Devices For High Voltage Ignition of Combustible Gas

Abstract

High voltage gas igniters are described, including a hand held portable gas torch igniter of the piezoelectric-type which includes a finger grip housing body actuated by inward depression of the push button igniter to generate a spark-producing voltage when held near the combustible gas exiting the bum tube of a torch or combustible gas exit of a heating device. The igniter has a tube electrode for easy construction, and deflector shield for user protection and gas mixing. Other igniters have multiple spark gaps for increased effective spark length.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority from and is entitled to the benefit of the filing date of U.S. Provisional Patent Application Ser. No. 60/619,968 filed 19 Oct. 2004 under the title Multiple Devices For Piezoelectric Ignition Of Combustible Gas by one or more of the inventors named in this application.

TECHNICAL FIELD

[0002] The invention relates to high voltage gas ignition devices.

BACKGROUND ART

[0003] Piezoelectric high voltage ignition devices of both impact type and gradual squeeze type are known in the prior art. Piezoelectric ignition devices use a specific location of spark generation to generate combustible gas ignition when compared to flint striker sparks which are haphazardly produced during the striking process. The impact type ignition devices have a considerable cost advantage over squeeze devices as less bulky arrangements are required in order to provide the necessary force, and dimensional tolerances are much less severe.

[0004] As noted by Miller in U.S. Pat. No. 4,348,172 "piezoelectric spark-producing devices for use in igniting combustible fuels such as propane gas and similar fuels which can be stored in portable containers have been known for a number of years. Such devices typically have a hammer which is moved into force impact with an anvil structure of a piezoelectric crystal assembly forming part of an electrical circuit having a spark gap. When the crystal is deformed by the hammer blow, a voltage is generated in the circuit of sufficient magnitude to create a spark in the gap area of the circuit. Typical of such piezoelectric spark-producing devices are those shown in prior U.S. Pat. No. 3,509,388 dated Apr. 28, 1970 and U.S. Pat. No. 4,139,792 dated Feb. 13, 1979, both assigned to Matsushita Electric Industrial Co., Ltd. In those devices, the hammer is actuated by moving a slidable finger-piece or plunger slidably supported in telescoping relation projecting into the outer housing, which during an initial portion of its inward stroke arms a spring while restraining the hammer against movement towards the crystal, and then suddenly releases the hammer to be driven by the spring into spark generating impact with the crystal stack. Other mechanical arrangements have also been devised in prior art piezoelectric-type spark-producing devices for driving the hammer into spark generating impact with the crystal structure."

[0005] Improvements to and alternate designs for high voltage igniters are desirable.

DISCLOSURE OF THE INVENTION

[0006] In a first aspect the invention provides a combustible gas igniter including a piezoelectric spark generator, a first electrode, and a generally tubular second electrode. The tubular second electrode has opposing first and second ends and a longitudinal axis. The first electrode is located on the longitudinal axis of the tubular second electrode. The second electrode extends beyond the first electrode along the axis in the direction of the first end and in the direction of the second end. The first end is open to the first electrode. The igniter also has a combustion zone between the first electrode and the second electrode.

[0007] The spark generator may be located partially within the second end and may enclose the second end. The igniter may also include a one-handed finger grip and pushbutton to hold the second electrode and to activate the spark generator. The igniter may also include a deflecting shield to direct combustion gases away from the user of the igniter. The igniter may also include a deflecting shield to allow proper mixing of gas and air in the combustion zone. The deflecting shield may extend asymmetrically from the first end of the tubular electrode parallel with the longitudinal axis to allow access to the combustion zone by a stream of incoming gas and to allow exit of combustion gases away from the user. The first end of the second electrode may open at an angle to the axis to provide a deflecting shield for directing combustion gases away from the user.

[0008] In a second aspect the invention provides a portable combustible gas handheld torch igniter comprising finger-grip and conducting metal tube electrode as outer housing body. The outer housing body contains an inner housing case of impact type piezoelectric spark generator. The impact type piezoelectric spark generator has a push button plunger for depression in the direction of longitudinal axis of impact type piezoelectric spark generator inner housing case and outer housing body. The impact type piezoelectric spark generator push button depression to generate a spark-producing voltage force with resulting spark occurring at a spark gap between terminal electrode of impact type piezoelectric generator and conducting metal tube electrode near open end of conducting metal tube electrode housing body. The spark between terminal impact type piezoelectric electrode and conducting metal tube housing body near open end of conducting metal tube housing body causing ignition of combustible gas within the spark gap near open end of conducting metal tube electrode housing body. The ignition taking place when open end of conducting metal tube electrode housing body of igniter is actuated upon or near exit end of burn tube following opening of burn tube control valve. The ignition of combustible gas at spark gap with resulting flame transferred to the exit end of the burn tube having open control valve of the hand held torch.

[0009] In a third aspect the invention provides a method and process wherein a piezoelectric generated pulse and current will cause ignition of a combustible gas or mixture of combustible gases with greater frequency and efficiency. The electrical pulse and current traversing a series of multiple spark gaps. The spark gaps containing a combustible gas resulting in ignition of the combustible gas.

[0010] In a fourth aspect the invention provides a method and process including causing ignition of a combustible gas or mixture of gases with greater frequency and efficiency by increasing the length of the spark gap within a combustible gas. The increased spark gap length significantly increasing the surface exposure area of said combustible gas, thereby increasing the frequency of ignition.

