GB2366086A - Electrical connection for heated car mirror - Google Patents

Abstract

A heatable mirror (10) includes a backplate (11) supporting a reflector substrate (12); and a heating material such as a PTC layer (16). The backplate (11) includes an aperture (13) communicating with the heating material and has integrally formed therewith an upstanding housing (17) having a hollow interior (19) communicating with the aperture (13). The housing (17) includes an opening (23) for receiving a conductor terminal (26) intended to contact the heating material; and a locking plug (27) for releasably retaining the conductor terminal (26) in the hollow interior (19). The arrangement of the invention avoids the need for a soldered connection to the heating layer.

Description

2366086 A MIRROR AND A MIRROR ASSEMBLY This invention relates to a mirror;

and to an assembly including a mirror.

5 In the automotive industry, and in other industries, there is a need for heatable mirrors that resist or clear misting and can melt frost. Such a mirror is usually positioned on the exterior of a vehicle as a rear view mirror and includes an electric heater element for heating the reflective material of the mirror, as desired, under control of switches and controllers located lo elsewhere on the vehicle.

In the automotive industry in particular there is a need for such a mirror that may be mass produced (for example in production runs of tens of hundreds of thousands) and readily stored or transported ready for installation on a 15 vehicle. Such a mirror must be effective in clearing condensed or frozen water, from the mirror reflector, when assembled into a vehicle.

It is known to provide a mirror in which a layer of a positive temperature coefficient (PTC) material is bonded to the rear (non- reflecting) surface of 20 the mirror reflector.

The PTC material is electrically conducting and is such that its temperature increases, usually up to a maximum determined by the nature of the PTC material, when an electric current flows through it.

In the known mirror the PTC has bonded to its rear surface, remote from the reflector of the mirror, a series of conducting tracks (eg. of printed, etched or deposited copper or silver) that when connected in an electrical circuit cause heating of substantially all the PTC layer. As an alternative to 30 conducting tracks, regions of conducting material (that may also be eg.

I printed, etched or deposited copper or silver) may be applied to the rear surface.

One way of bonding the PTC material to the mirror reflector is to 5 manufacture a self-adhesive sheet including a layer of PTC material and a conducting material bonded to the PTC material. The sheet has on an exposed face adjacent the PTC layer an adhesive material for securing the sheet to the mirror reflector with the PTC layer in heat conducting contact with the reflector substrate. The adhesive typically is a high track adhesive.

A conductor tag or terminal of L-shaped profile is conductingly secured eg. by soldering or riveting onto the sheet such that the terminal is in good electrical contact with the conducting tracks. The terminal protrudes rearwardly from the mirror via an aperture in a moulded backplate that 15 covers the PTC layer. The backplate electrically insulates and prevents damage to the PTC layer and provides thermal insulation thereby minimising heat loss from the rear surface of the PTC layer.

Another form of mirror includes (instead of the PTC layer) a constant 20 wattage resistive heater including a substrate carrying an electrically insulating layer on its rear surface. A layer of resistive material is applied to the insulating layer as one or more conductive tracks with connecting means, essentially the same as the L-shaped terminal described hereinabove, rivetted or soldered thereto in conducting contact with the 25 track. The tracks of the conductive layer may be formed, eg. by printing, in the same way as the tracks disclosed hereinabove, but the resistivity of the tracks is selected to provide a desired amount of resistive heating.

The heating components of this form of mirror may also be supported on a 30 self-adhesive sheet, as in the case of the PTC version.

2 Regardless of the precise heater design, the soldered terminal is shaped to receive a crimped connector that is conductingly connected to a conductor wire forming part of a vehicle wiring harness. In practice there are two of 5 the soldered terminals, for connection of both the high and low potential sides of the harness to the mirror to allow current flow around the network of conducting tracks and hence heating of the mirror.

When connected to the wires of the harness the mirror is mounted in a shell Io that surrounds the rear (non-reflecting) side of the mirror and provides an aerodynamic cover for the non-reflecting parts. The shell usually also contains a two degree of freedom (d.o.f.) actuator and a pivoting mounting for the mirror,, that are used for remotely adjusting the orientation of the mirror from within the vehicle.

