Female electrical terminal

Abstract: A female electrical terminal has clamping segments 13 with contact faces 15A for tab-type terminals and contact faces 14A for pin-type terminals. A receiving segment 16 has a tab-type terminal contact face 15B and pin-type terminal contact faces 14B. The space between the tab-type terminal contact faces 15A and 15B forms a tab-type terminal insertion slot 17. The space enclosed by the pin-type terminal contact faces 14A, 14A, 14B forms a pin-type terminal insertion slot 19. Various configurations are disclosed.

Description: TECHNICAL FIELD The present invention relates to a female terminal adapted to establish electrical contact by having a male terminal inserted therein. BACKGROUND OF THE INVENTION For making contact in electrical connectors, two representative types of male terminal are the flat tab-type and the cylindrical pin-type. Figure 6 of this specification shows a typical tab-type male terminal formed by bending and shaping a thin metal plate. Tts rear end has sleeve portions 8B and 8C formed thereon into which electrical wires (not shown) are crimped; and its front comprises a double thickness projecting tab 8A. Figure 10, of this specification illustrates a conventional female terminal 100 corresponding to this tab-type terminal 8 and which is also formed by bending and shaping a thin metal plate. Its rear end has sleeve portions 101 and 102 formed thereon into which electrical wires (not shown) are crimped; and its front comprises has a box member 103 whose extreme end is open. A resilient contact segment 104 is double-folded and extends into the box member 103 from the lower side (as viewed). An insertion slot 105 adapted to receive the tab 8A is formed between the contact segment 104 and the top side of the box member 103. When the tab 8A is inserted into the slot 105, the upper and lower faces of the tab 8A come into contact respectively with the top side of box member 103 and the contact segment 104. As a result, a specified amount of contact pressure is maintained due to the restoring force of the contact segment 104, and electrical continuity is established between the male terminal 8 and the female terminal 100. Figure 7 thereof shows a pin-type male terminal 9 formed from a linear metallic material. At the front end it has an elongated, thin insertion pin 9A that is circular when seen in cross-section, and at the rear sleeves 9B and 9C are provided into which electrical wires (not shown) are crimped. As shown in Figure 11 hereof, a female terminal 110 made from a metallic material and corresponding to the pin-type terminal 9 has an insertion tube 111 fixed at the extreme front end whose interior portion comprises a circular insertion slot 112. The rear end of the female terminal 110 has sleeves 113 and 114 into which electrical wires (not shown) are crimped. A resilient contact member (not shown) is formed on the inner circumference of the insertion tube 111 and projects inward slightly. When the insertion pin 9A of the pin-type terminal 9 is inserted into the insertion slot 112, the resilient contact member, by virtue of its inherent restoring force, applies a specified contact pressure on and makes contact with the outer circumference of the insertion pin 9A, thereby establishing electrical continuity between the male terminal 9 and the female terminal 110. The above-mentioned prior art female terminals 100 and 110 are designed to have the most appropriate shape and length so as to exclusively accept the tab type terminal 8 and the pin-type terminal 9 respectively. Consequently, even if the length of the insertion pin 9A of the pin-type terminal 9 were such as to allow its insertion into the female tab type terminal 100 problems would occur, such as the difficulty of maintaining the rounded insertion pin 9A stable, the difficulty of achieving the specified contact pressure, etc. Furthermore, it is clearly impossible to insert the male tab-type terminal 8 into the female pin-type terminal 110 due to the difference in shape. Thus, hitherto, even when standards regarding the electrical current values etc. are the same, different female terminals have to be used depending on the shape of the male terminals required. As a consequence, production and management costs etc. are increased and operating efficiency is low. The invention described in this specification has been developed after taking into consideration the problems discussed above and aims at providing a female terminal that can be used both with tab-type and pin-type male terminals. SUMMARY OF THE INVENTION According to the invention there is provided a female electrical connector for receiving a male connector of the tab-type or of the pin-type, the connector having three inwardly directed resilient contact members defining at least one aperture and, adapted to receive a tab-type male connector or a pin-type male connector, the contact members being adapted to contact a tab-type male connector on both flat sides thereof and a pin-type male connector at three points around the circumference thereof. Two of said contact members are provided as a handed pair and comprise arcuate resilient arms having free ends directed towards said third contact member, and the third contact member having a root portion spaced from said two of said contact members and having a free end bent back so as to lie between said root portion and the free ends of said two of said contact members. Such a female connector is adapted to receive either kind of male connector. The tab of a tab-type terminal can be received within the terminal insertion slot of the female terminal fitting, and the tab-type terminal contact faces make contact with and grip the tab. As a result, the tab-type male terminal is stably supported and electrical connectivity between the female terminal fitting and the tab-type terminal is obtained. Further, the insertion pin of the pin-type terminal can be received within the terminal insertion slot of the female terminal fitting, and the pin-type terminal contact