FR2582450A1 - ELECTRICALLY INSULATING SUPPORT FOR ELECTRICAL CONTACT BLADES, MANUFACTURING METHOD, AND CONTACT BASE FOR IMPLEMENTING SAME - Google Patents

Abstract

THE PRESENT INVENTION CONCERNS AN ELECTRICAL DEVICE OF THE TYPE INCLUDING A SUPPORT IN ELECTRICALLY INSULATING MATERIAL OVERMOLDED ON AT LEAST ONE CONTACT STRIP OF ELECTRICALLY CONDUCTIVE MATERIAL. ACCORDING TO THE INVENTION, TO ENSURE THE ELECTRICAL CONNECTION OF THE CONTACT STRIP WITH AN ELECTRICAL ACCESSORY, THE DEVICE FURTHER INCLUDES AN INTERMEDIATE CONTACT SOCKET 40 IN ELECTRICALLY CONDUCTIVE MATERIAL INCLUDING A PLATE 46 EQUIPPED WITH AN OPENING 41 AND, AT THE LEVEL OF THIS, OF AT LEAST ONE ELASTIC LIP 42, 43, FORMING A CLAMP, TO ALLOW THE ENGAGEMENT OF THE BASE 40 ON ONE END OF A CONTACT LEAF, AND KEEP THE BASE ON IT THANKS TO THE ELASTIC LIP, AND A CONTACT TAB MECHANICALLY ENGAGED WITH THE ELECTRICALLY INSULATING SUPPORT AND RESTING AGAINST THE INTERMEDIATE BASE 40, WHICH IS ELSEWHERE CONNECTED WITH THE ACCESSORY.

Description

The present invention relates to the manufacture of electrical devices

  of the type comprising a support of electrically insulating material overmolded on at least

  a contact strip of electrically conductive material

  tor intended to be electrically connected with at least

an electrical accessory.

  In the following description, we should understand

  dre the expression "electrical.accessory" in a sense

  large, the expression "electrical accessory" before

  cover any type of transmitting electrical device or

  electrical information receiver.

  The present invention finds in particular applica-

  tion in the realization of measuring devices for

motor vehicles.

  Mention will be made, by way of nonlimiting example, of producing electrically insulating caps supporting contact blades closing the boot of a device.

  temperature measurement with bimetal warning contact.

  In a large number of cases, the connecting part

  electrically conductive connected to the electric accessory

  that has a complex shape, imposed by the environment-

  of the electrical accessory to be connected.

  In the case for example of the temperature measurement device with the aforementioned alert contact, the geometry

  of these contact strips must take into account the dimensions

  geometry of the internal chamber of the shoemaker containing the bimetallic element, and more often than not containing a heat-resistant element for the measurement

of temperature.

  The production of such supports - of electrically insulating material overmolded on at least one contact strip of electrically conductive material, of complex geometry, has not been resolved with satisfaction so far.

  The first possibility offered for the realization

  tion of these devices, which consists of onma-r in'iraD-

  ment, according to the required geometry, the omtact lamellae, then later, to overmold the isolate support if these lamellae, requires the realization of oles holding

  account of the specific geometry of the islands of oMtact.

  It follows on the one hand that these molds are t

  expensive. Furthermore, the molds as well as me-

  can be used only for the realization of a par type

  peculiar to devices, the geometry of lamlle de am

  contact varying widely from one applicatim to another.

  The second posi hility offered is -réa isa-

  tion of these devices consists in overmolding the support of electrically insulating material on dm lelles of

  electrically conductive contact, initial and reti-

  lines, then to conform, after support surmaiaae,

  the contact strips according to the geoni: e ise.

  In practice, taking into account the weak

  sions of the electrically insulating supports g- aLct used, in particular in vehicles where it is very difficult to conform by folding, with

  precision, contact strips post r t to over-

t

mulching of the insulating support.

  For example, the gap between two lamellae

  of adjacent contact can be of the order of a Millimeter.

