WO2000073705A1

WO2000073705A1 - Spark igniter for gas torch

Info

Publication number: WO2000073705A1
Application number: PCT/BR1999/000036
Authority: WO
Inventors: Rogerio Oliveira Rosa; Valdeci Ademir Flores De Almeida; Marcelo Souza De Bastiani
Original assignee: Springer Carrier Ltda
Current assignee: Springer Carrier Ltda
Priority date: 1999-05-28
Filing date: 1999-05-28
Publication date: 2000-12-07
Anticipated expiration: 2001-11-28

Abstract

A spark igniter (10) for a gas torch (12) which is configured to generate an electrical pulse output when energized by an electric power source (22), which is typically an AC source of power (22). A pair of spaced electrodes (38) are configured to have sparks occur therebetween when electrically connected to the electrical pulse output of said igniter (10). An electrical circuit is provided for operatively interconnect the power source (22), the igniter (10) and the spaced electrodes (38). A normally open electrical switch (30) is positioned in the electrical circuit at a location such that it normally interrupts the electrical connection between the igniter (10) and said electrodes (38). The switch (30) is configured to close the electrical connection between the igniter (10) and the electrodes (38) when the gas torch (12) is positioned in close proximity to said electrodes (38), and to return to its normally open condition when the torch (12) is removed from such position. As a result, when the electric source (22) is energized, and the torch (12) is positioned in close proximity to the electrodes (38), the igniter (10) will cause sparks to occur at the electrodes (38) thereby igniting the torch (12).

Description

SPARK IGNITER FOR GAS TORCH

Technical Field

The present invention relates to an igniter for a gas torch, and more particular, to an igniter which uses an electrical pulse generating igniter and a spark plug. Background Art

Commonly, the lighting of conventional gas torches for brazing, welding, etc., is accomplished by a flint lighter in which the operator must strike a spark with the flint while holding the torch close to the flint. Such manual igniters have inherent disadvantages and a variety of devices have been developed which facilitate igniting the torch by the operator. For example, U.S. patent 3,919,522 discloses a cordless electric ignition tool having a handle portion comprising a housing containing a battery, a pair of terminals and a normally open switch in circuit with the battery and the terminals.

U.S. patent 874,357 discloses another hand-held lighter. The '357 lighter includes a hollow body and means associated with the body for closing an electric circuit associated with the body with either a resistance in or out of the same. The introduction of resistance helps prevent injury to the hollow body.

Although helping to reduce the possibility of operator injury, these hand-held designs still require the operator to use both his hands. U.S. patent 3,090,856 entitled "Gas Torch Lighter" to H. Rorvig discloses a torch lighter having a housing, which is fastened to a work bench. The housing has a heating unit mounted on the top thereof, which includes a coil of high resistance wire such as Nichrome which is wound upon a suitable insulated mounting block. The torch igniter includes electrical cables and a suitable plug for connecting it to a source of electric current.

The igniting coil is enclosed by a hood for confining the gas from the torch in the area immediately surrounding the igniting coil to permit quick lighting or lighting thereof. A switch unit is also mounted atop the box in front of the heating unit and preferably in substantial alignment therewith. This switch unit comprises a pair of circuit breakers, each having opposed, disconnected convex ends defining therebetween a valley or seat for receiving the tip or nozzle of a gas torch. To light the torch, the operator rests the tip of the gas torch in the valley provided by the convex ends to bridge the gap with a nozzle directed towards the heating unit. The engagement of the tip of the torch with the contact elements closes the circuit of the torch lighter and causes the heating coil to heat to a high temperature sufficient to ignite the gas from the torch.

U.S. patent 5, 182,436 entitled "Portable Bench-Type Electric Ignite For Gas Welding Torches" to Polidoro discloses a portable gas torch igniter which includes a housing having a flame duct formed therein for introduction of a gas torch. A glow plug is secured to the surface of the flame ducts. A battery provides an electric power source for providing electric current to the glow plug. An electrical switch attached to the housing conducts current between the battery and the glow plug. The switch is positioned so as to switch on when the tip of the welding torch is positioned in proximity to the glow plug. The flame duct is open at its rear end and has a front portion arranged substantially horizontally and has an open front end into which the torch to is inserted for ignition. It is desirable to have a torch igniter which provides a positive source of ignition in a very short period of time, without requiring the flow of electric current to heat a torch igniting element, such as the glow plug of the '436 patent. Disclosure of the Invention

According to the present invention, an igniter for a gas torch includes an igniter which is configured to generate an electrical pulse output when energized by an electric power source, such as an AC source of power. A pair of spaced electrodes are configured to have sparks occur therebetween when electrically connected to the electrical pulse output of the igniter. An electrical circuit is provided to operatively interconnect the power source, the igniter and the spaced electrodes. A normally open electrical switch is positioned in the electrical circuit at a location such that it normally interrupts the electrical connection between the igniter and the electrodes. The switch is configured to close the electrical connection between the igniter and the electrodes when the gas torch is positioned in close proximity to the electrodes, and to return to its normally open condition when the torch is removed from such position. As a result, when the electric source is energized, and the torch is positioned in close proximity to the electrodes, the igniter will cause sparks to occur at the electrodes thereby igniting the torch. Brief Description of the Drawings

The invention may be better understood and its objects and advantages will become apparent to those skilled in the art by reference to the accompanying drawings, in which: Figure 1 illustrates the spark igniter of the present invention with a gas torch illustrated in operative position therewith; and

Figure 2 is an electrical circuit of the components of the spark igniter of the present invention. Best Mode For Carrying Out The Invention And Industrial Applicability

Figure 1 illustrates the spark igniter 10 with a gas torch 12 in operative position relative thereto. Figure 2 illustrates a circuit diagram of the components of the spark igniter 10. The spark igniter 10 comprises an electromechanical igniter generally represented by reference numeral 16 and including the components in the circuit between the parallel lines 18 and 20. An AC power source 22 is connected to the input lines 24 of the electromechanical igniter. Serially arranged on the output side 28 of the electromechanical igniter 16 is a proximity switch 30 and a spark plug 32.

