GB2047394A - Automatic electric cigar lighter - Google Patents

Abstract

A cigar lighter for an automobile comprises a holder device (12) including a socket having two contacts (12, 26) forming part of a cigar lighter circuit, and an ignitor plug (14) receivable in the socket, comprising a manually operable part (50, 51). A heating element (104) is carried at the inner end of the plug. For controlling the cigar lighter circuit, there is provided an electrical switch having cooperable parts (142, 144) carried by the plug, and which can be closed in response to actuation of the manually operable part. A bimetallic member (146) is also carried by the plug, having a circuit-opening position and a closed-circuit position. The member has a bimetallic actuator portion which is free and clear of attachment to the switch and to any other parts of the plug, but can engage one of the cooperable parts (142) of the switch to effect opening thereof after a sufficient desired degree of heating of the heating element has occurred. <IMAGE>

Description

SPECIFICATION Automatic electric cigar lighter This invention relates generally to cigar lighter devices for automobiles and the like, and more particularly to automatic lighters which are especially adapted to heat to useful incandescence in relatively short intervals of time.

In the past, a large number of different automatic lighter constructions have been proposed and produced. Generally they employed bimetallic spring fingers carried in a socket and which were engageable with the side surfaces of a heating element cup that was carried on the inner end of the ignitor plug.

When the plug was depressed, the fingers latched over the sides of the cup establishing a circuit through the heating element. As the element reached useful incandescence, the bimetallic fingers became heated and would then spread and release the cup and the ignitor plug, enabling the same to retract and break the circuit through the element.

Numerous refinements to this basic structure have been achieved over the years. However, problems sometimes arose, as when one of the bimetallic fingers, for reasons sometimes obscure, shifted into the path of the ignitor plug while the latter was being depressed, resulting in breakage and possible short-circuiting of the socket. This would cause either a blown fuse or else a burned-out wiring harness, depending on the degree of current overload protection built into the particular electrical system of the automobile. In other cases, the bimetallic fingers underwent an aging deformation after prolonged use.

When this occurred, the socket usually had to be removed, in most cases involving work underneath or to the rear of the dashboard.

Where the socket was not readily accessible, such repair or replacement was sometimes difficult and time consuming.

Typically in automatic lighters there is a period of ten to fifteen seconds following actuation of such ignitor plugs, until the heating element has reached useful incandescence and the plug snaps out in readiness for use.

In the past, a number of efforts have been made to reduce this waiting time to just a few seconds. Generally, such innovative units have employed a bimetal disk disposed adjacent to the heating element, the disk constituting one contact of a switch which was adapted to open after the element reached incandescence. By positioning the disk right next to the element, response times on the order of only several seconds have been achieved, particularly when an applied voltage which exceeded the continuous rating of the heating element was employed.

Prior lighters of the type employing bimetallic disks all had a number of distinct disadvantages. Generally where the contact area of the disk was at its center, the socket was arranged to secure the disk at its periphery. The mounting for the disk had to be such that it would not interfere with its flexing and snaptype movements. This imposed stringent requirements on the tolerances of both the disk and the part which carried it. Also, in most cases the disk constituted part of the "hot" side of the circuit, and thus had to be insulated from the remainder of the socket. Accordingly, such mountings were often awkward and prone to malfunction in use.

In other constructions, as where the contact area of the disk was at its periphery, the disk was mounted by means of a stud passing through a hole in its center, and the end of the stud being stacked to hold the disk in place. The problem with this arrangement was that the support area was too small, and the disk eventually loosened, causing poor electrical contact with the stud. Or, if the support area was made sufficiently large, then its freedom of movement was impaired, and its proper functioning. Since both the stud and the disk were current-carrying members, any loosening caused either excessive voltage drops, or else open circuits, resulting in malfunction or failure of the device.Where the bimetallic disk itself was employed as one contact of the circuit-breaking switch, there occurred burning and pitting at the points of contact, this resulting in both a poor electrical connection and in deterioration of the disk itself, after a relatively short period of use.

Moreover, where the disk was a current carrier, the relatively heavy current flow associated with such ignitor devices resulted in resistance-heating of the disk, aside from the heating effect due to its proximity to the coil.

The resistance or self-heating effect depended on the resistances of the electrical path through the disk and stud; there were thus introduced other undesirable variables into the design of the lighter, which caused problems during manufacturing runs where large numbers of units were to be mass produced, from components possibly having slightly different physical and/or electrical characteristics.

Generally, the heating element of a cigar lighter is carried in a metal cup at the inner end of the ignitor plug. With spiral wound ribbon or coil type elements, the outermost convolution of the coil is as a rule secured by welding it to the annular wall of the cup. A slitted rivet or stud is disposed in the bottom wall of the cup, with the other end of the coil being inserted and secured thereto. Since the cup constituted a current carrying member in the "hot" side of the circuit, it required special material in order to insulate it from the remainder of the ignitor plug, as well as from the rivet, which is in the "cold" side of the circuit. Various arrangements for mounting the cup and rivet were employed. Different combinations of insulating bushings and/or washers generally met with success, as a rule.

But with such constructions, of course, care had to be exercised in the assembly, in order to insure proper seating of the washers, and to make certain that short-circuiting of the rivet to the cup would not occur.