  The present invention now improves

  rer the situation by proposing a new elective

  sheet comprising a support of insulating material overmolded on at least one contact strip of electrically conductive material, characterized by

  the fact that it includes, to ensure the electrical connection

  plate of the contact strip with a transmitting or receiving electrical accessory:

  - an intermediate contact base in material

  electrically conductive line comprising a plate provided with an opening and, at the level of this, at least elastic lip forming a clamp, to allow the engagement of the base on one end of the contact strip and the maintenance on this thanks to the elastic lip, and - a contact tongue in mechanical engagement with the electrically insulating support and resting against the intermediate base, which is also connected with the accessory. In other words, according to the present invention, it is proposed to produce the link member worn

  by the electrically insulating support and in electrical contact

  stick with the accessory in the form of two separate elements

  res corresponding to a form contact strip

  standard on which the electrical support is overmolded-

  insulating, the other to a contact tongue of required geometry, mechanically fixed on the support

  electrically insulating and electrically connected to the

  contact melle through the intermediate base.

  Thus, according to the present invention, the molds

  used to ensure overmolding of the electrical support

  only insulating on the contact strips can be standard

  Likewise, the contact tabs being

  set separately, its geometry can be defined

precisely denied.

  It will also be noted that the electrical support

  insulating three-piece overmolded on at least one contact strip, in accordance with the present invention, constitutes a standard product capable, depending on the geometry of the

  contact strips which will be associated with it later

  rement, to be used for a large number of applications.

  Thus, the present invention makes it possible to obtain

  economical, reliable and pre-

  cis, moreover making it possible to solve in a broad

  measure, the stock problems so far posed.

  Furthermore, the present invention justifies and authorizes, thanks to the standard form of the parts used, and the simplicity of the

  system, an automatic assembly.

  Preferably, according to the invention, the immobilizer

  mechanical position of each contact tab on the support

  electrically insulating port is made by engagement of a protruding lug-provided-on the contact tab

  in a complementary recess in the support.

  More precisely, preferably, according to the pre-

  invention, each contact tab has two projecting lugs penetrating into respective respective recesses provided in the support on either side

  of the electrical contact strip.

  According to an embodiment considered current-

  As a preference, each base has two elastic lips.

converging ticks.

  More precisely still, preferably, according to the invention, the lips are formed by cutting a

  "H" shaped opening in the base.

  It is more advantageous that the two aforementioned lips have two parallel free edges intended to be applied on either side of the lamella

  contact carried by the electrically insulating support.

  Tests have shown that it is more

  tagous to use a slightly concave base plate, the lip (s) being placed protruding on the plate

opposite of concavity.

  According to the invention, the contact strips preferably have a cross section of rectangular shape. The present invention also relates to a process for manufacturing the aforementioned electrical device as well as the previously mentioned intermediate contact base. Other features and benefits of the

  present invention will appear on reading the

  detailed description which will follow, and with regard to the

  attached sins, given by way of nonlimiting examples and in which: Figure 1 shows a schematic view, partially in longitudinal axial section, of a device according to an exemplary embodiment of the present invention, - Figure 2 shows a end view of an electrically insulating support overmolded on contact strips, according to a view illustrated by the arrow referenced II in Figure 4, - Figure 3 shows a partial sectional view of the same device, according to a sectional plane referenced III-III in Figure 2,

  - Figure 4 shows a view in axial section longitu-

  dinal of the same device according to a section plane referenced IV-IV in FIG. 2, - FIG. 5 represents a side view of an exemplary embodiment of contact tabs used in the context of the present invention, - FIG. 6 represents a view of the same tab along a longitudinal sectional plane referenced VI-VI in FIG. 5, - FIG. 7 represents a plan view of an intermediate contact base according to the present invention, - FIG. 8 represents a view in section of the same base according to a section plane referenced VIII-VIII on

Figure 7.

