GB2089012A

GB2089012A - Electric Lighter for Vehicles

Info

Publication number: GB2089012A
Application number: GB8134894A
Authority: GB
Original assignee: IAO Industrie Riunite SpA
Current assignee: IAO Industrie Riunite SpA
Priority date: 1980-12-05
Filing date: 1981-11-19
Publication date: 1982-06-16
Also published as: DE3146881A1; IT8068857A0; ES261885U; IT1166499B; FR2495553A1; GB2089012B; FR2495553B3; ES261885Y; DE3146881C2

Abstract

An electric lighter for a motor vehicle, comprises a sheet metal sleeve (10) in the form of a cylindrical cup for receiving a removable lighter plug (not shown), the sleeve has a circular base wall (14). A riveted central fixing member (34) fixed within the sleeve the diametral yoke (28) of a bimetallic-strip pincer member (26) for receiving a frontal heating element of the lighter plug. Between the yoke and the base wall are a deformable washer (44) of electrically-insulating, heat-resistant sheet material, in contact with the yoke, and a sheet metal plate (46) which is in electrical contact with the base wall. The washer and the sheet metal plate are locked together by the central fixing member (34). The sheet metal plate has a central aperture (50) the edge of which surrounds the fixing member without contacting it. The base wall (14) has an eccentric slit (72) through which a peripheral extension (54) of the plate, which is bent at right angles, extends outwardly of the sleeve. This extension constitutes an electrical earth connection blade. The plate also has a pair of folded tabs (56) on opposite sides of its periphery which embrace the yoke (28) with the interposition of corresponding, deformed, peripheral parts of the insulating washer (44). <IMAGE>

Description

SPECIFICATION Electric Lighter for Vehicles This invention relates to an electric lighter for a motor vehicle, of the kind including a sheet metal sleeve in the form of a cylindrical cup for receiving a removable lighter plug, in which the sleeve has a circular base wall to which is fixed, within the sleeve itself, by means of a central riveted fixing member and with the interposition of an electrically-insulating, heat-resistant element, the diametral yoke of a bimetallic-strip pincer member for receiving a frontal heating element of the lighter plug, in which the central fixing member also retains a pair of blades for electrical connections outside the sleeve, one of which is an earth blade in electrical contact with the base wall of the sleeve and the other of which is isolated from the sleeve and is electrically connected to the yoke of the pincer member through the central fixing member, and in which the peripheral wall of the sleeve has, adjacent the base wall, a pair of diametrally opposed windows in correspondence with which are located the arms of the bimetallic pincer member.

There are well known, and in widespread use, electrical lighters of the aforesaid kind in which the electrically-insulating, heat-resistant element interposed between the yoke of the pincer member and the base wall of the sleeve is constituted by a substantially cylindrical block of steatite or like material. A diametral groove is formed in the face of this block turned towards the base wall in which the yoke of the bimetallic pincer element is housed. The base wall and the face of the block applied against it are formed with mutually interengageable keying elements.

The central fixing member is constituted by a rivet. Due to the mutual engagement of the block and the base wall and the disposition of the yoke of the pincer member in the groove in the base wall, the rotation of the pincer member about the axis of the rivet is prevented so that the arms of the pincer member remain centred in correspondence with the windows in the peripheral wall of the sleeve, which act as heat dissipators.

In known lighters of this kind, the block of steatite or similar material, as well as being expensive is also fragile. As a result of this fragility, it is not infrequent for the block to shatter under the riveting pressure when the rivet is upset.

The object of the present invention is to provide a lighter of this kind in which the angular keying and the electrical isolation of the bimetallic pincer member from the base wall of the sleeve are achieved more ecomomically and, in particular, without the use of an expensive, fragile block of steatite or the like.

According to the invention in its broadest aspect, an electric lighter of the kind referred to is characterised in that the electrically-insulating, heat-resistant element is constituted by a washer of deformable sheet material, that between the washer and the base wall is clamped, by means of the central fixing member, a sheet metal plate in electrical contact with the base wall, which plate has a central aperture the edge of which surrounds the fixing member without contact, that the base wall has an eccentric slit, the plate has a peripheral extension, bent at right angles, and extending outwardly of the sleeve through the slit and constituting the earth blade, and that the plate further has a pair of folded tabs on opposite sides of its periphery which embrace the yoke with the interposition of corresponding, deformed, peripheral portions of the insulating washer.

Thanks to this solution, e keying of the pincer member, such that its two/arms are in correspondence with the windows in the sleeve, is achieved by means of the folded tabs of the plate which in its turn is angularly keyed due to the engagement of its extension in the slit in the base wall. The fragile and expensive steatite block is replaced by a simple and economical washer of sheet material. This material is, advantageously, mica.