U.S. Patent No. 3,870,857 issued to Laurence G. Horwitt shows a recent arrangement for mounting a heating element cup and rivet, wherein the cup is insulated from the remainder of the ignitor plug by means of a mica washer. A series of nibs on the bottom wall of the cup is received in corresponding recesses in a transverse wall of the plug body, with the mica washer being sandwiched between the two walls. This permits the use of automatic assembly equipment, in that the nibs of the cup can become seated in the recesses of the transverse wall, as a consequence of proper rotational orientation of the cup and plug body. This construction has met with wide acceptance and considerable success due to the savings of labor that were achieved while maintaining reliability.

The present invention provides an automatic cigar lighter, comprising in combination a holder device including a socket having two contacts forming part of a cigar lighter circuit, and ignitor plug receivable in the socket, said plug having a manually operable part, a heating element carried at the inner end of the plug, means for establishing a circuit from the holder device contact through the heating element, said means including an electrical switch having cooperable parts carried by the ignitor plug, means for closing said switch and energizing said heating element in response to actuation of said manually operable part, and means responsive to heating of said heating element, for opening aid switch to deenergize the element, said immediately preceding means including a bimetallic member carried by said plug and having a circuitopening position and closed-circuit position, said member having a bimetallic actuator portion which is free and clear of attachment to any other parts, said actuator portion being adapted for abutting engagement with one of the cooperable parts of said switch to effect said opening of the switch.

Another embodiment of the invention provides a cigar lighter ingiting unit, comprising in combination a heating element having elec trical terminal elements, and metallic means simultaneously mechanically securing said terminal elements in spaced-apart relation to constitute a unitary assemblage and insulating said elements from each other, said means comprising an anodized aluminum mounting member having anodized electrically insulating surface areas directly engaged with said terminal elements.

Yet another embodiment of the invention provides an electric cigar lighter, comprising in combination, a holder device including a socket having two contacts forming part of the cigar-lighter circuit, an ignitor plug receivable in the socket, comprising a manuallyoperable part movable in the socket between energizing and de-energizing positions, said plug having a heating element carried at its inner end, means for establishing a circuit from the holder device contacts through the heating element when the said manually-operable part is shifted to its energizing position, the said means including an electrical switch having relatively-movable cooperable contact parts, and means becoming operative in response to heating of said heating elements, for operating said electrical switch to break said circuit and de-energize the element, said operating means including a bimetallic member having a circuit-opening position and a closed-circuit position, said bimetallic member having an actuator portion which is free and clear of permanent attachment to any other parts of the holder device, said actuator portion being adapted to cooperate with one of the cooperable contact parts of said switch to effect the operation thereof.

Still another embodiment of the invention provides an electrical cigar lighter, comprising in combination a holder device including a socket having two contacts forming part of a cigar lighter circuit, an ignitor plug receivable in the socket, said plug having a manually operable part, a heating element carried at the inner end of the plug, means for establishing a circuit from the holder device contacts through the heating element, said means including an electrical switch having cooperable parts carried by the ignitor plug, means for closing said switch and energizing said heating element in response to actuation of said manually operable part, means responsive to heating of said heating element, for opening said switch to de-energize the element, said means including a bimetallic member carried by said plug and having a circuit-opening position and a closed-circuit position, said member having a central bimetallic actuator portion which is adapted to actuate one of the cooperable parts of said switch to effect said opening of the switch, and clamping means engaging peripheral portions of said bimetallic member, said clamping means comprising an abutment member and a coil spring engaging opposite sides of the bimetallic member.

In order that the invention may be more readily understood, reference will now be made to the accompanying drawings, in which: Figure 1 is a vertical sectional view of the automatic cigar lighter, showing the ignitor plug disposed in the holder device or receptacle, in its unenergized or storage position wherein a switch carried by the plug is open.

The bimetallic switch actuator member or disk is in its circuit-opening position.

Figure 2 is a view like Fig. 1 but partly in elevation, showing the manually operable part of the ignitor plug as having been shifted to a deep position in the socket of the holder device and prior to its return after finger pressure is removed. Its cooperable switch parts have been closed to effect energization of the heating element. The bimetallic switch actuator disk is in its closed-circuit position.

Figure 3 is a view like Figs. 1 and 2, wherein the bimetallic member or disk associated with the switch is still in its closed-circuit position and is being rapidly heated due to its closer proximity to the energized heating element. The spacer member 50 and knob 51 have returned to the position of Fig. 1 due to the removal of finger pressure.

Figure 4 is a right end elevation of the contact cup carried by the ignitor plug shown in Figs. 1-3, the cup constituting one of the cooperable switch parts.

Figure 5 is a left end elevation of a bearing cup carried by the ignitor plug, for enabling limited sliding movement of the contact cup with respect to the plug body.

Figure 6 is a side elevational view of the bimetallic member or disk associated with the ignitor plug of Figs. 1-3.

Figure 7 is a right end elevational view of a heating element mounting member or mounting cup carried by the ignitor plug of Figs.

1-3.

Figure 8 is a right end elevational view of a contact member or terminal element which carries the heating element, the contact member being associated with the mounting member of Fig. 7 in the ignitor plug of Figs. 1-3.

Figure 9 is a left end elevational view of dish-shaped contact member carried in the socket of the igniting unit of Figs. 1-3.

Figure lOis a view, partly in side elevation and partly in section, of a tubular friction sleeve associated with the ignitor plug of Figs.

