Patent Publication Number: US-9847593-B2

Title: Electrical connector assembly and connection arrangement

Description:
The invention refers to an electrical connector assembly comprising a terminal holder, and a clamping assembly for clamping a plurality of terminals in the direction of a longitudinal axis for an electrical connection between said terminals, said clamping assembly including a first clamping element made of a metal material and a second clamping element which first and second clamping elements are connected to each other for clamping said terminals and which define a terminal receiving area. In addition, the invention refers to a connection arrangement comprising such a connector assembly and a first terminal and a second terminal received in the terminal receiving area of the clamping assembly and being clamped by said clamping assembly for an electrical connection between said first and second terminals. 
     Electrical connector assemblies of that type are described in U.S. Pat. No. 8,672,700 B2 and US 2011/0070761 A1. 
     A motor vehicle includes a variety of electronic devices. A hybrid car or an electric car includes, for example, an electric motor and an inverter to invert a direct current power of a battery to an alternating current power. It is known that a connector assembly is utilized for connection between the motor and the inverter. The connector connected to the motor with an electrical wire is attached to a connector receptacle of the inverter is, for instance, described in JP H11-126661 A. The connector assembly of JP H11-126661 A includes a connector (an assembly of connection terminals) and a connector receptacle. The connector has a terminal and a connector housing receiving the terminal. The terminal has a hole to accept a bolt. 
     The connector receptacle has a box shaped case with an insertion hole to accept entry of the connector, and a terminal portion to be superposed with the terminal when the connector is positioned in the insertion hole. The terminal portion has a second hole to be communicated with the hole of the terminal. The insertion hole is disposed on a side surface of the case. The case has a fastening hole at an upper surface. The fastening hole communicates with the insertion hole and accepts a bolt (fastening member) to fasten the terminal and the terminal portion together. 
     The connector assembly is assembled with the connector and the connector receptacle as follows. The connector is approached to the side surface of the case and inserted into the insertion hole. The terminal is superposed on the terminal portion to communicate the hole and the second hole one another. The bolt is then inserted from the upper surface of the case through the fastening hole into the communicated hole and the second hole so that the terminal and the terminal portion are fastened with the bolt. 
     In the conventional connector assembly, the connector is inserted into the insertion hole of the connector receptacle from the side surface of the case, and the fastening member is inserted from the upper surface of the case through the fastening hole to fasten the terminal and the terminal portion. It is thus necessary for the case to have an insertion space at the side surface to accept entry of the connector and a fastening area at the upper surface of the case to accept entry of the fastening member. 
     The necessity of the attachment spaces (insertion space and fastening area) limits an effective use of a limited space in the car. 
     U.S. Pat. No. 8,672,700 B2, therefore, proposes a solution permitting attachment of a connector to a connector receptacle in a reduced space. Accordingly the connector assembly described in U.S. Pat. No. 8,672,700 B2 comprises: a connector including a terminal and a connector housing for receiving the terminal; a connector receptacle including a case having an insertion hole for accepting entry of the connector, and a terminal portion received in the insertion hole and to be connected with the terminal; and a fastening member for fastening the connector and the connector receptacle together, wherein the terminal has an electrical connection portion to be connected with an electrical wire, and an electrical contact portion upstanding from the electrical connection portion and having a hole, the connector housing includes a housing main body for receiving the electrical connection portion, and a column portion connected to the housing main body and having the central axis along an insertion direction of the connector, and for receiving the electrical contact portion with the hole disposed along the insertion direction, the terminal portion has a connection portion with a second hole to be communicated with the hole when the electrical contact portion is superposed on the connection portion, the case includes a case main body having the insertion hole, and a housing portion attached to the case main body and supporting the connection portion so that the second hole is aligned with the insertion direction, and wherein when the connector is positioned inside of the insertion hole of the connector receptacle, and the electrical contact portion is superposed on the connection portion, the fastening member is insertable from the opening of the column portion into the communicated hole and the second hole, and is capable of fastening the electrical contact portion and the connection portion together. 
     The fastening member is a screw as a first fastening member which is screwed into an inside thread of a second fastening member. Between the two fastening members the connection portion as a first terminal and an electrical contact portion as second terminal are clamped. The screw is in direct electrical contact to the terminals so that there is the need to use special electrical insulated tools for fastening the fastening assembly and there is the danger for the assembling person to touch current leading members of the connector assembly. 