faces make contact with the pin so as to contact it at at least three points. As a result, the pin-type terminal is stably supported and electrical connectivity with the pin-type terminal is obtained. Other features of the invention will be apparent from the following description of preferred embodiments shown by way of example only in the accompanying drawings in which: Figure 1 is a partially cut-away isometric view of a female terminal constituting the first embodiment of the present invention; Figure 2 is a vertical cross-section showing the front portion of the female terminal of Fig. 1; Figure 3 is a front elevation showing the state preceding the insertion of a male terminal; Figure 4 is a front elevation showing the state following the insertion of a tab-type terminal; Figure 5 is a front elevation showing the state following the insertion of a pin-type terminal; Figure 6 is a isometric view of a prior art tab-type terminal; Figure 7 is an isometric view of a prior art pin-type terminal; Figure 8 is a front elevation showing the state following the insertion of a tab-type terminal into a female terminal according to a second embodiment of the invention; Figure 9 is a front elevation showing the state following the insertion of a pin-type terminal into the female terminal of the second embodiment; Figure 10 is an isometric view of a prior art female terminal fitting for tab-type terminals; and Figure 11 is an isometric view of a prior art female terminal fitting for pin-type terminals. The first embodiment of the present invention is described hereinbelow, with reference to Figures 1 to 7. A female terminal 1 of the present invention is formed from a thin electrically conductive metal plate. Its rear portion has a wire sleeve 1A into which electrical wires (not shown) are crimped, and an insulation sleeve 1B. The front portion consists of a thin, elongated insertion member 10 which extends longitudinally and into which a male terminal is inserted. The insertion member 10 has side walls 12 which rise upwards from the left and right sides of the bottom wall 11 (as viewed). A pair of resilient clamping segments 13 curve inwardly from the upper ends of the side walls 12. The clamping segments 13 curve to form an approximate semi-circle from the upper ends of the side walls 12 and, upon reaching a perpendicularly oriented point, extend diagonally in a downward and outward direction. Cross-sectionally, each has an unvarying shape along its entire longitudinal length. The adjacent faces of the diagonal portions comprise contact faces 14A for a pin-type terminal (Fig. 3). The extreme ends of the diagonal portions are approximately perpendicular to the side walls and from contact faces 15A for a tab type terminal (Fig. 4). The clamping segments 13 comprise a handed pair, that is to say segments of generally identical form but provided as left and right handed elements about an axis of symmetry. A resilient receiving segment 16 is provided continuously along the extreme front end of the bottom wall 11. This receiving segment 10 is bent over and extends downwards and backwards from the tab-type terminal contact faces 15A. The receiving segment 16 has a gentle slope whose peak constitutes a tab-type terminal contact face 15B which faces, and is separated by a specified distance from the contact faces 15A. The separation distance is slightly less than the thickness of the tab of a tab-type terminal 8 (Fig. 6). The tab-type terminal contact faces 15A, 15B and the side walls 12 form a tab-type terminal insertion slot 17. Around the vicinity of the highest (innermost) portion of the receiving segment 16, an insertion groove 18 is formed longitudinally over a specified distance by forming the segment 18 into a concave shape. The left and right extremities of the insertion groove 18 form pin-type terminal contact faces 14B in opposition to contact faces 14A. This pin-type contact face 14B makes linear contact along the entire length of the insertion pin of a pin-type terminal 9 (Fig. 7). Regarding the relative positions of the pin-type terminal contact faces 14A and 14B, the external diameter of an imaginary circle that touches the four contact faces 14A, 14B is arranged to be less than the external diameter of the corresponding pin 9A of the pin-type terminal 9. The space defined by these contact faces 14A, 14B forms a pin-type terminal insertion slot 19 which has a portion common with the tab-type terminal insertion slot 17. Consequently, the female terminal of the present embodiment can be connected with the commercially available male tab-type terminal (Fig. 6) and with the commercially available male pin-type terminal (Fig. 7). The operation of this first embodiment is now described. When a male tab-type terminal 8 is to be connected the tab 8A is inserted into the insertion slot 17, and the tab 8A slides along the upper face of the resilient receiving segment 16 so as not to abut the ends of the clamping segments 13. As the insertion progresses, the upper and lower faces of the tab 8A respectively come into contact with the contact faces 15A of the clamping segments 13 and the contact faces 15B of the receiving segment 16. Due to the thickness of the tab 8A, the clamping segments 13 undergo resilient deformation as the respective contact face 15A moves upward and, simultaneously, the receiving segment 16 undergoes resilient deformation in the downward direction. The resilient forces clamp the tab 8A from above and below. Accordingly, the tab-type terminal 8 is supported in a specified position making electrical contact with a specified contact pressure. When the pin-type terminal 9 is to be connected, the insertion pin 9A is inserted into the insertion slot 19, and the insertion pin 9A slides along the upper face of the resilient receiving segment 16 so as not to abut the extreme ends of the clamping segments 13. As the insertion progresses, the external surface of the pin 9A comes into contact with the contact faces 14A of the clamping segments 13, and the contact faces 14B of the