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(11) | EP 0 235 193 B1 |
| (12) | EUROPEAN PATENT SPECIFICATION |
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| (54) |
ELECTRICAL CONNECTOR ASSEMBLY ELEKTRISCHER STECKVERBINDER FICHE DE RACCORDEMENT ELECTRIQUE |
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| Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention). |
[0001] The present invention relates to an electrical connector of the type having contacts that can penetrate the insulation of an electrical wire.
[0002] Electrical connectors of this type are well known and widely used for telephone cables. An electrical connector of this type has been already proposed by the present applicant in Japanese Unexamined Patent Publication No. 59-78 481. An example of this electrical connector is shown in Figures 5 and 6 of the accompanying drawings. A plug 3 connected to a number of insulated wires 4 is inserted into a plug receiving aperture 2 in a receptacle 1, allowing plug contacts 6 of plug 3 to be connected with receptacle contacts 2a of receptacle 1. Plug contacts 6 are press-fitted into plug 3 from a series of contact receiving slots 5a formed in the undersurface of a dielectric housing 5 of plug 3. An upper part of each plug contact 6 penetrates the insulation of each insulated electrical wire 4 inserted into housing 5, thus forming a connection with the conductor 4a of wire 4 as is shown in Figure 7 of the accompanying drawings. As can be seen, pressure exerted on each plug contact 6 causes upper portions 6a of plug contact 6 to pierce and penetrate the insulation of each wire 4, thus forming art electrical connection between conductor 4a and contact 6.
[0003] A major problem is present with the above- described connector. An adequate force must be applied to plug contact 6 in order for portions 6a to pierce the insulation of wires 4, causing housing 5 to be bent upward by the force, as shown by the dotted line in Figure 8 of the accompanying drawings. This problem is magnified as the number of wires is increased. With an increased number of wires, the housing must have a larger width causing the housing to be more flexible which in turn causes a greater bend of the housing when the force is applied, resulting in an incomplete electrical connection between wires 4 and plug contact 6. To avoid this problem, an upper wall 5a of housing 6 must be made thicker to increase the rigidity. This is not a desirable solution since it necessitates the production of a larger, more costly plug.
[0004] In an effort to solve the above-mentioned problems, Japanese Unexamined Patent Publication No. 61-131 379 has been proposed, as shown in Figures 9 and 10 of the accompanying drawings. A plurality of contacts 11 are equipped with connecting portions 11 a abutting against electrical wires 4. The contacts are electrically connected with conductors 4a of wires 4 by pushing the ends of connecting portions 11 a through the insulation of the wires. Each contact has projections 11 b press-fitted into apertures 12a of cover 12 of housing 13 and retained on housing 13 by latching projections I I b. This prevents warping of the upper wall of the housing, as shown in Figure 8. However, it is necessary to move the connecting portion 11 a laterally relative to the projections 11 of the contact 11 to avoid an abutment between the projections 11 b and the wire 4. Therefore, there is a possibility that the connecting portion 11 a may be bent by the effect of a torsional moment as the connecting portion 11 a penetrates the electrical wires 4. Moreover, when the connecting portion 11 a is bent, a problem of incomplete connection between the conductor 4a and connecting portion 11 a can occur.
[0005] Moreover, US-A-4 109 991 also discloses an electrical connector assembly of the type having contacts that can penetrate the insulation of an electrical wire located in a cavity in the connector housing. The terminals included in this connector comprise front and back projections positioned on either side of a connecting portion of the terminal, the projections extending to both sides of the centre line of the terminal such that as the cover is placed over the housing, the wire is guided directly into the connecting portions; and the connecting portions extend into a wire receiving cavity so that the wire remains stationary as the connecting portions pierce the insulation of the wire. Since the wire is forced downwards into the cavity as the connecting portions pierce the insulation, harmful stresses are imparted to the wire as it is displaced into the cavity and piercing occurs.
[0006] It is an object of the present invention to provide an electrical connector, the contacts of which are protected from torsional and other harmful forces that may occur when the contact penetrates the insulation.
[0007] The present invention provides an electrical connector assembly comprising; a dielectric housing having a plurality of terminal receiving cavities where each said cavity is provided with a terminal secured therein by first securing means,
a dielectric cover having a like plurality of slots such that when said cover is brought into engagement with said housing, the slots of said cover align with the cavities of the housing to form wire receiving cavities for receiving respective Insulated wires, and
wire insulation piercing connecting portions of the terminals extending into the wire receiving cavities such that as said cover is placed over said housing with the wires in the corresponding slots, the wire engages the connecting portion allowing the connecting portion to pierce the insulation of the wire, placing a conductor of the wire in electrical contact with the terminal, the connector being characterized in that:
said insulation piercing connecting portion is axially oriented on said terminal, and, front and back projections are positioned on the terminal one on each side of the connecting portion, the projections extending to opposite sides of the centerline of the terminal and axially displaced from said connecting portion, such that as said cover is placed over said housing, the wire is guided directly onto the connecting portion in such a manner so as not to create torsional force;
the connecting portions of the terminals extending into the wire receiving cavities such that the wire remains essentially straight and stationary as connecting portions pierce wires, thereby eliminating the harmful stresses which result when said wires are displaced as piercing occurs; and
first means for latchably securing said cover with said terminals, thereby maintaining constant pressure on said wires, and second means for securing said cover to said housing.