Although the aforesaid, known mirror is highly successful, there is scope for still further improvements in the art of heatable mirrors.

According to a first aspect of the invention there is provided a heatable 20 mirror comprising:

a backplate supporting a reflective member; an electrically conducting or resistive heating material, for heating the reflective member, between the backplate and the reflective member, the backplate including at least one aperture communicating with the heating 25 material or with a conducting material in conducting communication therewith; and a housing having a hollow interior communicating with the aperture, the housing including:

(i) an opening for receiving a conductor terminal; and 30 (ii) a retainer for releasably retaining a conductor terminal within 3 the housing in conducting contact with the heating material or the said conducting material via the aperture.

The presence of the aperture and the hollow housing permit the use of 5 crimped terminals, connected to the wires of the wiring harness, for supplying current to the heating material via the conducting tracks. As alternatives to crimped terminals it is possible within the scope of the invention to use eg. welded, soldered or otherwise secured terminals.

lo The use of the aperture and housing offers the following advantages:

(i) During manufacture of the mirror there is no need for the step of soldering of the tag to the conducting tracks on the heating material.

This eliminates the cost of the tag and the solder; and saves time during manufacturing of the mirror.

(ii) The aperture and housing simplify installation of the mirror onto a vehicle, since the step of inserting a crimped terminal, that is already secured to a harness, into the aperture is simpler and quicker than attaching a connector to the prior art soldered terminal.

(iii) When manufactured as a conducting material/PTC sheet as aforesaid, the sheet has a more even profile than in the prior art arrangement including protruding terminals. Consequently sheets constituting part of the invention may be more densely packed, stored and transported, than the prior art sheets.

(iv) The use of the housing and the absence of the soldered terminals reduce the risk of damage to the heater connections during transportation and installation of the mirrors.

4 (v) The arrangement of the invention reduces the number of interconnects in the mirror assembly from three, in the prior art, to two, thereby improving reliability of connection of the mirror in use.

(vi) The prior art, soldered terminals required the presence of a pad of the material of the conducting tracks, to ensure good contact, even though the conducting tracks are not on the whole as wide as the pad. The elimination of the soldered contact allows use of a smaller pad.

10 Since the pad may be a layer of copper or silver, this results in cost savings. Also, the pads sometimes result in cold spots on the mirror surface. The use of smaller pads reduces the sizes of the cold spots.

(vii) The housing provides a degree of inherent environmental protection 15 for the conductor terminal that is not easily possible in the prior art arrangement.

Conveniently the mirror includes a locking plug at least part of which is releasably receivable in the hollow interior, for retaining the conductor 20 terminal, the locking plug including a resiliently deformable detent that is releasably engageable with a formation on the housing; and a restraint member for engaging a said conductor terminal and securing it in the hollow interior when the detent engages the formation.

25 This advantageously provides a ready means for releasably securing the connector terminal in place in the housing.

More preferably the hollow interior of the housing includes one or more walls defining respective chambers for the locking plug and a said terminal, 3o an aperture in a said wall communicating between the chambers whereby on insertion of the locking plug into the hollow interior the restraint member passes through the aperture to engage the conductor terminal.

The use of separate chambers for the conductor terminal and the locking 5 plug conveniently means that the conductor terminal may be constrained in all directions, other than the direction of its insertion and removal, by the chamber walls. The protrusion of part of the locking plug, from the plug chamber into the terminal chamber, provides for constraint of the conductor terminal in the said direction of insertion and removal in a simple and io reliable manner.

In particularly preferred embodiments the formation in the housing is an aperture and the detent is a harpoon-type detent that engages the aperture on insertion of the locking plug into the hollow interior. These features 15 advantageously assist in permitting mass production of the components of the invention.

Conveniently the locking plug is insertable into the hollow interior via an opening, the said opening and the profile of the locking plug being such as 20 to permit insertion of the locking plug in a limited member of orientations. This advantageously permits insertion of the conductor terminals in a preferred orientation. This helps to minimize assembly errors.