[0011] For example, the piezoelectric spark generator effectiveness, when igniting a combustible gas, is enhanced by having the flow of piezoelectrical current passing through multiple spark gaps. The piezoelectric current and sparks produced are from a voltage capable of arcing the gaps of a series of interrupted conducting material or materials to the opposite pole of the piezoelectric generator. The multiple sparks are produced by a voltage capable of arcing between all interrupted conducting material or materials having gaps on the surface of a dielectric material. The multiple spark gaps allow multiple locations for interacting with and causing combustion of a combustible gas on or near the surface of a combustion chamber.

[0012] Also for example, the effective spark gap length of the piezoelectric produced current may be increased by using a conductive thin film electrode where the resistance of the thin film electrode allows only partial conductivity of a conducting path. The remainder of electric current arcs on or near the thin film conducting electrode path. The path allows either controlled or uncontrolled direction of a conducting current and arcing on or near the conducting film electrode path. The thin film conducting electrode path is in contact with a dielectric material. The thin film conducting path corona or arc interacts with a combustible gas on or near the surface of a combustion chamber.

[0013] In a fifth aspect the invention provides a combination of clusters of multiple spark gaps and thin film conducting electrode paths placed upon a dielectric material, as described in the methods and processes above to jointly allow a functionally acting ignition method and process for a combustible gas on or near the surface of a combustion chamber.

[0014] The finger-grip assembly and conducting metal tube electrode may be electrically insulated with non conductive coatings or materials that are non conductive. The finger-grip assembly may be made of non-conductive materials such as plastic, rubber, nylon, or other non-electrically conductive materials.

[0015] The terminal impact type piezoelectric electrode may be connected to or protected by a heat resistant ceramic shield or material such as a coating of sand or other heat resistant or thermal insulating substance or combination thereof, in such a manner as to protect exposed plastic of the impact type piezoelectric spark generator inner housing case near the terminal impact type piezoelectric electrode from the effects of the ignited flame and heat or conducting wire that may lead to the ceramic shield or combination thereof. The conducting wire may be connected to terminal impact type piezoelectric electrode allowing outer conducting metal tube electrode housing body to be extended.

[0016] The impact type piezoelectric spark generator having push button plunger for depression in direction of longitudinal axis of impact type piezoelectric spark generator inner housing case and housing body and movable relative to its inner housing case and housing body may exert a force within piezoelectric spark generator on a first electrical contact that is transferred directly to a piezoelectric pulse generating crystal.

[0017] The piezoelectrical spark generator may include a hammer for striking the first electrical contact with a force required to generate said electrical pulse and spark. The piezoelectrical spark generator may include a return spring for returning the hammer to an initial position away from the first electrical contact. The hammer may include a first extended portion configured to be received within the return spring.

[0018] The piezoelectrical spark generator may include an energy storage spring for storing potential energy which is released to propel the hammer toward the first electrical contact. The hammer may include a second extended portion configured to be received within the energy storage spring.

[0019] The impact type piezoelectric spark generator may include a crystal receptacle carried within the inner housing case for securement of the crystal and the first and second electrical contacts.

[0020] The crystal receptacle may define a shoulder on which a collar defined by the hammer rests prior to activation of the igniter.

[0021] The impact type piezoelectric spark generator hammer collar may define a distal surface sloped away from the second extended portion in order to assist in disengaging the hammer from the shoulder.

[0022] The impact type piezoelectric spark generated ignition efficacy may be enhanced by multiple spark gaps. The impact type piezoelectric spark generated efficacy may be enhanced by increasing the spark gap length.

[0023] The igniter may ignite a heating device, such as a combustible gas water heater, stove, or furnace.

[0024] The impact type piezoelectric spark igniter may include a geometric portion of the electrical conducting tubular metal material, along the open end of the longitudinal axis of said tubular metal, that is removed so that combustible gas escaping a nozzle of a torch will deflect off of that portion of tubular metal not removed along this same longitudinal axis of tubular metal in such a manner as to allow a 90 degree ignition of the combustible gas.

[0025] The combustible gas may be propane. The combustible gas may be acetylene. The combustible gas may be methylacetylene-propadiene or MAPP gas. The combustible gas may be a combination of gases. The combustible gas may be a volatile hydrocarbon gas, such as methane. The combustible gas may be a volatile nitrogen-based gas, such as ammonia.

[0026] The combustible gas may be a volatile hydrocarbon mist, such as atomized gasoline or diesel fuel, and nitrogen-based gas, such as ammonia. The combustible gas may have low flammability properties.

[0027] The second electrical contact may be separated from a heat resistant ceramic shield by a concussion absorbing adhesive.

[0028] In a sixth aspect the invention provides a gas igniter for use with a gas burner having a tubular gas orifice from which gas flows. The igniter includes an annular ring dimensioned to surround the tubular gas orifice such that gas flowing from the orifice is directed over the ring. The ring includes multiple spark gaps projecting from a top surface of the ring. The igniter also includes connectors for connection to a source of high voltage such that the multiple spark gaps are above the top surface of the ring over which the gas flows.