[0008] The invention will now be described by way of example with reference to Figures 1 to 4 of the accompanying drawings, in which:
Figure 1 is an exploded perspective view of one embodiment of an electrical connector assembly according to the present invention;
Figure 2A is a top plan view of a contact of the electrical connector assembly;
Figure 2B is a side elevational view of the contact of the connector assembly;
Figure 2C is a front end view of the contact of the connector assembly;
Figure 3 is an exploded perspective view of one contact and a corresponding cover of the connector assembly;
Figure 4 is a longitudinal cross-sectional view of an assembled connector assembly;
Figure 5 is a perspective exploded view of an electrical connector of the prior art of JP-A-5 978 481.
Figure 6 is a longitudinal cross-sectional view of the electrical connector of Figure 5;
Figure 7 is a perspective part cross-sectional view of the plug connector of Figures 5 and 6;
Figure 8 is a cross-sectional view of the plug connector taken along the line 8-8 in Figure 7;
Figure 9 is an exploded perspective view of one contact and a corresponding cover of another electrical connector of the prior art of JP-A-61 131 379; and
Figure 10 is a longitudinal cross-sectional view of an assembled electrical connector
of Figure 9.
Referring to Figures 1 to 4, the electrical connector assembly of the present invention
comprises a plurality of terminals 50, a housing 20, and a cover 30.
[0009] Each terminal 50, as best shown in Figures 2A, 2B and 2C, is stamped and formed from sheet metal having appropriate conductive and spring characteristics. A bifurcated female contact section 51 is provided at a front end of each terminal 50 for engagement with a corresponding male contact of another connector assembly. A middle section of terminal 50 has a projection 52 which is press-fitted into a contact receiving cavity 21 of housing 20. Interference-fit projections 53 are also provided on the middle section of terminal 50 proximate projection 52 opposite contact section 51. Projections 53 extend in opposite directions laterally from the longitudinal axis of terminal 50 and have latching projections 53a on the ends thereof. Connecting portion 54 of each terminal 50 is disposed between projections 53 and includes spaced wire penetrating members that penetrate through the insulation of an electrical conductor 4 which is guided to connecting portion 54 between projections 53. As shown in Figure 2A, projections 53 are located to the front and rear of portion 54, as well as being symmetrically arranged to the right and left of portion 54. A wire retaining projection 55 is formed to the rear of projection 53. A projection 56 is also provided below projection 55 for engagement with an engaging slot 23a of housing 20 as shown in Figure 1. Projection 56 limits vertical movement of a rear portion of contact 50 in housing 20.
[0010] Housing 20, made of insulating material, holds a plurality of contacts 50. A plurality of contact cavities 21 are provided in housing 20 to receive contact sections 51 of contacts 50. A like plurality of contact receiving slots 22 are provided in alignment with cavities 21 in housing 20 to re- ceive the rear portion of contacts 50. Slots 22 are separated by walls 23 which have engaging slots 23a provided in a back end of each wall 23.
[0011] A pair of mounting slots 24 and a pair of latching projections 25 are provided at both ends of housing 20 for engagement and retention of cover 30 (in the drawings, only a single end of housing 20 is shown due to the assembly being shown in cross section). Housing 20 has a symmetrical top and bottom half such that contacts 50 can be linearly arranged in the bottom half as well as the top half. Consequently, a second cover 30 is required for the bottom half.
[0012] Each cover 30 has a pair of opposing arms 31, as shown in Figure 1, one pair provided at each end of cover 30. Arms 31 have hooks 31 a extending from an end thereof for engagement with respective projections 25 in slots 24. Wire receiving grooves 32 are arranged on cover 30 such that grooves 32 align with slots 22 of housing 20 so that wire 4 may be properly inserted into grooves 32 and slots 22. Grooves 32 are separated by partition walls 33 having apertures 34 extending therein. A rib 35 is provided at an end of wall 33 to grip an end of wire 4.
[0013] To connect each wire 4 to the assembly, each contact 50 is fitted in housing 20 by inserting contact 50 into contact receiving cavity 21 from the rear. The rear portion of contact 50 is to be located in slot 22. At this stage, projection 52 is press-fitted into contact cavity 21 causing projection 56 to engage slot 23a. Contact 50 is now secured in housing 20.
[0014] The ends of wires 4 are pressed into grooves 32 of cover housing 30 such that wires 4 are held in place by ribs 35. This configuration acts as a strain relief preventing axial tension on wire 4.