In particularly preferred embodiments the housing is integral with the 25 backplate. More particularly the housing and backplate are injection moulded, for example from ABS.

In practical embodiments the backplate includes a plurality of the apertures for connecting a corresponding plurality of conductor terminals to the 3o heating material. This of course permits connection of the heating material 6 and (if present) the conductor tracks in a conducting circuit.

In one embodiment of the invention there is a plurality of the housings and locking plates corresponding in number to the plurality of apertures. Thus 5 in this embodiment each aperture is associated with its own housing and locking key, that retains a single conductor tenninal in contact with the heating material or a conductor track thereon.

This embodiment is advantageous when the conductor tracks are spaced far io apart from one another, eg. by a distance of about 30mm.

In an alternative embodiment the mirror includes a pair of the apertures in the backplate and a common housing for the said pair of apertures, the common housing including a hollow interior communicating with the said 15 apertures and the retainer releasably retaining a pair of conductor terminals within the housing in conducting contact with the heating material via the said apertures.

In this embodiment, that is preferably suited to arrangements in which there 20 is limited space within the overall mirror body, a single housing and locking plug retain a pair of the conductor terminals.

More specifically the locking plug preferably includes a pair of restraint members respectively for engaging the conductor terminals and securing 25 them in the hollow interior when the detent engages the formation. This conveniently permits the locking plug easily to retain two conductor terminals in the common housing.

When the housing is a common housing for two conductor terminals, the 30 walls define respective said chambers for the locking plug and each of the 7 conductor terminals, each said wall that separates the locking plug chambers from a said conductor terminal chamber including a respective aperture communicating between adjacent chambers whereby on insertion of the locking plug into the hollow interior the restraint members each pass 5 through a respective aperture to engage a conductor terminal.

This construction advantageously facilitates the use of a single locking plug to retain two conductor terminals. It is therefore advantageous, in preferred embodiments of the invention, for the or each locking plug to include a io plurality of resiliently deformable detents, eg. of the harpoon type, that are releasably engageable with a corresponding plurality of formations.

Preferably the heating material is or includes a layer of PTC material.

15 Alternatively the heating material is or includes a layer of electrically insulating material that, in conjunction with appropriately chosen conducting tracks, defines a constant wattage heater.

The invention is also considered to reside in a mirror assembly including a 20 mirror as defined herein and having secured therein one or more conductor terminals in conducting contact with the heating material.

Preferably the or each conductor terminal is a crimp-type terminal conductingly crimped onto a conductor wire and including a resiliently 25 deformable, conducting portion for engaging the heating material and/or a conductor thereon.

The use of a crimp-type of terminal including a resiliently deformable, conducting portion that engages the heating material or a conductor track 30 thereon advantageously encourages wiping of the heating 8 material/conductor track by the conductor terminal each time the mirror assembly is assembled. This may occur eg. on initial installation of the mirror of the invention into a vehicle; and each time the mirror of the invention is so installed following repair or replacement of components.

5 The wiping action of the terminal tends to remove dirt, oxides and other low conductivity particles from the region of contact of the conductor terminal with the heating material or conductor track.

Conveniently the heating material in the mirror of the invention is or io includes a layer of PTC material. Alternatively the heating material is or includes a layer of electrically insulating material.

The invention also resides in a mirror assembly, as defined herein, in which the conductor wire is connected to or forms part of a vehicle wiring harness.

Preferably the mirror assembly of the invention includes an insulating boot covering the or each conductor terminal and closing the opening in the housing, the boot including one or more apertures for passage of a conductor wire therethrough. The boot provides additional environmental 20 protection for the conductive components of the mirror assembly.

There now follows a description of preferred embodiments of the invention, by way of non-limiting example, with reference being made to the accompanying drawings in which:

25 Figure I shows a cross-section through part of a typical mirror, including a PTC layer as the heating material; Figure 2 shows a cross-section through part of another kind of mirror, in which the heating material is an electrically insulating layer; Figure 3 shows, in exploded perspective view, part of a first 3o embodiment of a mirror, in accordance with the invention; and 9 Figure 4 shows, in exploded perspective view, part of a second embodiment of a mirror, in accordance with the invention.