     The object of the present invention is to provide a connector assembly and a connection arrangement better protecting persons assembling the connector assembly from high voltage power. 
     The object is solved by the subject matter according to the independent claims. Preferred embodiments of the invention are described in the dependent claims. 
     The advantage of such an electrical connector assembly and such a connection arrangement is that the fastening assembly is completely electrically isolated from the electrical connection, i.e. from all parts being energized. The insulation arrangement ensures that the terminals which are to be clamped are not in electrical contact to the fastening assembly so that if the terminals are energized the fastening assembly is not energized and there is no electrical hazard if a person assembling the electrical connector assembly touches the fastening assembly even when using usual metallic tool. 
     Usually, in electrical vehicle or hybrid vehicle, bolt tightened eyelet connections are used. Therefore, the first fastening member is a screw (bolt) having a threaded shaft and a screw-head. The second fastening member has an inside thread receiving said threaded shaft of said screw. The terminals, in form of eyelet terminals or fork-like terminals, can be mounted onto the threaded shaft of the screw and can be tightened by the screw and the second fastening member, which preferably is a screw-nut. 
     Preferably, the insulation arrangement comprises an insulation sleeve made of an electrically insulating material and receiving the threaded shaft of the screw. The electrical terminals in the form of eyelet terminals or fork-like terminals are arranged around the insulation sleeve so that they do not contact the screw. 
     In order to further ensuring that the terminals cannot touch the screw, the insulation sleeve may be provided at one end with a flange abutting the screw-head of the screw. 
     The insulation arrangement may further comprise an insulation washer made of an electrically insulating material and abutting the second fastening member. The threaded shaft of the screw is led through a hole of the insulation washer. Hence, the insulation washer abuts the second fastening member so that, even if the second fastening member is made of a metal material it is ensured that neither the first fastening member nor the second fastening member can contact one of the terminals. The terminals are clamped between the screw-head and the second fastening member wherein between the screw-head and one of the terminals the flange portion of the insulation sleeve is arranged and between the second fastening member and one of the terminals the insulation washer is arranged. In addition, between the threaded shaft and all of the terminals the insulation sleeve is arranged so that the complete fastening assembly is electrically insulated from the terminals. 
     The hole of the insulation washer may have a portion of an increased diameter receiving a part of the insulation sleeve and supporting the insulation sleeve in a radial direction. It makes it easier to pre-assemble the insulation arrangement avoiding an unintentional movement of the insulation sleeve relative to the insulation washer unless the threaded shaft is led through the sleeve. 
     In order to further enable a pre-assembling of the electrical connector assembly the terminal holder may have a receptacle for receiving and holding the fastening assembly. Preferably, the terminal holder is made of an electrically insulating material such as a resin material. 
     The receptacle, preferably, has a first opening for inserting the fastening assembly and/or a first terminal of the plurality of terminals in a radial direction in relation to the longitudinal axis. 
     The receptacle may further have a second opening for inserting a second terminal of the plurality of terminals in a radial direction relative to the longitudinal axis. 
     In order to facilitate the pre-assembling of the insulation arrangement within the terminal holder the receptacle may have two oppositely arranged guiding grooves for receiving the flange of the insulation sleeve in a direction transversal to the longitudinal axis. The grooves are arranged parallel to each other wherein the flange may have a rectangular outer shape so that edges of the flange are parallel to the guiding grooves and can be guided therein. 
     The receptacle, further, may have a first recess for receiving the second fastening member and supporting the second fastening member against rotation about the longitudinal axis. Preferably, the second fastening member is a screw-nut having a hexagonal outer shape. The first recess, preferably, has a complementary hexagonal shape receiving the screw-nut and supporting the screw-nut against rotation. However, the second fastening member and the first recess may have any outer shape deviating from a circle line as long as the rotation of the second fastening member within a first recess about the longitudinal axis is avoided. 
     The receptacle may also have a second recess for receiving the insulation washer and supporting the insulation washer against radially removing the insulation washer out of the receptacle. The second recess and the insulation washer may also have an outer shape which deviates from a circle line such that the insulation washer is further supported within the second recess against a rotation about the longitudinal axis. 
     The object is also solved by a connection arrangement comprising an electrical connector assembly as described above and comprising a first terminal and a second terminal received in the terminal receiving area of the fastening assembly and being clamped by said fastening assembly for an electrical connection between said first and second terminals. The connection arrangement may comprise more than just two terminals. 