1-3.

Figure 11 is a fragmentary section of the sleeve of Fig. 10.

Figure 12 is a side elevational view of a tubular ashguard associated with the ignitor plug of Figs. 1-3.

Figure 13 is a front elevational view of the ignitor plug of fig. 1, except with the knob removed.

Referring first to Figs. 1-3 there is illustrated a cigar lighter of the type adapted to be mounted on an automobile dashboard, comprising a receptacle or holder device 1 2 which includes a socket, and a generally cylindrical ignitor plug 14. The receptacle 1 2 has a radially outwardly extending annular flange 1 6 which engages the front surface of the automobile dashboard 1 8. At the rear, the receptacle mounts a threaded shell 20, on which there is screwed a tubular clamping shell 22 having a corresponding threaded portion 24 mating with the shell 20. The front end of the clamping shell bears against the rear surface of the dashboard as shown, to thereby hold the receptacle 1 2 in a fixed position thereon.

The receptacle or socket 1 2 has a dishshaped metal contact member 26 constituting one of the socket contacts, which is insulatedly mounted therein by means of a threaded stud 28 and nut 30. Carried on the stud are insulating washers 32, 34 and a spring washer 36. The stud extends through aligned apertures in the inner transverse wall 38 of the receptacle 1 2 and in the transverse or bottom wall 40 of the screw shell 20, thereby to retain the contact member 26, receptacle 1 2 and screw shell 20 in assembled relation.

The transverse wall 40 includes alignment nibs 42 which are stamped out therefrom and which extend into corresponding apertures 44 in the shell. These key the shell 20 to the remainder of the receptacle 1 2 and prevent relative turning movement between the two parts during installation of the unit.

As shown, the contact member 26 has a conical seat 46 at its center. The diameters of the aligned apertures in the walls 38, 40 exceed the diameter of the stud 28 by a substantial amount, thereby providing clearance space between the walls of the apertures and the stud to insure adequate insulation of the stud. Similarly, the diameter of the hole in the spring washer 36 is sufficiently large to provide adequate clearance around the stud.

The portion 48 of the washer 32 is deformed to extend partially into the aperture in the transverse wall 38 of the receptacle 12, and the conical seat 46 thus centralizes the stud with respect thereto during assembly.

Referring again to Fig. 1, the ignitor plug 1 4 includes a tubular plug body assemblage 49 comprising a manually operable part of spacer member 50 and a knob 51, the member 50 being generally in the form of a hollow cylinder. A friction sleeve 52 is telescopically carried on the spacer member 50, and a retractable ashguard generally designated 54 and particularly illustrated in Fig. 1 2 also constitutes part of the plug body assemblage and is telescopically carried by the spacer member 50 and movable thereon between limits, as will be later brought out. Disposed at the end of the spacer member 50 is a cap 56 having an annular flange 58 extending past the periphery of the member 50. The cap 56 has a series of slots 60, as shown in Fig.

13, and corresponding lugs 62 on the spacer member extend through the slots and are bent radially inward to thereby hold captive the cap 56. The cap 56 also has a central indented portion 64 which is apertured to receive a threaded mounting stud 66 of the knob 51.

The cap 56 includes an integral spring pressure tooth 70 which engages the threads of the stud and enables the knob to be merely screwed into the cap as shown.

The flange 58 constitutes a seat for one end of a coil spring 72, the other end of the spring bearing against an internal shoulder 74 on the friction sleeve 52 and the latter having an outwardly extending annular curl 80 which normally bears against a transverse shoulder 82 on the spacer member 50. As shown in Fig. 12, the ashguard 54 has a series of lugs 84 struck from its annular wall portion. In the present construction, three such lugs are disposed circumferentially about the body of the guard. The lugs 84 project inwardly into the path of the curl 80 when the ignitor plug is being withdrawn from the socket, and position the ashguard so as to encircle a heating element to be described below, as the plug is removed from the receptacle.The ash guard 54 further includes a circumferential bead 86 which is engaged by one or more spring fingers 88 lanced form the annular wall of the receptacle 12. The fingers include camming portions 90 which limit outward or rearward axial movement of the ashguard when the ignitor plug 14 is being withdrawn, as there occurs engagement of the ends of the lugs 84 with the curl 80 of the friction sleeve 52. This results in the heating element being recessed within the ashguard at such times that the ignitor plug is withdrawn from the socket.

At its front end the friction sleeve 52 has an outwardly extending annular flange 92 which normally bears against a corresponding flange 94 on the ashguard 54. The limits of relative axial movement of the friction sleeve 54 with respect to the ashguard 54 are thus determined in one direction by the engagement of the flanges 92, 94 and in the other direction by engagement of the curl 80 with the lugs 84 of the ashguard.