[0029] In a seventh aspect the invention also provides a gas igniter for use with a gas burner from which gas flows. The igniter includes a block having multiple spark gaps projecting from an exterior surface of the block. The igniter also includes a block mount for mounting the block near the gas burner such that gas flowing from the burner is directed over the block. The igniter further includes connectors for connection to a source of high voltage such that the multiple spark gaps are adjacent the exterior surface of the block over which the gas flows.

[0030] Other aspects of the invention will be evident from the description and drawings provided herein.

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] For a better understanding of the present invention and to show more were clearly how it may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, which show the preferred embodiments of the present invention and in which:

[0032] FIG. 1 is an exploded side view of a preferred embodiment of an igniter in accordance with the present invention.

[0033] FIG. 2 is a side view of the igniter of FIG. 1 with a tube electrode in cross section.

[0034] FIG. 3 is an end view of the igniter of FIG. 1 without a ceramic shield.

[0035] FIG. 4 is a diagrammatic view of the igniter as shown in FIG. 2 in use with a gas torch.

[0036] FIG. 5 is a side view of an alternative multiple spark gap embodiment of an igniter in accordance with the present invention, with a tube electrode in cross-section and using a dielectric adhesive.

[0037] FIG. 6 is a top view of the igniter of FIG. 5 using sand in place of the dielectric adhesive.

[0038] FIG. 7 is a bottom view of the igniter of FIG. 5 with the tube electrode shown in cross-section.

[0039] FIG. 8 is the end view of the igniter of FIG. 5.

[0040] FIG. 9 is a side view of the igniter of FIG. 5 with the tube electrode and a portion of a piezo electric spark generator in cross-section, using a ceramic shield with intermittent wire in place of the dielectric adhesive.

[0041] FIG. 10 is the end view of the igniter of FIG. 9.

[0042] FIG. 11 is a side view of the igniter of FIG. 1.

[0043] FIG. 12 is a partially exploded cross-section of the igniter of FIG. 1.

[0044] FIG. 13 is a side view of an extended igniter in accordance with an alternative embodiment of the present invention with a tube electrode in cross-section.

[0045] FIG. 14 is a side cross-section illustration of a multiple-spark gap shield for use in the igniter of FIG. 8.

[0046] FIG. 15 is a side cross-section illustration of an alternative multiple-spark gap shield for use in the igniter of FIG. 8.

[0047] FIG. 16 is a side cross-section illustration of an alternative multiple-spark gap shield for use in the igniter of FIG. 8.

[0048] FIG. 17 is a side cross-section of the igniter of FIG. 1 with a deflection shield and absorbing adhesive.

[0049] FIG. 18 is a diagrammatic illustration of ignition of gas while using the igniter of FIG. 17 positioned at 90 degrees relative to the end of a torch.

[0050] FIG. 19 is a side view of the igniter of FIG. 1 with an insulating spacer.

[0051] FIG. 20 is a side cross-section of an igniter in accordance with FIG. 17 and alternative absorbing adhesive configuration.

[0052] FIG. 21 is a side cross-section of a preferred embodiment of an extended igniter in accordance with the present invention.

[0053] FIG. 22 is a top view of a preferred embodiment of a ring igniter in accordance with the present invention used in association with a gas burner with deflector plate removed.

[0054] FIG. 23 is a diagrammatic illustration of the ring igniter and gas burner of FIG. 22 from a side looking through the ring igniter as if it were transparent.

[0055] FIG. 24 is a side cross-section of a block igniter in accordance with the present invention used in association with a gas barbeque.

MODES FOR CARRYING OUT THE INVENTION

[0056] Referring to the FIGS., wherein like reference characters designate corresponding parts throughout the FIGS., a portable combustible gas igniter is indicated generally by the reference character 1. The igniter 1 has a portable impact type piezoelectric spark generator 6 and housing has a finger-grip 2, which is most commonly an electrically non-conductive washer placed over the inner housing case 3 of the piezoelectric spark generator 6. A conducting metal tube electrode 4 placed over the same inner housing case 3 of the piezoelectric spark generator 6 allows for a potential difference between tube electrode 4 and generator electrode 9. The generator electrode 9 is located on a longitudinal axis of the tube electrode 4 to provide a spark gap 8 surrounding the electrode 9 between the electrode 9 and electrode 4. The tube electrode 4 has opposing first end 4c and second end 4d. The first end 4c is an open end that is open to the electrode 9. The second end 4d is enclosed by spark generator 6. Spark generator 6 is located partially within the tube electrode 4 at the second end 4d. This electrically conducting metal tube electrode 4 may be made from any rigid or flexible conducting metal tube that fits over the inner housing case 3 of the impact type piezoelectric spark generator 6 or may be made with a plastic tubular material having a thin coating or film consisting of electrically conducting materials within the lining of said plastic tube, said tubular material holding finger-grip 2 washer in place against inner housing case 3 and inner housing case collar 41. Together, the finger-grip 2 washer and conducting metal tube electrode 4 comprise the outer housing body 5 of the device. Insulating paint, lacquer, tape, plastic, or heat shrink tubing 23 is placed on the conducting metal tube electrode 4 external surface to increase electrical insulation for preventing inadvertent shocking to user. Depression of push button 7 activates the internal mechanism of the impact type piezoelectric spark generator 6 to produce an electrical pulse and spark at the spark gap 8 located between the terminal piezoelectric generator electrode 9 and corresponding conducting metal tube electrode 4 near its open end.

