WO2006016859A1

WO2006016859A1 - Timer of a household gas burner

Info

Publication number: WO2006016859A1
Application number: PCT/SI2005/000024
Authority: WO
Inventors: Tase Lazovski
Original assignee: Tase Lazovski
Priority date: 2004-08-10
Filing date: 2005-08-10
Publication date: 2006-02-16
Also published as: SI21860A

Abstract

A timer of a household gas burner of the invention offers a possibility of setting the duration of burning of a gas burner without any risk of gas leakage once the flame is off and the valve still open. A timer (1) of the invention intended to be built on the gas burner (2), where there is a safety element against gas leakage from the burner (2) with an open valve and extinguished flame foreseen in the form of a thermal element (3) is conceived in a way that into the circuit formed by the thermal element (3), electric conduits (4, 5) and a coil (6) of a valve (7) of the burner (2) there is a series-connected circuit breaker (14) controlled by a programme clock (15), whereby the electric-mechanical connection of the circuit breaker (14) is implemented in the circuit via an interface (13) in a way that electric and mechanical properties are preserved by the thermal element (3), the electric conduits (4, 5) and the coil (6).

Description

TIMER OF A HOUSEHOLD GAS BURNER

Subject of Invention

The subject of the invention is a timer of a household gas burner offering a possibility of setting the duration of burning of a gas burner without any risk of gas leakage once the flame is off and the valve still open.

Technical Problem

A technical problem solved by the invention is how to conceive such timer of a household gas burner fitted in an optional kitchen element e.g. a cooker with several gas and/or electric hot plates that will automatically shut off gas supply to the burner after the manually set interval. At the same time all safety elements of the burner preventing leakage of gas with the valve open and with the flame extinguished will remain unchanged, moreover the timer will be adapted for the first and second fitting without any modifications of a burner as such both for the cookers connected to electricity network voltage and those foreseen to be connected to it and as far as a user's point of view is concerned, it will be the same as a timer of other electric household heating elements.

Prior Art

Gas burners of household cookers are equipped only with a safety device against gas leakage with a gas valve open and the flame extinguished. A timer of a gas cooker similar to that of electric plates on hot plates or in ovens has not been known.

There is a need for such timer of a gas burner of household cookers that is used similarly to that of electric plates. Often, there are gas burners and electric heating means on the same cooker. Each type of heating bodies has its own thermal properties that a user selects with respect to the mode of thermal treatment of food. A disadvantage of gas burners seems to arise in that they cannot be regulated as to the time of burning and a user is forced to be attentive to the time of thermal treatment on a gas burner also when food needs no manual processing, e.g. stirring or adding ingredients during thermal treatment.

Solution to the Technical Problem

The described technical problem is solved by a timer of the invention, the essential characteristic of which is as follows: in a conductor connecting a thermal element near the flame on the nozzles of a burner and an electric coil of a gas valve there is a series-connected time switch that after a predetermined time interval interrupts electric current produced by a thermal element and supplied to the electric coil of the valve so that the valve remains in open state, thus simulating the extinguishing of a flame and causing closing of a valve. When the current in the valve is interrupted, the coil allows the closing element in the valve due to the action of a spring in opposite direction from the coil operation to switch the valve into the closed position and interrupt gas supply to the burner. A characteristic of a timer of the invention lies in that the timer is connected to circuit formed by a thermal element and the coil of a gas valve arranged on the position of a screw connection of a thermal element to the housing of a valve with an intermediate element, so that there is no need of any adaptation of a bolted connection and pins neither on the housing of the valve nor on the thermal element. The timer of the invention can thus simply be used when a kitchen appliance is fitted upon manufacture or subsequently fitted as the improvement of an existing household appliance. This solution is adapted to standard structural concepts of known household gas burners of this type, in which connections between a thermal element and a valve are implemented as bolted connections. Another solution of the invention foresees an embodiment, in which a thermal element with an outlet of two flexible wires is used, said wires being connected with a coil of a valve in an optional known way only with a connection of wire conductors.

The essence of the invention will now be described in more detail in the continuation of the description by way of both embodiments and enclosed figures, on which

Fig. 1 shows an electric wiring diagram of a timer of the invention, Fig. 2 shows a longitudinal cross-section of a timer of the invention arranged between a valve and a thermal element of the first embodiment.

