US 3760150 A
An instant cigar lighter comprising a holder adapted for mounting on an automobile dashboard, an elongate igniter plug receivable in the holder and having a spiral heating coil disposed at its inner end, a metal cup surrounding the heating coil and at one end connected thereto, and means for establishing an electrical circuit through the cup and heater coil to enable energization of the latter. The lighter is intended for use with a source of power having a higher voltage than the voltage rating of the coil, and has special heat responsive means comprising a bimetal disk engageable with the rim of the cup and closely juxtaposed to the heating coil for substantially instantly opening the circuit in response to heating of the coil to a useful predetermined temperature. The bimetal disk and the metal cup can cooperate to constitute a tightly closed enclosure closely surrounding the heating coil, the disk comprising one large wall of the enclosure whereby heat from the coil is immediately experienced by the disk to effect a very rapid response of the latter. The voltage rating of the heating coil can be one-half of the output voltage from the power source such that the coil becomes heated at a greatly increased rate and reaches a useful temperature in a period of less than several seconds, after which its circuit is opened to prevent burn-out.
Description (OCR text may contain errors)
United States Patent [1 1 Fenn et al.
[451 Sept. 18,1973
1 ELECTRIC CIGAR LIGHTER WITH THERMOSTATIC BIMETALLIC CURRENT CONTROL  Inventors: Lawrence E. Fenn, 40 Anchorage  Filed: June 9, 1972 211 Appl. No.1 261,233
 11.8. CI. 219/265, 219/267  Int. Cl. F23g 7/02  Field of Search 219/264, 265, 267
 References Cited UNITED STATES PATENTS 2,137,195 1lll938 Cohen 219/264 2,151,622 3/1939 Sinko.... 219/264 2,207,462 7/1940 Kurtz.... 219/265 X 2,207,601 7/ 1940 Shakespeare et al 219/265 2,220,978 11/1940 Shakespeare et a1... 219/265 2,503,103 4/1950 Eskuchen 219/264 2,637,799 5/1953 Wood 219/265 3,381,109 4/1968 Youhouse 219/265 Primary Examiner-Volodymyr Y. Mayewsky Attorney-H. Gibner Lehmannet al. I
'l'l'l'l'l  .ABSTRACT An instant cigar lighter comprising a holder adapted for mounting on an automobile dashboard, an elongate igniter plug receivable in the holder and having a spiral heating coil disposed at its inner end, a metal cup surrounding the heating coil and at one end connected thereto, and means for establishing an electrical circuit through the cup and heater coil to enable energization of the latter. The lighter is intended for use with a source of power having a higher voltage than the voltage rating of the coil, and has special heat responsive means comprising a bimetal disk engageable with the rim of the cup and closely juxtaposed to the heating coil for substantially instantly opening the circuit in response to heating of the coil to a useful predetermined temperature. The bimetal disk and the metal cup can cooperate to constitute a tightly closed enclosure closely surrounding the heating coil, the disk comprising one large wall of the enclosure whereby heat from the coil is immediately experienced by the disk to effect a very rapid response of the latter. The voltage rating of the heating coil can be one-half of the output voltage from the power source such that the coil becomes heated at a greatly increased rate and reaches a useful temperature in a period of less than several seconds, after which its circuit is opened to prevent burn-out.
9 Claims, 7 Drawing Figures 52 F198 53 64 63 2832 50 20 en PATENTEDSEPHBIBB I l 3 760 150 SHEET 1 U? 2 ELECTRIC CIGAR LIGHTER WITH THERMOSTATIC BIMETALLIC CURRENT CONTROL BACKGROUND This invention relates generally to cigar lighter devices, and more particularly to lighters of the type employing an electrically energized heating coil disposed in a manually operable igniter plug which is receivable in a panel-mounted socket. In the past, large numbers of different lighter constructions of the above type have been proposed and developed. In general, most employed a spiral heating coil disposed within a cylindrical cup, the annular surface of the cup being engageable by bimetal fingers carried in a socket of a holder structure. In the devices heretofore proposed the continuous voltage ratingof the coil had to be substantially equal to the output voltage of the source applied thereto, to prevent severe overheating and subsequent burn-out of the heating element before the relatively slow-heating bimetal fingers operated to release the plug and open the circuit. As aresult, in virtually all cases the element would require ten or more seconds to reach the incandescent temperature which would satisfactorily provide a light for a cigar or cigarette.