[0015] Cover 30 is then press-fitted onto housing 20 causing hooks 31a of arms 31 to latchably engage projections 25 in slots 24. As shown in Figure 4, projections 53a are then press-fitted into apertures 34 of cover 30. At the same time, portions 54 press wires 4 against an undersurface 32a of slots 32 and portions 54 penetrate the insulation of wires 4 causing conductors 4a of wires 4 to engage portions 54 creating electrical contact therebetween.
[0016] As the above-mentioned termination occurs, contacts 50 remain free from torsional force due to projections 53 being symmetrically arranged with respect to the centerline of contact 50 and portions 54 being in alignment with the centerline of contact 50. This configuration positions wires 4 directly above portions 54 thus eliminating unequal force being exerted from either side of the centerline. As termination occurs, forces exerted are symmetrical about the centerline axis of contacts 50 thereby eliminating the problem of contacts 50 making poor electrical contact with wires 4 due to torsional forces being exerted on contacts 50.
[0017] Also, as shown in Figure 4, when cover 30 is fitted to housing 20 to hold wires 4 therebetween, projections 55 also engage wires 4, the end part of projections 55 penetrating slightly into the insulation. Accordingly, this penetration prevents wires 4 from being pulled out by an extemal force, providing an axial strain relief.
a dielectric cover (30) having a like plurality of slots (32) such that when said cover (30) is brought into engagement with said housing (20), the slots (32) of said cover (30) align with the cavities (22) of the housing (20) to form wire receiving cavities for receiving respective insulated wires (4), and
wire Insulation piercing connecting portions (54) of the terminals (50) extending into the wire receiving cavities such that as said cover (30) is placed over
said housing (20) with the wires (4) in the corresponding slots, the wire (4) engages the connecting portion (54) allowing the connecting portion (54) to pierce the insulation of the wire, placing a conductor (4a) of the wire (4) in electrical contact with the terminal, the connector being characterized in that:
said insulation piercing connecting portion (54) is axially oriented on said terminal, and, front and back projections (53) are positioned on the terminal, one on each side of the connecting portion (54), the projections (53) extending to opposite sides of the centerline of the terminal and axially displaced from said connecting portion (54), such that as said cover is placec over said housing (20), the wire (4) is guided directly onto the connecting portion (54) in such manner so as not to create torsional force;
the connecting portions (54) of the terminals (50) extending into the wire receiving cavities such that the wire (4) remains essentially straight and stationary as connecting portions (54) pierce wires (4), thereby eliminating the harmful stresses which result when said wires are displaced as piercing occurs; and
first means (34, 53a) for latchably securing said cover with said terminals, thereby maintaining constant pressure on said wires, and second means (24, 25, 31, 31 a) for securing said cover (30) to said housing (20).
un boîtier diélectrique (20) présentant plusieurs cavités (21, 22) de réception de bornes, une borne (50) étant fixée dans chacune desdites cavités par des premiers moyens (52) de fixation,
un couvercle diélectrique (30) présentant un nombre égal de rainures (32) de manière que, lorsque ledit couvercle (30) est amené en enclenchement avec ledit boîtier (20), les rainures (32) dudit couvercle (30) s'alignent avec les cavités (22) du boîtier (20) pour former des cavités de réception de fils destinées à recevoir des fils isolés respectifs (4), et
des parties (54) des bomes (50) , pour la connexion et le percement de l'isolant des fils, s'étendant dans les cavités de réception de fils de manière que, lorsque ledit couvercle (30) est placé sur ledit boîtier (20) alors que les fils (4) sont dans les rainures correspondantes, le fil (4) porte contre la partie (54) de connexion, permettant à la partie (54) de connexion de percer l'isolant du fil, plaçant un conducteur (4a) du fil (4) en contact électrique avec la borne, le connecteur étant caractérisé en ce que :
ladite partie (54) de connexion et de percement de l'isolant est orientée axialement sur ladite borne et des saillies avant et arrière (53) sont placées sur la borne, une de chaque côté de la partie (54) de connexion, les saillies (53) s'étendant sur des côtés opposés de l'axe central de la borne et étant décalées axialement par rapport à ladite partie (54) de connexion, de manière que, lorsque ledit couvercle est placé sur ledit boîtier (20), le fil (4) soit guidé directement jusque sur la partie (54) de connexion de manière à ne pas engendrer de force de torsion ;
les parties (54) de connexion des bomes (50) s'étendant à l'intérieur des cavités de réception de fils de manière que le fil (4) reste essentiellement droit et immobile pendant que les parties (54) de connexion percent les fils (4), éliminant ainsi les contraintes nuisibles qui résultent lorsque lesdits fils sont déplacés pendant que le percement a lieu; et
des premiers moyens (34, 53a) destinés à fixer et verrouiller ledit couvercle avec lesdites bomes, maintenant ainsi une pression constante sur lesdits fils, et des seconds moyens (24, 25, 31, 31a) pour fixer ledit couvercle (30) sur ledit boîtier (20).