A timer 1 of a household gas burner 2 according to the first embodiment of the present invention is intended to be built on the gas burner 2, where there is a safety element against gas leakage from the burner 2 with an open valve and extinguished flame foreseen in the form of a thermal element 3 having electric conduits 4, 5 connecting the thermal element 3 and a coil 6 of a valve 7 of the burner 2, said conduits being conceived as concentric conduits, of which one conduit 4 is an electrically conductive tube, another conduit 5 is within it and separated from its internal wall with electric insulation 8. A connection 9 of the thermal element is conceived in a way that the conduit 4 is equipped with an electrically conductive threaded part 10 for connection, through which a connector 11 of the conduit 5 is led in an electrically insulating manner. The connector 11 in presently known appliances without a timer is foreseen for a contact with the coil 6 of the valve 7. Between the connector 9 of the thermal element 3 and a housing 12 of the valve 7 there is an interface 13 allowing electrical series connection of a circuit breaker 14 controlled by a programme clock 15 to an electric circuit between the thermal element 3 and the coil 6 of the valve 7. The interface 13 is conceived in a way that it is both mechanically and electrically suited to the thermal element 3 and the housing 12 of the valve 7.

The connector 11 is intended for electric connection of the conduit 5 via the circuit breaker 14 of the timer 1 with one connector 16 of the coil 6, whereas the conduit 4 of the thermal element 3 is electrically connected via the threaded part 10 with the housing 12 of the valve 7 and the latter with a second connection 17 of the coil 6.

The timer 1 consists of a circuit breaker 14 controlled by the programme clock 15, of a pair of electric conduits 18 and an interface 19 between the thermal element 3 and the housing 12 of the valve 7 of the gas burner 2.

The programme clock 15 is of an optional known concept and can be either mechanical - when it is not foreseen for a household appliance with the burner 2 to be connected to network voltage - or electrical or electronic when electric power is supplied from an electric battery. The programme clock 15 is intended to operate on the circuit breaker 14 at set time. Two conduits 20 are connected to the circuit breaker 14, said conduits being connected to the conduits 18 and 19 of the interrupted conduit 5 in the interface 13.

The interface 13 consists of a housing 21 having a threaded hole 22 at one side, into said hole fitting the threaded part 10 together with the connector 11 for connection of the thermal element 3. The threaded part 10 connects the conduit 4 of the thermal element 3 with the housing 21 and the connector 11 connects the conduit 5 of the thermal element 3 with a conduit 19 in the interface 13. The second conduit 18 is connected with a connector 23 positioned within a threaded plug 24 conceived in the housing 21 of the interface 13, whereby the plug 24 and the pin 23 are the same concerning connection dimensions of the bolted part 10 and the connector 11.

The conduits 18 and 19 and the connector 23 are electrically insulated with means 8 from the housing 21 of the interface 13.

The plug 24 and the connector 23 abut against the existing threaded hole 25 and a contact 26 in the housing 12 of the valve 7 both mechanically and electrically, so that the conduit 4 of the thermal element 3 is electrically conductively connected via its threaded part 10, the housing 21 and the threaded plug 24 of the interface 13, the housing 12 of the valve 7 with one connector 17 of the coil 6 of the valve 7.

The timer 1 of the invention functions as follows: on the programme clock 15 the time of operation on the circuit breaker 14 is set. Until the moment of the set time of switch-off, the above-mentioned electric circuit is closed, thus allowing the thermal element 3 heated by the flame of the burner 2 to produce electric current causing the coil 6 to keep the valve 7 in the open position after it has been manually opened and the flame set by a user. Within the set period of time the circuit breaker 14 in the programme clock 15 interrupts the circuit for a moment and the coil 6 releases the locking element 27 of the valve 7, so that a spring 28 pushes it into the closed position thus interrupting gas leakage from the valve 7. As soon as the flame extinguishes, the temperature on the thermal element 3 immediately decreases so much that the voltage supplied by the thermal element 3 to the coil 7 is no longer sufficient to return the locking element 27 into the open position after the circuit breaker 14 is turned on again and thus the circuit re-established. Once the circuit is closed again, the burner is prepared for manual setting the flame upon safety operation of the thermal element 3 with an additional setting of the switch-off time of the burner with a programme clock 15 or without any setting.

The second embodiment of the present invention uses the thermal element 3 with similar wires as integrated into measurement instruments or as a sensor in control technology. Electric connection is in this case implemented by a series-connected circuit breaker 14 in the circuit between the thermal element 3 and the coil 6 of the valve 7, said circuit breaker 14 being controlled by the programme clock 15, which can be either mechanical, electric or electronic, as described in the previous embodiment.

