ELECTRICAL CONTACT

Abstract: A terminal (2) comprises a body section (6) integrally formed with the contact section (8). The body section (6) has resilient locking lances (56) that are generally flush with side walls (20) of the body. The body section has a slight taper to enable a locking protrusion of a connector housing to pass over the attachment end (58) of the locking lance and engage the locking lance (56) at an intermediate position thereafter whereby the lance is biased into the body section. The smooth outer profile and substantially flush locking lance enables easy insertion and extraction of the contact through a seal, in addition to preventing entanglement of the lance with wires of a harness.

Description: ELECTRICAL CONTACT This invention relates to an electrical contact, in particular an electrical contact with resilient locking lances for securing in a cavity of a connector housing. It is common to find electrical contacts with box shaped bodies stamped and formed from sheet metal, for assembly in cavities of electrical connector housings. In certain applications, such as found in the automotive industry, it is often desirable to seal connectors to prevent ingress of dirt or fluids at the contact mating areas of the connector. It is a continuous requirement to provide more cost effective connectors and terminals whilst nevertheless providing the required electrical characteristics. In many applications it is also desirable to provide more compact connection systems which may entail reducing the size of the contacts and reducing the distance between adjacent contacts positioned in a connector housing. It is also a continuous requirement in many applications to provide a sturdy and robust contact as damage to contacts can incur relatively high costs. For example, contacts that are terminated to conducting wires of an automotive harness may entail expensive reparation of the harness (labor and time) due to damage to only one of the contacts even though the actual cost of the contact is insignificant in comparison. If reparation or replacement of a connector housing or contact is required, it is often desirable that this is manageable with ease, in particular that the contacts can be inserted and removed through a sealing member of a connector without damage thereto. It is common to find electrical terminals that are provided with a box-shaped body on which a resilient locking lance is provided, the locking lance projecting obliquely outward from the body. Extraction of such a terminal through a seal however causes problems due to the outwardly projecting lances and the sharp edges that result from the stamping out of the locking lance from sheet metal. Furthermore, during handling of harnesses, wires or other external objects can get entangled with the locking lance causing damage thereto. A further disadvantage, is that the locking lances require additional space in the connector housing, as the locking lances project beyond the outer periphery of the contact body section, thus increasing the volume of connectors. In order to ensure reliability of the contacts, it is important to protect the contact spring arms, and the contact area from damage. It is an object of this invention to provide an electrical terminal that is robust and reliable. It is a further object of this invention to provide a compact and cost effective electrical terminal. It would be advantageous to provide an electrical terminal having a resilient locking lance that is protected from damage by external objects. It would be advantageous to provide an electrical terminal that can be easily inserted and extracted through a seal member of an electrical connector. It would be advantageous to provide an electrical terminal that can be positioned in an electrical housing at a compact spacing from an adjacent terminal, whilst nevertheless ensuring sufficient and reliable electrical characteristics. Objects of this invention have been achieved by providing an electrical terminal comprising a connection section for connection to an electrical conductor, a contact section for mating with a complementary terminal, and a body section comprising at least one resilient locking lance attached to the body towards the mating end of the connector and extending therefrom to a free end having a locking shoulder for cooperation with a locking shoulder in the cavity of an electrical connector housing, wherein the locking lance is generally flush with an outer wall of the body section. In particular, the locking shoulder of the lance is substantially flush or recessed within the body outer wall. Advantageously, the body section of the terminal can be inserted and extracted through a seal, without catching on the locking shoulder or other parts of the locking lance. Furthermore, the lance is protected from damage by external objects, for example avoiding entanglement with wires of a harness. The receptacle body could be box-shaped comprising a top, bottom and side walls whereby the locking lance extends substantially in the plane of one or both of the side walls. The terminal could advantageously be stamped and formed from sheet metal out of a single part for a cost effective construction. The resilient locking lance could be in the shape of a cantilever beam, biased into the body section during insertion past a locking shoulder in a cavity housing. The latter enables a very compact spacing between terminals positioned in a connector housing. For a receptacle terminal, the outer body could further be provided with spring contact arms positioned within the body such that the contact section is well protected. The outer body could be provided with spring support arms formed out of the top and bottom walls and biasable against the spring contact arms for increasing the spring pressure thereof. Further advantageous