[0057] The igniter 1 is an impact type piezoelectric high voltage spark generator 6 and housing assembly that has a low number of relatively low cost parts that allow simple assembly and smooth and reliable operation.

[0058] The igniter 1 is portable, handheld and suitable for portable hand torch ignition. The igniter 1 is operated single-handedly. The igniter is activated by holding the device with two fingers while a third finger is used for depression of a button plunger to actuate the device within a combustion zone of a hand held torch. Holding and depressing the button plunger of the piezoelectric igniter 1 is similar to holding a syringe while giving an injection.

[0059] When compared to flint striker ignition devices the igniter 1 provides additional safety. Ignition of hand held torches may be required to take place in a confined space, such as a plumber may find in crawl spaces of homes. In this situation flint strikers used to produce hot sparks which ignite the hand held torch may be required to be used near one's face and eyes. As the direction of ejected flint fragments is unpredictable when striking a flint striker one must wear safety goggles to protect one's eyes from superheated fragments. The igniter 1 provides a known location of spark to insure greater safety.

[0060] The igniter 1 also provides additional repetitions when compared to flint strikers. It is commonly known in both art and practice that the flint within flint strikers is not durable and must be frequently replaced. The degree of hand and finger pressure used in activating a flint striker is directly related to the number of repetitions that might be expected before replacement of flint striker or flint within a flint striker. The greater the hand and finger pressure while striking the flint the greater the volume of hot flint sparks that are produced. Due to wind, rain or wet conditions this may be needed to produce ignition of combustible gases but would also reduce the number of repetitions available before the flint is depleted.

[0061] Generally, less than 1,000 strikes are available from a common flint striker with any routine use. The igniter 1 may be expected to provide up to 100,000 to 150,000 strikes.

[0062] On testing of a common model of flint striker, the BernzOmatic Flint Spark Lighter, Model BZTX405C, sold by BernzOmatic , a Newell Company, of Medina, N.Y., the number of repetitions found to produce flint sparks with six replaceable flints supplied by the same manufacturer resulted in repetitions of 295, 334, 338, 278, 355, and 281 respectively before depletion of the flint within each replaceable flint casing.

[0063] Common impact type piezoelectric spark generator barbecue igniters, such as those produced by Channel Products, Inc., Chesterland, Ohio, have been independently tested by placing the impact type piezoelectric spark generator on a test jig. The jig fired the generator at a rate of 25 times per minute with igniter failure at 111,000 repetitions. Channel Products, Inc. literature indicates 150,000 repetitions is not uncommon for their impact type piezoelectric spark generators. Potentially lifelong use may be achieved in practical conditions and use with the igniter 1.

[0064] The combustible gas may be propane. The combustible gas may be acetylene. The combustible gas may be methylacetylene-propadiene or MAPP gas. The combustible gas may be a combination of gases. The combustible gas may be a volatile hydrocarbon gas, such as methane. The combustible gas may be a volatile nitrogen-based gas, such as ammonia.

[0065] The combustible gas may be a volatile hydrocarbon mist, such as atomized gasoline or diesel fuel, and nitrogen-based gas, such as ammonia. The combustible gas may have low flammability properties.

[0066] Where low flammability gas is used then multiple spark gaps or a lengthened spark gap as discussed later herein may provide additional benefits.

[0067] Referring to FIGS. 5, 6, 7, and 8, an inlet port 4a for the gas may be provided in the tube electrode 4 perpendicular to the longitudinal axis of the electrode 4 to provide an alternate location for combustion zone 22 as the tube electrode 4 meets the inlet port 4a. Combustion gases can continue to exit away from the user through open end 4b of tube electrode 4. The inlet port 4a perpendicular to the longitudinal axis of tube electrode 4 effectively provides a deflector shield similar to deflector shield 42 described later herein.

[0068] A coating of a dielectric adhesive 40 and sand 10 or use of other heat resistant dielectric materials, such as a heat resistant ceramic shield 11, may be used to protect the plastic inner housing case 3 of the piezoelectric spark generator 6 or conducting wire or wires 24 that lead to the terminal piezoelectric generator electrode 9. Referring to FIGS. 9 and 10, the protected thermal and electrically insulated wire or wires 24 connect to the ceramic shield 11 thereby extending the length of the external housing body conducting metal tube electrode 4 and in doing so effectively extends the terminal piezoelectric generator electrode 9.

[0069] Referring to FIG. 12, the actuating mechanism within the inner housing case 3 is comprised of a first electrical contact 12 with first electrical contact electrode 25 coming in contact with outer housing body metal tube electrode 4, a second electrical contact 13 ending with the terminal piezoelectric generator electrode 9, piezoelectric crystal 14, hammer 15, return spring 16, energy storage spring 17, crystal receptacle 18, and hammer collar 19. A control valve 20, which turns the hand held torch gas on and off is noted.

[0070] Referring to FIG. 4, 5, 8, 9, 14, 15, 16, 18, 20, the location of the combustion zone 22 and placement of the device near or upon the burn tube 21 having exiting combustible gases where ignition takes place is shown. As mentioned, an adhesive coating 10 on the inner housing case 3 may fasten a heat resistant material, such as sand, or a heat resistant ceramic shield 11.