:Roughlyover 40 years have passed since the beginning of cigar lighter technology, and the problem of shorten ing the interval between actuation of the lighter and heating of the elementto adequate incandescence has existed and'hasdefeated attempts to solve it nearly as long. In this period of more than 40 years there has been achieved virtually no substantial progress toward economically solving theproblem. Inaddition, quite a few of the lighter designs of the past have 'had a large number of individual parts, thus requiring adherence to closetolerances. Also, many were relatively expensive to manufacture and maintain while giving no worth- :while advantages. Frequently, in lighters employing spring fingers to momentarily retain the igniter plug in the energized position, problems occurred with breakage or bending of the fingers after a number of operations. Such broken fingers would frequently cause a short circuit in the socket, which led to abnormally high currents flowing in the leads running between the battery and socket. This inevitably resulted in either a blown fuse or else a fire in the electrical cabling, the latter sometimes having disastrous and damaging effects.
SUMMARY cially simple and economical in construction and reliable in operation, but which successfully provides the long-eluded very rapid heating response following its initial actuation. A related object is the provision of an instant" lighter as above characterized, wherein the cost ofmanufacture is substantially less than that of lighter devices currently produced.
The above objects are accomplished by the provision of a combination comprising a holder device presenting a socket, an igniter plug receivable in said socket, an electrical circuit comprising a heating element carried by the igniter plug and characterized by a certain continuous duty voltage rating, a source of power providing a voltage to said circuit substantially greater than said continuous voltage rating of the coil and a unique heat-responsive means which is closely juxtaposed to the heating element and which completely opens the circuit thereof substantially instantly in response to heating of the element to a predetermined useful temperature. The heating element is disposed in and electrically connected to a metal cup having a sharp rim portion constituting an electrical contact, said cup being mounted on the inner end of the igniter plug. The said heat responsive means comprises a bimetal disk especially arranged to be engageable with the sharp rim of the cup and to effect electrical contact thereto. Upon actuation of the lighter plug, the contact established between the disk and sharp edge of the cup effects quick heating of the coil, which then immediately causes the edge portions of the bimetal disk (which are in contact with the cup rim) to snap backward so as to disengage the cup, thus completely opening the circuit and de-energizing the heating element just when its useful predetermined temperature has been reached. The disk and cup together can form a flat, almost wafer-like enclosure which closely confines the heating element. The bimetal disk constitutes one large side wall of this enclosure, disposed broadside to the element. With such an arrangement a very rapid and reliable response of the disk to the heat is had, and also there results a reliable, instant opening of the circuit when the element attains the proper operating temperature. Since the continuous voltage rating of the element is only a fraction of the applied voltage, the heating of the coil occurs at a greatly increased rate, thus providing a substantially instant lighter which is characterized by aresponse on the order of two seconds or so. The bimetallic snap disk is especially simple and foolproof as compared with the previous construction involving a plurality of stamped, bimetal fingers whereby the cost is appreciably reduced and the reliability is increased.
Other objects and advantages will hereinafter appear.
in the figures, illustrating several forms of the invention:
FIG. 1 is an axial sectional view of the improved lighter of the present invention, showing the igniter plug in the shallow, unenergized position prior to actuation.
FIG. 2 is a similar view of the lighter, showing the igniter plug fully depressed to its deep, energizing position wherein the cold bimetal disk engages the sharp rim of the metal igniter cup.
