US3824072A - Gas lighter burner ignition device - Google Patents

Abstract

A lighter ignition mechanism includes a rectangular magnetic yoke, one leg of which is a permanent magnet, another leg of which is swingable to a yoke opening position, and a coil being wound upon another leg. A burner includes a metal top plate having a central nozzle opening communicating with a gaseous fuel source and defining a plate electrode and a needle electrode is resiliently biased to contact the plate electrode at a point offset from the nozzle, the electrodes being connected to the winding with the needle electrode positive. A resilient arm is connected to the swingable leg to, upon depression, open a gas valve to the nozzle, open the yoke, and then separate the electrodes.

Description

United States Patent 1191 Makino 1 July 16, 1974 1 1 GAS LIGHTER BURNER IGNITION DEVICE [75] Inventor: Minoru Makino, Tokyo, Japan [73] A ssignee: Kabushiki Kaisha Tanita Seisakusho, Tokyo-to, Japan 22 Filed: Nov. 15, 1973 211 Appl. No.: 416,155

Related US. Application Data 1 Division of Ser. No. 259.7 10.1une 5.1972.

Oyamada et a1 317/81 X 3,424,950 1/1969 Halm 317/93 3,442,598 5/1969 Halm 431/255 3,444,435 5/1969 Halm i 1 317/81 3,449,636 6/1969 Wosylus i 317/81 3,559,131 1/1971 shindler 335/229 10/1972 Halm 317/81 Primary ExaminerVolodymyr Y. Mayewsky 5 7 ABSTRACT A lighter ignition mechanism includes a rectangular magnetic yoke, one leg of which is a permanent magnet, another leg of which is swingable to a yoke opening position, and a coil being wound upon another leg. A burner includes a metal top plate having a central nozzle opening communicating with a gaseous fuel source and defining a plate electrode and a needle electrode is resiliently biased to contact the plate electrode at a point offset from the nozzle, the electrodes being connected to the winding with the needle electrode positive. A resilient arm is connected to the swingable leg to, upon depression, open a gas valve to the nozzle, open the yoke, and then separate the electrodes.

6 Claims, 13 Drawing Figures 1 GAS LIGHTER BURNER IGNITION DEVICE REFERENCE TO RELATED APPLICATION The present application is a continuation-in-part of a division of co-pending US. Pat. application Ser. No. 259,710, filed June 5, 1972.

BACKGROUND OF THE INVENTION The present invention relates generally to improvements in electrical ignition devices, and it relates particularly to an improved electromagnetic mechanism for producing an electrical discharge in the proximity of a lighter fuel outlet or burner nozzle.

Many forms of electromagnetic lighter ignition mechanisms have been proposed and these generally include a step up transformer whose secondary winding is connected to spaced discharge electrodes in the vicinity of the lighter nozzle. The transformer includes a primary winding which is rapidly energized or deenergized by an associated battery and switch arrangement or a transformer magnetic yoke includes a permanent magnetand a movable leg in the yoke magnetic path so that a discharge is produced between the electrodes attendent to the separation of the movable yoke leg whereby to ignite the fuel, which may be, for example, in gaseous form.

The conventional and proposed ignition mechanisms of the above type possess numerous drawbacks and disadvantages, being generally characterized by an electrical discharge of. such short duration as to necessitate a very close time correlation between the opening of the lighter fuel nozzle and the establishment of the electrical discharge and hence very close manufacturingtolerances and frequently complicated mechanisms and very low reliability. Furthermore, in the type of electromagnetic ignition mechanism heretofore proposed, the high voltage step up transformer required a primary as well as secondary winding, which is of considerable bulk, so it has been impractical to produce a lighter employing this type of ignition system which is compact enough for use as a conventional pocket lighter, but is limited to use as a stationary type of lighter and otherwise leaves much to be desired.

SUMMARY OF THE INVENTION It is a principal object of the present invention to provide an improved ignition mechanism.

Another object of the present invention is to provide an improved electromagnetic ignition mechanism in which the need for batteries is obviated and which is so compact as to be suitable for portable pocket lighters.

A further object of the present invention is to provide an ingnition mechanism of the above nature characterized by its simplicity, ruggedness, high reliability, obviation of close operational tolerences, low cost and high versatility.

The above and other object of the present invention will become apparent from a reading of the following description taken in conjunction with the accompanying drawings which illustrate preferred embodiments thereof.

In a sense the present invention contemplates the provision of an ignition device comprising a solenoid, a pair of discharge electrodes including a plate electrode and a needle electrode movable between normally closed contacting and open separated positions and coupled to opposite "terminals of the solenoid, means for producing a current inducing pulse of varying magnetic flux through the space delineated by the soleniod, and means foropening the electrodes following the initiation of said magnetic pulse and during the presence of induced current.