In order to provide a smooth, non-binding and sliding engagement between the friction sleeve 52 and the ashguard 54, there are provided on the cylindrical exterior surface of the sleeve a plurality of circumferentially spaced longitudinal ribs 96 which slidably engage the inner cylindrical surface of the ashguard. These ribs are particularly illustrated in Figs. 10 and 11, and operate to reduce binding between the parts and prevent axial misalignment thereof. In order to exert frictional resistance against relative axial movement of the friction sleeve 52 and the ashguard 54, the cylindrical body of the sleeve is lanced at several locations, preferably spaced circumferentially about the sleeve, providing yieldable friction fingers 98 which bear with calibrated pressure against the inner cylindrical surface of the ashguard.The pressure is sufficient to retain the ashguard in any selected axial positions to which it is moved with respect to the sleeve. The ribs 96 of the sleeve assure constant uniform spacing between the two parts, to prevent undesirable variation in the side pressure exerted on the inner surface of the guard by the friction fingers 98. Accordingly the base area of the fingers 98 will not be "sprung" by improper alignment. Disposed at the inner end of the ignitor plug 14 is a spiral-wound heating element or coil 104 which can be constituted as a ribbon of "V" cross section with successive convolutions interlocking one another to form a disk-like structure.

The mounting arrangement for the heating element involves mainly a single metallic, dual-function member which effects both a mechanical support for and electrical insulation between the opposite ends of the heating element 104. In the assemblage involving such dual-function member there is included an annular, metal terminal element 106 which is particularly illustrated in Fig. 8, having an outer wall 108 and a curled-in rim 110. As shown, the heating element 104 is disposed within the terminal element 106, with its outer end or terminal portion 11 2 secured by being sandwiched or crimped under the rim 110. This can be accomplished in a suitable punch and die (not shown) which effect both the initial curling operation and the final crimping operation in a single step.By such an arrangement, the outer terminal portion 11 2 of the heating element 104 is permanently both mechanically secured and electrically connected to the terminal element 106.

The terminal element 106 also functions as a contact member; in this connection, there is provided an inturned flange 114 lying substantially in a radial plane, having a series of resilient lugs 11 6 extending inwardly therefrom. These lugs 11 6 are adapted to engage dish-like contact member 26 of the receptacle 1 2 when the ignitor plug 14 is in the positions of Figs. 1, 2 and 3. The lugs 11 6 are formed with strengthening, spacer ribs 11 8 which protrude toward the heating element 104 from the plane of the flange 114 and engage the outermost element convolutions to provide mechanical support thereto.

The dual-function member comprises an anodized aluminum mounting member or mounting cup 1 20 in which the terminal element 106 is nested. The mounting member 1 20 has three lugs 1 23 shown in Fig. 7 which are bent inward after the assembly with the terminal element 106, thereby to hold captive the terminal element 106, and the mounting member has an annular side wall 122 and bottom wall 1 24 provided with a tubular boss 1 30 defining a central aperture 1 26 (Fig. 7). The bottom wall 1 24 of the mounting member 1 20 also has a series of circumferentially-spaced heat-passages or holes 1 28 surrounding the central aperture, for purposes shortly to be described. The inner surface of the annular wall 122 of the mounting member 1 20 engages the annular external surface area of the wall 108 of the metal terminal element 106 but remains adequately electrically insulated therefrom by virtue of the anodizing of the mounting member.

Pressed into the boss 1 30 is a metal rivet 1 32 constituting a second terminal element which is connected to the innermost end 1 34 of the heating element 104. The surface of the boss 1 30 which engages the rivet 1 32 also has an insulating anodized coating, enabling the rivet to remain electrically insulated from the mounting member 1 20 even though it is mechanically secured thereto. The rivet 1 32 has a stop shoulder 1 36 and is slotted to receive the inner end portion 1 34 of the heating element.

Further, there is provided a two-part electrical switch connected in circuit with the heating element 104, and a bimetallic actuator member 146 associated therewith, adapted to open the circuit through the element after it has reached useful incandescence.

One part of the switch comprises a movable contactor device or contact cup 142 which is particularly illustrated in Fig. 4, and the other part includes a contact portion or surface 144 on that end of the rivet 1 32 which extends forward from the boss 1 30. The bimetallic member or operator 1 46 is in the form of a disk, (Fig. 6), having a central aperture 147 surrounded by an actuator portion which is adjacent to the contact cup 142 of the switch.

As shown, the disk 146 lies in a plane which is generally perpendicular to the axis of the plug body 50. A bearing cup 148 constituting a guide for the contact cup 142 is also provided, said bearing cup having outer and inner concentric annular walls 150, 1 52 respectively connected by a conical wall 1 54.

The bearing cup is closely-fitted in the body or spacer member 50, and seats against an annular internal shoulder 1 56 therein. The walls 1 50 and 1 54 together form a seat for one end of a compression coil spring 158, the other end of which bears against one face of the bimetallic disk 146. The peripheral portions of the other face of the disk 146 seat against an annular shoulder 1 60 on the anodized mounting member 1 20. The disk is thus sandwiched in an operative position between the member 1 20 and the spring 1 58 even when the latter undergoes compression, as will be explained below.

Referring again to Figs. 1-3, the contact cup 142 has an annular wall 162 which has a sufficiently loose, non-binding fit with the wall 1 52 of the bearing cup so as to enable free sliding movement of the two parts. A compression coil spring 1 64 is carried by the contact cup, engaging the transverse or bottom wall 1 66 thereof and having its other end seating against a transverse or bottom wall 168 of the bearing cup 148.The wall 166 of the cup 1 42 comprises an inwardly offset portion 1 70 which constitutes a contact surface for engagement with the contact portion 144 of the rivet 1 32. In addition, at the center of the offset 1 70 is an aperture 1 72 of smaller diameter than the dimensions of the end of the rivet 132, this construction resulting in a more even distribution of the contact pressures of the switch.

