M2. The second timing controller T2 establishes electrical connection with either the first winding L1 or the second winding L2 according to the time when the electromagnetic switch M is energized. For example, in an embodiment of the present invention, in a time period of 2-3 seconds for conduction on, the second timing controller T2 is electrically connected to a circuit composed of the first winding L1 to supply a first electrical current I1 of 300 mA (I1 being illustrated in FIG. 2) to the electromagnet M2, so that a relatively large magnetic force is generated to overcome the return spring force of the return spring M3. After a lapse of 2-3 seconds of conduction on, since the electromagnet M2 has overcome the return spring force of the return spring M3, the second timing controller T2 cuts off the connection thereof with the circuit of the first winding L1 and establishes, instead, electrical connection with a circuit composed of the second winding L2 to supply a second electrical current I2 of 160 mA (I2 being illustrated in FIG. 3) to the electromagnet M2. In other words, the second electrical current I2 so supplied is less than the first electrical current I1, so that the electrical loading current of the safety timing control device 1 can be cut down by approximately 50% and this helps prevent burning out the winding through which the electrical currently is continuously supplied for an excessively long period of time. Further, spring wire gauge and elastic module of the return spring M3 may be determined according to the magnitude of the first electrical current I1 in order to control the speed of the plug M1 opening the gas passage G. In an embodiment of the present invention, the return spring M3 is made with a spring wire gauge being selected 0.6 mm according to a first electrical current I1 of 300 mA.

Tanking the gas range as an example, reaching a predetermined time of shutting down indicates the time period that is set for cooking food has elapsed and thus, automatic closing of the gas passage G of gas range is conducted to prevent a continuous supply of fuel gas to the gas range that might lead to an unexpected event of for example explosion. Similarly, when the operation and use of a water heater has reached a predetermined time period, indicating the use of the water heater by a user is completed, automatic closing of the gas passage G of the gas appliance is conducted to prevent potential risks that fuel gas has not been completely combusted and poisoning caused by carbon monoxide may occur.

It is noted here that the alarm unit B is electrically connected to the electrical power supply unit V by the first timing controller T1. In other words, when the first timing controller Ti has not reached the predetermined period of time of operation, the alarm unit B is in an open-circuiting condition with respect to the electrical power supply unit V; and when the first timing controller T1 reaches the predetermined period of time of operation, the alarm unit B is electrically connected through the first timing controller T1 to the electrical power supply unit V for being energized to generate an alarm signal.

Further, referring to FIG. 5, a schematic view is given to demonstrate an embodiment of a third timing controller of the safety timing control device of the gas appliance according to the present invention. The safety timing control device 1 according to the present invention may further comprise a third timing controller T3, which counts a time period of alarming by the alarm unit B and is electrically connected to the first timing controller T1 and the alarm unit B. The time period of alarming of the alarm unit B can be set to for example a period of 5-10 seconds for informing a user that the gas passage G of the gas appliance has been closed. When the gas appliance has reached the predetermined period of time of operation, the first timing controller T1 switches the electrical connection thereof to the third timing controller T3 so that the third timing controller T3 is electrically connected to the electrical power supply unit V. When the time period of alarming of the alarm unit B elapses, the third timing controller T3 cuts off the electrical connection between the alarm unit B and the first timing controller T1.

Further, in an embodiment of the present invention, the alarm unit B comprises a buzzer or an alarm light. The alarm sound may be of fixed intensity or the intensity is increased from a low level to a high level. The alarm light may comprise a lighting element, such as a light-emitting diode (LED). Further, in the present invention, the first timing controller T1, the second timing controller T2, and the third timing controller T3 may be time relays.

Further, in addition to time counting of the predetermined time period of operation of a gas appliance, the safety timing control device 1 of the present invention further provides a function of detecting leakage of fuel gas of the gas appliance or carbon monoxide generated by incomplete combustion of fuel gas. Referring collectively to FIGS. 6A and 6B, schematic views are give to illustrate an operation of a carbon monoxide and gas leakage detector of the safety timing control device of the gas appliance according to the present invention. A carbon monoxide and gas leakage detector S is electrically connected to the first timing controller T1 so that when the carbon monoxide and gas leakage detector S detects fuel gas leaking outside the gas passage G or carbon monoxide generated by incomplete combustion of fuel gas has a concentration that exceeds a predetermined threshold level, an electrical signal is generated and applied to the first timing controller T1 to have the first timing controller T1 cuts off the electrical connection with the electrical power supply unit V so that the power converter C no longer converts and transfers electrical power supplied from the electrical power supply unit V through the first timing controller T1 to the second timing controller T2 and thus no electrical power is fed to the electromagnet M2. Under such a condition that no electrical power is fed to the electromagnet M2, the magnetic force of the electromagnet M2 varnishes and the spring return force of the return spring M3 causes the plug M1n to move back to close the gas passage G, preventing undesired continuous supply of fuel gas to a flaming site of the gas appliance. The first timing controller T1, when cutting off the electrical connection of the electrical power supply unit V, is switched to connection with the alarm unit B. In an embodiment of the present invention, the predetermined threshold level of the concentration of carbon monoxide or fuel gas can be standards stipulated in local regulations of each country or can be set by a user. Further, the carbon monoxide and gas leakage detector S of the present invention is combinable inside the safety timing control device or externally and electrically connectable to the safety timing control device.