An embodiment of the invention will now be described by way of example with reference to the accompanying drawings, in which: Fig. 1 is a longitudinal section of the sleeve of the lighter and of its fixed elements in which the removable lighter plug is also shown engaged in the sleeve in a partially cut-away side elevation: Fig. 2 is an exploded perspective view of the sleeve and its fixed elements; Fig. 3 is a fragmentary longitudinal section taken at 900 to Fig. 1 and on line Ill-Ill of Fig. 1, Fig. 4 is a transverse section taken on line IV IV of Fig. 3, in which the bimetallic pincer member is shown only fragmentarily, and Fig. 5 is a cut-away, fragmentary perspective view, of part of the base of the sleeve and of the elements fixed to it.

Referring to the drawings, an electric lighter includes a sleeve 10 in the form of a cylindrical cup, for example of galvanised steel. The sleeve 10 can be fixed by known means, not shown, for example into a hole formed in a dashboard of a motor vehicle.

The sleeve 10 comprises a peripheral wall, or skirt, 12 and a base wall 14.

In the sleeve 10 is engaged a removable lighter plug 1 6 which includes, among other things, a cylindrical metal body, for example of galvanised steel.

In the body 18 is axially movable, in known manner, a device which includes an external knob 20, a frontal heating element 22 and a shaft 24 which interconnects the knob 20 and the heating element 22. The element 22 is of the well known type of spiral electrical resistance. In the body 18 there is a return spring (not shown) which maintains the device in the withdrawn position in which it is shown.

To the base wall 14 of the sleeve 10 there is fixed, as will be described below, a pincer member 26 formed from a bimetallic strip. The pincer member 26 includes a yoke 28, which extends diametrally of the sleeve 10, and a pair of shaped, springy arms 30 which are intended to receive the heating element 22 when the device, of which the element forms part, is thrust against the force of its spring by means of pressure on the knob 20. The arms 30 are intended to supply electricity to the heating element 22, in known manner, and diverge when heated to allow the release of the device to the rest position shown in Fig. 1.

The arms 30 of the pincer member 26 are each located in correspondence with one of a pair of diametrally opposed windows 32 formed in the peripheral wall 12 of the sleeve 10. The windows 32 allow the circulation of air within the sleeve 10 so as to prevent overheating both of the pincer member 26 and of the heating element 22.

The pincer member 26 is fixed to the base wall 14 by means of a central riveted member. This member is, advantageously, in the form of a copper eyelet 34 which has a preformed annular head 36, a tubular stem 38 and an annular head 40 made by riveting.

The two heads 36 and 40 lock together a set of elements which will now be described in successive order from the interior to the exterior of the sleeve, and from right to left in Figs. 1 to 3.

The first element is the yoke 28 of the pincer member 26 against which the head 36 bears and which has a hole 42 for the passage of the stem 38.

The second element is a simple washer 44 cut from a deformable sheet material which is electrically insulating and resistant to heat. The washer 44 is preferably made from mica.

The third element is a sheet metal plate 46, preferably of galvanised steel. The plate 46 is made by cutting and drawing so as to present a generally circular peripheral edge 48 the diameter of which corresponds to the internal diameter of the skirt 12 for use in centering the skirt itself.

In the plate 46 is formed a circular, central aperture 50 the diameter of which is greater than the diameter of the stem 38 which passes through this aperture. Around the aperture 50 is formed, by drawing, an annular central portion 52 which is axially offset with respect to the periphery of the plate 46.

The plate 46 has a peripheral extension 54, formed by cutting and bending at right angles, which, as will be better seen below, constitutes an earth connection blade.

The plate 46 also has a pair of diametrallyopposed tabs 56 formed by cutting and bending from its periphery.

The tabs 56 embrace the yoke 28 of the pincer member 26, as illustrated in Figs. 4 and 5, with the interposition of opposing peripheral portions 44a of the insulating washer 44. These portions 44a are deformed out of the general plane of the washer 44 during riveting of the eyelet 34.

During this riveting, the central part of the insulating washer 44, which delimits the central hole, is deformed by the riveting compressive forces and is made to fill the space between the edge of the aperture 50 in the plate 46 and the stem 38 of the eyelet 34, as iilustrated at 44b in Figs. 1 and 3. The deformed portion 44b ensures the mutual isolation and the mutual centering of the plate 46 and the eyelet 34.

The axially-offset portion 52 of the plate 46 defines, with the base wall 14, an annular space 58 surrounding the stem 38 of the rivet 34.

Within this annular space is located an annulus 68 of a low melting point metal which is enclosed between the base wall 14 and the offset portion 52. Advantageously, the annulus 68 is constituted by a simple fragment of tin soldering alloy curved so as to form a turn or split ring. The purpose of the fusible ring 68 is to cause, by its fusion, a short circuit between earth, represented by the sleeve 10 and the plate 46, and the eyelet 34, should defective operation of the heating element 22 produce overheating. The short circuit in its turn, and in known manner, results in the breakdown of a protection fuse.