aspects of the invention are described in the claims, or will be apparent from the following description and drawings. An embodiment of this invention will now be described by way of example with reference to the figures, whereby; Figure 1 is an isometric view towards a mating end of a terminal according to this invention; Figure 2 is an isometric view of the terminal figure 1 but from the conductor receiving end; Figure 3 is an isometric view of part of the terminal of figure 1, with part of the outer body broken away; Figure 4 is an isometric view of terminals according to figure 1 in the process of being stamped and formed from sheet metal. Referring first to figures 1 and 2, an electrical terminal 2 comprises a connection section 4, a body section 6 and a contact section 8. The connection section 4 comprises a crimping barrel for crimping to a conducting wire, but of course could be any other connection means. The body section 6 extends from a connection section end 10 to a mating end 12 in a mating direction. Referring to figure 3, the body section will now be described. The body section 6 comprises an outer wall 14 having a box shape formed by top and bottom walls 16,18 and side walls 20,22, further provided with a front wall 24 at the mating end 12. The front wall 24 extends transversely to the mating direction. Still referring to figure 3, the contact section 8 comprises resilient contact arms 26 in the shape of cantilever beams attached at an end 28 to the body section 6 proximate the connection end 10, and extending therefrom to free ends 30 proximate the mating end 12. Arcuate contact sections 32 are provided intermediate the free end 30 and attachment end 28 for receiving a complementary tab terminal therebetween. As can be seen in figure 4, the contact arms 26 are attached to the body section 6 by a folded or U-shaped bridging portion 36 such that an attachment portion 38 of the contact arm lies against the inside of the top and bottom walls 16,18 of the outer body. Referring to figure 3, the front wall 24 comprises a cut-out 38 that enables insertion of the complementary terminal therethrough. The front wall 24, in conjunction with the side, top and bottom walls provide protection for the contact arms 26. In particular, external objects can not abut or catch onto the free ends 30 of the contact arms or can not access the contact section 32 except through the cut-out 38 which is adapted to prevent reception of objects larger than the mating contact. The cut-out 38 also ensures that the mating terminal is correctly guided between the contact sections 32. Corners 40 and 42 that join the front wall 24 to the top and bottom and side walls respectively, are rounded and thus enable smooth insertion of the body section through a sealed member, or into a cavity of a housing. The rounded corners 40 are advantageously formed by the folding of the top wall 16 over the bottom wall 20, the top and bottom walls being joined together by the front wall 24. The body section outer wall 14 is joined together by laser welds 44 that join together the seam 46 formed between the top wall 16 and side walls 20,22, proximate the connection end 10, when the top wall is folded over the bottom wall. The laser weld provides for a very compact and robust closing of the seams 46. The box shaped body section outer wall 14 thus forms a robust shell due to the front wall 24 integrally formed with the side, top and bottom walls via rounded corners, and the closed periphery at the connection end 10 where the seams 46 are attached. Furthermore, provision of the outer body and contact section from an integral sheet of metal, provides for cost effective manufacturing of the terminal. The side walls and bottom wall 20,18 join the connection section 4 via rounded corners 48 that not only ensure a more rigid structure but in particular provide for smooth extraction through a seal member. The top and bottom wall 16,18 can be provided as shown in this embodiment (figure 3) with spring support arms 50 that are in the shape of cantilever beams attached to the side wall at an attachment end 52 proximate the connection end 10 and extending therefrom to a free end 54 which is inwardly bent into the body section for abutment against the spring contact arms 26 at a position proximate the contact section 32. The spring support arms 50 increase the spring pressure of the contact arms 26. Resilient locking lances 56 in the shape of cantilever beams extend along the side walls 20 from an attached end 50 to a free end 60 which is directed towards the connection end 10. The attached end 58 is integrally formed with the rounded corner 42 of the front wall 24. The locking lance 56 is positioned within a cut-out 62 of the side wall 20 and is free to resiliently bias into the body section 14. A locking protrusion positioned in a cavity of a connector housing, would thus inwardly bias the locking lance 56 during insertion of the locking lance into the cavity until the free end 60, which also forms a locking shoulder, snaps behind the protrusion for locking of the terminal in the housing cavity. In this embodiment, the terminal 56 is shown flush with the side wall 20. The locking shoulder 60 does therefore not extend beyond the side wall 20 thereby enabling insertion and extraction of the terminal through a seal member, or preventing entanglement with external objects. The lance is therefore well protected. The lance 56 could also be slightly recessed with respect to the side wall 20, in particular the locking shoulder 60, however it would also be possible to imagine that a portion of the locking lance 56 positioned between the attachment and free ends extends beyond the side wall 20, as long as the locking shoulder 60 can not get entangled or caught on an external object. In this sense, the locking lance 56 is described as