receiving segment 16 at four circumferential points equidistantly located. The clamping segments 13 and receiving segment 16 undergo resilient deformation as previously described. Accordingly, the pin-type terminal 9 is supported in a specified position, and the contact faces 14A, 14B make electrical contact with a specified contact pressure. Since the female terminal fitting 1 of the present embodiment allows the insertion of both the tab-type and the pin-type male terminals it is superior to all those female terminals which are specially designed for the one or the other type of male terminal from the point of view of production, management and other costs, operating efficiency, etc. Moreover, unlike female terminals in which support members are located in different positions, the female terminal 1 of the present embodiment can be miniaturized since the pair consisting of the clamping segments 13 and the receiving segment 16 support both the tab-type terminal and the pin-type terminal 19. The second embodiment of the present invention is described with reference to Figures 8 and 9. The resilient clamping segments 23 of the present embodiment have a shape that differs slightly from that of the first embodiment, but the terminal has approximately the same configuration in all other respects; the clamping segments 23 also comprise a handed pair. A resilient receiving segment 26 does not have anything corresponding to the insertion groove 16 provided in the first embodiment, nor the pin-type terminal contact faces 14B. However, the segment 26 has a contact face 24B which is common to both the tab-type terminal and the pin-type terminal and which is formed in a width direction on a centrally located portion of the peak formed by the receiving segment 26. The space between tab-type terminal contact faces 25A, 25A of the clamping segments 23, and the common contact face 24B is less than the thickness of the tab of a tab-type terminal as in the case of the first embodiment. Since an insertion groove is not provided in the receiving segment 26, the position of a pin during insertion is rather higher (as viewed). However, the distance between pin-type contact faces 24A is greater than the space between the corresponding contact faces 14A of the first embodiment. Accordingly, this difference in the height of the insertion pin 9A is accommodated. When a pin-type terminal is to be connected into the present embodiment, the insertion pin is inserted into the slot 29 and the two contact faces 24A, make contact from a diagonally upward direction; the common contact face 24B makes contact from below. The pin-type terminal 9 is thus supported in a stable configuration from three sides by the contact faces 24A and 24B. The insertion of the tab-type terminal 8 is carried out in the same way as in the case of the first embodiment. The tab inserted into the slot 27 is clamped from above and below by the contact faces 25A and the common contact face 24B. The present invention is not limited to the embodiments described above, and may be embodied in various ways within the scope of the claims appended hereto. In the first and second embodiments, the pin-type terminal contact faces 14A and 24A are flat surfaces. However, according to the present invention, the pin-type terminal contact faces can be arcuate in shape so that the insertion pin makes contact over a large area thereof. Furthermore in the first embodiment the insertion pin 9A is arranged to make linear contact with the pin-type contact faces 14B, formed in the sides of the insertion groove 18; the insertion groove can be made larger so that the insertion pin makes contact in the circumferential direction with the inner circumferential face thereof. Although in the first embodiment the pin-type terminal contact faces 14B of the insertion groove 18 is sharp, they can alternatively be made arcuate.

Claims: A female electrical connector (1,2) for receiving a male connector of the tab-type or of the pin-type, the connector (1,2) having three inwardly directed resilient contact members (13,16; 23,26) defining at least one aperture and, adapted to receive a tab-type male connector or a pin-type male connector, the contact members being adapted to contact a tab-type male connector on both flat sides thereof and a pin-type male connector at three points around the circumference thereof, characterised in that two of said contact members (13,23) are a handed pair, and disposed substantially opposite a third contact member (16,26), said two contact members (13,23) comprising arcuate resilient arms having free ends (14A, 24A) directed towards said third contact member (16,26), and the third contact member (16,26) having a root portion (11) spaced from said two of said contact members (13,16) and having a free end bent back so as to lie between said root portion (11) and the free ends (14A, 24A) of said two of said contact member (13,23). The female connector of Claim 1 wherein the root of said resilient arms (13,23) each extends away from the third contact (16,26) member and the free ends (15A) curve inwardly towards the third contact member (16,26). The female connector of any preceding Claim wherein said free ends (15A) comprise electrical contacts. The female connector of any preceding Claim wherein all of said contact members (13,16; 23,26) are adapted to contact a tab-type connector. The female connector of any preceding Claim wherein all of said contact members (13,16; 23,26) are adapted to contact said pin-type connector. The female connector of any preceding Claim wherein said third contact member (16,26) includes an inwardly directed groove (18) adapted for co-operation with a pin-type connector, the groove defining two contact parts 14B. The female connector of any preceding Claim and formed from a sheet metal blank.

Inventors: ABE YUKIYASU, ABE, YUKIYASU, ABE, YUKIYASU, C/O SUMITOMO WIRING SYSTEMS, LTD.
Applicants: SUMITOMO WIRING SYSTEMS, SUMITOMO WIRING SYSTEMS, LTD.
Application year: 1995
Main classification: H01R13
IPC codes: H01R13