FR2701438A1 - Removable cap of cigarette lighter, especially for motor vehicles. - Google Patents

Abstract

The removable cigarette lighter cap has a movable part comprising a button (2), an insulating part (3), with a tail (31) attached to the button (2) and connecting to a base (36) from which extends centrally as an axial projection a core (32) serving as a centralizer for a support (7) of a heating body. A return spring (8) is supported on an electrically conductive contact zone (6) through which the central core (32) passes while being in contact with the bottom (36) of the insulating part. The support (7) has assembly tabs (71) passing through said bottom (36) for its assembly with said insulating part (3). Automotive vehicle application.

Description

The present invention relates to removable cigarette lighter plugs,

  especially for motor vehicles. As is known and as described for example in document FR-A-2,457,787 (FIG. 1), the plug is adapted to be housed inside a hollow body, said ignition body, fixed directly or indirectly, via an illuminating ring, to a wall of the vehicle. This electrically conductive body is provided with electrical supply tabs connected to the terminals of the vehicle battery, as well as a bimetallic end whose hook-shaped ends are intended to cooperate with a cup of the plug receiving a heating electric resistance, forming heating body. This cup is secured to a resistance support, itself secured to a movable button against the action of a spring bearing on a

  guide belonging to a guide part.

  When the electrically insulating button is depressed, the blades of the bimetallic strip engage with the cup and an electrical circuit is established between the tabs through the bimetallic strip, the heating resistor, the resistance support, the return spring, the guide, a sunshade, that includes the cap, and the ignition body. The blades of the bimetallic strip, heated by the resistor, are curved so that, for a certain temperature of the resistance, the spring exerts its return action and releases the cup. It then remains for the user to extract the cap It is therefore important that the

  button is well thermally insulated.

  In document FR-A-2 457 787 the button is connected to the resistance support via a threaded metal rod and two insulating washers, arranged on either side of the support and a conductive bowl of electricity in contact with the bottom of the

  support and serving as seat to the return spring.

  All this makes the button is not as cold as desired. To reduce the temperature of the button, provision has already been made (FIG. 2) for an arrangement in which the button 2 is connected to a thermally and electrically insulating part 3, provided with a button assembly tail 2 and a central core. mounting bracket 7 of the

heating resistor 13.

  The support 7 is fitted on said core, forming a centralizer, which is hollowed out locally for

  crimped fastening of the support 7 on the part 3.

  This piece 3 also has a bottom, in the form of a bowl, for receiving the turns of one of the ends of the return spring 8, the other end bears on the fixed guide 5 overmolded on a

  flange 15 This guide 5 is coupled to the ash screen 12.

  Moreover, a decorative washer 54 is

  mounted between the piece 3 and the button 2 gripping.

  All this is satisfactory from a cold button thermal point of view - but requires having an insulating piece with a large mounting core

length.

  In addition, the electrical contacts are made locally between the last turn of the spring 8, in support

on the piece 3, and the support 7.

  The present invention aims to overcome these disadvantages and thus to create, in a simple and economical way, a new cold button cap, while having a shortened insulating piece and increasing the

  areas of electrical contact of the return spring.

  According to the invention, a plug of the above type

  indicated is characterized in that the return spring is supported on a contact area, electrically conductive, traversed by the central core of the insulating part being in contact with the bottom thereof and in that the support has legs assembly passing through said bottom for its assembly with the insulating part. Thanks to the invention, the mounting core is shortened and the electrical contact areas of the spring increased thanks to the contact zone.

  possible to shorten the cap and therefore

  cigars and a larger electric current can cross the plug because of the increase in

electrical contacts.

  In addition the core is simplified since the assembly of the support is achieved using the assembly tabs The core therefore no longer has an assembly function. The insulating part, making it possible to obtain a cold button, is therefore easier to produce and more resistant because the openings for passage of the assembly tabs are smaller than the openings of the prior art.

  provided for the passage of the crimping tool.

  The bottom of this insulating piece remains

globally unchanged.

  It will be appreciated that the phenomena of incrustation of the return spring in the insulating part are reduced or even canceled by the contact zone, for example

  in the form of an optionally fragmented washer.

  The return spring therefore operates in good conditions for the benefit of proper operation and

  a long life of the cap.

  The following description illustrates the invention

  with reference to the accompanying drawings, in which: FIG. 1 is a view in axial section of a plug according to the invention; FIG. 2 is a view identical to FIG.

a plug of the prior art.

  In FIG. 1, the elements common to the stopper according to the invention and to the stopper according to the prior art

  will be assigned the same reference signs.

  Thus, the stopper, of annular shape here, comprises a guiding portion 5, 12 of hollow form and a movable part 2,3, 7, 9, 11 housed partly inside the guiding portion while being movably mounted by relative to this one against the return spring 8, here of the type coil spring shaped

barrel.

  This spring 8 builds on one of his

  ends on the guide portion 5,12.

  This part includes guide 5 harnessed by

  form cooperation, in a manner known per se, to the

  ashes 12 with the help of burnt out of the ashes

in slots of the guide 5.