With reference to Figure 1 , the proximity switch 30 and the spark plug 32 are mounted within a spark igniter housing 34 with the sensing portion 36 of the proximity switch 30 and the electrodes 38 of the spark plug 32 mounted on a common surface 40 and in close proximity to one another. The electromechanical igniter 16 may be located within the housing 34 or may be externally located. If the electromechanical igniter 16 is within the housing, the input wire 46 passing to the housing 34 represents the output 28 of the electromechanical igniter 16. And, if the electromechanical igniter 16 is located outside of the housing, the input wire 46 to the housing represents the input 24 to the igniter from the AC power line 22. The electromechanical igniter 16 is preferably of the type which is commonly used for igniting the flame in a gas or LP kitchen stove. The igniter used in the preferred embodiment is available as a one burner Scintilla igniter from Centelha Industria E Comercio Exportacao Electromecanica Ltda., Rua Siano Cappel, 3 15 - Navegantes, Porto Alegre CEP 90240-210, Brazil. The igniter is configured to operate on an AC power source of 100-240 VAC at a frequency of 50 to 60 FIz. It produces a pulsed output of 100 to 360 sparks per second with a gap between sparking electrodes of 3 to 4 millimeters.

The proximity switch 30 is a two wired normally open switch, which includes an inductive proximity sensor, which is capable of detecting the nearness of metal parts, components and machine elements, and thus replacing conventional electromechanical switches. Detection occurs without physical contact between the sensor 36 and the activated element, thus increasing sensor service life inasmuch as it has no moving parts subject to mechanical wear. The operating principal of the sensor is based on the generation of a high frequency electromagnetic field. The field is generated by a resonant coil mounted on the sensing surface. The coil is part of an oscillating circuit that, in its normal status, (deactivated) generates a sine signal. When a metal part comes near the field, it absorbs the field energy by means of surface current thereby decreasing the amplitude of the signal generated in the oscillator. The amplitude range of this signal is converted into a continuous variation that, when it is checked against a pattern, starts actuating in the output state. The sensor used in the preferred embodiment is manufactured by SENSE - Sensors and Gauges, Rua Teixeira de Melo, 295, Tatuape, Sao Paulo, Brazil, as model number PS2- 12GM60-WA. While the inductive proximity switch has such advantages, it should be understood that a common electromechanical switch may be satisfactorily used in place of the inductive sensor, in which case the tip of the torch would make contact with a moveable component of the switch to complete the circuit and thereby actuate the pulse output of the igniter and sparking at the spark plug electrodes. The spark plug is a resistive spark plug manufactured by

Robert Bosch Limitada, Via Anhanguera Km 98, Campinas, Sao Paulo, Brazil. Part numbers H4VC, SR5DS and others will operate satisfactorily in the igniter system.

During operation of the spark igniter 10 with the igniter energized, the tip 42 of the gas torch 12 is positioned above the sensor 36 of the proximity switch 30 with the open end 44 thereof near the spark plug 32. The appropriate gas and oxygen valves, generally 44, are opened and the torch is immediately ignited by the sparking, which occurs across the electrodes 38 of the spark plug 32. When the tip of the torch is removed, the sparking ceases until another torch is placed into position to be ignited or the torch needs to be relit.

Claims

CLAIMSWhat is Claimed is:

1. A spark igniter for a gas torch comprising: an igniter configured to generate an electrical pulse output when energized by an electric power source; an electrical power source for providing an electric current to energize said igniter; a pair of spaced electrodes configured to have sparks occur therebetween when electrically connected to said electrical pulse output of said igniter; an electrical circuit for operatively interconnecting said power source, said igniter and said spaced electrodes; and a normally open electrical switch in said electrical circuit at a location such that it normally interrupts the electrical connection between said igniter and said electrodes, said switch being configured to close the electrical connection between said igniter and said electrodes when the gas torch is positioned in close proximity to said electrodes, and to return to said normally open condition when the torch is removed from such position; whereby, when said electric power source is energized, and said torch is positioned in close proximity to said electrodes, said igniter will cause sparks to occur at said electrodes thereby igniting the torch.

2. The spark igniter of claim 1 further including a housing defining a mounting surface, wherein said pair of spaced electrodes are mounted to said housing such that they extend outwardly from said mounting surface, and wherein said electrical switch is mounted to said mounting surface in close proximity to said electrodes.

3. The spark igniter of claim 2 wherein said electrodes are defined by a spark plug.

4. The spark igniter apparatus of claim 2 wherein said electrical switch comprises a proximity sensor therein, which senses the presence of said torch to thereby close said switch.

5. The spark igniter of claim 2 wherein said switch comprises a normally open electromechanical switch.

6. The spark igniter apparatus of claim 1 wherein said igniter comprises an electromechanical igniter.

7. The spark igniter of claim 6 wherein said pair of electrodes are defined by a spark plug and said electrical switch comprising an inductive proximity sensor switch.