Abstract:
The present invention relates to a female connector assembly, comprising a base part having one or more conductor channels, each conductor channel having a first and a second end. Each of the one or more conductor channels houses at least one bent resilient conductor having a first portion and a second portion, where the second portion is displaceable in a track defined in at least a part of the base part. The first portion extends through the second end of the conductor channel. Each conductor channel is adapted to receive a rod-shaped conductor from a male connector assembly so that the rod-shaped conductor is retained in that conductor channel by a biasing force provided by the bent resilient conductor of that conductor channel.

Description:
This application claims the benefit of Provisional application Ser. No. 60/448,098, filed Feb. 20, 2003. 

   FIELD OF THE INVENTION 
   The present invention relates to a connector for providing electrical connection between a first conductor and a second conductor. In particular, the present invention relates to miniature connector assemblies having small dimensions so as to be used in e.g. hearing aids. 
   BACKGROUND OF THE INVENTION 
   U.S. Pat. No. 4,125,309 discloses a miniature pin board assembly comprising a miniature matrix having coplanar conductive strips in a first row overlaid by a second row of coplanar strips. Both rows of strips are embedded within a moulded substrate of an elastomer-based material which is sufficiently rigid to maintain the rows in a predetermined spatial relationship. 
   A plurality of recesses is arranged in the substrate. The recesses are arranged in columns and rows. Each recess exposes a conductor in the first row and a conductor in the second row where such conductors cross each other. 
   A conductive pin may be inserted into a selected aperture to engage the corresponding exposed conductors, thereby making a cross point connection. The elastomer-based material encircling the selected recess is elastically expanded upon insertion of the pin and exerts a resilient and residual retention force on the pin biasing the same into positive electrical contact with the cross point connected conductors. 
   The resilient properties around the recesses of the pin board assembly of U.S. Pat. No. 4,125,309 are provided by the elastomer-based material. Thus, it is the mechanical properties of the elastomer-based material that keeps a male connector (pin) in position when inserted into a recess. Furthermore, the pin board assembly of U.S. Pat. No. 4,125,309 is mainly suitable for mounting on e.g. printed circuit boards. 
   U.S. Pat. No. 4,466,684 discloses a low insertion force connector with resilient metal conductors in the openings of an insulating connector body. Each conductor has a square opening and has integral leaf springs extending from the respective sides of the square towards a terminal entry end of the openings. The four leaf springs are grouped in two pairs that can engage with the entering terminal either simultaneously or shifted relative to each other. To orient and to fixate the conductors in the openings the conductors comprise tabs precisely fitted to be received in grooves of the connector body. 
   It may be an object of a preferred embodiment of the present invention to provide a miniaturised connector assembly where the resilient properties are provided by a resilient conductor in a simple way. 
   It may also be an object of a preferred embodiment of the present invention to provide a miniaturised connector assembly comprising a reduced number of mechanical elements. 
   SUMMARY OF THE INVENTION 
   The above-mentioned objects are complied with by providing, in a first aspect, a female connector assembly, comprising
         a base part comprising one or more conductor channels, each conductor channel having a longitudinal centre axis, a first end, and a second end, and   a bent resilient conductor comprising first and second portions separated by a bend and having the first portion positioned in a conductor channel, wherein said conductor channel is adapted to receive a rod-shaped conductor from a male connector assembly so that the rod-shaped conductor is retained in said conductor channel by a biasing force provided by the bent resilient conductor positioned in said conductor channel,
 
wherein the second portion of the bent resilient conductor is displaceable in a track disposed at a surface of the base part upon receiving the rod-shaped conductor in said conductor channel. Preferably, the first and second portions of the bent resilient conductor are substantially perpendicular. Preferably, the track is disposed at a surface of the base part being substantially perpendicular to the centre axis of said conductor channel.
       

   Each of the one or more conductor channels may host at least one resilient conductor. At least a part of the track, in a cross-section, may define a semi-circle. It may also be so that at least a part of the track encircles at least a part of the second portion of the bent resilient conductor displaced in the track. 