  The sunshade 12 surrounds the guide 5 and is able to come into electrical contact with the ignition body. It is made of electrically conductive material,

  here metallic, just like the guide 5.

  The guide 5 has a bottom perforated centrally for passage of the support 7 of resistance It is on this bottom, whose inner periphery has an axial return in the form of a ring for guiding the support 7, that takes

  support at one of its ends the spring 8.

  The movable part comprises electrically conductive parts, here metallic, namely the cup 11, the fastening rivet 9 and the hollow support 7 of resistance It comprises electrically and thermally insulating parts namely a washer 10, the insulating part 3, the button 2 and an envelope 1, styling fixing the button 2, and a decoration piece 4 interposed between the assembly 1-2 and the face

  dorsal 37 of the bottom 36 of the piece 3 described below.

  More specifically, the support 7, in the form of a bush, has a bottom with a central hole for passage of the shaft of the rivet 9 allowing the cup 11 to be assembled to the support 7 with the interposition of the washer 10.

  as described in FR-A-2,457,787.

  As can be seen in FIG. 2, this cup receives internally the heating resistor 13

spiral shape.

  The edge of this cup is folded over the outer periphery of the resistance 13, of curved shape,

with interposition of a ring 16.

  An electrically insulating washer 14 is housed in the bottom of the cup to receive bearing the outer turn of the heating coil 13, the central zone of this washer being in abutment against an annular shoulder inclined wall provided on the rivet 9 having an axis split end for fixing

  the inner end of the spiral.

  The other end of the rivet is folded

bottom contact 7.

  The cup 11 is intended to cooperate, in the aforementioned manner, with the blades of the bimetal strip when the

  button 2 is depressed by the user inside the screen.

  ashes 12 (the spring 8 being compressed).

  The insulating part 3 carries the support 7 and has a tail 31, here fluted, forcibly engaging in a blind hole of the button 2 for assembly and connection with the latter. Alternatively, it is possible to proceed by bonding , ultrasonic welding,

force fitting or other.

  This tail 31, on the one hand, is connected centrally to a bottom 36, in the form of a bowl, having at its outer periphery an annular rim 34 of axial orientation, and, on the other hand, through the piece 4, of shape hollow, resting by its annular flange on the dorsal face 37, turned towards the button 2, bottom

36.

  The rim 34 serves to guide the movable part by contact with the internal bore of the guide 5, which surrounds the core 32 and the support 7, the button 2, as well as the part 4, projecting in axial projection with respect to said guide 5, in order to be seized by the occupant of the vehicle. A core 32 extends centrally in axial projection from the bottom 36 and towards the

cup 11.

  This core 32 has a free end of penetrating shape, here chamfered, for penetration and fitting inside the support 7 The core 32 has a shape complementary to that of the internal bore of the

  support 7 and serves as a centering device thereof.

  More precisely, to reduce the height of the central core 32, to simplify the part 3, and to improve the electrical contacts, according to the invention the return spring 8 bears on an electrically conductive contact zone 6, through which the central core 32 passes through. the insulating part 3 being in contact with the bottom 36 thereof, and the support 7 has assembly tabs 71 passing through said bottom 36 for its

  assembly with said insulating part 3.

  Thus the last turn of the spring 32 is wedged between the zone 6 and the support 7, so that the electrical contacts are of greater extent, said spring allowing the passage of the current during the

heating the cup 11.

  Here the contact zone 6 consists of an electrically conductive contact washer and three tabs 71

  regularly distributed circularly are provided.

  Each of these tabs passes through an opening 33 provided for this purpose in the bottom 36 and has its end folded transversely in contact with the dorsal face 37 of the bottom 36. The tabs 71 are folded in Figure 1

  transversely in the direction opposite to the axis of the plug.

  Thus the tabs 71 extend axially in the direction of the button 2 and extends the support 7 These tabs therefore extend axial projection relative to

the free end of the support 7.

  The washer 6 reduces the phenomena of incrustation of the spring 8 in the bottom 36 and ensures a

  good electrical contact with this one.

  The means for assembling the support 7 to the workpiece 3

  therefore have a reduced number of parts.

  It will be appreciated that the hollow-shaped decoration piece 4 constitutes a mask protecting the end of the tabs 71. These tabs 71 pass through the washer 6

  the favor of slash 61 assembly thereof.

  Thus this washer 6 is applied against the front face 35, facing the cup 11, of the bottom 36

  being assembled by the legs 71.

  The punctures 61 penetrate the openings 33, so that a good immobilization of the washer 6 and

of the support 7 is obtained.

  It will be noted that the height of the centralizing core 32 is less than the greatest height of the rim 34, delimiting with the core 32 a receiving groove for

the washer 6 and the spring 8.

  Of course, the assembly of the support 7 with the part 3 can be achieved by means of assembly means comprising a washer in contact with the dorsal face 37 and traversed by the tabs 71, the ends of which are crimped in contact with said In a variant, an assembly may be provided by means of a Belleville washer, in contact with the face 37, with internal tabs gripping on the assembly tabs 71.

  gluing the tabs on said washer.