In the third embodiment, especially in the variant for secondary fitting, where the distance of the interface 13 and the circuit breaker 14 with the programme clock 15 is unpredictable and depends on a user, the ohmic resistance in the circuit between the thermal element 3 and the coil 6 of the valve 7 is also unpredictable. The secondary fitting may prove to provide too much discrepancy from the prescribed length, material and cross-section of conduits 20 and thus their ohmic resistance. Large discrepancy from the foreseen ohmic resistance in this conduit may result in poorer operation of the timer of the invention. It is therefore intended for the conduits 20 to be determined by the manufacturer as to their ohmic resistance, so that regardless of the location of the programme clock 15 unchanged ohmic resistance of the entire circuit is ascertained. The influence of unauthorised installation of a device in secondary fitting should be abolished. In the scope of the mentioned problem a circuit breaker 14 should be used in secondary and also first fitting, if such solution proves to be wiser, said circuit breaker being placed in the vicinity of the programme clock 15 and in the vicinity or rather in the interface 13 assembly, so that the ohmic resistance of the electric circuit between the thermal element 3 and the coil 6 of the valve 7 is determined by the manufacturer of the device. A person using or installing the device in the cooker should not have access to said circuit. The circuit breaker 14 is conceived as a relay, a semi-conducting switch and the like controlled by the programme clock 15 in the same way as described above in the previous embodiments.

It is understandable that a man skilled in the art can conceive other embodiments based on the description of the invention and the embodiments without circumventing the characteristics of the invention described in the appended patent claims.

Claims

1. A timer (1) of a household gas burner (2) intended to be built on the gas burner (2), where there is a safety element against gas leakage from the burner (2) with an open valve and extinguished flame foreseen in the form of a thermal element (3) characterized in that into the circuit formed by the thermal element (3), electric conduits (4, 5) and a coil (6) of a valve (7) of the burner (2) there is a series-connected circuit breaker (14) controlled by a programme clock (15), whereby the electric-mechanical connection of the circuit breaker (14) is implemented in the circuit via an interface (13) in a way that electric and mechanical properties are preserved by the thermal element (3), the electric conduits (4, 5) and the coil (6).

2. A timer according to claim 1, and in which electric conduits (4, 5) connecting the thermal element (3) and a coil (6) of a valve (7) of the burner (2) are conceived as concentric conduits, of which one conduit (4) is an electrically conductive tube, and another conduit (5) is within it and separated from its internal wall with electric insulation (8), characterized in that an interface (13) consists of a housing (21) having a threaded hole (22) at one side, into said hole fitting the threaded part (10) together with the connector (11) for connection of the thermal element (3), whereby the threaded part (10) connects the conduit (4) of the thermal element (3) with the housing (21) and the connector (11) connects the conduit (5) of the thermal element (3) with a conduit (19) in the interface (13), whereas the conduit (18) in the housing (21) is connected with a connector (23) positioned within a threaded plug (24) conceived in the housing (21) of the interface (13), whereby the plug (24) and the connector (23) are the same concerning connection dimensions of the threaded part (10) and the connector (11), so that the plug (24) abuts against the existing threaded hole (25) and a contact (26) in the housing (12) of the valve (7), whereas the conduit (4) of the thermal element (3) is electrically conductively connected via the threaded part (10), the housing (21) and the threaded plug (24) of the interface (13), the housing (12) of the valve (7) with one connector (16) of the coil (6) of the valve (7) and the conduit (5) of the thermal element (3) via the connector (11), the conduit (19), the circuit breaker (14), the conduits (20), the conduit (18), the connector (23), the contact (26) with another connector (16) of the coil (6) of the valve (7).

3. A timer according to claims 1 and 2, characterized in that the conduits (18) and (19) and the connector (23) are electrically insulated with means (8) from the housing (21) of the interface (13).

4. A timer according to claims 1 and 2, characterized in that a timer (1) consists of a programme clock (15), a circuit breaker (14) controlled by the programme clock (15), para-electric conduits (20) and an interface (13) positioned between the thermal element (3) and the housing (13) of the valve (7) of the gas burner (2).

5. A timer according to claims 1 to 4, characterized in that the conduits (20) are conceived with known and unchangeable ohmic resistance regardless of the distance of the circuit breaker (14) from the interface (13), so that the ohmic resistance in the circuit between the thermal element (3) and the coil (6) of the valve (7) is determined by the manufacturer of the device.

6. A timer according to claims 1 to 6, characterized in that the circuit breaker (14) is placed in the vicinity or rather in the interface (13) assembly, said circuit breaker (14) and the interface (13) being linked by conduits (20), whereby the person installing the device of the invention into the cooker does not need to enter or is even disabled to enter said circuit breaker (14) assembly, of the interface (13) and the conduits (20).

7. A timer according to claims 1 to 3, characterized in that the programme clock (15) can be mechanical or electric or even electronic.