FIG. 3 is an axial sectional view of the lighter, showing the igniter plug fully depressed to its deep, energizing position and showing the bimetal disk sprung or snapped to its circuit opening position wherein it is out of engagement with the metal cup on the igniter plug.
FIG. 4 is an axial sectional view of the lighter, showing the igniter plug replaced to its shallow position in the holder after use; the bimetal disk is shown as being still sufficiently hot to remain in the circuit opening position of FIG. 3.
FIG. 5 is an axial sectional view of another embodiment of the invention, wherein two spring-like latching clips are employed to retain the bimetal disk in its snapped position, disengaged from the igniter plug until the latter is either removed or else replaced, depending on the timing and the heat loss from the disk.
FIG. 6 is an inside elevational view of a thermostatic control member in the form of a disk with slabbed-off sides, which is substitutable for the full disk control of FIGS. 1-5.
FIG. 7 is a fragmentary side elevational view of a modified holder device employing a back-up spring ring to reinforce lanced spring fingers.
Referring first to FIG. 1, there is illustrated a cigar lighter generally designated by the numeral 10, comprising a holding device 12 having an annular flange 14 adapted to engage a supporting panel 16 such as the dashboard of an automobile. The holding device has a threaded end portion 18 which receives a cylindrical mounting member 20, the latter being adapted to en gage the rear face of the supporting panel 16 to thereby support the holding device 12 in a well known manner. The holding device 12 presents an outwardly facing socket 21 in which there is receivable an elongate igniter plug 22having an outer electrically conducting shell 23 the inner end portion of which constitutes an ash guard. The plug 22 further includes a spiral heating coil or element 24 located at that end which is received in the socket 21, and a metal cup 26 having a sharpedged rim portion 28 which surrounds the coil as well as a stud 30 that is fastened to the inner end of the coil to thereby provide support for and carry current from the latter. The outer end of the coil 24 is preferably welded to the metal cup at location 32.
As illustrated in FIG. 1 the metal cup 26 is carried by the stud 30 but is electrically insulated therefrom by means of a pair of insulated washers 34 and 36 which can be of mica or other heat-resistant insulating material. The washers 34 and 36 are tightly secured to the opposite faces of the disk-shaped bottom wall of the cup by a retainer washer 38 and bushing 40. The stud 30 is secured to the body 41 of the igniter plug by means of a support bushing 42 disposed within the conducting shell 23; the stud thus being electrically connected to the shell to carry current thereto.
By the above arrangement an electrical circuit through the igniter plug is established, beginning at the contact rim 28 of the metal cup 26, through the heating coil 24 to the stud 30 and thence to the outer conducting shell 23. The igniter plug further comprises a knob 44 on the body 41, by which the unit can be readily grasped and held. The stud 30 is threaded for a portion of its length and is inserted in a tapped hole 46in the body 41. An additional bushing 48 provides a convenient means for securing the plug body 41 to the conducting shell 23.
In FIG. 1 there is further illustrated one of a plurality of lanced spring fingers 50 integral with the annular wall of the holding device 12. The igniter plug is provided with an annular groove 52 about its periphery for cooperation with the lanced fingers 50. The spring fingers 50 bias the igniter plug to the shallow position illustrated in FIG. 1, hereinafter also referred to as the storage or unenergized position. The igniter plug can be depressed from such position to the energizing position illustrated in F IG. 2 against the action of the spring fingers 50, this position hereinafter being also referred to as the deep" position.
In accordance with the present invention there is provided a novel and unique automatic circuit control by which a surprisingly new and striking result is obtained,
that of being able to substantially instantaneously heat the coil to useful incandescence without causing any overheating or bum-out thereof. This improved circuit control establishes an electrical circuit from one portion of the holding device through the metal cup and heating coil to another portion of the holding device and is characterized by an especially simple and effective heat-responsive member closely juxtaposed to the heating coil and adapted to substantially instantly completely open the electrical circuit thereof in response to extremely quick heating of the coil to a pre-determined useful temperature. In conjunction with said automatic control there is utilized a source of power which provides a voltage substantially greater than the continuous-duty voltage rating of the coil, as for example a voltage of twice said rated voltage. Thusthe coil 24 could be a 6-volt coil, and the power source could be a l2-volt battery.