Referring to Figure I there is shown a known mirror 10 comprising a 5 reflective mirror substrate 12 provided by a glass sheet with a reflective coating 14 on a rear surface thereof. In Figure 1, the front surface is shown facing downwardly and the rear surface 14 facing upwardly which is a suitable orientation for manufacture of the first illustrative mirror. The mirror substrate has a layer 16 of electrically conductive material namely a io positive temperature coefficient resistive material (PTC material) applied to the rear surface 14. To the layer 16 are applied a series of electrically conductive tracks 18 configured to provide an electrical power supply to the PTC layer which provides a resistive heating element. PTC heating elements are known to those skilled in the art.

The mirror 10 further comprises connecting means, in the form of Lprofile tag 20 soldered, rivetted or otherwise conductingly connected to a conducting track 18, for connecting an electrical supply to the pattern of conductive tracks 18 so that an electric current can be passed through the 20 conductive tracks 18 to the PTC layer 16 whereby to provide resistive heating of the mirror. A layer 22 of electrically insulating polymeric material is applied over the top of the layer of reflective material on the rear surface 14 of the mirror substrate thus to electrically insulate the PTC layer from the reflective coating. The layer 22 is sufficiently thin and heat 25 conductive to not significantly restrict transfer of heat from layer 16 to the mirror substrate and may assist in providing an anti-shatter coating for the mirror.

An electrically insulating sealing layer 24 is applied over the conductive 30 tracks 18 and the PTC layer 16 at the rear surface 14 of the substrate 12.

The layer 24 provides electrical insulation for the circuitry and an environmental seal preventing contamination of the electrical circuitry by dirt or water. The layer 24 is also chosen to provide a shatter resistant coating for the mirror which minimises the risk of glass fragments being 5 forcibly ejected if the mirror substrate is broken. As can be seen viewing Figure 1, the connecting means 20 extends through an opening in the layer 24.

In the manufacture of the mirror 10 of Figure 1, the conductive tracks 18 are io preferably applied by screen printing an electrically conductive ink onto PTC layer 16 on the rear surface of the mirror substrate.

In another known arrangement the tracks 18 are printed directly onto the insulating layer 22. The PTC layer is then applied over the pattern of 15 conductive tracks 18,, leaving a sufficient opening for securing of the terminal 20.

Figure 2 shows in cross-section a further, known mirror 10 including a constant wattage resistive heater. Mirror 10 in Figure 2 comprises a 20 substrate 12 carrying an electrically insulating layer 22 on its rear surface 14. A layer of resistive material is applied to the insulating layer 22 as a conductive track 18 with connecting means 20, similar or identical to terminal 20 of Figure 1, in an appropriate position. A sealing layer 24 is applied over the conductive track 18.

The tracks 18 of the mirror 10 of Figure 2 are printed in the same manner as the tracks 18 in Figure I but the ink is selected to have a resistivity appropriate to provide a required amount of resistive heating from the tracks 18. The tracks 18 are positioned eg. following a tortuous path to provide a 3o desired heating performance for example uniform heating over the area of 11 the mirror 10.

Referring now to Figures 3 and 4 there are shown mirrors 10, and parts of mirror assemblies, in accordance with the invention. The mirrors 10 of 5 Figures 3 and 4 are of similar basic construction to the mirrors 10 of Figures I and 2, the laminated structures of which are in accordance with an aspect of the invention.

Mirror 10 of Figure 3 includes a backplate 11 that supports a reflecting i o member that may be in the form of substrate 12 as shown in Figures I and 2.

An electrically conducting layer such as PTC layer 16; or alternatively an insulating layer 22, may serve as a heating material, in the manner and 15 construction shown in Figures I and 2, lying between the backplate 11 and the reflective member 12.