[0071] Referring to FIGS. 14, 15, and 16, diagrammatic drawings of different methods and processes that achieve multiple spark gaps 8 are shown. Having multiple spark gaps 8 effectively acts to increase spark gap length throughout the combustion zone 22 by offering a greater surface area of piezoelectric spark exposure to multiple locations of different combustible gas and oxygen mixtures within the combustion zone 22. In particular, FIG. 14 illustrates the use of conductor metal filings 27 adhered to a dielectric adhesive 40 surface with combustible gas 26 and air or oxygen molecules 29 located within spark gap 8 micro-combustion zones 22. FIG. 15 illustrates the use of an interrupted conducting wire 30 within a heat resistant dielectric material, such as a ceramic shield 11, having multiple spark gaps (as previously shown in FIG. 9). FIG. 16 illustrates the use of a thin film conducting metal 28 applied by sputtering, spray, or other common thin film deposition methods to a dielectric surface, such as a ceramic, glass, mica, plastic or dielectric adhesive 40.

[0072] Multiple spark gaps can provides a method and process for improved efficiency and frequency of combustible gas ignition. The following definitions and comments may be helpful to understanding the dynamics of multiple spark gaps.

[0073] Resistance, denoted R, is a measure of the extent to which a substance opposes the movement of electrons among its atoms. The more easily the atoms give up and/or accept electrons, the lower the resistance, which is expressed in positive real number ohms. Resistance is observed with alternating current (AC) and also with direct current (DC). Examples of materials with low resistance, known as electrical conductors, include copper, silver, and gold. High-resistance substances are called insulators or dielectrics, and include materials such as polyethylene, mica, and glass. A material with intermediate levels of resistance is classified as a semiconductor. Examples are silicon, germanium, and gallium arsenide.

[0074] DC (Direct current) is the unidirectional flow or movement of electric charge carriers, usually electrons. The intensity of the current can vary with time, but the general direction of movement stays the same at all times. As an adjective, the term DC is used in reference to voltage whose polarity never reverses.

[0075] In a DC circuit, electrons emerge from the negative, or minus, pole and move towards the positive, or plus, pole. Nevertheless, physicists define DC as traveling from plus to minus.

[0076] Ohm's Law is the mathematical relationship among electric current, resistance, and voltage. The principle is named after the German scientist Georg Simon Ohm.

[0077] In direct-current (DC) circuits, Ohm's Law is simple and linear. With Ohm's Law a resistance having a value of R ohms carries a current of I amperes. The voltage across the resistor is then equal to the product IR. There are two corollaries. If a DC power source providing B volts is placed across a resistance of R ohms, then the current through the resistance is equal to E/R amperes. Also, in a DC circuit, if E volts appear across a component that carries I amperes, then the resistance of that component is equal to E/I ohms.

[0078] Mathematically, Ohm's Law for DC circuits can be stated as three equations:

E=IR

I=E/R

R=E/I

[0079] A capacitor is a passive electronic component that stores energy in the form of an electrostatic field. In its simplest form, a capacitor consists of two conducting plates separated by an insulating material called the dielectric. The capacitance is directly proportional to the surface areas of the plates, and is inversely proportional to the separation between the plates. Capacitance also depends on the dielectric constant of the substance separating the plates.

[0080] A dielectric material is a substance that is a poor conductor of electricity, but an efficient supporter of electrostatic fields. If the flow of current between opposite electric charge poles is kept to a minimum while the electrostatic lines of flux are not impeded or interrupted, an electrostatic field can store energy.

[0081] The properties of low capacitance and low resistance conductors, as well as uniform dielectric materials are used in the multiple spark gaps of the igniter 1 to increase spark gap length and thereby enhance combustible gas ignition and frequency of said ignition.

[0082] In practice, most dielectric materials are solid. Examples include porcelain (ceramic), mica, glass, and plastics. Some liquids and gases can serve as good dielectric materials. Dry air is an excellent dielectric, and is used in variable capacitors and some types of transmission lines. Distilled water is a fair dielectric. A vacuum is an exceptionally efficient dielectric.

[0083] An important property of a dielectric is its ability to support an electrostatic field while dissipating minimal energy in the form of heat. The lower the dielectric loss (the proportion of energy lost as heat), the more effective is a dielectric material. Another consideration is the dielectric constant, the extent to which a substance concentrates the electrostatic lines of flux. Substances with a low dielectric constant include a perfect vacuum, dry air, and most pure, dry gases such as helium and nitrogen. Materials with moderate dielectric constants include ceramics, distilled water, paper, mica, polyethylene, and glass. Metal oxides, in general, have high dielectric constants.

[0084] The prime asset of high-dielectric-constant substances, such as aluminium oxide, is the fact that they make possible the manufacture of high-value capacitors with small physical volume. But these materials are generally not able to withstand electrostatic fields as intense as low-dielectric-constant substances such as air. If the voltage across a dielectric material becomes too great that is, if the electrostatic field becomes too intense--the material will suddenly begin to conduct current. This phenomenon is called dielectric breakdown. In components that use gases or liquids as the dielectric medium, this condition reverses itself if the voltage decreases below the critical point. But in components containing solid dielectrics, dielectric breakdown usually results in permanent damage.