FIG. 1 illustrated the novel control as comprising a thermostatic, dish-like member of large expanse, in the form of a bimetal disk 54 mounted in the socket 21 of the holding device 12 and supported by a threaded stud 56, the latter being secured to the holding device by means of a threaded bushing 58, washer 60 and nut 62. The bimetal disk 54 has an annular peripheral contact portion 64 adapted to engage the sharp edge 63 of the rim 28 of the metal cup 26, the contact portion 64 thus constituting one part of a means for establishing an electrical circuit from one portion of the holding device through the igniter plug and to another portion of the holder. As illustrated in FIG. 1, the power source can comprise a 12-volt battery 66 having one terminal 67 permanently connected to the stud 56 and the other terminal 68 connected to the panel 16 of the dashboard (not necessarily at the location shown). It will be understood that when the igniter plug occupies the shallow position of FIG. 1 the conducting shell 23 will be at the same potential as the battery terminal 68, since the panel or ground 16 contacts the annular wall of the holding device 12 which in turn contacts the shell 23.
The invention provides that the heating coil 24 be characterized by a particular continuous duty voltage rating, representing the maximum voltage which can safely be applied thereto for a prolonged period of time without causing damage due to overheating, and that the battery 66 supply a voltage substantially in excess of such continuous voltage rating, whereby the continuous-duty rating is a fraction of the available output voltage range supplied by the battery. As previously mentioned, the coil could be one rated for six volts whereas the battery 66 could have a potential of 12 volts. If recharged by an alternator, as in the case of an automobile, the battery voltage could be brought up to a somewhat higher value. By this arrangement, the coil heats in about two seconds or substantially instantly, and thus would be subject to burn-out if energized by this source for an interval of more than several seconds.
The operation of the present cigar lightercan now be readily understood by referring to FIGS. 1-4. The igniter plug 22 is normally yieldably held in the shallow position of FIG. 1 by the spring fingers 50, and the bimetal disk 54 when at ambient temperature has the position shown. Actuation of the lighter is effected by manually depressing the knob 44 such that the plug 22 is shifted further into the socket, to the deep position illustrated in FIG. 2. As this is done, the sharp-edge 63 of the rim 28 of the cup 26 engages the contact portion or surface 64 of the bimetal disk 54 and applies a force to the latter such as to cause it to become slightly less concave. As a consequence, the contact area and pressures existing between the cup 26 and disk 54 are maximized whereby more reliable electrical connection is established therebetween. The edge 63 of the rim 28 presses uniformly against the disk, resulting in a effective contact pressure. After the rim 28 has thus slightly flattened the disk, the ash guard 23 of the plug engages the bushing 58 whereby the latter provides a fixed abutment vfor positively determining the insertion limit of the plug into the deep position. Accordingly, the danger of depressing the plug too far and thus possibly permanently deforming or damaging the disk 54 is effectively eliminated.
At the time that the disk 54 is engaged by the cup, the coil 24 virtually instantaneously heats to incandescence. The phrase instantaneous as used herein is intended to denote a time interval generally on the order of two seconds, one and one-half seconds or less. The proximity of the coil to the disk and the tight, closely fitting enclosure formed by the cup and disk with the disk forming one large wall broadside to the coil, all cause the disk to become heated very quickly, and as a result its periphery snaps backward or to the left as viewed in the figures, whereby the annular contact portion or area 64 moves axially away from the coil 24 and edge 63 of the cup 26, to thus completely open the circuitand de-energize the coil. The plug must be held in during this very short interval, at least a second or so, or until an audible snap of the disk is heard, at which time the igniter plug is sufficiently heated and ready for use.