  We see in Figures 1, 2 and 4, a sup-

  port 10 made of electrically insulating material overmolded

  three contact strips 20, 21 and 22 made of electric material

triconductive.

  As an example, each of the slats me czmacr

  is formed by a flat strip of straight section

  gular. At the overmolding level, each of the lamellae

  contact 20, 21 and 22 is provided with sdihmati-

  only referenced 23, preferably on its face of lesser width. The purpose of these projections 23 is to ensure effective mechanical retention of the contact strips

, 21 and 22 in the overmolding 10.

  Overmolding 10 is carried out so that the contact strips, generally parallel, emerge

on either side of it.

  Preferably, as shown in par-

  particular in FIG. 4, and illustrated under the references

  24 and 25, each contact strip 20, 21 and 22 is bi-

  skeletonized at its free ends, in order to facilitate

  on the one hand, the engagement of an intermediate contact base 40, as shown in FIGS. 7 and

  8, on the other hand, the engagement of electrical connection means

additional cudgel.

  Preferably, as mentioned above, the electrically insulating support 10 is intended to close a casing housing measuring means intended to be

  electrically connected to the contact strips 20, 21 and 22.

  In this hypothesis, the face 11 of the electrically insulating support directed towards the internal chamber of the shoemaker is preferably generally planar. On the other hand, on the opposite side, the electrically insulating support 10 preferably forms a skirt 12 surrounding the free end of the contact strips 20, 21 and 22 at a distance, in order to protect them, and to receive the insulating boot 'an oem = I electrical connector intended to cooperate with the cozact 2D, 21 and

22 in a conventional manner per se.

  It will be noted on examining FIG. 4 that, from

  preferably on its face 11 against which will be later

  laughingly affixed the intermediate contact bases

  , the overmolded support 10 has a chamfer in reinforcement

  darkly surrounding each of the contact blades 20,

21 and 22.

  These chamfers make it possible in particular to avoid the presence of burrs of electrically insulating material, during molding, on the periphery of the contact strips 20, 21 and 22 to subsequently guarantee that the bases

  contact intermediates 40 can be worn in con-

  close contact with the face 11 of the insulating support 10.

  Furthermore, on its surface 11 directed towards the side receiving the intermediate contact bases 40, the insulating support 10 has a plurality of recesses

  13 intended to ensure the mechanical immobilization of the

contact lookouts.

  Preferably, two recesses are thus placed

  on either side of the contact strips 40.

  We thus see in Figure 2 two pairs

  blind recesses 13 of general cross section rec-

  tangular. Where appropriate, as illustrated in FIGS. 2 and 3, the face 11 of the support 10 may also have

a projection 14 forming a key.

  As illustrated in Figures 7 and 8, each

  intermediate contact base 40 is formed by a plate

  that provided with an opening 41 defining at the latter at least one elastic lip 42, 43 allowing

  the engagement of the base 40 on the end 27 of the

  contact pins and the maintenance of the base on them

ci by elastic pinching.

  As illustrated in FIG. 7, according to an embodiment currently considered as preferential,

  an H-shaped opening 41 is made in the container.

  base 40 to delimit two lips 42, 43 of generally rectangular outline, converging, forming elastic clamp. Preferably, as illustrated in FIG. 8, the lips 42 and 43 are deformed projecting by the same

side of base 40.

  Preferably, the free edges 44, 45 of the

  lips 42 and 43, arranged opposite, are parallel.

  In use, the lips 42 and 43 will rest at these free edges 44 and 45 against the respectively opposite sides of the contact strips 20, 22

carried by the support 10.

  The distance separating the free edges 44 and 45 of the elastic lips 42, 43 must of course be less than the width of the contact strips 20, 21, 22 supported by the base 10, in order to ensure effective support of the bases 40 on the contact strips. Preferably, as appears on examination

  in Figure 8, the body 46 of the base 40 is light-

  concave and the elastic lip (s) 42, 43 are arranged projecting from the base opposite

concavity.