In the embodiments of Figures 3 and 4 the orders of the various layers may be eg. as shown in Figure 1 or Figure 2, although alternative arrangements 20 (such as those in which conducting tracks lie in direct contact with a PTC layer, for example) are possible.

Backplate 11 includes a through going aperture 13 (shown in dotted lines) communicating with the heating material 16/22, or, depending on the 25 precise design of the mirror 10, with a conducting material in conducting communication with the heating material.

The conducting material in the embodiments shown takes the form of one or more of the electrically conducting tracks 18. The material need not be laid 30 in tracks. Other patterns and shapes of the conducting material are possible 12 within the scope of the invention.

Backplate 11 includes a cuboidal housing 17, defined by interconnected outer walls 17a- I 7d, that is upstanding from the rear face of backplate 11 5 when the mirror 10 is oriented as shown. Housing 17 has a hollow interior 19 and includes an opening 23 for receiving a conductor terminal 26, described in more detail below, when the mirror 10 forms part of a mirror assembly according to the invention. Of course the invention embraces within its scope non-cuboidal housings including but not limited to eg.

io domes and other tapering shapes; irregular, flat sided shapes; and noncuboidal, regular shapes.

Mirror 10 also includes a retainer in the form of releasable locking plug 27 that is receivable in hollow interior 19 via opening 23, in a manner 15 described below. Locking plug 27 releasably retains a terminal 26 within the housing 17 in conducting contact with either the heating material (be it a PTC material or a resistive heating material); or with a conducting track 18, depending on the design of the layered part of mirror 10.

2o At least a part, and in practice almost all, of locking plug 27 is receivable within hollow interior 19. Locking plug 27 includes an upper grip portion 29 having depending downwardly therefrom a resiliently deformable detent 28 that in the embodiment shown is of the harpoon type. Grip portion 29 is not an essential part of the locking plug 27. Grip portion 29 assists a user to 25 assemble and dismantle the connection, but its function may be provided by another means such as a slot for a screwdriver or another tool; or it may be dispensed with entirely.

Harpoon type detent 28 is defined by a limb 31 depending downwardly 30 from grip portion 29 and having extending from its lower, free end 3 1 a, an 13 integrally formed hairpin member 28a that extends upwardly towards the underside of grip member 29. Part way between free end 31a and grip member 29, hairpin member 28a includes a barb 28b the shoulder of which faces grip member 29.

The material of hairpin member 28a (and in practice of the entire locking plug 27, since in preferred embodiments the locking plug 27 is moulded as a single item) is resiliently deformable to permit sprung movement of hairpin member 28a, and hence the barb, towards and away from limb 3 1.

In another arrangement the upper end of hairpin member 28a is spaced from the underside of grip member 29. In this embodiment the connection to limb 31 at the base of hairpin member 28a may be thickened to provide a preferred spring force in the hairpin member 28a.

On insertion of locking plug 27 into hollow interior 19 in the orientation shown in Figure 3, the upper face of the barb of detent 28 engages a formation, in the form of rectangular aperture 32 in the wall 17a of housing 17 releasably to retain plug 27 in interior 19.

The action of barb 28b in aperture 32 is the per se known action of a resilient harpoon detent, in that the said face of the barb engages the underside of the aperture 32. For the avoidance of doubt the aperture 32 need not extend as shown all the way to the base of housing 17 adjacent the 25 remainder of back plate 11; and indeed aperture 32 could be replaced by a recess formed in the interior surface of a wall of housing 17. These embodiments may reduce the risk of water seepage into the housing.

In a simple form, the locking plug may omit resiliently deformable parts. In 30 this form of the invention, the plug may include eg. a solid protuberance, 14 whereby the locking plug will function in a manner similar to a wedge to retain the terminal 26 within the hollow housing.

Yet a further possibility, that is also within the scope of the invention, is to 5 provide a protuberance, that may be solid or resiliently deformable as desired, protruding from an interior wall of the housing to wedge or otherwise retain the locking plug 27 in the housing. In this embodiment the locking plug 27 may if desired omit protuberances such as barb 28b; or such features may be retained for interengagement with a housing-mounted lo protuberance.