[0085] Voltage, also called electromotive force, is a quantitative expression of the potential difference in charge between two points in an electrical field. The greater the voltage, the greater the flow of electrical current (that is, the quantity of charge carriers that pass a fixed point per unit of time) through a conducting or semiconducting medium for a given resistance to the flow. Voltage is symbolized by an uppercase italic letter V or E. The standard unit is the volt, symbolized by a non-italic uppercase letter V. One volt will drive one coulomb (6.24.times.1018) charge carriers, such as electrons, through a resistance of one ohm in one second.

[0086] Voltage can be direct or alternating. A direct voltage maintains the same polarity at all times. In an alternating voltage, the polarity reverses direction periodically. The number of complete cycles per second is the frequency, which is measured in hertz (one cycle per second), kilohertz, megahertz, gigahertz, or terahertz. An example of direct voltage is the potential difference between the terminals of an electrochemical cell. Alternating voltage exists between the terminals of a common utility outlet.

[0087] A voltage produces an electrostatic field, even if no charge carriers move (that is, no current flows). As the voltage increases between two points separated by a specific distance, the electrostatic field becomes more intense. As the separation increases between two points having a given voltage with respect to each other, the electrostatic flux density diminishes in the region between them.

[0088] In the igniter 1 with multiple spark gaps isolated conductive materials are used with a low resistance and low capacitance charge at their tips or along the surface of the conductive material. However, as the electrostatic flux density builds, due to the increased potential difference and polarization of a non-discharged piezoelectric crystal which has been stressed or strained, arcing takes place through the air and combustible gas in areas determined by the spark gaps or location of thin film conductors. Due to the nature of high impact piezoelectric crystals dry air increases the resistance at the spark gaps and over thin film conductors. This in turn creates a larger potential difference within the piezoelectric crystal, resulting in a higher voltage pulse. Notwithstanding ambient conditions, all commercially available combustible gases are dry and the presence of an additional and displacing combustible gas creates the conditions needed for a higher voltage pulse from the piezoelectric crystal. These higher voltage potential differences eventually pulse and arc between spark gaps having large electrostatic flux densities created at the tips of the conductors with a subsequent dielectric breakdown (arcing) within the air and combustible gas surrounding the spark gaps. Dielectric materials separating the conductive materials must have a resistance greater than that of dry air or combustible gases. Additionally, a similar arc is created over thin film conductors, as the resistance of the thin film conductor is less than the current and voltage load capable of being conducted within the thin film conductor. With a thin film conductor, the electrostatic field immediately above the thin film conductor allows a dielectric breakdown within the air and/or combustible gas and an arc occurs. In this sense, a dielectric breakdown is "controlled" and what is commonly known as a fault or problem to be avoided in electronic engineering is both directed and encouraged within the igniter 1 with multiple spark gaps.

[0089] Referring to FIG. 17, a concussion absorbing adhesive 50 absorbs impact of hammer 15, thereby lessening damage and cracking of ceramic shield 11. The conducting metal tube electrode 4, near the open end of said metal tube, is cut at an angle such that a portion of the tube electrode extends asymmetrically beyond an opposing portion of the tube electrode to form a deflecting shield 42 for combustible gas exiting burn tube 21, as is shown in FIG. 18. Referring to FIG. 18, the exit direction of combusted gases 43 from the igniter 1 is at a 90-degree angle formed by the longitudinal axis of the igniter 1 and longitudinal axis of the burn tube 21.

[0090] The deflector shield 42 allows for mixing of gas and air in the combustion zone 22 for improved combustion conditions. The igniter 1 has simplicity of design and ignition when compared to many sophisticated existing devices. There is no venting, venturi apparatus, calibrated mixing of air and combustible gas, or complex engineering and tooling required for manufacturing and assembling the outer housing of the igniter 1. A less expensive burner can be used on the torch and the igniter 1 is a less expensive external ignition device.

[0091] The deflecting shield 42 provides additional safety by directing gases away from the user; however, both with and without the shield 42, the igniter 1 provides combustible gas ignition safety when compared with a common flint striker. Spark ignition tends to be more reliable and predictable then that of a flint striker. Also, the most common ignition of a combustible gas with a flint striker and hand held torch occurs when a user holds the flint striker at approximately ninety degrees to the torch. The hand of a flint striker user squeezes the flint striker in such a manner as to create pressure of flint being scratched upon a roughened surface of iron. Ignition with a common flint striker most often takes place within a cup-like apparatus allowing the ignited flame to combust and travel in a 360-degree plane from the flint striker surface. In so doing, that part of the hand closest to the flint may be briefly exposed to the ignited flame. With the igniter 1 the same ninety-degree angle of ignition can be attained with less exposure to both heat and flame to the user, particularly when the deflecting shield 42 is used.

[0092] Referring to FIG. 19, the conducting metal tube 4 is shortened with a non-conducting spacer 44 so that a metal washer 45 may be used as a finger grip without becoming an inadvertent conducting path. From first electrical contact electrode 25 through tube electrode 4 to metal washer 45 through user to metal conducting handle or bottle of hand held torch, through burn tube 21, and arcing to the terminal piezoelectric generator electrode 9 of the second electrical contact 13.

[0093] Alternatively, the finger grip 2, housing case collar 41 and insulation 23 could be formed from a single insulative piece, formed for example from plastic, and held to the tube electrode, for example by a screw or other fastening mechanism, not shown.