  Where appropriate, as appears on examining FIGS. 7 and 8, two tabs 47, 48 intended to rest in use against the face 11 of the electrically insulating support 10 are provided on either side.

of the body 46 of the base.

  Such bases 40 can be produced

  from flat metal blanks thanks to opera-

  conventional die-stamping and folding in themselves.

  Illustrated in Figures 5 and 6 an embodiment of the contact tabs 30 intended

  to ensure the electrical connection of a contact strip

  tact with an associated electrical accessory.

  Essentially, these contact tabs 30 comprise a body 31 intended to be electrically connected to the electrical accessory, and shaped according to the geometry and dimensions required by the environment thereof, as well as means 32 intended for come into mechanical engagement with the electrically insulating support and rest against

  an intermediate base engaged on a contact strip

  tact. In this case, according to the illustration shown in Figures 5 and 6, the means 32 include a

  trigger guard 33 extending transversely to the direction of

  along the body 31 and provided opposite it with two lugs 34, 35 generally parallel intended to

  respectively penetrate into 13 recesses

  provided in the electrically insulating support

10.

  Furthermore, as appears on examining FIG. 5 and as illustrated schematically by the reference 36, the free end of the studs 34, 35 by which these are engaged in the recesses 13 is preferably bevelled so to facilitate such engagement. It will also be noted on examining the figure that the pins 34, 35 are preferably slightly tapered over their width, in the direction of the aforementioned free ends and have transverse support surfaces schematically illustrated 37, directed towards the body 31, i.e. use towards opening

  recesses 13 in order to prohibit the withdrawal of the lans

  contact outlets 30 out of the recesses 13.

258245C

  As illustrated in FIG. 5, the trigger guard 33 can have a median recess 38 open in the direction of the lugs 34, 35 to allow the contact tongue

  overlap the contact strips 20 as illus-

  very top of Figure 1. The trigger guard 33 preferably has a surface

  support 39 flat and perpendicular to the direction-

  of elongation of the body 31 and of the pins 34, 35, intended

  in use to rest against the base 40, and pre-

  ference against elastic lips 42 and 43.

  The method of manufacturing the aforementioned device comprises the steps consisting in: - supporting at least one contact strip in a mold, overmolding the electrically insulating support on the contact strip, so that the latter emerges from both sides other of the insulating overmolding, and

  providing mechanical fixing means for the lan-

  outlets, on the insulating overmold 10, - to engage an intermediate contact base on the lamellae, at their opening 41, the intermediate contact base 40 being held on the contact lamellae by virtue of the elastic lips,

  - finally engaging the lugs 34, 35 of the lans

  contact outlets 30 in the recesses 13 complementary

  shutter of the insulating support 10 until a mechanical connection is obtained between the electrically insulating support and the tongues 30 and a support of the surface 39 of the

  tabs against the intermediate base of the contacts 40.

  After completion of these operations, the

  contact plates 30 are held firmly on the overmolded insulating support 10 on the one hand, and the contact tabs 30 are electrically and reliably connected to the contact strips 20, 21 and 22 via

bases 40, on the other hand.

  As shown in Figure 1, if necessary, some of the bases 40 can be used

  to directly ensure the electrical connection with the ac-

  cessory. To do this, preferably, the bases 40 in question are provided with a curved elastic wing.

  49 intended to come into contact directly or indirectly

  with the electrical accessory.

  Of course, the present invention is in no way limited to the embodiment which has just been described but extends to any variant conforming

to his mind.

  According to an embodiment in accordance with the

  present invention, given by way of non-limiting example

  tif, the contact strips have a thickness of 0.9 mm and a width of the order of 2.5 mm, while the base 40 is made of an alloy plate

  0.15 mm thick copper, pre-

  feeling two lips with a width (corresponding to the length of the free edges 44, 45) of the order of 1.4 mm, of a height (considered transversely to the free edges) of the order of 0.6 mm, the radius of curvature of the concave body of the base being of the order of 6 mm, the free edge of the lips 42, 43 being projecting from

  0.2 mm above the domed concave body.