Locking plug 27 optionally includes a restraint member in the form of downwardly extending wall 33 that is perpendicular to the face of limb 31 remote from detent 28. The main purpose of restraint member 33 is to 15 retain, in a manner described below, conductor terminal 26 within housing 17 when the mirror 10 forms part of an assembly.

The interior 19 of housing 17 includes a wall 34 that interconnects opposed walls 17b, 17d of the housing. Wall 34 extends from opening 23 to the 2o bottom of the interior 19, thereby dividing interior 19 into two chambers 19a, l9b respectively for receiving the locking plug 27 (in chamber 19a) and the conductor terminal 27 (in chamber 19b).

Wall 34 includes an elongate aperture 36 that provides communication 25 between the locking plug chamber 19a and the conductor terminal chamber 19b. When locking plug 27 is inserted into chamber 19a after insertion of conductor terminal 26 into chamber 19b, restraint member 33 engages a protrusion 25 formed on the body of terminal 26 on its side adjacent aperture 36 and urges conductor terminal 27 downwardly so that the lower end of terminal 27 extends through aperture 13 to engage eg. conductor track 18 visible in Figure 3.

Clearly the action of detent 28 locks locking plug 27 in its position holding conductor terminal 26 in contact with track 18, once locking plug 27 is 5 pushed sufficiently far into chamber 19a.

A secondary function of member 33 is to guide and limit movement of plug 27 as it is inserted into and withdrawn from chamber 19a. This arises from the formation of restraint member 33 as an elongate, downwardly io depending wall of only slightly smaller dimensions than aperture 36 in wall 34, whereby member 33 is slideable along aperture 36.

Downwardly depending limb 31 is only slightly narrower than the width of chamber 19a, whereby limb 31 is slideably receivable in chamber 19a.

The combined effect of the member 33 and limb 31 is to permit insertion of plug 27 into chamber 19a in only one orientation, ie. that which aligns detent 28 for engagement in aperture 32; and member 33 for engagement with conductor terminal 26.

Other arrangements are possible, in which more than one orientation of plug 27 are permitted.

On insertion of plug 27 into interior 19, member 33 engages per se known 25 protrusion 25 formed on terminal 26, to urge terminal 26 downwardly through aperture 13.

As is visible in Figure 3, the cross-section of chamber l9b is such as to permit insertion of conductor terminal 26, whose design is described in 30 more detail hereinbelow, in only one preferred orientation. This derives 16 from the presence of optional limb 21 protruding generally at right angles to the longitudinal axis of terminal 26 for slideably engaging a slot 21a extending downwardly from the open upper end of housing 17.

5 Housing 17 is formed integrally with backplate 11, eg. by injection moulding. A suitable material for forming the backplate is ABS.

The embodiment visible in Figure 3 shows two parallel ribs 37 upstanding from the rear face of backplate 11, and moulded integrally with housing 17 lo and backplate 11. Depending on the precise design of the mirror 10, the ribs may serve as reinforcements for the joint between housing 17 and backplate 11.

In the majority of embodiments of the invention there is a requirement for 15 connection of both the high and low voltage sides to the conductor tracks 18, at locations spaced from one another around the circuit defined thereby.

In such embodiments there are usually two or more of the apertures 36, communicating with respective tracks 18 (or with distinct parts of a 20 common track 18). One way of connecting a connector terminal 27 into each of the apertures 36 is to provide a plurality of the housings 17,corresponding in number to the plurality of apertures. Each such aperture has associated therewith a locking plug 27.

25 This arrangement is particularly suited to mirrors 10 in which the backplate I I includes eg. two apertures spaced apart from one another by a comparatively large distance (such as about 30mm).

An alternative arrangement, that is more suitable for embodiments in which 30 there is limited space within the overall mirror body.

17 In the Figure 4 embodiment two apertures 113a and 113b, each similar to aperture 36 of Figure 3, underlie a cominon housing 117.