[0094] Referring to FIG. 20, another design is shown with less adhesive acting to absorb concussion 50 from repeated and multiple impacts of hammer 15, thereby lessening potential damage and cracking of ceramic shield 11.

[0095] Referring to FIG. 21, a longer tubular design is shown with an extended terminal piezoelectric generator electrode 9 fitting through the center of the ceramic shield 11. In this illustration the extended conducting metal tube electrode 4 is placed over the inner housing case 3 of the piezoelectric spark generator 6 (not shown in this drawing) and allows for a potential difference and spark gap 8 (not shown in this drawing). The adhesive acting to absorb concussion 50 from repeated and multiple impacts of hammer 15 (not shown in this drawing), thereby lessening potential damage or cracking of ceramic shield 11.

[0096] Various embodiments of the present invention provide inexpensive impact piezoelectric high voltage igniters for hand held torches and provide igniters with easier assembly than existing devices.

[0097] Various embodiments of the present invention provide a unique combustion zone design which does not include the engineering of a venturi apparatus or the need to manufacture air vents within the housing assembly for the mixing of combustible gas with the oxygen in the air, thus lessening the costs of manufacturing and eliminating concern with debris plugging air vents or venturi intake of air.

[0098] Referring to FIGS. 22 and 23, in current gas stoves, whether in the home or camp stove, there may be a single piezo spark in place of a traditional pilot light system. Again, this creates a single location where combustible gas can ignite. This assumes that the proper gas-air mixture is conducive for ignition. A multiple spark gap annular ring 2201 provides alternate multiple spark gaps 2203 (a few of which are referenced in FIGS. 22 and 23) surrounding a gas orifice 2205 and an equal number of combustible gas ignition points, one for each spark gap 2203. Gas 2206 flows from the orifice 2205 beneath a deflector plate 2206a. The orifice 2205 has an exit flange 2206B over which gas 2266 flows. The ring 2201 can be mounted to the exit flange 2206B, or otherwise. The number of spark gaps 2203 used may be limited by the available voltage from a piezo electric crystal, not shown. One can utilize a high-voltage transformer and mains power for spark generation, for example in stoves. This may allow for a greater number of spark gaps 2203 as shown in FIG. 22. A high voltage source, indicated by +, - in FIG. 22 and partially by + in FIG. 23, such as a piezoelectric generator or transformer and mains power is connected at connections 2207. The multiple spark gaps 2203 of ring 2201 can be provided in a manner similar to those discussed previously herein for other embodiments, for example interrupted conducting wire 2209 in a heat resistant dielectric material 2211.

[0099] The ring 2201 can be dimensioned to fit gas burners, not shown, of circular configuration having different dimensions, for example, where a deflector plate, not shown, forms an enclosure over the orifice 2205 and the plate has small apertures from which gas flows. In this case the ring 2201 would surround the burner provided that the gas is directed over the ring 2201 to provide conditions for combustion at one or more of the spark gaps 2203.

[0100] For burners of other configurations a multi-spark gap ring could be provided about the perimeter of the burner. Referring to FIG. 24, alternatively, if gas is partially trapped near to a burner 2401, such as with a barbeque 2403 or oven burner, then a multiple spark gap block 2405 could be placed nearby to provide ignition. The block 2401 has a block mount 2407 such that the block 2401 can be mounted in the appliance nearby the burner 2403 such that multiple spark gaps, for example provided by interrupted conducting wire 2409 embedded in a heat resistant dielectric material, or otherwise as discussed previously, project from an exterior surface 2411 of the block 2401. The block 2401 has connections 2412 to a source of high voltage, such as spark generator 2413. Gas 2415 flowing from the burner is partially trapped in barbeque housing 2417 such that gas 2415 will flow over the exterior surface 2411 of the block 2401 and will be ignited when the spark generator 2413 is activated to cause the multiple spark gaps to spark. Again, the block 2401 would be powered by a piezoelectric generator 2413, particularly for portable or remote applications, or another source of high voltage, such as a transformer and mains power source for example in an oven burner.

[0101] It will be understood by those skilled in the art that this description is made with reference to the preferred embodiment and that it is possible to make other embodiments employing the principles of the invention which fall within its spirit and scope as defined by the following claims.

Claims

1. A combustible gas igniter comprising: a.) a piezoelectric spark generator; b.) a first electrode, c.) a generally tubular second electrode, having opposing first and second ends and a longitudinal axis, wherein the first electrode is located on the longitudinal axis of the tubular second electrode, the second electrode extending beyond the first electrode, along the axis in the direction of the first end and in the direction of the second end, and the first end is open to the first electrode, d.) a combustion zone between the first electrode and the second electrode, and e.) a deflecting shield to direct combustion gases away from a user of the igniter.

2. The igniter of claim 1 wherein the spark generator is located partially within the second end and encloses the second end.

3. The igniter of claim 1 further comprising a one-handed finger grip and pushbutton to hold the second electrode and to activate the spark generator.

4. (canceled)

5. The igniter of claim 1 wherein the deflecting shield is at the first end of the second electrode to allow proper mixing of gas and air in the combustion zone.

6. The igniter of claim 5 wherein the defecting shield extends asymmetrically from the first end of the tubular electrode parallel with the longitudinal axis to allow access to the combustion zone by a stream of incoming gas and to allow exit of combustion gases away from the user.