Referring again to Figs. 1-3, it can be seen that the aperture of the bimetallic disk 146 provides clearance for the rivet 1 32 and boss 1 30 of the mounting member 1 20. As shown, sufficient clearance is provided so that no engagement between the two parts occurs.

The spring 1 64 normally maintains the wall 1 66 of the contact cup 142 in engagement with the central portions of the disk 146 for the open-circuit condition of the lighter shown in Fig. 1.

It will be seen from Figs. 1-3 that although the disk 1 46 is at "ground" to return-circuit potential, it does not at any time carry the heating element current, because of its mounting. The spring 1 58 and shoulder 1 60 constitute a means which mounts the bimetallic member 146 in the plug 49 so as to maintain the central bimetallic actuator portions thereof out of contact with any parts of the heating element circuit when the member is in the closed-circuit position of Figs. 2 and 3. In some of the appended claims, the mounting member 1 20 is referred to as an abutment member, since it backs up or abuts the bimetallic member 146, and together with the spring 158, constitutes a mounting therefor.

The operation of the automatic lighter may now be readily understood by referring to Figs. 1-3 in succession. Fig. 1 illustrates the relative positions of the various components with the lighter in the storage or unactuated position, wherein the positive terminal of the battery is intended to be connected to the stud 28, this being conveniently hereinafter referred to as the "hot" side of the circuit.

The other terminal of the battery is connected to the vehicle dashboard 18, constituting the return side of the circuit. It is noted that with the component positions of Fig. 1, the lugs 11 6 of the contact member 106 (Fig. 8) are in engagement with the dish-like contact member 26 of the socket. No current flows through the heating element, however, since the switch parts 132, 1 42 are disengaged by virtue of the bimetallic disk 146 biasing the contact cup 142 toward the left.

When it is desired to use the lighter, the manually operable part comprising the knob 51 and spacer or body member 50 is depressed in the socket from the shallow position of Fig. 1, to the deep position of Fig. 2.

This accomplishes several things. The spacer member 50 has carried the bearing cup 148 toward the right, while the mounting member 120, contact member 106, and heating element 104 remain stationary. The hard anodizing of the aluminum mounting member 1 20 presents a good slide bearing surface in engagement with the wall 1 76. This enables a smooth movement to occur between these parts as the knob 51 is being depressed. The unitary assemblage consisting of the mount ing member 120, contact member 106, and heating element 104 remains stationary. A peripheral flange 1 80 on the spacer member 50, which engages and holds captive the mounting member 1 20 for the position of Fig.

1, now has shifted and is engaged with the wall 38 of the receptacle. Compression of the spring 1 58 causes a tight engagement of the contact lugs 11 6 (Fig. 8) with the dish-like contact member 26, insuring good electrical contact therewith. Initially the bearing cup 148 and contact cup 142 have moved as a unit, until the latter became engaged with the contact portion 144 of the rivet, after which further movement of the bearing cup 148 effects compression of the spring 164, causing firm engagement of the wall 1 70 with the rivet contact portion 144. While the bearing cup 148 and contact cup 142 are initially moving together, a point is reached where the bimetallic disk 146 (still cold) snaps under the action of the bearing cup from the opencircuit position of Fig. 1 to the closed-circuit position of Fig. 2.This occurs before and during engagement of the cup wall 1 70 with the rivet 1 32. With the components in the relative positions of Fig. 2, a circuit is completed through the heating element 104 as follows: Current flows from the stud 28 through the contact member 26 to the contact member 106, through heating element 104 to the rivet 132, then to the contact cup 142 and spring 1 64 and to the cup 148, through the spacer member 50, friction sleeve 52 and ashguard 54 to the receptacle 1 2 and the panel 18. Portions of the inner walls of the receptacle 1 2 constitute one of the two contacts in the receptacle. Figs. 1-3 show in dotted outline one of the three friction fingers 98 on the friction sleeve 52.These bear against the inner surface of the ashguard 54, and thus insure good electrical contact therewith. After depressing the knob 51, the user removes the pressure, and the spacer member 50 and knob 51 are returned to the Fig. 1 position under the action of the spring 72, but the spring 1 64 now expands and maintains the contact between the cup 142 and rivet 1 32. This is illustrated in Fig. 3.

After several seconds have elapsed, the heating element 104 reaches the useful incandescence, and heat is transferred by radiation through the holes 1 28 (Fig. 7) to the bimetallic disk 146. When the disk has heated sufficiently, it snaps back to the position illustrated in Fig. 1, at the same time effecting disengagement of the cup 142 and rivet 132. This opens the circuit through the heating element 104. At the time that the disk snaps back to the position of Fig. 1, an audible click is heard, indicating to the user that the lighter is now ready for use.

As the knob 51 and spacer member 50 are withdrawn from the socket 12, the ashguard 54 at first remains stationary by virtue of the engagement of the bead 86 with the spring fingers 88. Thus, the spacer member 50, friction sleeve 52, cups 142, 148, mounting member 120, and heating element 104 move together as a unit with respect to the ashguard 54 until there occurs engagement of the lugs 84 and the outward annular curl 80 of the friction sleeve, following which the components listed above and the ashguard move as a unit. The heating element 104 is now recessed within the circular edge of the ashguard by 1/4 inch or so. Under such circumstances the annular flange 92 of the friction sleeve 52 is spaced a short distance from the flange 94 of the ashguard 54 while the ignitor plug is out of the socket.