In its preferred form the needle electrode is positioned proximate the free end of a resilient arm which normally urges the electrodes into engagement. The solenoid is wound about a leg ofa magnet yoke which includes, as sections thereof forming a normally closed magnetic path, a permanent magnet and a leg movable between a yoke closing'and opening positions and normally being in a closed position completing the magnetic path. A resilient lever is provided for swinging the movable leg to its open positon and the movable yoke leg is advanced during its opening to engage the needle electrode carrying arm and separate the electrodes following the opening of the yoke and while the magnetically induced current is present in the solenoid.

The electrical discharge by reason of the separation of the electrodes following the start of and during the presence of the induced current is of such a nature that it is hot and of relatively long duration so as to reliably insure the ignition of the fuel and the mechanism is simple, rugged, compact and inexpensive.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1(a) is a top plan view of the discharge electrodes of an ignition mechanism embodying the present invention;

FIG. 1(b) is a fragmentary schematic front elevational view of the improved mechanism;

FIG. 1(c) is a schematic view of the improved mechamsm;

FIG. 2(a) and 2(b) are diagrams showing the characteristic curve of the discharge voltage as related to the air gap formed between the discharge electrodes;

FIGS. 3(a) to 3(d) are diagrams showing the variation in magnetic flux passing through the ignition coil upon the opening of the magnetic yoke, the time of separation of the discharge electrodes and the variation of eletric current'and output voltage respectively in the coil as related to time;

FIG. 4 is a front elevational view of another embodiment of the present invention;

FIG. 5 is a view similar to FIG. 4 with the mechanism shown in activated condition; and

FIG. 6 is a fragmentary left hand view of the burner and electrode mechanism shown in FIGS. 4 and 5; and

FIG. 7 is a sectional view taken along line 7-7 in FIG. 6.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 2 is a magnetic leg la about which'is wound a suitable insulated coil or solenoid 4. Completing the yoke 1 is an iron piece or magnetic leg 3 whichextends between the top faces of andbridges legs la and 2, being hinged to the top outer corner of leg 2 so as to be swingable out of engagement with the top face of leg from its closed position to a position opening the yoke 1 and thereby sharply reducing the magnetic field through solenoid 4 by way of leg 1a to produce a sharply dropping magnetic flux pulse through the solenoid. To facilitate the rapid opening of leg 3 a lever or handle 3b is secured to the outer face of and separated from leg 3 by a spacer 2a so that inward pressure on handle 3b effects the snap opening-of leg 3.

It is important to note that the coil 4 is wound around the yoke leg 1a witha minimum of distributed capacity in order to facilitate the development of an arc and to suppress any spark quenching action. The-output terminals of coil 4 are connected with suitable shielding to a pair of discharge electrodes 6 and 7, respectively, which are kept in separable contact with each other as shown by FIG. 1(a). The electrodes 6 and 7 are located above leg 3 and, as shown by FIG. 1(a), include a pair of spaced parallel resilient arms, one pair of the end of which are fixed to the opposite faces of an insulator block 60. One electrode 7 has a pointed tip 7a directed toward and normally'in contact with the other electrode 6, The electrodes 6 and 7 preferably comprise leaf spring members provided with confronting followers and, as the movable iron piece 3 is swung out of contact with the yoke, leg la, a wedge shaped cam member 3a projecting upwardly from iron piece 3 is ad-' vanced between the followers on electrodes 6 and 7 so that the pointed tip 7a of the electrode 7 is retracted out of contact with the electrode 6. In FIGS. 1(a) and 1(b), 8 designates a burner nozzle for gaseous fuel which is opened as the movable iron piece 3 is brought out of contact with the yoke leg 1a by depression of the lever 3b in any suitable manner and is disposed slightly spaced from the electrode 6 and the pointed tip 7a of the electrode 7, as shown. It should be noted that discharge electrode 6 and pointed tip 7a of the discharge electrode 7 are preferably returned into contact with each other as rapidly as possible, and that the returning movement of the movable iron piece 3 after the lever 31] is released is smoothly and reliably accomplished by the'magnetic attractive force.