5 Housing 117 has a hollow interior 119 that differs from interior 19 in that there are two internal walls 134a, 134b that divide hollow interior 119 into three chambers 119c, 119d and 119c respectively for a modified locking plug 127 and for each of two conductor terminals 126a, 126b. Locking plug 127 is capable of retaining the two conductor terminals 126a and 126b io simultaneously within the respective chambers 119d and 119e. Each terminal 126a, 126b is similar to terminal 26 of Figure 3.

Locking plug 127 includes an optional grip member 129 that is similar to grip member 29. At either end of member 129 there is a downwardly extending wall 133a, 133b each of similar construction to wall 33 of Figure 3.

Each interior wall 134a, 136b includes a respective aperture 136 similar to aperture 36 providing communication between the respective apertures 11 9c, 11 9d and 11 9e. Thus when locking plug 127 is inserted into housing 117 after insertion of a said terminal 126a, 126b into a respective chamber 119d, 119c, the walls 133a, 133b pass through the apertures 136 engage the protrusions 125a, 125b on the respective conductor terminals 126a, 126b to retain their lower, free ends in contact with the conductor material 118 accessible via each aperture I I 3a, I I 3b.

Since one of the walls 133b in locking plug 127 occupies the space at one end of the plug taken up by detent 28 in the Figure 3 embodiment, in Figure 4 the detent 128 is located mid-way between two downwardly depending limbs 13 1.

18 Detent 128 includes a panel 138 of material moulded integrally with the remainder of plug 127. Panel 138 is attached on either side to the lowermost end of a respective said limb 13 1, thereby providing a resiliently 5 deformable connection 128a. The upper end of panel 138 need not be attached to grip member 129.

A barb 128b similar to barb 28b protrudes from panel 138 towards elongate wall 117d of housing 117. Wall 117d includes an aperture 132 similar to io aperture 32 for receiving barb 128b.

The various options described above that are alternative to or complementary to, barb 28b of Figure 3, for retaining plug 27, may equally be present for the purpose of retaining plug 127.

When locking plug 127 is inserted into housing 117 the respective retainer members 113a and 133b slide in the apertures 136 to guide locking plug to its locking location, in which the upper face of barb 128b engages the underside of the upper end of aperture 132.

In use of an assembly including a mirror 10 as disclosed herein, the or each conductor terminal 26, 126a, 126b is crimped or otherwise secured onto a respective conductor wire 39 that in turn forms part of or is connected to a vehicle wiring harness.

Each conductor terminal includes at its lowermost end a curl 40, 140 of conducting material that is resiliently deformable when pressed into contact with a conductor track 18.

3o The resilient deformability of each curl 40 (Figure 3)/140 (Figure 4) ensures 19 that the surface of conductor track 18 is wiped each time the assembly is assembled, thereby ensuring good electrical contact.

The curls 40/140 also provide a force tending to drive the detent 28/128 into 5 positive engagement with the associated aperture 32/132, thereby preventing the locking plug 27/127 from rattling in use.

The assembly including the mirror 10 and conductor terminals 26/126 may include an insulating boot 41 (Figure 3)/141 (Figure 4) of approximately the io same shape as housing 17/117/ Each boot 41, 141 may be of an elastomeric material and serves to provide enviromnental protection for the assembly. It also insulates exposed conductor parts from short circuits. Each boot 41, 141 includes a number of 15 apertures 42 appropriate to the number of conductor terminals accommodated in the assembly. Each aperture 42 may optionally include an upwardly directed sleeve as shown. The boot is threaded onto the wire(s) 39 by means of the aperture(s) 42. Following insertion of the locking plug the boot may be slid into an insulating position covering the 2o housing 17, with the wire(s) 39 protruding via the aperture(s) 42.