Upon reinstallation in the socket, the knob 51 is depressed a sufficient amount such that, after the ashguard flange 94 engages the socket flange 16, the friction sleeve 52 and spacer member 50 continue to move with respect to the ashguard until the flange 92 engages the flange 94. This corresponds to full retraction of the ashguard with respect to the contact member 106 and heating element 104. At this point the use will experience additional resistance toward further insertion of the knob and spacer member into socket, and the nesting engagement of the flanges 92, 94 will provide a visual indication to the user that the plug is now returned to the normal unenergized or storage position.

The above construction is seen to have the following advantages, resulting in improved operation and long life expectancy. Since the contact areas of the two-part switch are independent of the bimetallic member or disk, the latter does not undergo any deterioration due to arcing or pitting of switch contacts. Also the bimetallic member does not suffer any appreciable wear or abrasion. Accordingly its function is not impaired even after extended periods of use. Moreover, since the member is not a part of the electrical circuit, there is eliminated from the design of the lighter, undesirable variables relating to the physical electrical-resistance characteristics of the member itself, such as the self-heating effect due to current flowing through it, or contact and surface resistances associated therewith.

There is thus retained in the lighter design the high reliability inherent in such a simple bimetallic disk, the latter being virtually unmodified when installed and used in the ignitor device.

The close proximity of the bimetallic member to the heating element results in a relatively thick response, enabling the use of a heating element which heats rapidly at the applied voltage, without danger of over-heating or burnout.

The combination involving the mechanical support for the heating element represents a very workable solution to the problem of prop erly mounting it, at the inner end of an ignitor plug. There is eliminated the use of insulating washers and bushings, thus minimizing the possibility of short-circuiting; simplified as sembly is thus realized, with no sacrifice in overall reliability.

In the present construction, unlike many other cigar lighters built in the past few years, the ignitor plug does not move outwardly from the socket when the heating coil has reached incandescence. But the unit still provides an audible "click" when ready, as the bimetallic member opens the switch. There are no sudden acceleration or deceleration "impulse" forces applied to the heating ele ment, as will be understood. This has been a problem in other lighter designs, since im pulse movements experienced by many of the devices heretofore known resulted in severe mechanical shock to the heating element, these being especially damaging when the element was in an incandescent state. Weakening and fatigue of the element eventually occurred as a result. It should be realized that the heating element ribbon weakens physically as its temperature is increased.Also, by the present construction which involves no bimetallic spring fingers, there is eliminated the possibility of the plug popping completely out of the socket. This was a problem in some prior units, wherein the inertia of the plug as the fingers released the heating element cup could cause the plug to eject.

In the present construction all critical or moving parts are carried in the ignitor plug and not in the socket. Should failure ever occur it is most likely to be associated with parts carried by the plug, and not the socket.

Accordingly, by the present construction, servicing is simplified since it involves a mere replacement of an ignitor plug rather than a repair of the socket. Since the socket contains so few parts, there is little or no occasion for maintenance or servicing of the same. While there are a number of separate components involved in the present lighter, they are readily assembled to one another without reliance on special tools, and without involvement in critical positioning or placement of the parts.

Accordingly, some production steps can be handled by automatic assembly equipment, resulting in low costs, especially where manufacturing runs of several hundreds of thousands of units are being made.

The present lighter construction also features a convenient re-light capability. Following an initial energization, the plug can be quickly re-energized, since the resetting is effected by the depressing movement of the plug.

As a consequence of the features outlined above, many of the undesirable characteristics of prior lighter devices have been eliminated.

There is thus provided a unit having substantially less likelihood of malfunction and failure, especially after a period of use involving thou sands of repeated operations under extremes of temperature normally experienced in auto mobiles and other vehicles.

Variations and modifications are possible.

Claims (38)

1. An automatic cigar lighter, comprising in combination a holder device including a socket having two contacts forming part of a cigar lighter circuit, an ignitor plug receivable in the socket, said plug having a manually operable part, a heating element carried at the inner end of the plug, means for establishing a circuit from the holder device contacts through the heating element, said means including an electrical switch having cooperable parts carried by the ignitor plug, means for closing said switch and energizing said heating element in response to actuation of said manually operable part, and means responsive to heating of said heating element, for opening said switch to de-energize the element, said immediately preceding means including a bimetallic member carried by said plug and having a circuit-opening position and a closedcircuit position, said member having a bimetallic actuator portion which is free and clear of attachment to any other parts, said actuator portion being adapted for abutting engagement with one of the cooperable parts of said switch to effect said opening of the switch.

2. An automatic cigar lighter as claimed in claim 1, and further including means mounting said bimetallic member in the ignitor plug to maintain said bimetallic actuator portion out of contact with any parts of the heating element circuit when the member is in its closed-circuit position.

3. An automatic cigar lighter as claimed in claim 1, wherein said manually operable part of the ignitor plug is movable between deep and shallow positions in said socket, and spring means biasing one of said cooperable switch parts into engagement with the other when the manually operable part of the ignitor plug is disposed in its deep position in the socket.