     The first terminal, preferably, has an eyelet portion with a hole wherein the fastening assembly is led through said hole. The second terminal may have a fork-like portion with a slot for radially mounting the second terminal onto the fastening assembly. 
     Hence, the first terminal may be mounted to the fastening assembly by axially moving the fastening assembly through the hole of the eyelet portion of the first terminal. The second terminal can be mounted to the fastening assembly by radially moving the second terminal onto the fastening assembly. Preferably, in such a configuration, the fastening assembly comprises a first fastening member in form of a screw and a second fastening member in form of a screw-nut. 
    
    
     
       A preferred embodiment is described with reference to the following drawings, wherein 
         FIG. 1  is a perspective exploded view of a connection arrangement with an electrical connector assembly within a case; 
         FIG. 2  is a longitudinal section of the arrangement according to  FIG. 1 , 
         FIG. 3  is a perspective view of the terminal holder of the electrical connector assembly according to  FIG. 1 , and 
         FIG. 4  is a perspective view of the terminal holder according to  FIG. 3  with inserted fastening assemblies and terminals. 
         FIGS. 1 to 4  do depict the invention in different views and are described together. 
     
    
    
     The Figures show a connector assembly  1  which is encapsuled by a box shaped case  2  and which serves to electrically connect first terminals  3 ,  3 ′ with second terminals  4 ,  4 ′. The first terminals  3 ,  3 ′ may be connected to a cable leading to a battery. The second terminals  4 ,  4 ′ are connected to shielded wires  5 ,  5 ′ in order to distribute the electrical energy of the battery. The connector assembly  1  is a two-pole design with two pole, each of which has one first terminals  3  and one second terminal  4 . Generally, the connector assembly  1  can also be of a one-pole of multiple pole design. In the following, if only one of the first terminals  3 ,  3 ′ or only one of the second terminals  4 ,  4 ′ is mentioned, it is described representing all other poles. 
     The cables (not shown) which are to be connected to the first terminals  3 ,  3 ′ are guided through an opening  61  within a housing  7  of the case  2 . The first terminals  3 ,  3 ′ are arranged within the case  2 . Each of the shielded wires  5 ,  5 ′ is guided through insertion holes  6 ,  6 ′ in the housing  7  so that the second terminals  4 ,  4 ′ are completely arranged within the case  2 . The second terminals  4 ,  4 ′ are electrically connected to conductors of the shielded wires  5 ,  5 ′. The shielded wires  5 ,  5 ′ are coupled to shield connectors  8 ,  8 ′ which are mounted to the case  2 . The shield connectors  8 ,  8 ′ comprise shield terminals  9 ,  9 ′ which are held in contact and, therefore, having an electrical connection to the case  2  wherein the case  2  is made of a metal material. The shield terminals  9 ,  9 ′ constitute a ground connection to the case  2 . The shield terminals  9 ,  9 ′ are electrically connected to shield conductors  15 ,  15 ′ of the shielded wires  5 ,  5 ′ wherein the shield conductors  15 ,  15 ′ are braided conductors surrounding the main conductor  14 ,  14 ′ and a cable insulation  16 ,  16 ′. 
     In order to reach the connector assembly  1  to establish a connection between the first terminal  3 ,  3 ′ and the second terminals  4 ,  4 ′ the case  2  has an opening  17  which is closed by a cover  10 . Between the cover  10  and the housing  7  a seal  11  is arranged. The cover  10  is fixed to the housing  7  by fastening bolts  12 . 
     The housing  7  of the case  2  is fastened to an electrical device by fastening bolts  13 . 
     The connector assembly  1  comprises a terminal holder  18  made of an electrically insulated material. The terminal holder  18  has for each hole a receptacle  19 ,  19 ′ which accommodates a fastening assembly  20 ,  20 ′. As can best be seen from  FIG. 2  the receptacle  19  has a first opening  21  for inserting the fastening assembly  20  and the first terminal  3  into the receptacle  19 . Further, the receptacle  19  has a second opening  22  for inserting the second terminal  4 . 
     The fastening assembly  20 , which is identical to the other fastening assembly  20 ′ as shown in  FIG. 1  and which is described in the following representing the other fastening assembly  20 ′, comprises a first fastening member  23  in form of a screw with a screw-head  24  and a threaded shaft  25 . The screw-head  24  has a hexagonal recess  26  for a tool. In the area of transition between the screw-head  24  and the threaded shaft  25  the screw-head  24  has a circumferential collar  27 . 
