Terminal locking means for electrical connectors

Abstract: An electrical connector (10) is disclosed with a dielectric housing (12) having a through passage (18) for receiving a female terminal (14) which includes a terminating end (32) for engaging a conductor and a mating end (34) for receiving a male terminal (52). A resilient locking arm (22) is formed on the housing and is adapted to engage a locking surface (54) on the female terminal (14) for locking the female terminal in the passage. The locking arm (22) is located for engagement by the male terminal (52) upon entering the passage to prevent the locking arm (22) from disengagement with the locking surface (54).

Description: This invention relates to an electrical connector assembly according to the preamble of claim 1. There are many electrical connectors available of a type having a locking mechanism by which male or female terminals of the connector are locked in a connector housing. The locking mechanism defines a fully inserted position of a terminal and prevents the terminal from backing out of a dielectric connector housing opposite its direction of insertion. Many such locking mechanisms are provided in the form of resilient latch arms which lockingly engage the terminals. Often, the resilient latch arms are integrally molded with the dielectric housing for pivoting in a cantilevered fashion. In a known connector assembly of the precharacteristic kind (EP-A 0 108 608), the male connector comprises a housing having side walls which are adapted to enter the space around the mating end of the female terminal so as to lock the resilient locking arm of the female connector. This locking mechanism necessarily is somewhat bulky and does not lend itself to miniaturization. Problems with locking mechanisms of the character described above are becoming increasingly prevalent due the ever-increasing miniaturization of electrical connectors and their respective housings and terminals. In fact, the miniaturization of such electrical connectors has reached a point where such locking mechanisms hardly resist even moderate pullout forces on the respective termins. This invention is directed to solving such problems by providing a locking means or system which can withstand relatively high pullout forces on the terminals which are locked within the connector housing. An object, therefore, of the invention is to provide a new and improved locking system for terminals in an electrical connector. The electrical connector assembly according to the invention is defined in claim 1. In the exemplary embodiment of the invention, an electrical connector is disclosed to include a dielectric housing having a through passage for receiving a first terminal including a mating section for mating with a second terminal. Generally, locking means are provided on the housing and adapted to engage a locking surface on the first terminal for locking the first terminal in the housing. The locking means is located for engagement by the second terminal upon mating with the first terminal to prevent the locking means from disengagement with the locking surface. In claims 2 and 3 a female connector of the electrical connector assembly is defined independently. As disclosed in the preferred embodiment, the locking arm projects through an open mating end of the socket. When the male terminal or pin is inserted into the socket, it engages the locking arm to sandwich the locking arm between the male terminal and the side wall of the socket, thereby preventing the locking arm from lifting out of the recess. The objects and advantages of the invention will be apparent from the following detailed description taken in connection with the accompanying drawings. Brief Description of the Drawings The features of this invention which in combination are believed to be novel are set forth with particularity in the appended claims. The invention, together with its objects and the advantages thereof, may be best understood by reference to the following description taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements in the figures and in which: FIGURE 1 is a top plan view of an electrical connector embodying the concepts of the invention; FIGURE 2 is a vertical section taken generally along line 2-2 of Figure 1; FIGURE 3 is a view similar to that of Figure 2, but with the terminal removed to facilitate an illustration of the details of the housing; FIGURE 4 is a top plan view of one of the terminals in the electrical connector of Figures 1 and 2; FIGURE 5 is a side elevational view of the terminal; FIGURE 6 is an end elevational view of the mating end of the terminal, as looking toward the left-hand end of Figure 5, and showing a male pin inserted into the terminal mating end; and FIGURE 7 is a view similar to that of Figure 6, but showing the location of the locking arm engaged by the male terminal. Detailed Description of the Preferred Embodiment Referring to the drawings in greater detail, and first to Figures 1 and 2, an electrical connector, generally designated 10, is illustrated to include a dielectric housing, generally designated 12, and a pair of female terminals, generally designated 14. Although the illustration shows an electrical connector having a pair of terminals, it should be understood that the invention is applicable for any type of electrical connector of the character described herein regardless of the number of terminals employed by the connector. Referring to Figure 3 in conjunction with Figures 1 and 2, housing 12 of electrical connector 10 includes a unitary housing 16 molded of dielectric material such as plastic or the like and including a through passage 18 for receiving each terminal 14. Each terminal is inserted into its respective passage in the direction of arrow "A" (Fig. 3). Each passage 18 includes a chamfered open end or mouth 20 at the mating end of housing 16 and through which a male terminal or pin is inserted in the direction of arrow "B" (Fig. 3) for mating with the respective terminal 14. Lastly, locking means in the form of a resilient locking arm 22 is integrally molded with housing 16 and projects rearwardly into passage 18 from open mouth 20 of the passage. At this point, it should be noted that a bottom surface 24 of locking arm 22 is spaced above the bottom of passage 18 as can be seen clearly in Figure 3. The locking arm has a hook portion 26 defining a forwardly facing locking shoulder 28. The bottom wall of the housing has an opening 30 to accommodate the projecting hook portion of the locking arm. Referring to Figures 4 and 5 in conjunction with Figures 1 and 2, each terminal 14 is a female terminal having a rear terminating end 32 and a front mating end 34. The terminal is unitarily formed as by stamping and forming from sheet metal material. The terminal has a pair of insulation displacement sections 36 stamped and formed upwardly out of a bottom wall 38 of the terminal. The insulation displacement sections have notches 40, the edges of the notches being designed to pierce through the insulation of an insulated wire and establish conductivity with the conductor core of the wire. A pair of crimp arms 42 are provided at the rear distal end of the terminal for clamping onto the outside of the insulated wire. Each terminal 14 is generally U-shaped in cross section, and mating end 34 includes a pair of side walls 44 upstanding from bottom wall 38. The side walls are formed inwardly to define opposing dimples 46 which define a gap, as indicated at 48 in Figure 4, for receiving a male terminal or pin there-between. In essence, bottom wall 38 and side walls 44 define a socket for the terminal, with the socket having an open mating end 50 (Fig. 4) for receiving the male terminal or pin. Figure 6 shows, somewhat schematically, a male terminal or pin 52 inserted into the socket defined by mating end 34 of the terminal, the male terminal being inserted between side walls 44. Lastly, bottom wall 38 of mating end 34 of the terminal has a rearwardly facing edge 54 which defines a recess or a locking surface for cooperating with hooked latch arm 22 to lock the terminal in its passage 18 of connector housing 16, as described below. When one of the terminals 14 is inserted into its respective passage 18 in connector housing 16 in the direction of arrow "A" (Fig. 3), the forward edge of bottom wall 38 of mating end 34 of the terminal engages a rearwardly facing chamfered surface 60 (Fig. 3) of hook portion 26 of locking arm 22. Consequently, the locking arm will be biased upwardly in the direction of arrow "C" (Fig. 3), whereupon further insertion of the terminal will cause rear edge or locking surface 54 (Figs. 4 and 5) of the locking surface to move past locking shoulder 28 of the latch arm. The latch arm will snap back downwardly, under its own resiliency, whereupon hook portion 26 will move into the recessed area of the terminal behind locking surface 54 and lock the terminal within the housing by engagement of locking shoulder 28 on the locking arm and locking surface 54 defined by bottom wall 38 of the terminal. Theoretically, when the terminal is fully inserted into the housing as described immediately above, pulling forces on the terminal, as by pulling on an insulated wire terminated to the terminal in a direction opposite arrow "A" (Fig. 3), will prevent the terminal from being pulled out of locking interengagement of locking shoulder 28 on the locking arm and locking surface 54 on the terminal. However, with the ever-increasing miniaturization of electrical connectors, the locking arm has difficulty resisting such pull-out forces. The invention solves these problems by the structural combination described above and as explained hereinafter. More particularly, Figure 7 is a view similar to that of Figure 6, except that the location of locking arm 22 is shown within the mating end 34 of terminal 14, and in relation to an inserted or mated male terminal or pin 52. It can be seen that, upon insertion of the male pin into the housing passage and between side walls 44 of the mating end of the terminal, the locking arm is located immediately below the male terminal or pin. Consequently, when any pull out forces on female terminal 14 in a direction opposite arrow "A" (Fig. 3), which would tend to bend locking arm 22 upwardly and release the locking engagement of the arm, the terminal pin provides a supporting backing against the top of the locking arm to prevent or at least resist disengagement of locking shoulder 28 on the locking arm from locking surface 54 on bottom wall 38 of the terminal. Of course, it can be imagined that an extremely large pull out force could cause the terminal to be pulled out of the connector regardless of any provision of any locking means and, in essence, destroy the entire connector. However, under normally expected conditions, the location of the locking arm, so as to be backed-up by the more rigid metal terminal pin, essentially prevents the locking arm from disengagement from the terminal. In essence, the resilient locking arm is sandwiched between the metallic bottom wall 38 of the terminal at the mating end thereof and the metallic male pin. It will be understood that the invention may be embodied in other specific forms without departing from the definition provided in the claims. The present examples and embodiments, therefore, are to be considered in all respects as illustrative and not restrictive, and the invention is not to be limited to the details given herein.