FIG. 3 illustrates the plug in the deep position immediately after the disk has snapped away from the cup and with the plug still being held in. If the lighter plug is now released, it will assume the position illustrated in FIG. 4, which is identical to that of FIG. 1 except that the disk is still hot and occupies the opposite convex position shown. It will be understood, of course, that after the snap of the disk is heard, the plug can be immediately removed for use, and the coil 24 will be in an incandescent state. However, the proper operation of the lighter does not depend on hearing the disk snap. The user merely judges the short two-second or less time interval and quickly learns the rapid timing that is possible by virtue of the fast, unique automatic circuit control provided by the invention.
We have found that a coil having a six-volt rating operates very satisfactorily in the above described manner when energized from a nominal 12-14 volt source, generally providing a useable coil incandescence in less than 1.5 seconds. The greatly increased heating is realized because the power supplied to the 6-volt coil 24 as energized from l2 volts is four times that which would be supplied by a 6-volt source. In consequence, instead of requiring 6 or more seconds as is the case where a 6-volt'source is employed the coil as automatically controlled in the lighter of the present invention reaches incandescence in 1.5 seconds, which is a truly great advance and improvement in lighter technology. The coil 24 does not suffer from damage due to overheating, since the actual temperature attained is no more than would normally occur in a conventional 6- volt unit energized from a 6-volt battery. However, by thepresent invention, the coil 24 reaches such a temperature much sooner. The proximity of the bimetal disk 54 to the coil 24 insures that rapid heating of the disk will occur, and that the circuit will be opened before excessive coil temperatures are realized.
Another embodiment of the invention is illustrated in FIG. 5. A holding device is shown, presenting an outwardly facing socket 71 in which there is receivable an elongate igniter plug 72. The plug 72 comprises a metal cup 74 having a sharp edge 75 on the rim portion 76, and having a heating coil 77 disposed therein similar to the coil 24 discussedin connection FIGS. 1-4. The cup 74 is carried by a threaded stud 78 and is electrically insulated therefrom by insulating washers similar to those designated 34 and 36 in FIG. 1, one of which is shown in FIG. 5 and designated 80. The stud 78 is threaded into a threaded spacer and clamp bushing 82, and into a tapped hole 84 in the body 85 of the knob 86 of the plug. A metal cup 88 of the knob surrounds but is spaced from the conducting cup 74 of the plug 72. The holding device has a plurality of lanced spring fingers 89 which cooperate with a contact or conductive sleeve 91 press-fitted onto the cup 88 to normally bias the igniter plug to the shallow position illustrated in FIG. 5. With the above arrangement the metal shell 70 of the holding device is at ground potential, being grounded to the panel 94, and thus the ground potential appears on the cup 88 and stud 78 of the igniter plug. A cylindrical mounting or clamping member 92 is employed to retain the holding device on the panel 94 (which could be the automobile dashboard or instrument panel)." I
As with the previous embodiment of the invention there is provided a bimetal circuit-control disk 96 disposed in the socket of the holding device 1 70 and mounted on an electrically insulated stud 98. The stud 98 is secured in place by an insulated threaded bushing 100, and by a washer 102 and nut 104. In this embodiment of the invention a disk latching means is provided, comprising a pair of spring fingers 106, 108 which can temporarily latch the disk 96 in its heated, circuitopening position (shown in dotted lines in FIG. 5). The latching fingers 106, 108 are carried by the insulated bushing 100, and have camrning control portions 110, 112 which are engageable with an external annular bead disposed on the igniter plug. The fingers 106 and 108 can be advantageously constituted of phosphor-bronze to provide adequate resilience. As shown, the fingers 106 and 108 carry insulating wedges 107 and 109 respectively, which can have elongate ribs 111, 113 press-fitted into slots of the fingers. The wedges are preferably constituted of an electrical insulating material such as aluminum oxide, in order to electrically insulate the bimetal disk from the spring fingers when the latter are engaging the disk. This prevents short-circuiting between the disk 96 and the holding device 70..