4. An automatic cigar lighter as claimed in claim 1, wherein said ignitor plug includes means for mounting the heating element at the inner end of the plug, said mounting means comprising a mounting member, and a rivet carried thereby, connected with one end of said element, said rivet having a contact portion at one end, said contact portion constituting one of said cooperable switch parts.

5. An automatic cigar lighter as claimed in claim 3, wherein said ignitor plug comprises a tubular plug body, said one cooperable switch part comprising a contact cup, and means carried by the plug body and providing a guide to enable the contact cup to have limited sliding movement with respect to the body, as the cooperable switch parts are be ing brought into engagement with one another.

6. An automatic cigar lighter as claimed in claim 5, wherein said guide comprises a bearing cup disposed in the tubular plug body, said cups having annular telescoping wall portions respectively slidably engaging one another, said spring means engaging bottom wall portions respectively of said cups.

7. An automatic cigar lighter as claimed in claim 4, wherein said ignitor plug comprises a tubular plug body, the other of said cooperable switch parts comprising a contact cup carried by the plug body, said contact cup having a bottom wall providing a contact surface for engagement with the contact portion of said rivet.

8. An automatic cigar lighter as claimed in claim 7, wherein said bottom wall of the contact cup has an aperture substantially aligned with the axis of said rivet, said contact surface being annular and closely adjacent the walls of the aperture.

9. An automatic cigar lighter as claimed in claim 1, wherein said ignitor plug comprises a tubular plug body, a mounting member carrying said heating element at the inner end of said body, said mounting member having means providing a bearing surface of said plug body, said mounting member being movable between advanced and retracted positions with respect to said plug body, and spring means carried by said body and biasing said mounting member to an advanced position with respect to said body, said mounting member assuming a retracted position with respect to the body when the manually operable part is actuated.

10. An automatic cigar lighter as claimed in claim 1, wherein said ignitor plug comprises a tubular plug body, a mounting member carrying said heating element at the inner end of said body, said mounting member normally engaging pheripheral edge portions of one face of said bimetallic member, and constituting a seat therefor, and a coil spring carried by the plug body and having one end engaging the other face of the bimetallic member, to thereby hold the latter in an operative position against the mounting mem- ber.

11. An automatic cigar lighter as claimed in claim 10, wherein central portions of said other face of the bimetallic member are engaged with one cooperable part of said switch, for effecting actuation of the same.

1 2. An automatic cigar lighter as claimed in claim 10, and further including a rivet carried by said mounting member and secured to one end of the heating element, said rivet projecting beyond adjacent portions of said mounting member, and constituting one of said switch parts, means defining a central aperture in said bimetallic member, portions of said rivet extending through said aperture, for engagement with the other Qf said switch parts during actuation of said switch.

1 3. An automatic cigar lighter as claimed in claim 1, wherein said circuit-establishing means comprises a contact member engageable with one of said socket contacts, and spring means carried by said plug for biasing said contact member into firm engagement with said one socket contact.

14. An automatic cigar lighter as claimed in claim 13, wherein said bimetallic member is disposed intermediate said contact member and said spring-biasing means, said spring biasing means engaging peripheral portions of one face of said bimetallic member to thereby hold the latter in an operative position.

1 5. An automatic cigar lighter as claimed in claim 1, wherein one of said socket contacts comprises a dish-like contact member, said circuit establishing means comprising an annular contact member on the plug, connected with said heating element and cooperable with said one socket contact member, said plug contact member having multiple resilient lugs adapted for engagement with peripheral portions of said dish-like socket contact member.

1 6. An automatic cigar lighter as claimed in claim 15, wherein said heating element is disposed within said plug contact member, said lugs having reinforcing ribs extending toward the heating element and adapted to engage and to provide support for peripheral portions thereof.

1 7. An automatic cigar lighter as claimed in claim 1, and further including a mounting member disposed at the inner end of said ignitor plug, said heating element being carried by said mounting member, one wall of said mounting member being disposed between the heating element and the bimetallic member, said wall having apertures to enable heat from the heating element to be transferred to the bimetallic member by radiation.

1 8. An automatic cigar lighter as claimed in claim 1, wherein said ignitor plug comprises a tubular plug body, and means on said body for mounting said bimetallic member in an operative position lying generally in a plane substantially perpendicular to the axis of the tubular plug body.

1 9. An automatic cigar lighter as claimed in claim 18, and further including an annular mounting member carrying said heating element and disposed at the inner end of said ignitor plug, said mounting member having an annular shoulder engaged with the bimetallic member, and a coil spring disposed in said body and having one end engageable with peripheral portions of said bimetallic member to bias the latter against said shoulder.

20. An automatic cigar lighter as claimed in claim 1, wherein said ignitor plug comprises a tubular plug body, one of said switch parts comprising a movable contact device, and a bearing member carried by the plug body and slidably mounting the contactor device within the tubular body.

21. A automatic cigar lighter as claimed in claim 20, wherein said bearing member is received in the tubular plug body, and com prising spaced-apart outer and inner annular walls, said inner annular wall slidably engag ing the contactor device.

22. A cigar lighter igniting unit, compris ing in combination a heating element having electrical terminal elements, and metallic means simultaneously mechanically securing said terminal elements in spaced-apart relation to constitute a unitary assemblage and insulating said elements from each other, said means comprising an anodized aluminum mounting member having anodized electrically insulating surface areas directly engaged with said terminal elements.

