US2493662A - Cigarette lighter - Google Patents

Description

Jan. 3, 1950 R. T. FITZPATRICK 4 9 C IGARETTE LIGHTER Filed May 1, 1947 2 Sheets-Sheet l [mm/tor Richard 7." F ifzpafrick Home);

Jan. 3, 1950 R. T. FITZPATRICK 2,493,662

CIGARETTE LIGHTER Filed May 1, 1947 2 Sheets-Sheet 2 [urea/tor Richard 7? F ifzpafrick Patented Jan. 3, 1950 UNITED STATES PATENT OFFICE CIGARETTE LIGHTER Richard T. Fitzpatrick, Marcellus, N. Application May 1, 1947, Serial No. 745,223

2 Claims. (01. 175-296) This invention relates generally to cigarette lighters, and more particularly to a cigarette lighter characterized by having an induction coil with a condenser having a capacity of a predetermined value related to the value of the inductance of the coil primary and the natural mechanical frequency of the interrupter, the lighter being adapted for production as a table lighter or cigar lighter and being readily portable, with the source of electrical energy normally constituting dry cells contained Within the casing of the lighter.

It is a primary object of this invention to provide a lighter in which the current drain is a minimum and in which satisfactory lighting is assured by the production of a very hot spark.

Another object of this invention is to provide a lighter in which no physical mechanical effort is required to operate the lighter, other than the closing of an electric switch.

Another object of this invention, ancillary to the penultimate object, is to provide for the enclosure of a satisfactory lighter within a small case of light weight, since the cell or battery of cells required for the operation of the lighter need not be large, inasmuch as the current drain is very small, that is, the net current drain is small.

Another object of this invention is to provide a lighter in a case having a removable cap, with the interrupter secured within this cap, to provide for easy access thereto for inspection and repair and adjustment.

A last object to be specifically mentioned is to provide a lighter of this character which is relatively inexpensive and completely practicable to manufacture, extremely convenient and simple to use, and which will give generally eflicient and durable service.

With these and other objects definitely in view, this invention resides in certain novel features of construction, combination and arrangement of parts and portions as will be hereinafter described in detail and particularly set forth in the appended claims, reference being had to the accompanyin drawings which form a material part of this application, and in which:

Figure 1 is a perspective view of the assembled lighter;

Figure 2 is a perspective view of the cap, switch and fuel tank, showing the position or relationship of these elements;

Figure 3 is a similar view of the coil, attachment plate, interrupter and condenser;

Figure 1 is a perspective view of the apertured 2 casing body member with a pair of dry cells partially inserted therein;

Figure 5 is a perspective view of the attachment plate, and it will be noted that the Figures 2, 3, 4 and 5 are arranged on the sheet in a manner constituting substantially an exploded view of the main elements of this invention;

Figure 6 is a perspective view of the structure shown in Figure 3 and viewed from another direction;

Figure 7 is a part plan view of the casing body portion;

Figure 8 is a top plan view of the structure shown in Figure 3;

Figure 9 is a perspective view of the fuel tank and the wick protruding therefrom;

Figure 10 is a lower plan view of the attachment plate;

Figure 11 is a schematic view illustrating the electrical circuit of the lighter; and

Figure 12 is a perspective view of the push button used in the controlling switch.

Similar characters of reference designate similar or identical parts and portions throughout the specification and throughout the several views of the drawings.

Referring now to the drawings in detail, which drawings represent one preferred embodiment of this invention, it will be noted that the body por-' tion IU of the casing is of generally rectangular shape in horizontal cross section, all the corners thereof being rounded or streamlined, and this body portion will be constructed of insulative material.

As best illustrated in Figure 4, this body portion H] is provided with four cylindrical apertures, disposed in parallel relation and comprising a receptacle l2 for the coil l4, receptacles l6 and I8 for a pair of dry cells 20 and 22, and a receptacle 24 for the fuel tank 26. The casing also includes a bottom plate 28 which may be secured to the under side of the body portion Ill by screws inserted through screw holes 30, an attachment plate 32 of similar form and adapted to be secured to the top surface of the body portion 10 by screws inserted through the screw holes 34, into the holes 36 in the upper surface of the body portion Ill, and the casing is provided with a cap 38 which has a peripheral depending flange 40 adapted to rest upon the body portion In and to space the top panel of the cap therefrom, in order to provide accommodation for the condenser 42, the interrupter comprised essentially of the fixed upper plate 44, the spring plate 46 and a set of contact points 48, and this cap also houses the spring contact 50 which is insulatively secured to the attachment plate 32 and is positioned and adapted to be operated by the push button 52, a portion of which extends upwardly through the top panel of the cap 38. The fuel tank which is, of course, cylindrical to fit within the recess 24 is provided with a cap 54 which closes the top of the tank and is provided with a neck 56 for the wick 58, the cap, neck, and wick being shown as extending above the level of the top panel of the cap 38, in order to facilitate the replenishment of this tank with fuel. The simplified form of this invention, illustrated in the drawing, has a spark gap structure including a contact 60 electrically conductively secured on the metal tank 26 which is grounded, 'as'hereinafter described, and a second contact 62 secured on the upper surface of the cap 38, and thus automatically insulated, this contact 62 beingc'onductively secured to the end of the secondary coil winding 64, the other end of the c'oil winding 64 being grounded, to complete the secondary circuit, 'it being understood that 'thespark gap disposed adjacent the wick 58 exists betw'een the contacts '60 and 62.