Considering now the operation of the ignition mechanism described above, the lever 3b is depressed to swing the movable iron piece 3 out of contact with the yoke leg la, about the upper end of the permanent magnet 2 to insert and advance the team or wedge defining projection 3a located on movable iron piece 3 between the followers on discharge electrodes 6 and 7 to thereby retract the pointed tip 7a of discharge elecwith pointed tip 7a of the electrode 7 (ii). to (iv) corresponds to the states in which both discharge electrodes 6 and 7 are spaced from each other with air gaps 1d,, M and Id respectively. The discharge voltage Vd developing between the electrode 6 and the pointed tip 7a of the electrode 7 which varies depending upon the air gap formed between electrode 6 and pointed tip 7a experiences the following sequence. First, in the state of air gap 1d,, the discharge voltage Vd consists of an oscillating voltage of high frequency and small amplitude as shown by (ii) in FIG. 1(b), which effects a socalled shower discharge; when the state of air gap [d 7 is attained, there is developed a discharge voltage the yoke leg 1a. FIG. 2(b) shows a characteristic curve which uniformly rises and an arc occurs as the air gap across the electrode 6 and the pointed tip 7a' of the electrode 7 increases; and finally the discharge voltage Vd reaches the maximum level (approximately 2,500 volts although it may be more-or less, for example, as low as 1,000 volts) when the state of air gap Id is attained (i.e., when the lever 3b is depressed substantially to the final stage of depression) and thereafter a state of resonance occurs which is a function of the inductance and distributed capacity, substantially corresponding to self inductance and distributed capacity of the coil 4, in which state a dampedoscillation voltage occurs.

r The time'point at which the maximum voltage level is developed is within the range between 800M and 1,200M seconds after the separation of the electrode 6 and the pointed tip 7a and the first peak of the damped voltage appears approximately 200M seconds after the time of the maximum voltage level. The nozzle 8 for gaseous fuel, therefore may be opened approximately from the moment at which an air gap across the electrode 6 and the pointed tip 7a occurs corresponding to the state shown by (ii) in order that the ignition of the gaseous fuel is assured by the discharge voltage under the conditions of resonance voltage at the steps (ii) to (iv) and the following conditions as shown inFiG. 2(b).

' FIGS. 3(a) to 3(d) illustrate the variation in magnetic flux passing through coil 4 from the moment at which the opening of movable iron piece 3 is initiated, the

time point at which the electrode 6 and the pointed electrode tip 7a are separated from each other, and the variation of electric current and output voltage respectively in coil 4 as related to time t. As is seen from FIG. 3(b), the variation of electric, current and output voltage reaches a maximum at the moment at which the electrode 6 and the pointed tip 7a are separated from each other. I

The pointed tip 7a of the electrode7 and the portion of the electrode 6 that is engageable by pointed tip 7a, including the area adjacent to tip 7a, are susceptible to soot and the other dust which progressively accumulates thereon with repeated ignitions. This soot and dust are, however, removed under cleaning effect not only of the chattering phenomenon occurring during the separation of both electrodes 6 and 7 which serves to clean these contact surfaces, but also by reason of a metal catalytic action during conbustion of the gaseous fuel, so that effective and reliable ignition is always assured.

Referring now to FIGS. 4 to 7 of the drawings which illustrate another embodiment of the present invention, the reference numeral 10 generally designates a liquified gas lighter employing the improved ignition system, the lighter including at its base a pressurized liquified fuel gas tank 11 of known construction. The tank 11 is provided at its top wall with a conventional tubular valve member which is biased to a depressed closed condition, the raising of valve member 12 providing communication through the valve to the tank 1 1, a valve opening adjustment member of known type (not shown) being provided and accessible at the tank bottom wall which also contains a gas filler wall. The tank 11 is normally filled with liquified butane.

A vertical U-shaped mounting bracket, preferably formed of a rigid insulating material such as a thermoset polymeric resin, is mounted atop the tank 11 and includes a horizontal side leg 13 provided with a bottom flange 14 overlying and secured to the top wall of tank 11. A cross arm projects upwardly from one end of side arm 13 and terminates at its top in a horizontal side arm 16 substantially co-extensive and coplanar with side arm 13. A rectangular frame magnetic yoke 17 for affording a low reluctance magnetic path for the magnetic field effected by a suitable high strength permanent magnet 18 which constitutes a leg of the yoke and extends upwardly along the cross arm of the mounting bracket from one end a horizontal laminated yoke bottom leg 19 which rests on flange l4 and is secured to side arm 13 along which it extends. Alsoprojecting upwardly from the yoke bottom leg 19 and transversely spaced from the permanent magnet leg 18 is a verticallaminated magnetic leg 20 which is engaged by a coaxial solenoid or winding 21 wound in a suitable insulated spool including end flanges 22.