In an embodiment of the present invention, the electrical power supply unit V supplies to the first timing controller T1 an alternating current, which is converted by the power converter C into a direct current fed to the second timing controller T2. The alternating current that is supplied from the electrical power supply unit V may be of any voltage levels supplied according to the local requirement. For example, to use the safety timing control device 1 of the present invention in Taiwan, the electrical power supply unit V receives and supplies an alternating current of 110 volts and the power converter C converting the alternating current of 110 volts into a direct current of 12 volts to be fed to the second timing controller T2. To use the safety timing control device 1 of the present invention in the mainland of China, the electrical power supply unit V receives and supplies an alternating current of 220 volts and the power converter C converting the alternating current of 220 volts into a direct current of 12 volts to be fed to the second timing controller T2. Further, in an embodiment of the present invention, the power converter C comprises a device that converts electrical power, such as a transformer.

In summary, the present invention provides a safety timing control device of a gas appliance that is applicable to general home environment and comprises a timer interface that is easy to operate so as to help the elders or young children to conveniently, easily, and efficiently set a desired operation time of the gas appliance in order to prevent potential risks caused by an undesired continuous supply of fuel gas to a flaming site of the gas appliance and to prevent the potential risk of poisoning caused by carbon monoxide generated through incomplete combustion of fuel gas by the gas appliance.

Further, the safety timing control device of the gas appliance according to the present invention can be installed on all types and models of gas appliance, such as a water heater operated with natural gas or a gas range operated with liquidized petroleum gas, all allowing for easy installation with only one gas hose fixed at a proper location on the gas appliance and connecting the gas hose to the safety timing control device and providing electrical connection with an electricity source to allow a proper and normal operation of the safety timing control device. During the operation of the safety timing control device, since the opening and closing of a gas passage of the gas appliance is only conducted with a timer, the original functionality of the gas appliance is generally not affected. Thus, the original way of operation of the gas appliance can be maintained. This allows the popularization of the safety timing control device to be widened for applications in all sorts of gas appliance.

Although the present invention has been described with reference to the preferred embodiments thereof, it is apparent to those skilled in the art that a variety of modifications and changes may be made without departing from the scope of the present invention which is intended to be defined by the appended claims.

Claims

1. A safety timing control device of a gas appliance, comprising:

an electromagnetic switch, which comprises an electromagnet, a connection bar, a return spring, a housing, and a plug, the housing being mounted to an opening of a gas passage, the plug being received in the gas passage, the connection bar having a first end extending through the housing and coupled to a plug, the return spring disposed around and encompassing the first end of the connection bar and received in the housing, the connection bar having a second end that is movable by a magnetic force generated by the electromagnet;

a first timing controller, which is operable to count a predetermined time period of operation of the gas appliance and is electrically connected to an electrical power supply unit;

a second timing controller, which is electrically connected to the electromagnetic switch to count a time period of conduction-on of the electromagnetic switch;

a power converter, which is electrically connected to the first timing controller and the second timing controller to convert and transfer electrical power supplied from the electrical power supply unit from the first timing controller to the second timing controller; and

an alarm unit, which is electrically connected to the first timing controller so that when the predetermined time period of operation of the gas appliance elapses, the first timing controller controls the alarm unit to issue an alarm signal;

wherein the electromagnetic switch is in a conduction-on condition during the predetermined time period of operation and the electromagnet generates a magnetic force that overcomes a return spring force of the return spring to attract and move the second end of the connection bar so as to open the gas passage; and when the first timing controller reaches the predetermined time period of operation, the first timing controller cuts off the electrical connection with the electrical power supply unit to set the electromagnetic switch in a cut-off condition, where the magnetic force of the electromagnet varnishes and the plug is forced back by the return spring force of the return spring to close the gas passage.

2. The safety timing control device as claimed in claim 1, wherein the connection bar comprises a material that is magnetically attractable.

3. The safety timing control device as claimed in claim 1 further comprising a first winding and a second winding wound around and encompassing the electromagnet, the second timing controller being electrically connectable to the first winding or the second winding according to a time of conduction-on of the electromagnetic switch, wherein during a time period of conduction-on of 3 seconds for the electromagnetic switch, the second timing controller is electrically connected to the first winding and after time lapse of 3 seconds of conduction-on time of the electromagnetic switch, the second timing controller is electrically connected to the second winding.

4. The safety timing control device as claimed in claim 3, wherein a first electrical current flowing through the first winding is greater than a second electrical current flowing through the second winding.

5. The safety timing control device as claimed in claim 1 further comprising a third timing controller, which counts an alarm time period of the alarm signal and is electrically connected to the first timing controller and the alarm unit.

6. The safety timing control device as claimed in claim 1, wherein the electrical power supply unit supplies to the first timing controller an alternating current, which is converted by the power converter into a direct current to be fed to the second timing controller.

7. The safety timing control device as claimed in claim 1, wherein the power converter comprises a transformer.

8. The safety timing control device as claimed in claim 1, wherein the alarm unit comprises a buzzer or an alarm light.

9. The safety timing control device as claimed in claim 1 further comprising a carbon monoxide and gas leakage detector, which is electrically connected to the first timing controller so that when the carbon monoxide and gas leakage detector detects gas leaking outside the gas passage or carbon monoxide generated by incomplete combustion of gas has a concentration exceeding a threshold, an electrical signal is generated and applied to the first timing controller to have the first timing controller cut off the electrical connection with the electrical power supply unit and establish a connection with the alarm unit.

10. The safety timing control device as claimed in claim 5, wherein the first timing controller, the second timing controller and the third timing controller are time relays.