SINGLE PIECE POLARIZED ELECTRICAL TERMINAL

Abstract: A single piece electrical receptacle terminal comprises a box-shaped contact section (6) having a polarizing extension (12) extending above a top wall (14) from a first side wall (12), the top wall integrally attached to a resilient contact arm (26) folded thereunder through a fold (28).

Description: SINGLE PIECE POLARIZED ELECTRICAL TERMINAL This invention relates to a single piece electrical receptacle terminal with a polarization feature. In European Patent EP 0 390 865 a stamped and formed electrical receptacle terminal for mating with pin contacts having a square profile is disclosed. The terminal is made of two parts, an inner contact body and an outer body enclosing a contact section of the inner body. The outer body is provided with a locking lance and a polarizing feature in the form of an extension of one of the side walls of the outer body. Two part terminals are generally more expensive to produce than single part terminals. They are also usually more difficult to manufacture in miniature form because of the difficulty of handling and assembling separate miniature parts. It is common to provide single piece terminals which are stamped and formed from a single piece of metal. A terminal of this nature is disclosed in U.S. 5,281,175. The latter discloses a box-shaped receptacle terminal for mating with a pin terminal. A contact arm is folded from one side wall, and is overlapped by a top wall folded from the other side wall, from which also extends a polarizing tab. The top wall is also provided with a rigid locking shoulder for engaging a resilient lance of a connector housing. One of the disadvantages of this construction is that it is relatively fragile, for example the polarizing feature is fairly small and can easily be bent or damaged, and the top wall can be relatively easily bent or damaged due to the various functional parts such as the support spring, locking shoulder and polarizing feature cut out from the material of the top wall. Furthermore, it is desirable in many connector systems to provide the resilient retention member on the contact, rather than on the housing which is usually made of a plastic material and is less resistant than the metal contact. It is therefore an object of this invention to provide an improved single piece stamped and formed electrical receptacle terminal with a polarizing feature. In particular, such contact should be more robust, yet simple and cost-effective to stamp and form. In order to reduce cost, it would also be advantageous to optimize use of the stamped and formed material. It would also be particularly advantageous to be able to employ the terminal in cavities of existing housings adapted to receive two-piece terminals according to EP 390 865. Objects of this invention have been achieved by providing a receptacle terminal according to claim 1. In particular, a single piece electrical receptacle terminal for mating with a pin terminal, comprises a connection section for connection to a conducting wire, and a contact section having a box-shape defined by a bottom wall, side walls extending therefrom, and a top wall opposed to the bottom wall, the walls surrounding a cavity area for receiving a pin terminal therein, wherein one side wall is provided with a polarizing extension projecting beyond the top wall, and wherein the top wall is joined through a corner to the opposite side wall, the top wall further attached via a fold proximate the first side wall to a resilient contact arm. Advantageously therefore, a long and stable polarizing extension can be provided, and the top wall can be rigidly connected at a corner with the side wall having the polarizing extension. The fold over of the contact arm from the top wall into the cavity area further rigidifies the top wall and enables provision of a robust resilient locking lance that can be provided across a substantial width of the top wall, and which is protected by the polarizing feature. Due to the few functional features that are cut out from the top wall, a robust and simple construction is provided. Inwardly stamped tabs from the side walls may be provided to engage the resilient contact arm such that it is held in a pre-stressed condition in order to reduce mating forces with a complementary contact, whilst providing high contact force. The bottom, side and top walls may be provided with short inwardly tapered extensions projecting from the mating end in order to protect the entrance of the contact cavity, and which may also assist insertion through a seal member. A resilient contact arm may be stamped from the bottom wall, opposed to the upper contact arm for providing a more flexible contact section if desired. Further advantageous aspects of this invention are described in the claims, or will be apparent from the following description and drawings. Embodiments of this invention will now be described by way of example, with reference to the figures, in which; Figure 1 is an isometric view of a terminal according this invention; Figure 2 is a cross-sectional isometric view of a terminal according to this invention; Figure 3 is a cross-sectional isometric view of another embodiment; Figure 4 is an isometric view towards a mating end of the terminal ; Figure 5 is another isometric view towards a bottom wall of the terminal; Figure 6 is an isometric view of the terminal towards a bottom wall, of the second embodiment according to Figure 3. Referring to the figures, an electrical receptacle terminal 2 stamped and formed from a single sheet of metal, comprises a connection section 4 in the form of a deformable crimping barrel for crimping to a conducting wire, and contact section 6 extending therefrom. Other conventional connection sections may also be provided, such as insulation piercing or displacement contacts. The contact section 6 comprises a bottom wall 8, a first side wall 10 and a second side wall 12 opposed thereto and extending from the bottom wall 8, and a top wall 14 opposed to the bottom wall 8. The walls form a box-shape of substantially square cross-section extending in an axial direction (a) and forming a pin-receiving cavity 16 therein. The contact section 6 extends in the axial direction (a) from a connection end 18 to a mating end 20 where the mating pin contact is received. The first side wall 10 is integrally connected to the top wall 14 through a corner 22, and the top wall 14 joins the second side wall 12 at a seam 24. The top wall 14 is further attached to a contact arm 26 through a fold 28 proximate the connection end 18. The fold 28 is substantially a 180° bend of the material extending from the top wall such that the contact arm 26 extends below and along the top wall 14 within the cavity 16. The contact arm 26 is provided in the shape of a cantilever beam contact extending from an attachment 30 that is folded against the top wall 13, the contact arm 26 comprising a spring arm portion extending obliquely away from the top wall, from the attachment portion 30 towards the mating end 26 to a contact portion 32, and subsequently diverging therefrom to a free end 34. Proximate the contact portion 32 which is in the form of a protrusion directed towards the bottom wall, a tab 36 bent inwardly from the side wall 10 or 12 engages the contact arm in order to hold it in a prestressed position for increasing the contact force against a mating pin, whilst decreasing the insertion forces. From the top wall 13, a resilient locking lance 40 is provided, the locking lance 40 extending a substantial width across the top wall 14 and attached thereto at an attachment end 42 arranged towards the mating end 20, and extending obliquely outwardly therefrom to a free end 44 arranged towards the connection end 18. The top wall 14 is free to provide a robust and large locking lance with respect to the terminal size due to the top wall being free from removal of material for other functional parts such as a polarizing feature, contact arm, or a pre-stressed tab. The locking lance 40 may be provided with an embossed rib 41 in order to further strengthen the locking lance. The second side wall 12 is provided with a polarizing extension 46 extending within the plane of the side wall beyond the top wall 14 to a height substantially at or beyond the free end 46 of the locking lance. The polarizing member 44 extends along a substantial length of the contact section 6, from the connection end 26 to the mating end 20, with cutouts 48 being provided for laser weld connection or crimping of mechanical tabs at the seam 24. The latter closes and rigidifies the box shape, where the weld connections 50 may be provided proximate the mating end 20 and the connection end 26 respectively. The polarizing extension is thus robust, and due to its length also provides a stabile guiding and location of the terminal in a corresponding housing cavity. Additionally, the polarizing extension 46 is adjacent the locking lance and provides protection to the locking lance, for example preventing wires or other foreign objects from catching under the locking lance thereby damaging it . The inwardly folded contact arm 26 further assists in rigidifying the top wall 14 and box-shaped body. Short protection flaps 50 extend from the mating end 20 and are inwardly bent to cover a portion of the mating end of the cavity 16. The inwardly bent protection flaps 50 ensure correct location and insertion of a mating pin, thereby preventing damage to the contact portions 32. The flaps 50 may also assist smooth insertion of the terminal through a seal member of a connector housing. The protective flaps 50 are stamped from each of the walls. In the embodiment according to Figures 2 and 5, the bottom wall 8 is provided with a resilient contact arm 52 in the shape of a cantilever beam extending from an attachment end 54 to a free end 56 arranged towards the mating end 20, in an opposed relationship with respect to the upper contact arm 26, for receiving a mating pin therebetween. The cantilever beam contact 52 increases the flexibility and thereby ability to absorb tolerances in position or thickness of the mating pin. Due to the simple stamping and forming and folding together of the contact section, a particularly cost-effective terminal to manufacture is provided. The lower contact 52 may be replaced by a contact protrusion 52' as shown in the embodiment of Figures 3 and 6, the contact protrusion being embossed from the bottom wall 8.