23. A cigar lighter igniting unit as claimed in claim 22, wherein one of said terminal elements is of annular configuration, said heating element being disposed within said one terminal element, the latter being received in the anodized aluminum mounting member, and having an annular external surface area engaging one of the electrically insulating surface areas of the mounting member.

24. A cigar lighter igniting unit as claimed in claim 22, wherein one of said terminal elements has an annular wall and a curledover rim, one end portion of said heating element being juxtaposed to said annular wall, said curled-over rim tightly engaging said one end portion whereby the latter is sandwiched between the curled-over rim and the annular wall, and is both permanently mechanically secured to the wall and electrically connected thereto.

25. A cigar lighter igniting unit as claimed in claim 23, and further including means on said mounting member for securing the said one terminal element thereto.

26. A cigar lighter igniting unit as claimed in claim 25, wherein said securing means comprises retaining lugs on the mounting member, clinched over adjacent portions of the said one terminal element.

27. A cigar lighter igniting unit as claimed in claim 23, and further including a holderdevice comprising a socket having a contact member, said one terminal element including a peripheral flange lying substantially in a radial plane, and a series of lugs extending radially inward from said flange for engagement with the contact member in the holder device socket.

28. A cigar lighter igniting unit as claimed in claim 27, wherein said lugs have reinforcing ribs extended toward the heating element and adapted to engage and to provide support for peripheral portions thereof.

29. A cigar lighter igniting unit as claimed in claim 22, and further including a tubular plug assemblage on which the heating ele ment is disposed, an electrical switch in the plug assemblage, connected in circuit with the heating element and adapted to open the circuit when the element reaches useful incandescence, a bimetallic member carried by the plug assemblage and constituting an operator for the switch, said mounting member being disposed between the heating element and the bimetallic member, and having apertures in its wall to enable heat to be transferred from the heating element to the bimetallic member by radiation.

30. A cigar lighter igniting unit as claimed in claim 22, wherein one of said terminal elements comprises a rivet, one end portion of said heating element being secured to said rivet, means defining an aperture in said mounting member, the wall of said aperture constituting a portion of said insulating surface areas, said rivet being pressed into said aperture and being mechanically secured therein but electrically insulated therefrom, whereby the mounting member is electrically insulated from the heating element.

31. A cigar lighter igniting unit as claimed in claim 22, wherein one of said terminal elements comprises a rivet, one end portion of said heating element being secured to said rivet, means defining a hollow boss in said mounting member, the inner walls of said hollow boss constituting a portion of said insulating surface area, said rivet being pressed into said hollow boss and being mechanically secured therein but electrically insulated therefrom, whereby the mouting member is electrically insulated from the heating element.

32. A cigar lighter igniting unit as claimed in claim 22, wherein said mounting member comprises a mounting cup, one of said terminal elements being of annular configuration, said heating element being disposed within said one terminal element, said one terminal element being received in said mounting cup in nesting relation, and having an annular external surface area engaging one of the electrically insulating surface areas of the mounting cup and being electrically insulated therefrom.

33. An electric cigar lighter, comprising in combination, a holder device including a socket having two contacts forming part of the cigar-lighter circuit, an ignitor plug receivable in the socket, comprising a manuallyoperable part movable in the socket between energizing and de-energizing positions, said plug having a heating element carried at its inner end, means for establishing a circuit from the holder device contacts through the heating element when the said manually-operable part is shifted to its energizing position, the said means including an electrical switch having relatively-movable cooperable contact parts, and means becoming operative in response to heating of said heating element, for operating said electrical switch to break said circuit and de-energize the element, said operating means including a bimetallic member having a circuit-opening position and a closedcircuit position, said bimetallic member having an actuator portion which is free and clear of permanent attachment to any other parts of the holder device, said actuator portion being adapted to cooperate with one of the cooperable contact parts of said switch to effect the operation thereof.

34. An electric cigar lighter as claimed in claim 33, and further including spring means biasing said manually operable plug part to its de-energizing position in the socket.

35. An electric cigar lighter as claimed in claim 33, and further including means insulating said actuator portion of the bimetallic member from said one cooperable contact part of the switch.

36. An electric cigar lighter, comprising in combination a holder device including a socket having two contacts forming part of a cigar lighter circuit, an ignitor plug receivable in the socket, said plug having a manually operable part, a heating element carried at the inner end of the plug, means for establishing a circuit from the holder device contacts through the heating element, said means including an electrical switch having cooperable parts carried by the ignitor plug, means for closing said switch and energizing said heating element in response to actuation of said manually operable part, means responsive to heating of said heating element, for opening said switch to de-energize the element, said immediately preceding means including a bimetallic member carried by said plug and having a circuit-opening position and a closedcircuit position, said member having a central bimetallic actuator portion which is adapted to actuate one of the cooperable parts of said switch to effect said opening of the switch, and clamping means engaging peripheral portions of said bimetallic member, said clamping means comprising an abutment member and a coil spring engaging opposite sides of the bimetallic member.

37. An automatic cigar lighter as claimed in claim 36, wherein said bimetallic actuator portion is free and clear of attachment to any other parts, said actuator portion being adapted for solely abutting engagement with said one switch part.

38. An automatic cigar lighter substantially as hereinbefore described, and with reference to the accompanying drawings.