  It will be appreciated that the axial size of the plug can be reduced by virtue of the reduced height of the plastic core 32, just like the button 2 and the envelope 1. These parts can easily be produced by molding, the mold of the insulating part being simplified.

  compared to that of Figure 2.

  As will be understood during manufacture, the assembly of the support 7 of the washer 6 is first carried out with the part 3, then at the fixing of the button 2 coated with its envelope 1 on the tail 31 with the interposition of the hollow part 4 for protecting the

legs 71.

  Naturally, the present invention is not limited to the embodiment described. In particular, the return spring could be constituted for example by a stack of Belleville washers surrounding the support. The shape of the stopper can be any and depends solely on the form of the ignition body serving as a receptacle for said removable plug Thus the insulating part 3, annular in Figures 1 and 2, like the other parts of the plug, may have another

form.

  The heating resistor 13 generally forms a heating body and can be replaced for example by an electrically conductive ceramic-based resistor or a high temperature ceramic resistor as described in FIG.

document FR-A-2 640 803.

  Alternatively some of the tabs 71 may be used for positioning Thus at least one of the tabs 71 may be longer than the others and used for angular indexing of the support 7 relative to the workpiece

  insulating 3 This tab can be folded or not.

  In a general manner, the tabs 71 can also be folded transversely in the direction of

  the axis of the button or in both directions.

  The electrical contact washer 6 can be fixed by overmolding at the bottom 36 so that the presence of the punctures 61 is no longer necessary, the internal bore of

  this washer allowing the passage of the legs 71.

  This washer can be in one piece with the support 7 Indeed one can form at the free end of the support 7 (the one opposite the bottom bearing the cup 11) a collar interrupted by the legs 71 In this

case, the washer 6 is fragmented.

  Alternatively the contact zone may be obtained by metallization of the face 35 of the bottom 36 and more precisely of the bottom of the groove defined by the core 32 and the flange 34. For example, it may be coated with a metallic paint, and that eventually a

part of the core 32.

  The tabs 71 may be anchored in the bottom 36. For example, each leg is provided on each of its lateral faces with a projection in the shape of a point of a

alone holding with the paw.

  These projections are force-fitted into the openings 33 and cut grooves, so that the

  protrusions constitute means of attachment.

  In a variant, the projection may consist of a

  inclined tongue cut in the leg.

  In this case it is possible to fix the contact washer 6 on the face 35 by gluing, or alternatively to proceed to a

overmolding.

Claims (9)

  1 removable cigarette lighter cap, in particular for motor vehicles, of the kind comprising a guiding portion (5, 12) of hollow form and a movable part (2,3, 7, 9, 11) housed in part to the interior of the guide portion (5, 12) being movably mounted relative thereto against a return spring (8) resting on the guide portion (5, 12), said moving part comprising a button (2), made of electrically and thermally insulating material, an electrically and thermally insulating piece (3), said insulating piece, with a shank (31) fixed to the button (2) and connected to a bottom (36) to from which extends centrally in axial projection a central core (32) serving as a centering device for a support (7) of a heating body (13), characterized in that said return spring (8) bears on an area electrically conductive contact (6) through which the central core (32) of the insulating part (3) passes through. t with the bottom (36) thereof, and in that the support (7) has assembly tabs (71) passing through said bottom (36) for assembly with said part insulation (3).   2 cap according to claim 1, characterized in that each of the assembly lugs (71) through an opening (33) provided for this purpose in the bottom (36) and its end folded transversely to the contact   the dorsal face (37) of the bottom (36).   3 cap according to claim 1 or 2, characterized in that the support (7) has at least   a longer tab than the assembly tabs (71).   4 cap according to claim 1 or 2, characterized in that the assembly of said support (7) with the insulating part (3) is carried out using a washer in contact with the dorsal face (37) of the bottom ( 36) and traversed by the assembly tabs (71), whose   ends are crimped in contact with said washer. Stopper according to any one of   Claims 1 to 4, characterized in that the area of   contact consists of a contact washer (6) in one piece with the support (7) and is formed in favor of a flange, that has the free end of said support (7), said flange being interrupted for   forming the assembly tabs (71).   6 Stopper according to any one of   Claims 1 to 4, characterized in that the area of   contact consists of a contact washer (6) fixed on   the bottom (36) of the insulating piece (3).   7 Stopper according to any of   Claims 1 to 4, characterized in that said area   contact consists of an electrically conducting contact washer (6) and that the assembly tabs (71) pass through said washer (6) at the   favor of puncturing (61) assembly thereof.   8 Stopper according to any one of   Claims 1 to 4, characterized in that the area of   contact consists of a metallization of the bottom (36) of the insulating part (3).   9 Stopper according to any one of   preceding claims, wherein a hollow part   of decoration (4) is interposed between the button (2) and the insulating part (3), characterized in that the decoration piece (4) constitutes a mask for the ends legs (71).   10 Stopper according to any one of   Claims 1 to 9, in which the insulating part (3)   has at its outer periphery an annular flange (34) of axial orientation, characterized in that the height of the central core (32) is smaller than the largest height of said flange (34).