   The female connector may further comprise a top part arranged on the base part. The base and the top part may, in combination, define the track so that one part of the track is defined in the base part whereas another part of the track is defined in the top part. The track may be defined by a first recess defined in a surface of the base part and a second recess defined in a surface of the top part. 
   Preferably, the top part is fixedly attached to the base part. This fixed attachment may be provided by several means such as a snap-lock, threads in either base or top part being adapted to receive bolts or the like. The top part may also be glued to the base part or the top part may be attached to the base part by providing heat to either of the two parts. Also, techniques such as ultrasonic welding may be applied to attach the top part to the base part. 
   A conductor recess may be defined in at least one of the conductor channels. The conductor recess may extend continuously from the first end of the conductor channel to the second end of the conductor channel. The first portion of the bent resilient conductor may be adapted to be received in the conductor recess when the second portion is received in the track. 
   A third portion of the bent resilient conductor may be defined between the first portion and the second portion, the third portion being adapted to engage with at least a part of the rod-shaped conductor from a male connector assembly. The third portion may comprise a sharply bended section, said bended section being adapted to engage with e.g. a recess of the rod-shaped conductor. 
   The female connector may further comprise blocking means for blocking at least a part of the track so as to limit the sliding movement of the second portion of the bent resilient conductor when displaced in the track. The blocking means may be a separate rod inserted in the track or it may be implemented by tapering the track to dimensions smaller than the second portion of the bent resilient conductor. 
   The female connector may further comprise sealing means adapted to seal at least one of the conductor channels. The sealing means may further be adapted to provide a fluid tight seal. The sealing means may comprise a flexible membrane having a passage adapted to receive the rod-shaped conductor of the male connector. The flexible membrane may be made of a rubber or a silicone material. Preferably, the flexible membrane may comprise a bead. Preferably, the sealing means is positioned between the base part and a top part. More preferably, the top part is fastened to the base part. In principle, the top may be fastened by any means such as gluing, soldering, interface locking, clamping, joining by heating, snap-locking, welding or the like. Preferably, ultrasonic welding is applied to fasten the top part to the base part. The sealing means may also be fastened to the base part and/or the top part by any suitable means such as ultrasonic welding, welding, laser welding, gluing, joining by adhesive strips and joining by heating, 
   In principle, the base part may comprise an arbitrary number of conductor channels, such as 1, 2, 3, 4, 5 or even more conductor channels. 
   Preferably, the female connector has a volume between 2 mm 3  and 10 mm 3 , such as between 4 mm 3  and 8 mm 3 , 5 mm 3  and 7 mm 3 , such as approximately 6 mm 3 . The cross-sectional area of at least one of the conductor channels is preferably between 0.1 and 0.3 mm 2 , such as approximately 0.2 mm 2 . 
   The female connector may in principle take any form. Thus, the base and/or top part may define, in a plane substantially perpendicular to the conductor channels, a substantially rectangular cross-sectional shape. The length of the connector may for example be approximately 2.5–3.0 mm, more preferably 2.67 mm. The width of the connector may for example be approximately 1.3–1.7, more preferably 1.53 mm. The height of the connector may for example be approximately 1.2–1.8, more preferably 1.6 mm. Alternatively, the base and/or top part may define, in a plane substantially perpendicular to the conductor channels, a substantially circular cross-sectional shape. The diameter of the substantially circular shape may be within the range 1–2 mm. 
   At least one of the bent resilient conductors may be fabricated in a material selected from the group consisting of aluminium, magnesium, titanium, copper, nickel, zinc, tin, lead, chrome, tungsten, molybdenum, silver, gold, platinium and any alloy thereof. The base part and/or the top part may be fabricated in a material selected from the group consisting of elastomers, polymers and any other plastic material. 

   
     BRIEF DESCRIPTION OF THE INVENTION 
     Preferred embodiments of the invention will be described in detail below with reference to the accompanying  FIGS. 1–9 , where 
       FIG. 1  shows a partly exploded view of a connector according to the present invention, 
       FIG. 2  shows a top part according to the present invention, 
       FIG. 3  shows a base part according to the present invention, 
       FIG. 4  shows a conductor and a sectional view of the base part according to the present invention, 
       FIG. 5  shows a top view of the base part according to the present invention, 
       FIG. 6  shows a rear view of the base part according to the present invention, 
       FIG. 7  shows in an exploded view an embodiment of a base part and a top part with an intermediate flexible membrane according to the present invention, 
       FIG. 8   a  shows a perspective view of a rod-shaped conductor and the flexible membrane according to the present invention, whereas  FIG. 8   b  shows a cross-sectional view of the circumferential bead of the membrane, and 
       FIG. 9  shows a cross-sectional view of a rod-shaped conductor entering a passage of the flexible membrane according to the present invention. 