An optional feature is for each rib 37, 137 to terminate a short distance from the adjacent housing 17, 117 and to include an undercut shoulder 37a, 137a for the purpose of retaining the boot 41, 141 on the housing 17, 117. This is 25 achieved by virtue of the periphery of the lowermost part of the boot 41, 141 including an outwardly directed bead 4 1 a, 141 a of material that engages under the shoulder 37a, 137a for retention of the boot.

k

Claims (20)

1. A heatable mirror comprising:

a backplate supporting a reflective member; 5 an electrically conducting or resistive heating material, for heating the reflective member, between the backplate and the reflective member, the backplate including at least one aperture communicating with the heating material or with a conducting material in conducting communication therewith; and 10 a housing having a hollow interior communicating with the aperture, the housing including:

(i) an opening for receiving a conductor terminal; and (ii) a retainer for releasably retaining a conductor terminal within the housing in conducting contact with the heating material or the said 15 conducting material via the aperture.

2. A mirror according to Claim I including a locking plug at least part of which is releasably receivable in the hollow interior, for retaining the conductor terminal, the locking plug including a resiliently deformable 2o detent that is releasably engageable with a formation on the housing; and a restraint member for engaging a said conductor terminal and securing it in the hollow interior when the detent engages the formation.

3. A mirror according to Claim 2 wherein the hollow interior includes 25 one or more walls defining respective chambers for the locking plug and a said terminal, an aperture in a said wall communicating between the chambers whereby on insertion of the locking plug into the hollow interior the restraint member passes through the aperture to engage the conductor terminal.

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4. A mirror according to Claim 2 or Claim 3 wherein the formation in the housing is an aperture and the detent is a harpoon-type detent that engages the aperture on insertion of the locking plug into the hollow interior.

5. A mirror according to Claim 2 or any claim dependent therefrom, wherein the locking plug is insertable into the hollow interior via an opening, the said opening and the profile of the locking plug being such as to permit insertion of the locking plug in a limited member of orientations.

6. A mirror according to any preceding claim wherein the housing is integral with the backplate.

7. A mirror according to Claim 6 wherein the housing and backplate are 15 injection moulded.

8. A mirror according to any preceding claim, wherein the backplate includes a plurality of the apertures for connecting a corresponding plurality of conductor terminals to the heating material.

9. A mirror according to Claim 8 including a corresponding plurality of the housings and the locking plates.

10. A mirror according to Claim 8 including a pair of the backplate 25 apertures and a common housing for the said pair of apertures, the common housing including a hollow interior communicating with the said apertures and the retainer releasably retaining a pair of conductor terminals within the housing in conducting contact with the conducting material via the said apertures.

22 I

11. A mirror according to Claim 10 when dependent from Claim 2 wherein the locking plug includes a pair of restraint members respectively for engaging the conductor terminals and securing them in the hollow interior when the detent engages the formation.

12. A mirror according to Claim 10 when dependent from Claim 3, wherein the walls define respective said chambers for the locking plug and each of the conductor terminals, each said wall that separates the locking plug chambers from a said conductor terminal chamber including a lo respective aperture communicating between adjacent chambers whereby on insertion of the locking plug into the hollow interior the restraint members each pass through a respective aperture to engage a conductor terminal.

13. A mirror according to any preceding claim wherein the heating 15 material includes a layer of PTC material.

14. A mirror according to any of Claims I to 12 wherein the heating material includes a layer of electrically insulating material.

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15. A mirror assembly including a mirror according to any preceding claim having secured therein one or more conductor terminals in conducting contact with the conducting material.

16. A mirror assembly according to Claim 15 wherein the or each 25 conductor terminal is a crimp-type terminal conductingly crimped onto a conductor wire and including a resiliently deformable, conducting portion for engaging the PTC layer and/or a conductor thereon.

17. A mirror assembly according to Claim 16 wherein the conductor wire is connected to or forms part of a vehicle wiring harness.

23

18. A mirror assembly according to Claim 15 or any claim dependent therefrom, including an insulating boot covering the or each conductor terminal and closing the opening in the housing, the boot including one or more apertures for passage of a conductor wire therethrough.

19. A mirror generally as herein described, with reference to and/or as illustrated in the accompanying drawings.

io

20. A mirror assembly generally as herein described, with reference to and/or as illustrated in the accompanying drawings.

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