     The fastening assembly  20  further comprises a second fastening member  29  in form of a screw-nut. The screw-nut has an inside thread  28  in which the threaded shaft  25  is threaded. The second fastening member  29 , alternatively, can be formed by the terminal holder  18  or a part of the terminal holder  18  so that the screw  23  may be threaded into an inside thread of the terminal holder  18 . In the present embodiment the second fastening member  29  is a separate element. 
     The first terminal  3  and the second terminal  4  are clamped between the screw-head  23  and the screw-nut  29  in order to establish an electrical contact between the first terminal  3  and the second terminal  4 . The area between the screw-head  24  and the screw-nut  29  around the threaded shaft  25  can be considered as a terminal receiving area  37  in which connection ends of the terminals  3 ,  4  are arranged for clamping. 
     Both, the screw  23  and the screw-nut  29  are made of a metal material so that the fastening assembly  20  is able to apply a sufficient force to the terminals  3 ,  4  in order to establish a reliable connection between the terminals  3 ,  4 . In order to avoid an electrical contact between the fastening members  23 ,  29  and one of the terminals  3 ,  4  the fastening assembly  20  further comprises an insulation arrangement  30  comprising an insulation sleeve  31 . The insulation sleeve  31  has a central bore  36  for accommodating the threaded shaft  25  of the screw  23 . At an end of the insulation sleeve  31  which is arranged towards the screw-head  24  the insulation sleeve  31  has a flange portion  32  which extends radially from the insulation sleeve  31  and which is supported in axial direction related to the longitudinal direction L against the screw-head  24 . The insulation arrangement  30  further comprises an insulation washer  33  which is arranged at the other end of the insulation sleeve opposite to the flange portion  32  and which is in supporting contact to the screw-nut  29 . The insulation washer  33  has a hole  34 . The threaded shaft  25  of the screw  23  is guided through the hole  34  of the insulation washer  33  and is screwed into the inside thread  28  of the screw-nut  29  on a side of the insulation washer  33  which is opposite to the screw-head  24 . 
     In order to facilitate an easy pre-assembling of the insulation arrangement  30  the hole  34  of the insulation washer  33  has a portion of increased diameter  25  which is arranged towards the insulation sleeve  31  and which accommodates a part of the insulation sleeve  31  supporting the insulation washer  33  in a radial direction against the insulation sleeve  31 . 
     The insulation arrangement  30  is made of an electrically insulating material, such as Polytetrafluoroethylene (PTFE). Hence, the two fastening members  23 ,  29  are completely insulated by the insulation arrangement  30  towards the terminal receiving area  37 . 
     The first terminal  3  is configured in the form of a so called eyelet connector having a hole  38 . The threaded shaft  25  and the insulation sleeve  31  are accommodated within the hole  38  of the first terminal  3  so that the first terminal  3  cannot come into contact with the screw  23 . In an axial direction towards the nut  29  the first terminal  3  is supported against the insulation washer  33  so that the first terminal  3  cannot come into contact with the screw-nut  29 , either. 
     The second terminal  4  can either be also in the form of an eyelet connector comparable to the first terminal or, as shown in  FIG. 1 , the second terminal  4  can be in the form of a fork having a slot  39  so that the second terminal  4  can be slipped onto the insulation sleeve  31  in a radial direction. As shown in  FIG. 2  also the second terminal  4  is only in contact to the insulation sleeve  31  and is not in contact to the screw  23 . In an axial direction the second terminal  4  is supported against the flange portion  32  of the insulation sleeve  31  so that also a contact to the screw-head  24  is avoided. 
     Each receptacle  19  has two oppositely arranged grooves  40 ,  41  which are orientated parallel to each other. The flange portion  32  of the insulation sleeve  31  has a rectangular shape with two oppositely arranged parallel edges  42 ,  43  which are guided in the grooves  40 ,  41 . The grooves  40 ,  41  start from the first opening  21  so that the insulation sleeve  31  can be inserted into the receptacle  19  from the first opening  21 . The flange portion  32  is supported in an axial direction against the grooves  40 ,  41 . 
     In order to avoid that the insulation sleeve  31  can be pulled out of the grooves  40 ,  41  unintentionally the terminal holder  18  is provided with two elastic spring arms  44 ,  45  for each of the receptacles  19 ,  19 ′. The two spring arms  44 ,  45  are orientated parallel to the grooves  40 ,  41  and can be elastically deformed parallel to the longitudinal axis L. Each spring arm  44 ,  45  has a locking catch  46 ,  47  projecting from the spring arm  44 ,  45  towards the flange portion  32  and engaging front edges  48 ,  49  of the flange portion  32  so that the flange portion  32  is supported in a radial direction of the longitudinal axis L. 