7. The igniter of claim 1 wherein the first end of the second electrode opens at an angle to the axis to provide a deflecting shield for directing combustion gases away from a user

8. A portable combustible gas handheld torch igniter comprising finger-grip and conducting metal tube electrode as outer housing body, said outer housing body containing inner housing case of impact type piezoelectric spark generator, said impact type piezoelectric spark generator having push button plunger depressed in direction of longitudinal axis of impact type piezoelectric spark generator inner housing case and outer housing body and movable relative to its piezoelectric generator inner housing case and outer housing body, said impact type piezoelectric spark generator push button depression to generate a spark-producing voltage force with resulting spark occurring at spark gap between terminal electrode of impact type piezoelectric generator and conducting metal tube electrode near open end of conducting metal tube electrode housing body, said spark between terminal impact type piezoelectric electrode and conducting metal tube housing body near open end of conducting metal tube housing body causing ignition of combustible gas within spark gap near open end of conducting metal tube electrode housing body, said ignition taking place when open end of conducting metal tube electrode housing body of igniter is actuated upon or near exit end of burn tube following opening of burn tube control valve, said ignition of combustible gas at spark gap with resulting flame transferred to the exit end of the burn tube having open control valve of the hand held torch, wherein said impact type piezoelectric spark igniter having a geometric portion of the electrical conducting tubular metal material, along the open end of the longitudinal axis of said tubular metal, is removed so that combustible gas escaping nozzle of torch will deflect off of that portion of tubular metal not removed along this same longitudinal axis of tubular metal in such a manner as to allow a 90 degree ignition of said combustible gas.

9.-11. (canceled)

12. A portable combustible gas handheld torch igniter as defined in claim 8, wherein the terminal impact type piezoelectric electrode is connected to or protected by a heat resistant ceramic shield or material such as a coating of sand or other heat resistant or thermal insulating substance or combination thereof, in such a manner as to protect exposed plastic of the impact type piezoelectric spark generator inner housing case near the terminal impact type piezoelectric electrode from the effects of the ignited flame and heat or conducting wire that may lead to ceramic shield or combination thereof, said conducting wire being connected to terminal impact type piezoelectric electrode allowing outer conducting metal tube electrode housing body to be extended.

13. A portable combustible gas handheld torch igniter as defined in claim 8, wherein said impact type piezoelectric spark generator having push button plunger depressed in direction of longitudinal axis of impact type piezoelectric spark generator inner housing case and housing body and movable relative to its inner housing case and housing body exerts a force within piezoelectric spark generator on first electrical contact that is transferred directly to the piezoelectric pulse generating crystal.

14.-18. (canceled)

19. A portable combustible gas handheld torch igniter as defined in claim 8, wherein said impact type piezoelectric spark generated ignition efficacy is enhanced by multiple spark gaps.

20. A portable combustible gas handheld torch igniter as defined in claim 8, wherein said impact type piezoelectric spark generated efficacy is enhanced by increasing the spark gap length.

21. A method and process as described in claim 51, wherein said spark may ignite a heating device, such as a combustible gas water heater, stove, or furnace.

22. (canceled)

23. The method and process of claim 51, wherein said impact type piezoelectric spark igniter having a geometric portion of the electrical conducting tubular metal along the open end of the longitudinal axis of said tubular metal is removed so that combustible gas escaping nozzle of torch will deflect off of that portion of tubular metal not removed along this same longitudinal axis of tubular metal in such a manner as to allow a 90 degree ignition of said combustible gas.

24.-37. (canceled)

38. A portable combustible gas handheld torch igniter as defined in claim 8, wherein the second electrical contact is separated from a heat resistant ceramic shield by a concussion absorbing adhesive.

39.-40. (canceled)

41. A portable combustible gas handheld torch igniter as defined in claim 1, wherein said impact type piezoelectric spark generated ignition efficacy is enhanced by multiple spark gaps.

42. A portable combustible gas handheld torch igniter as defined in claim 1, wherein said impact type piezoelectric spark generated efficacy is enhanced by increasing the spark gap length.

43. A portable combustible gas handheld torch igniter as defined in claim 1, wherein said impact type piezoelectric spark igniter having a geometric portion of the electrical conducting tubular metal material, along the open end of the longitudinal axis of said tubular metal, is removed to provide the deflecting shield so that combustible gas escaping nozzle of torch will deflect off of that portion of tubular metal not removed along this same longitudinal axis of tubular metal in such a manner as to allow a 90 degree ignition of said combustible gas.

44.-47. (canceled)

48. The igniter of claim 1 further comprising an inlet port for incoming gas, wherein the inlet port is in the second electrode perpendicular to the longitudinal axis of the second electrode such that an opposing portion of the second electrode provides the deflecting shield.

49. The igniter of claim 48 wherein the deflecting shield allows access to the combustion zone by a stream of incoming gas and allows exit of combustion gases away from the user.

50. The igniter of claim 49 wherein the deflecting shield allows proper mixing of gas and air in the combustion zone.

51. A method and process for igniting a combustible gas, the method and process comprising: igniting the combustible gas using a handheld piezoelectric spark igniter while deflecting the gas off of a deflecting shield to direct combustion gases away from a user of the igniter.