generally or substantially flush with the side wall 20. By providing the resilient locking means on the terminal, construction of a connector housing can be simplified, for example only a simple locking protrusion is required instead of a resilient latch member molded with the connector housing. Not only is the connector more robust, but the spacing between adjacent terminals can be very compact. This is an added advantage of the substantially flush locking lance 56 which does not require a larger housing cavity that conventional locking lances require (in order to bias outwardly thereinto) . The body section outer wall 14 is provided, in the embodiment of figures 1 to 4, with a slight taper such that the cross sectional profile or periphery (cross section with respect to the mating direction) is greater at the connection end 10 than at the mating end 12. The taper may assist easier and smoother insertion of the contact through a seal. A taper, in particular of the side walls 20, 22 also enables a locking protrusion in a connector cavity to be inserted over the attachment end 58 of the locking lance,thereafter engaging and resiliently biasing the locking lance at an intermediate portion between the attachment end and the free end 58,60 respectively, during insertion of the terminal in the cavity. It would also be possible to provide the terminal 2 with another contact section, for example a pin terminal extending through the front wall cavity 38, whilst retaining the advantages of the body section 6 as described hereabove, in particular the smooth outer periphery and substantially flush positioning of the resilient locking lance. Advantageously therefore, the smooth outer profile of the terminal body section provides a contact that is easily insertable through a seal member, and which is less prone to damage from external objects, whilst nevertheless providing a resilient locking lance. In addition, compact positioning of terminals in a connector housing is improved. The robust enclosure that the forming of the outer wall of the body section forms and the stamping and forming from a integral piece of material provides a robust, reliable, yet cost effective terminal.

Claims: CIAIMS 1. An electrical terminal (2) insertable in an insertion direction into a connector cavity for assembly thereto,comprises a connection section (4) for electrical connection to a conductor, a contact section (8) for mating with a complementary contact in a mating direction and a body section (6) comprising an outer wall (14) and at least one locking lance (56) attached at an attachment end (58) to the body section proximate a mating end (12) thereof, and extending substantially in the insertion direction to a locking shoulder (60) positioned towards a connection end (10) of the body section, characterized in that the locking lance is substantially flush or recessed with respect to the outer wall (14) of the body section. 2. An electrical terminal (2) insertable in an insertion direction into a connector cavity for assembly thereto, comprises a connection section (4) for electrical connection to a conductor, a contact section (8) for mating with a complementary contact in a mating direction and a body section (6) comprising an outer wall (14) and at least one locking lance (56) having a locking shoulder (60) for engagement with complementary locking means of the connector cavity, the body section being box-shaped comprising a top wall (16) , bottom wall (18) opposed thereto, and side walls (20,22) extending therebetween, characterized in that the body section further comprises a front wall (24) transverse to the mating direction and positioned at a mating end (12), the front wall integrally attached to the top and bottom walls via corners (40) formed by folding of the top wall over the bottom wall, the front wall having a cut out (38) for extension of a contact therethrough. 3. The terminal of claim 1 wherein the body section (6) is box-shaped and comprises a top wall (16) , bottom wall (18) opposed thereto, and side walls (20,22) extending therebetween, whereby the locking lance (56) extends along a sidewall (20) . 4. The terminal of claim 1 wherein the body section (16) comprises a front wall (24) integrally attached to the top and bottom walls (16,18) via corners (40) at the mating end (24) . 5. The terminal of claim 4 wherein the corners and front wall result from the folding of the top wall over the bottom wall at the mating end. 6. The terminal of claim 4 or 5 wherein the front wall (24) has a cut out (38) adapted to allow passage of a complementary contact therethrough. 7. The terminal of any one of claims 2,4 or 5 wherein the locking lance (56) is attached to the front wall (24) via a corner (42) . 8. The terminal of any one of claims 2-7 wherein the side wall (20) along which the locking lance (56) extends is tapered such that a cross-sectional area or periphery of the body section (6) , with respect to the insertion direction, is smaller proximate the mating end (24) than proximate the connection end (10) . 9. The terminal of any one of the preceding claims wherein the contact section (8) comprises cantilever beam spring contact arms (26) attached to the body section (6) proximate the connection end (10) and extending to free ends (30) proximate the mating end (24) of the body section, the contact section being enclosed in the body section. 10. The terminal of claim 9 wherein the top and bottom walls (16,18) of the body section comprise spring support arms (50) extending alongside the contact arms (26) and biased into the body to provide added spring support to the contact arms.

Inventors: JOLY JEAN CLAUDE, JOLY, JEAN, CLAUDE
Applicants: JOLY JEAN CLAUDE, WHITAKER CORP, JOLY, JEAN, CLAUDE, THE WHITAKER CORPORATION
Application year: 1997
Main classification: H01R13
IPC codes: H01R13, H01R43