   

   While the invention is susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and will be described in detail herein. It should be understood, however, that the invention is not intended to be limited to the particular forms disclosed. Rather, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims. 
   DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1  shows a female connector  2  comprising a base part  4  and a top part  6  comprising a front surface  8  and a rear surface  10 . The base part  4  comprises a front surface  12  and a rear surface  14 . The rear surface  10  of the top part  6  is adapted to be attached to the front surface  12  of the base part  4 . The top part  6  comprises channels  16  extending from the front surface  8  to the rear surface  10 . The channels  16  are adapted to receive a rod-shaped element of a male connector (not shown). 
   The base part  4  additionally comprises channels  18  extending from the front surface  12  to the rear surface  14 . Near the front surface  12  the cross-sectional size and shape for the channels  18  is identical to the cross-sectional shape and size of the channels  16  of the top part  6 . On the rear surface  10  of the top part  6 , upper recess parts  20  are defined. On the front surface  12  of the base part corresponding lower recess parts  22  are defined. The upper recess parts  20  and the lower recess parts  22  together define track channels adapted to receive conductors  24 . The conductors may slide in the track channel, which is indicated by the arrow  26 . 
     FIG. 2  shows the top part  6  comprising the front surface  8 , the rear surface  10  and the channels  16 . The height of the side wall  28  is 0.4 mm. 
     FIG. 3  shows the base part  4  comprising five channels  18  having five corresponding lower recess parts  22 . In a side wall of the channels  18  conductor recesses  30  are defined. These recesses are adapted to receive part of conductors  24  (not shown). The front surface  12  of the base part  4  is provided with a welding liner  32  for ultra sonic assembling the top part  6  to the base part  4 . The height  34  of the base part is 1.6 mm, the width  36  of the base part  4  is 1.535 mm and the length  38  of the base part  4  is 2.67 mm. 
     FIG. 4  shows a cross section of the base part  4  comprising channels  18  with corresponding lower recess parts  22 . In a side wall of the channels  18  conductor recesses  30  extending from the front surface  12  to the rear surface  14  are defined. The channels  18  comprise bottom surfaces  40  and, thus, a part of the conductor recesses  30  defines a small channel  42  through which conductor  24  extends. 
   Conductor  24  comprises three parts: 1) a second portion  44 , 2) a first portion  46  and 3) a third portion  48 . The track channel defined by the upper recess parts  20  and the lower recess parts  22  are adapted to slidingly receive the second portion  44  of the conductor. The conductor recess  30  is adapted to receive the first portion  46  which extends through the small channel  42  when the second portion is received in the lower recess part  22 . A part of the first portion emerges on the rear surface  14  of the base part. The width  50  of the conductor  24  is 0.15 mm and the conductor comprises stainless steel—spring quality. 
   The third portion  48  of the resilient conductor is defined between the second portion  44  and the first portion  46 . The third portion  48  is adapted to engage with at least a part of a rod-shaped conductor from a male connector assembly (not shown). The third portion  48  comprises a sharply bended section being adapted to engage with e.g. a recess of the rod-shaped conductor. 
     FIG. 5  shows a top view of the front surface  12  comprising channels  18  and lower recess parts  22 . 
     FIG. 6  shows the rear surface  14  of the base part  4 . A part of the first portion  46  of the conductor  24  extends through the small channel  42 . The first portions of the conductors in combination define a substantially straight line  52 . This is to facilitate further assembling, e.g. for soldering of the first portions. 