  For example, the present invention also allows

  Also use non-rectangular section slats

laire, for example circular.

  In addition, the bases may include more than

  two elastic lips, three for example or more, in particular

  with circular section slats.

Claims (13)

  1. An electrical device of the type comprising a support (10) made of overmolded electrically insulating material   on at least one contact strip (20, 21, 22) made of material   electrically conductive line, characterized in that it comprises, to ensure the electrical connection of   the contact strip with an electrical accessory-   transmitter or receiver: - an intermediate base of conEact (40) made of electrically conductive material comprising a plate (46) provided with an opening (41) and, at the level of this, at least one elastic lip (42, 43), forming a clamp,   to allow engagement of the base (40) on an   mite the contact strip (20, 21, 22) and the maintenance thereon by means of the elastic lip and - a contact tongue (30) in mechanical engagement (13; 34, 35) with the electrically insulating support ( 10) and resting against the intermediate base (40), which is connected otherwise with the accessory.   2. Electrical device according to claim   1, characterized by the fact that each connecting tab   tact (30) has at least one protruding lug (34, 35)   trant in a complementary recess (13) formed in the support (1 0   3. Electrical device according to one of the res-   dications 1 or 2, characterized in that each lan-   contact point (30) comprises two pins (34, 35) penetrated   trant in complementary recesses in the electrically insulating support (10) on both sides   an electrical contact strip.   4. Electrical device according to one of the res-   dications 1 to 3, characterized in that each base   (40) has two elastic lips (42, 43) converging.   5. Electrical device according to claim 4, characterized in that the lips (42, 43) are formed by cutting an H-shaped opening (41) in the base. 6. Electrical device according to one of claims 4 or 5, characterized in that the two lips (42, 43) have two parallel free edges (44,)   7. Electrical device according to one of the res-   dications 1 to 6, characterized in that the plate (46) of the base (40) is slightly concave and the lip or lips (42, 43) are arranged projecting opposite the concavity.   8. Electrical device according to one of the res-   dications 1 to 7, characterized in that at least some of the   melle (20, 21, 22) has a straight cross-section general rectangular.   9. Electrical device according to one of the res-   dications 1 to 8, characterized in that at least some of the lamellae (20) have a cross section generally circular.   10. Method for manufacturing an electrical device   stick according to one of claims 1 to 9, charac-   terrified by the fact that it includes the steps of:   - overmolding a support (10) made of electric material   triply insulating on at least one contact strip of electrically conductive material (20 so that it emerges on either side of the insulating support (10s - to engage an intermediate contact base (40) in electrically conductive material, comprising a plate provided with an opening, and at the level thereof, of an elastic lip forming a clamp, on one end of a contact strip, holding the base (40)   on the contact strip being provided by the elastic lip-   tick, - mechanically fixing a contact tongue (30) on the electrically insulating support (10) by carrying a part of the contact tongue (30) bearing against   the intermediate contact base (40).   11. Method according to claim 10, character-   laughed at by the fact that the mechanical immobilization of a contact tongue (30) on the electrically insulating support (10) is carried out by engaging pins (34, 35), preferably tapered, provided on the tongue (30) ,in   complementary recesses (13) of the insulating support (10).   12. Intermediate contact base made of material   electrically conductive, for the implementation of the pro-   assigned according to one of claims 10 and 11 and the manufacture   cation of the electrical device in accordance with one of the   Claims 1 to 8, characterized in that it   comprises a plate provided with an opening (41) and, at the   level thereof, an elastic lip forming a clamp.   13.Embase.selon claim 12, characterized   by the fact that it includes two elastic lips   orchards (42, 43) produced by cutting an opening H-shaped in the base.