The operation of this embodiment of the invention can now be readily understood. As in the previous embodiment, a battery 118 having a nominal l2-volt output is employed to energize the heating coil which latter has a continuous voltage rating equal to a fraction of the output voltage of the battery 118, as for example one-half. When the igniter plug is held depressed so that the annular stop shoulder 114 of the plug engages the holding device mounting flange 1 16, the sharp edge 75 of the rim 76 of the cup 74 engages the bimetal disk 96 in a manner identical to that discussed in connection with FIGS. 1-4. This engagement of the cup 74 and disk 96 closes the circuit through the coil, and as a result the latter is quickly heated to incandescence. Due to the proximity of the disk and coil to each other, some of the heat from the latter is transferred to the disk virtually immediately, thus causing the edge portion of the bimetal disk to snap back or axially away from the cup to the position indicated in dotted lines in FIG. 5. The particular configuration of the insulating wedges 107 and 109 enables the disk to momentarily cam the fingers 106 and 108 outwardly and thus snap past the sharp-angled shoulders of the wedges 107, 109. The disk 96 will now remain latched in the hot position shown in dotted lines, and this will continue even after the disk cools, until it is released by outward flexing of the fingers 106 and 108. As seen in FIG. the fingers 106, 108 have rounded control portions 110, 112 respectively,"which cooperate with the annular bead 120 of the igniter plug.
it will now be noted that if the igniter plug 72 is inadvertently held in the deep position for a period of time longer than that required to heat the coil, the bimetal disk will become latched away and will remain so, since the control portions 110 and 112 are normally positioned inwardly. By this arrangement there is eliminated any danger of overheating of the coil due to cycling of the bimetal disk, should the plug be inadvertently held in the deep position.
' At the time that the plus 72 is released or removed, the bead 120 will urge the spring fingers 106, 108 outwardly a sufficient amount to release or unlatch the bimetal disk. Assuming the disk has cooled sufficiently, it will now assume its normal positionillustrated in solid lines in FIG. 5. By the above arrangement, once the coil has been heated and the disk has snapped away from the cup, it will remain latched in the circuit opening position until the igniter plug is either released or removed. There is thus no danger of overheating of the coil due to cycling of the bimetal disk.
As at present understood, the unexpected and surprisingly excellent success of the cigar lighter of this invention in safely providing instantaneous lights resides in the unique structure and mode of the operation above described wherein the thermostatic dish-like member or disk is one of two large walls of a small enclosure which closely confines the heating element, to the end that the member ordisk receives large amounts of heat quickly to effect reliable breaking of the circuit as the heating element attains its useful incandescence.
Still another embodiment of the invention is illustrated in FIG. 6, wherein a thermostatic snap member 54a of dish-like configuration is carried by a stud 56a, these parts being substitutable for the disk 54 and stud 56 of FIGS. 1-5. The member 54a can be formed of a snap disk having'two opposite'side portions slabbed off to provide straight edges as shown, or else it can be formed from bimetallic strip stock having the desired width. Operation of the member 54a is similar to that of the disk 54; essentially it completely closes the mouth of the cooperable heating element cup 26, as will be understood, so as to confine the element and receive a large amount of heat therefrom.
Yet another embodiment of the invention is shown in FIG. 7, which depicts a holder device 70a comprising a shell having outwardly lanced pairs of tabs 120 which position a split spring ring 122 that reinforces spring fingers 89a also lanced from the shell. The holder accommodates the igniter plug 72a having a metal cup 88a and conductive sleeve 91a, functioning like the similarly-numbered parts already explained above. By the provision of the spring 122 assurance is had that the fingers 890 will reliably bias the plug 72a to the opencircuit, storage position when finger pressure is removed. During outward deflection of the fingers 89a the spring 122 will yield slightly, as can be understood.