Claims: CLAIMS 1. A single piece electrical receptacle terminal (2) for mating with a pin terminal, comprises a connection section (4) for connection to a conducting wire, and a contact section (6) having a box-shape defined by a bottom wall (8), first (10) and second (12) side walls extending therefrom, and a top wall (4) opposed to the bottom wall, the walls surrounding a cavity area (16) for receiving the pin terminal therein, wherein the second side wall (12) is provided with a polarizing extension (46) projecting beyond the top wall (14), and wherein the top wall is joined through a corner (22) to the first side wall (10) , the top wall further attached via a fold (28) proximate the second side wall to a resilient contact arm (26) . 2. The electrical terminal according to claim 1 wherein a resilient locking lance (40) is stamped from the top wall (14), the locking lance attached at an attachment end (42) arranged towards a mating end (20) of the contact section (6), and extending obliquely outwards therefrom to a free end (44) arranged toward a connection end (18) of the contact section. 3. The terminal according to claims 1 or 2 wherein a pre- stressing tab (36) is stamped from one of the side walls (10,12) and engages the resilient contact arm (26) for pre- stressing thereof. 4. The terminal of anyone of the preceding claims wherein the polarizing extension (46) extends substantially from a mating end (20) to a connection end (18) of the contact section. 5. The terminal according to claim 2 wherein the locking lance occupies substantially the whole width of the top wall (14) . 6. The terminal according to any one of the preceding claims wherein protective flaps (50) extend from a mating end of the contact section and partially cover the entrance to the cavity area (16) for protection of the contact arm (26) . 7. The terminal according to any one of the preceding claims wherein a resilient contact arm (52) in the form of a cantilever beam is stamped from the bottom wall (8) . 8. The terminal according to any one of the preceding claims wherein the fold (28) of the resilient contact arm (26) is situated proximate the connection section (4), the contact arm comprising a spring arm extending therefrom to a contact protrusion (32) arranged proximate a mating end (20) of the contact section, the contact protrusion proximate a free end (34) of the contact arm.

Inventors: MANSUTTI PATRICK, MANSUTTI, PATRICK
Applicants: MANSUTTI PATRICK, WHITAKER CORP, MANSUTTI, PATRICK, THE WHITAKER CORPORATION
Application year: 1998
Main classification: H01R13
IPC codes: H01R13