     FIG. 7  shows in an exploded view an embodiment of a base part  4  and a top part  6  with an intermediate flexible membrane  60 . The flexible membrane  60 , which is fabricated of a rubber-like material or a silicone material, preferably butyl-silicone, establishes a fluid tight seal between base part  4  and top part  6 . Preferably, base part  4  and top part  6  comprises a material selected from the group consisting of: elastomers, polymers and any other plastic material. The projected area of the flexible membrane  60  is slightly smaller than the area of the rear surface  10  of the top part  6  and the front surface  12  of the base part  4  in order to allow abutting engagement between the rear surface  10  and the front surface  12  when assembled. In this embodiment the top part  6  is by ultrasonic means welded to the base part  4  at the abutting peripheral parts of the rear surface  10  and the front surface  12 , respectively, by an ultrasonic liner (not shown). The ultrasonic welding is performed at the entire abutting periphery, optionally only in selected points, e.g. at the corners of the base part  4  and top part  6 . In this way, the flexible membrane  60  is retained between the base part  4  and the top part  6 . To improve the sealing the flexible membrane  60  comprises a circumferential bead  65  located on the periphery of the flexible membrane  60 . Upon assembly the bead  65  is compressed in between the base part  4  and the top part  6  and provides a barrier to any incoming fluids. The flexible membrane  60  comprises a bead  65  on the side engaging the rear surface  10  and/or on the side engaging the front surface  12 . Optionally, the front surface  12  and/or the rear surface  10  comprise(s) tracks for receiving the bead  65  in order to improve the fluid sealing. 
   Preferably, the flexible membrane having five passages  61  each adapted to receive a rod-shaped conductor of the male connector is positioned between base part  4  and top part  6  when assembled. In order for the rod-shaped connector to be able to engage with the conductors channels  18  of base part  4 , the five passages  61  should be aligned with the five conductor channels  18 . 
     FIG. 8   a  shows a perspective view of a rod-shaped conductor  27  and the flexible membrane  60 . It is indicated how the conductor  27  is intended to penetrate the flexible membrane  60  through the passage  61 . The passage  61  has the form of a tubular hole with at least a closed position in which the passage  61  provides a fluid tight sealing and a receiving position in which the passage is capable of receiving the rod-shaped conductor  27 . In the receiving position the rod-shaped conductor  27  penetrating the passage  61  elastically extends the passage  61 . Due to the elastic extension of the passage  61 , the passage  61  provides a close fit around the rod-shaped conductor  27  so as to obtain a fluid tight sealing in the receiving position of the passage  61 . In the closed position the passage  61  has a maximum diameter of approximately 0.1 mm while the diameter in the receiving position is extendable up to at least 0.15 mm.  FIG. 8   b  shows a cross-sectional view of the circumferential bead  65  of the membrane. 
     FIG. 9  shows a cross-sectional view of a rod-shaped conductor  27  entering a passage  61  of the flexible membrane  60 . Upon entry of the rod-shaped conductor  27  the engaging sides of the passage  61  are bent downwards. In this embodiment the passage  61  has the form of tubular hole but many alternatives shapes and variations are available. The passage  61  may in a cross-sectional view e.g. have a tapering profile with an entry diameter being larger than the rear exit diameter so as to facilitate easy entry of the rod-shaped conductor  27 . In particular, the passage  61  may in a cross-sectional view have a conical form with the base of the cone pointing in the direction of the rear surface  10  which is the side where conductor  27  approaches. Alternatively, the base of the cone may be pointing in the direction of the front surface  12 . As the rod-shaped conductor  27  has a substantially circular form in a plane substantially perpendicular to the conductor channels, the passage  61  in the flexible membrane  60  may correspondingly define, in a plane substantially perpendicular to the conductor channels, a substantially circular opening in order to provide an optimal closest fit in a receiving position of the passage  61 . 
   More alternatively, the passage  61  may comprise cut out slits (not shown) in the flexible membrane  60  to facilitate easy access for the conductor  27 . The slits may have a common centre of origin and be symmetrically arranged around said centre of origin, e.g. four slits in the flexible membrane  60  with a common centre of origin may be oriented at right angles to each other forming a cross seen from a top view. Possibly, slits and holes of various forms may be combined to form different kinds of passages  61  adapted to provide a fluid tight sealing in both a closed position and a receiving position.