From the above it can be seen that we have provided a novel and improved instant lighter which is especially simple and inexpensive to produce, reliable in operation and which yields the surprising and unobvious result of safe, instant heating. The construction shown has been, by actual test, found to represent a very workable and practical solution to a problem which has existed for several decades, and thus it is seen to represent a distinct advance and improvement in cigar lighter technology.
Variations and modifications are possible without departing from the spirit of the invention.
1. A cigar lighter apparatus, comprising in combination:
a. a holding device having means for attaching it to a supporting panel, said device presenting an outwardly-facing socket,
b. an elongate igniter plug adapted to be received in the socket of the holding device, said plug being movable therein between shallow and deep positions and having a spiral heating coil at its inner end,
c. a metal cup surrounding and connected to the heating coil,
d. means establishing an electrical circuit from one portion of the holding device through the metal cup and heating coil of the igniter plug and back to another portion of the holding device in response to movement of the igniter plug from its shallow position in the socket to its deep position therein, thereby to effect energization of the coil,
e. said circuit-establishing means comprising a sharp edge on the rim of the metal cup and comprising an annular cooperable electrical contact on the holding device,
f. a source of electrical power having a given nominal output voltage range, connected to said portions of the holding device, and
g. a substantially flat heat-responsive means juxtaposed and disposed broadside to said heating coil for substantially instantly actuating said circuitestablishing means to completely open said electrical circuit in response to rapid heating of the coil to a predetermined useful temperature,
b. said heat-responsive means comprising a bimetallic, thermostatic dish-like member of large expanse which responds to heat by moving said annular contact axially away from said heating coil and rim of the metal cup of the igniter plug when the latter is continuously held in its deep position in the holding device, said member when cold having a concave side facing the heating coil,
i. the continuousduty voltage rating of said heating coil being a fraction of the nominal output voltage of said electrical power source such that the coil would heat substantially instantly and quickly burn out if the circuit through it remained closed for more than several seconds.
2. The invention as defined in claim 1, wherein:
a. said plug has an annular exterior groove,
b. said holding device having a lanced spring finger receivable in said groove for normally biasing the plug to its shallow position in the socket.
3. The invention as defined in claim 1, and further including:
a. latching means releasable upon removal of the igniter plug from the holding device, for latching the dish-like member in its heated, circuit opening position.
4. The invention as defined in claim 3, wherein:
a. said latching means comprises a pair of spring fingers carried by the holding device and disposed at peripheral portions of the dish-like member,
b. said spring fingers having control portions which are engageable with the igniter plug to spread the fingers apart when the plug is in its shallow position.
5. The invention as defined in claim 1, wherein:
a. the annular contact of the holding device comprises a peripheral portion of the dish-like member,
b. said cup and dish-like member when engaged constituting a substantially fiat, circular wafer-like enclosure closely confining the heating coil with the dish-like member comprising one large wall of the enclosure, disposed broadside and closely juxtaposed to the coil,
c. said dish-like member at its peripheral portion snapping away from the sharp edge on the rim of the metal cup when the heating coil reaches a useful incandescence.
6. The invention as defined in claim 5, wherein:
a. the dish-like member is engaged by the sharp edge of the cup and slightly flattened by force exerted by said edge as the plug reaches its deep position in the holding device, thereby establishing a more effective electrical contact between the dish-like member and sharp edge of the cup rim due to the increased force existing therebetween.
7. The invention as defined in claim 2, and further including:
a. a back-up spring carried by the holding device and bearing against said lanced spring finger to reinforce the biasing action of the same.
8. The invention as defined in claim 7, in which:
a. the back-up spring comprises a ring encircling the holding device and engaging an outer surface of the spring finger.
9. The invention as defined in claim 1, in which:
a. thedish-like member comprises a disk adapted to completely close-over the mouth of the cup.
* I II