     Each spring  44 ,  45  arm further comprises a wall portion  50 ,  51  projecting from the spring arms  44 ,  45  in a longitudinal direction on a side of the spring arms  44  which is opposite to the receptacle  19 . Each of the wall portions  50 ,  51  has a locking catch  52 ,  53 , wherein the locking catches  52 ,  53  are arranged towards each other. The screw-head  24  is arranged between the wall portions  50 ,  51  wherein the circumferential collar  27  of the screw-head  24  is held in its position by the locking catches  52 ,  53  as long as the screw  23  is not threaded into the nut  29 . 
     The nut  29  has a hexagonal outer circumference and is accommodated within a first recess  54  which has a complementary shape, i.e. a hexagonal profile so that the nut  29  is secured against the rotation about the longitudinal axis L within the first recess  54 . 
     The terminal holder  18  further comprises a second recess  55  for accommodating the insulation washer  33 . The insulation washer  33  has a square outer profile and the second recess  55  has a complementary shape so that the insulation washer  33  is supported against rotation about the longitudinal axis L and cannot be pulled out of the receptacle  19  unintentionally. 
     The terminal holder  18  is held in a support  58  of the housing  7  of the case  2 . The terminal holder  18  has two spring arms  56 , one of which is shown in the drawings and which are arranged in opposite sides of the terminal holder  18 . The spring arms  56  have a locking projection  57  which is in engagement with a complementary undercut of the support  58 . 
     In order to further ensure that a person assembling the connector assembly cannot touch any energized parts the portion of the first terminal  3  which projects out of the terminal holder  18  is covered by an insulating coating  59  as can be seen in  FIGS. 1 and 2  (indicated as thick black line in the cross-sectional view of  FIG. 2 ). The eyelet part of the first terminal  3  is uncoated. The second terminal  4  is covered by an insulating tube  60  so that from above through the opening  17  of the housing  7  an operator or a person assembling the connector assembly cannot touch one of the energized parts and cannot contact an ordinary metallic tool with one of the energized parts. 
     REFERENCE NUMERALS 
     
         
           1  connector assembly 
           2  case 
           3 ,  3 ′ first terminal 
           4 ,  4 ′ second terminal 
           5 ,  5 ′ shielded wire 
           6 ,  6 ′ insertion hole 
           7  housing 
           8 ,  8 ′ shield connector 
           9 ,  9 ′ shield terminal 
           10  cover 
           11  seal 
           12  fastening bolt 
           13  fastening bolt 
           14 ,  14 ′ main conductor 
           15 ,  15 ′ shield conductor 
           16 ,  16 ′ cable insulation 
           17  opening 
           18  terminal holder 
           19 ,  19 ′ receptacle 
           20 ,  20 ′ fastening assembly 
           21 ,  21 ′ first opening 
           22 ,  22 ′ second opening 
           23 ,  23 ′ first fastening member (screw) 
           24 ,  24 ′ screw-head 
           25  threaded shaft 
           26 ,  26 ′ hexagonal recess 
           27 ,  27 ′ collar 
           28  inside thread 
           29  second fastening member (screw-nut) 
           30 ,  30 ′ insulation arrangement 
           31 ,  31 ′ insulation sleeve 
           32 ,  32 ′ flange portion 
           33 ,  33 ′ insulation washer 
           34  hole 
           35  portion of increased diameter 
           36  bore 
           37  terminal receiving area 
           38  hole 
           39 ,  39 ′ slot 
           40 ,  40 ′ groove 
           41 ,  41 ′ groove 
           42  edge 
           43  edge 
           44 ,  44 ′ spring arm 
           45 ,  45 ′ spring arm 
           46 ,  46 ′ locking catch 
           47 ,  47 ′ locking catch 
           48  front edge 
           49  front edge 
           50 ,  50 ′ wall portion 
           51 ,  51 ′ wall portion 
           52 ,  52 ′ locking catch 
           53 ,  53 ′ locking catch 
           54 ,  54 ′ first recess 
           55 ,  55 ′ second recess 
           56  spring arm 
           57  locking projection 
           58  support 
           59  coating 
           60  tube 
         L longitudinal axis