The fourth element of the set is constituted by the base wall 14 which has a wide, central, circular aperture 70 through which the stem 38 passes without contact between the latter and edge of the aperture. The base wall 14 has an eccentric, tangential slit 72 through which the extension 54 projects outwardly to provide the earth connection blade.

A fifth element of the set is a simple insulating washer 74, for example of bakelized material or asbestos board.

The sixth and final element of the set, which is engaged by the riveted head 40, is a transverse part 76 of a lamellar connection element 78 which has a pair of tangs 80 bent at right angles.

One of the tangs 80 serves to connect the pincer member 26, through the eyelet 34, to one pole of a battery (normally the positive pole), the other pole of which is connected to earth through the extension 54. The other tang 80 may be used to connect another load to the battery through the connection element 78.

As will be understood, in the lighter shown, the plate 46 has the following functions:- connection of the sleeve 10 to earth; angular keying of the pincer member 26 so that its two arms 30 are located in correspondence with the windows 32 as a result of the insertion of the extension 54 in the slit 72 and of the fact that the yoke 28 is embraced tightly by the tabs 56 with the interposition of the deformed portion 44a of the insulating washer 44; centering of the whole pack described above and of the eyelet 34 as a result of the engagement of the circular edge 48 with the sleeve 10 and the interposition of the portion 44b of the washer 44 between the edge of the aperture 50 and the stem 38 of the eyelet 34; ; thanks to the centering, it guarantees the isolation of the stem 38 from the eyelet 34 and the edge of the aperture 70 in the base wall 14; it retains, by clamping, the fusible ring 68.

As will also be understood, the formation and the assembly of the set of elements are extremely economical due to the use of simple elements cut from sheet metal and insulating material, and of a fusible element of soldering wire. A further economical factor is the use of the eyelet 34 which is in itself more economical than a fully conventional rivet and which, furthermore, requires a lower pressure than that required to upset a conventional rivet. This lower pressure results in a clamping force on the set of elements between the heads 36 and 40 which is not very high but has been found to be sufficient to maintain the elements of the set firmly together, in that this pressure need not contribute to the angular key ring of the pincer member 26.

Claims

1. An electric lighter for a motor vehicle, of the kind including a sheet metal sleeve in the form of a cylindrical cup for receiving a removable lighter plug, in which the sleeve has a circular base wall to which is fixed, within the sleeve itself, by means of a central riveted fixing member and with the inter-position of an electrical ly-insulating, heat-resistant element, the diametral yoke of a bimetallic-strip pincer member for receiving a frontal heating element of the lighter plug, in which the central fixing member also retains a pair of blades for electrical connections outside the sleeve, one of which is an earth blade in electrical contact with the base wall of the sleeve and the other of which is isolated from the sleeve and is connected electrically to the yoke of the pincer member through the central fixing member, and in which the peripheral wall of the sleeve has, adjacent the base wall, a pair of diametrally opposed windows in correspondence with which are located the arms of the bimetallic pincer member, characterised in that the electrically-insulating, heat-resistant element is constituted by a washer (44) of deformable sheet material, that between the washer (44) and the base wall (14) is clamped by means of the central fixing member (34), a sheet metal plate (46) in electrical contact with the base wall (14), which plate has a central aperture (50) the edge of which surrounds the fixing member (34) without contact, that the base wall (14) has an eccentric slit (72), that the plate (46) has a peripheral extension (54), bent at right angles, and extending outwardly of the sleeve (10) through the slit (72) and constituting the earth blade, and that the plate (46) further has a pair of folded tabs (56) on opposite sides of its periphery which embrace the yoke (28) with the interposition of corresponding, deformed, peripheral portions (44a) of the insulating washer (44).

2. A lighter according to claim 1, characterised in that the sheet metal plate (46) has a central annular portion (52) which is offset so as to define, between this central part and the base wall (14), an annular space (58) thfgh the centre of which passes the fixing member (34), and in that in this annular space (58) is enclosed an annulus (68) of a low melting point metal.

3. A lighter according to claim 2, characterised in that the annulus (68) is constituted by a turn of tin alloy soldering wire.

4. A lighter according to claim 1, characterised in that a central portion (44b) of the insulating washer (44) is deformed due to the compression of the central riveted fixing member (34) so as to fill the space between the edge of the aperture (50) in the plate (46) and the central fixing member (34).

5. A lighter according to claim 4, characterised in that the plate (46) has a peripheral edge (48) which is generally circular and of a diameter corresponding to the internal diameter of the skirt (12) of the sleeve (10) and constitutes a centering element of the group including the central fixing member (34) and the elements (28, 44, 68, 14, 74, 76) clamped by the latter.

6. A lighter according to claim 1, characterised in that the insulating washer (44) is of mica.

7. A lighter according to any one of claims 1, 4, or 5, characterised in that the central fixing member is an eyelet (34) with an annular preformed head (36), a tubuiar stem (38) and an opposite riveted head (40).

8. An electric lighter for a motor vehicle substantially as described with reference to the accompanying drawings.