Secured to and extending along the front face of permanent magnet yoke leg 18 is a vertical plate 23 having an upper end projecting above yoke leg 18 and having an arcuate concave bearing recess 24 formed therein. Completing the yoke 17 is a swingable laminated magnetic yoke leg 26 having opposite slightly raised portions 27 at opposite ends of its underface which, in the closed condition of yoke 17 engage the top end faces of yoke legs 18 and 20. Secured to the end of the front face of yoke leg 26 is a shaft defining circular head 28 which is borne by the edge of arcuate recess 24, so that the opposite end of yoke leg 26 is swingableinto and out of contacting engagement with the confronting end face of yoke, leg 20. A resilient or spring arm 29 is secured at its top end to the end face of yoke leg 26 proximate yoke leg 18 and depends from yoke leg 26 and downwardly, outwardly, diverges from the outer side face of yoke leg 26 proximate yoke leg 18 yoke leg 18 when yoke leg 26 is in its closed condition as shown in FIG. 1(a). The arm 29 terminates atis bottom at about the medial level of bracket flange l4.

Projecting forwardly from the lower border of the free end of bracket arm 16 is an integrally formed bracket arm 30 having an enlarged opening 32 therein and having superimposed thereon a metal annulus 33 provided with a tab 34 which is connected to one terminal lead 36 of the winding 21. A cap shaped metal burner member 37 is coaxially positioned on annulus 33 and includes a circular top wall 38 which defines a plate electrode having a nozzle defining central opening. A skirt wall 40 depends from the periphery of plate electrode 38 into engagement with annulus 33. A vertical gas outlet tube 41 is supported coaxial with nozzle opening 39 with its top outlet below the level of plate electrode 38 so that gas flowing from the tube 41 is admixed with air as it flows to the nozzle 39, the chamber delineated by the burner 37 communicating with the atmosphere. The tube 41 is connected by a flexible tube 42 to the outlet valve 12. A vertically extending open topped shield 43 engages the burner 47 and has a longitudinal peripheral opening facing the opposite side of the lighter 10.

An integrally formed insulator arm 44 projects forwardly from the upper right hand border of bracket arm 16. A transversely extending resilient metal arm 46 has one end clamped between the underface of arm 46 and an underlying metal clamp plate 47 tightened to arm 44 by a pair of screws 48, one of the screws 48 having an annular electrical connector underlying and clamped by its head, the connector being connected to the other terminal lead 49 of the winding 21. The free end of arm 46 terminates in a upwardly directed leg 50 joining a longitudinally projecting arm 51 which terminates in a vertically depending pointed electrode defining leg 52. The side edges of arm 51 converge toward the outer end thereof and the side edges of leg 52 converge downwardly to a sharp tip which is bevelled to form a needle tipped electrode. Suitably affixed to the underface of arm 46 immediately inwardly of leg 50 and in vertical alignment with the free end of yoke leg 26 is a downwardly convex rubber bumper 53.

A valve actuator member 54 extends along and slightly above flange 14 and includes a bottom cross web 56 joining a vertical front wall 57 and a vertical ear 58 at one end of web 56. A pivot pin 59 secured to yoke leg 19 and bracket leg 17 engages aligned opnings in wall 57 and ear 58 to swingably support the valve actuator member 54 at an end thereof. The free end of web 56 terminates in an outwardly, upwardly inclined lip and a slot is formed in web 56 inwardly of lip 60 and engaging a perpheral groove in valve member 12 so that raising of the free end of actuator 54 opens the valve member 12.

An elongated slide plate 63 extends along the front face of yoke leg 19 and has aligned longitudinal slots 64 which respectively slideably engage pin 59 and a transversely spaced pin 65 projecting from yoke leg 19. The slide plate 63 is trensversely urged toward a right retracted position by a tension spring 66'whose ends are engaged by the pin 65 and a screw 67 located on plate 63 to the left of pin 65. Mounted on and projecting forwardly from slide plate 65 and slideable alongflange 14 is a wedge shaped cam member 68 having a tapered leading section 69 confronting lip 60 and spaced to the right thereof when slide plate 63 is in its retracted position as limited by pins 59 and 65. A leg 70 depends from the right end of slide plate 63 and registers with a slot in the corresponding end face of flange 14. Projecting rearwardly from the bottom right corner is a rod 71 whose outer face is engaged by the bottom confronting face ,of arm 29.