Claims: An electrical connector assembly comprised of a male and of a female connector for coupling respectively a male terminal (52) and a female terminal (14) comprising a dielectric housing (12) having a through passage (18) receiving said female terminal (14), which includes a termination end (32) for engaging a conductor and a mating end (34) for receiving said male terminal (52), a resilient locking arm (22) being provided on the housing (12) within said passage (18) to engage a recess (54) in said female terminal (14) so as to lock same in the passage (18), said dielectric housing (12) and said female terminal (14) forming the female connector (10) to have a space extending along said locking arm (22) and being adapted to be entered by a member of the male connector such as to engage said locking arm (22) and prevent same from disengagement with said recess (54), characterized by said space extending along said locking arm being a gap (48) between side walls (44) of the female terminal (14) and said entering member of the male connector being the male terminal (52) which engages said side walls (44) and is constructed to provide a backing for supporting the locking arm (22). The female connector (10) as set forth in claim 1, wherein the housing (12) is unitarily molded of dielectric material such as plastic, with the locking arm (22) being integral therewith in a cantilevered configuration, the locking arm (22) having a hook portion (26) at a distal end thereof and adapted to be biased into the recess (54) upon pivoting of the locking arm and wherein the recess (54) is located at the mating end (34) of the female terminal (14). The female connector (10) as set forth in claim 1 or 2, wherein the mating end (34) of the female terminal (14) is a socket including said gap (48), said socket having a bottom wall (38) with the recess (54) therein, and said locking arm (22) is located inside the socket, whereby when a male terminal (52) enters the socket and establishes electrical contact with the female terminal (14) it also engages the locking arm (22) to sandwich the locking arm between the male terminal (52) and the bottom wall (38) of the socket. The female connector (10) as set forth in claim 3, wherein the socket of the female terminal (14) defines an open mating end (50) for receiving the male terminal (52), and said locking arm (22) is located on the housing (12) for projecting into the socket through the open mating end (50). The electrical connector assembly as set forth in claim 1, wherein the male terminal (52) has a singular mating end.

Inventors: COLLERAN STEPHEN A, EDGLEY RICHARD R, COLLERAN, STEPHEN A., EDGLEY, RICHARD R.
Applicants: MOLEX INC, MOLEX INCORPORATED
Application year: 1992
Main classification: H01R13
IPC codes: H01R13, H01R4