The coil M has a core 66 and another, or primary, winding 68 which is connected in series with the cells 2!; and '22 and the interrupter, while a condenser 42'i's=connected--across or parallel with the contact points 48.

'To accomplish this connection, the top of the cell 22 may be grounded to the attachment plate 32 by a screw ll), the lower ends of the=ceIls 2ll and 22 being linked by a springconductor 'll secured by a rivet M, to the botto'm" plate 28, While the top of the cell z'll' is' in eleotricalcon nection with the spring contact plate 50',-'on'the upper face of the attachment plate 32-. Anex' tending portion of the hired contact plate is contacted by this plate 56 when the -push button 52- is depressed. This completes the circuit to the points of the interrupter and the vibrating plate 46 is electrically connected, through the plates 14 and E6, to one endof "said primary winding 58, the other end of this winding being grounded to the attachment Epl'ate 32 to 'co'mplete the primary circuit. IIhecondenser "42 is connected in parallel with theiinterrupterpoints Q8, by means of leads -18' and 8 8, as illustrated in Figure '8. the plate '32 'is of metal, in order "that it -may constitute a proper ground or conductor asrequired to complete the circuits described above,- and it should also be noted that the cell =2U ispreferably grounded to the plate 3.2 :by a spring contact =82, although the provision of this spring contact is not an essential featur'e of thi's invention.

It will, of course, be understood that This invention cannot be fully understood I without a careiul consideration being given to the manner in which the condenser 42 and the coil i l, that is, the primary 'winding 158 of the coil M, are chosen with regard to the respective capacity and inductance thereof. 'Inmost applications of induction coils, the provision "of sufficient primary current presents little difficulty, and the condenser is chosen 'wi'th a view solely to a proper quenching of the spark, that 15, the rapid demagnetization of "the core as a result of the condenseraction in absorbing the extracurrent at the time the circuit is broken and due tothe self-inductancedf the ooil.

In this application of Ian inductance c'oil it is of primary importance to ni'inimize the current 'drain, since it 'is highly preferableto asea very small cell or battery of cells. While this net current drain must be a minimum, it is also necessary to minimize the impedance to the current while the contacts are closed, so that a maximum variation in current in the primary is obtained, with consequent higher voltage cur rent in the secondary and production of a hot spark. In this invention, maximum fiow while the contacts are closed actually minimizes the net current drain on the battery over a lengthy period of use of the lighter because the hotter spark obtained lights the Wick immediately and the control switch need be closed. for a very short p'eriodeach time the lighter is used.

Accordingly, it is a feature of this invention to 'match or tune the condenser and the coil with a view to securing maximum intermittent current flow from such a small source of electricity. Since the current through the coil is an interrupted direct current, the characteristics thereof may becOHsidered somewhat-similar to thecharactcristics of an alternating current, or similar to a degree allowing th application of the principle of a tuned circuit to the device. In the alternating type of current, the frequency-equals the reciprocal of the square root of the product of the inductance in henrys multiplied by the capacitance in farads, times 6.28, and this formula has been used to calculate the proper sizes for these units. It will be understood that in the instant invention, the frequency is controlled, in large measure, by the mechanical characteristics of the vibrating portions. 'The length and strength of the spring, the mass of the spring and the contacts are of primary importance in determining the frequency at which the device will operate. When this natural frequency of the vibrating portions is known, the above formula is used to guide the choice of properly sized condensers and cells. In this tuned cirwit, the net impedance is greatly reduced and satisfactory operation may be-obtained by the use of avery small battery.

It should be noted that the proper quenching of the-spark in order to speed the demagnetization of the core 65 is of importance in this device, as in other applications of induction coils, and that the condenser should have sufilcient capacity to properly c'oact in this'type of circuit. Ordinarily, the coil will/therefore, be chosen to provide for a tuned circuit with a condenser of a size chosen with a view to this-other "function.

Many and various useful modifications maybe made in this invention, and though there has been shovvn a particular embodiment of this invention, this application is not limited to this particular embodiment, but it is desired to in clude in the scope of this invention the construction, combination and arrangementof'parts and portions substantially as set forth in the appended claims.

What is "claimed asnew and'des'ired to be socured by'Letters Patent-is:

l. A cigarette lighter case havinga body-portion with parallel cylindrical apertures, a- 'fue'l tank having a'wick and an electrode projecting from one end thereof, aninduction coil and a pair of dry cells, a removable base carrying -a spring contact bar for connecting adjacent terminals of said dry cells, a removable plate'having said induction *coil mounted on 'the inner side thereof and a condenser "on "the outer side thereof, said *plate having an aperture toreciVe an outer end portion of said "fuel ftaiik'saidful tank, induction coil and'dry'ccllsbeing ins'ertable into said apertures in the body portion, and a cap carrying a switch controlling a circuit through said induction coil and condenser, said cap being also apertured to receive the end of said fuel tank carrying the wick and carrying a second electrode, said electrodes comprising a spark gap adjacent said wick.

2. A cigarette lighter comprising a case, and an attachment plate therein, a fuel tank with a wick extending outside said case, a source of direct current, an induction coil mounted on said attachment plate and having an interrupter including a vibrating spring element carrying a contact, a condenser on said plate tuned with said coil, said source bein electrically connected with said coil, interrupter and condenser, the secondary of said induction coil having a spark gap adjacent said wick, and a switch to control the circuit through said source, said condenser and coil having predetermined capacitance and inductance respectively for minimum net impedance at the natural vibration frequency of said spring element.

RICHARD T. FITZPATRICK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS

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