The various components and elements of the lighter mechanism 10 are so dimensioned, proportioned, re-

lated and have properties that when the lighter mechanism is in its dormant or unactuated condition, as illustrated in FIG. 1(a) the yoke leg 26 is in its closed postion engaging yoke legs 18 and 20 and below bumper member 53, pointed electrode 52 is urged under the influence of resilient arm 46 into firm contact with plate electrode 38 and cam 68 is disposed rearwardly of lip 60 under the influence of spring 66 so that valve 12 is maintained closed. The resilience of arm 29 is such that upon the initial flexing thereof inwardly before sufficient force is applied to swing yoke leg 26 to its open position as shown in FIG. l( b), it urges slide plate 63 and cam 68 to the left to engage lip 60 and raise the cam actuator 54 to open valve 12. Upon further flexing of arm 29 the torque thereon is sufficient to swing yoke arm 26 about pin 28 out of engagement with yoke arm 20, the free end of yoke arm 26 striking the bumper 53 to raise arm 46 and separate electrodes 38 and 52. The opening of the magnetic yoke establishes a high voltage and current between the electrodes 38 and 52, causing arcing which ignites the gas flowing through nozzle 39 by way of the open valve 12.

The resilient arm 46 advantageously urges the tip of needle electrode 52 into engagement with plate electrode'38 at a pressure of between 40 and 200 grams and the side edges of electrode 52 converge at an angle of between 1 and 90. It is important that the point of contact between electrodes 38 and 52 be offset from nozzle 39 and the distance between the point of contact between electrodes 38 and 52 and the centre line of nozzle 39 be between 0.5 and 3.0 millimeter. In addition, the winding terminals are connected to electrodes 38 and 52 so that upon opening of yoke leg 26 to produce a magnetic flux pulse through winding 21, the positive side of the resulting electrical pulse is applied to needle electrode 52. The solenoid 21 advantageously has between 1,000 and 20,000 turns of wire having diameters between 0.1 and 0.025 millimeters.

While there have been described and illustrated preferred embodiments of the present invention, it is apparent that numerous alterations, omissions and additions may be made without departing from the spirit thereof.

I claim:

l. A gas burner device comprising a soleniod, a magnetic yoke transferable between an open and closed condition, and including a first leg registering with said soleniod, a permenent magnet second leg and a third yoke leg pivotally supported for swinging between a yoke closing and a yoke opening position, a plate electrode connected to one terminal of said soleniod, a nee-- dle electrode connected to the opposite terminal of said soleniod and separably, resiliently urged into engagement with said plate electrode, means for directing a flow of gaseous fuel proximate said plate electrode, means for opening said electrodes in operative association with the opening of said yoke and a resilient actuating arm extending from the pivoted end of said third yoke leg and being at an angle thereto.

2. The device of claim 1, wherein said plate electrode has a nozzle defining aperture formed therein, said flow directing means directing said gaseous flow through said aperture.

3. The device of claim 2, wherein the point of en-. gagement between said electrodes is offset from the center of said aperture between 0.5 and 3.0 millime ters.

4. The device of claim 3, including a resilient arm, means supporting one end of said arm above said yoke third leg, said needle electrode being located proximate the free end of said resilient arm and urged thereby into engagement with said plate electrode, and said third 6. The device of claim 3, wherein said solenoid and I permanent magnet yoke are so oriented that the positrode.

Claims (6)

1. A gas burner device comprising a soleniod, a magnetic yoke transferable between an open and closed condition, and including a first leg registering with said soleniod, a permenent magnet second leg and a third yoke leg pivotally supported for swinging between a yoke closing and a yoke opening position, a plate electrode connected to one terminal of said soleniod, a needle electrode connected to the opposite terminal of said soleniod and separably, resiliently urged into engagement with said plate electrode, means for directing a flow of gaseous fuel proximate said plate electrode, means for opening said electrodes in operative association with the opening of said yoke and a resilient actuating arm extending from the pivoted end of said third yoke leg and being at an angle thereto.

2. The device of claim 1, wherein said plate electrode has a nozzle defining aperture formed therein, said flow directing means directing said gaseous flow through said aperture.

3. The device of claim 2, wherein the point of engagement between said electrodes is offset from the center of said aperture between 0.5 and 3.0 millimeters.

4. The device of claim 3, including a resilient arm, means supporting one end of said arm above said yoke third leg, said needle electrode being located proximate the free end of said resilient arm and urged thereby into engagement with said plate electrode, and said third yoke leg upon swinging to its yoke open position engages said resilient arm to swing it in an electrode separating direction.

5. The device of claim 4, wherein said gas flow directing means conprises a normally closed valve providing communication with a source of said gas and including a valve opening member located in the path of the free end of said actuating arm.

6. The device of claim 3, wherein said solenoid and permanent magnet yoke are so oriented that the positive side of the pulse output from said solenoid upon opening of said yoke is connected to said needle electrode.

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