Electrical Connector With Flexible Terminal Latch Means and Terminal Position Assurance Device

This invention generally relates to the art of electrical connectors and, particularly, to an electrical connector which includes a terminal position assurance device.

Terminal position assurance devices are known for use in electrical connectors to assure that the terminals in the connector are properly positioned within the connector housing. Basically, a terminal position assurance device is movable between a first position and a second position. The device can move to the second position only when the terminal or terminals are properly positioned in their respective passages in the housing. If a terminal is not properly positioned, the terminal position assurance device cannot move to its second position. Such a device often is used to prevent mating of a connector with a complementary connector unless the terminal position assurance device(s) is moved to its second or enabling position.

In addition, various types of terminal latch means are provided to hold the terminals in the passageways against withdrawal therefrom. Basically, some form of flexible latch bosses, shoulders or the like snappingly interengage when a terminal is fully or properly positioned in its respective passageway in the connector housing. This type of latch means often is called the primary latch means for the terminals of the connector. In some connector constructions, secondary latch means are provided to prevent disengagement of the primary latch means.

This invention is directed to an electrical connector having a terminal position assurance device which also serves as a secondary latch means, particularly for use in an electrical connector in which a flexible wall of the connector housing provides part of the primary latch means for a terminal.

An object, therefore, of the invention is to provide a new and improved electrical connector with a terminal position assurance device of the character described.

In the exemplary embodiment of the invention, the electrical connector includes a dielectric housing defining at least one elongated terminal-receiving passageway with at least one flexible latch wall extending longitudinally of the passageway. A terminal is adapted to be inserted into the passageway. The terminal has a longitudinal axis, a side wall in proximity to the flexible latch wall of the housing and a mating portion adapted to mate with a complementary terminal means inserted into the passageway. Complementary interengaging primary latch means are provided between the side wall of the terminal and the flexible latch wall of the housing for holding the terminal in the terminal-receiving passageway.

The invention contemplates the provision of a terminal position assurance device mountable in the housing for movement between first and second positions only when the terminal is properly positioned in the passageway. The terminal position assurance device includes restriction means for engaging the outside of the flexible latch wall of the housing and the inside of the side wall of the terminal to prevent lateral separation of the walls and disengagement of the primary latch means and, thereby, provide a secondary latch means for the terminal.

As disclosed herein, the primary latch means include a laterally projecting latch boss on the flexible latch wall of the housing and a latch shoulder on the terminal for snapping behind the latch boss to prevent removal of the terminal from the passageway. The passageway and the terminal position assurance device are relatively sized and configured such that the terminal position assurance device is adapted to be inserted longitudinally into the passageway.

The invention is illustrated in an electrical connector wherein the housing has a pair of the flexible latch walls extending along opposite sides of each terminal-receiving passageway. The terminal includes a generally U-shaped portion defining a pair of side walls in respective proximity to the flexible latch walls. Primary latch means are provided between each latch wall and the respective side wall. The flexible latch walls have free longitudinal edges, and the side walls of the terminals have free longitudinal edges generally parallel to the free longitudinal edges of the latch walls. The terminal position assurance device includes a pair of channels for capturing the pairs of walls therewithin and preventing lateral separation of the walls.

Other objects, features and advantages of the invention will be apparent from the following detailed description taken in connection with the accompanying drawings.

The features of this invention which 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:

FIG. 1 is a perspective view, partially cut away to show the interior of a connector housing having two terminal-receiving passageways, along with one of the terminals, and incorporating the terminal position assurance device of the invention;

FIG. 2 is a horizontal axial section through the connector housing in the area of one of the terminal-receiving passageways;

FIG. 3 is a top plan view of a terminal for insertion into one of the passageways in the housing;

FIG. 4 is a view similar to that of FIG. 2, with one of the terminals inserted into the passageway of the housing;

FIG. 5 is a top plan view of the terminal position assurance device;

FIG. 6 is a bottom plan view of the terminal position assurance device;

FIG. 7 is an end elevational view of the terminal position assurance device;

FIG. 8 is a view similar to that of FIG. 4, with the terminal position assurance device inserted into the passageway;

FIG. 9 is a vertical section taken generally along line 9--9 of FIG. 8; and

FIG. 10 is an end elevational view looking into the passageway from the right-hand end of FIG. 9.

Generally, and referring to the drawings in greater detail, FIG. 1 shows a two-passageway connector housing, generally designated 10. The housing is adapted for receiving a pair of electrical terminals, generally designated 14 in FIGS. 1, 3 and 4. The invention contemplates a terminal position assurance device, generally designated 12, shown in FIGS. 1 and 5-10.

More particularly, referring to FIG. 1, dielectric housing 10 includes generally rigid wall means defining a pair of elongated terminal-receiving passageways indicated generally at 16a and 16b. The generally rigid wall means include a pair of outside walls 18 and a center wall or partition 20. A plurality of latch walls 22a and 22b are disposed within and extend longitudinally of each terminal-receiving passageway 16a and 16b. Specifically, outside latch wall 22a and inside latch wall 22b are disposed on opposite sides of each passageway.

Dielectric connector housing 10, including its generally rigid wall means 18 and 20, along with latch walls 22a and 22b, is unitarily molded of plastic material. It can be seen that each latch wall 22a and 22b is elongated and defines opposite longitudinal edges 24 and 26. Edges 24 are joined to the respective walls 18 and 20. Edges 26 are free and project into the respective terminal-receiving passageways for transverse flexing about joined edges 24 in the direction of double-headed arrows "A". In essence, with the housing unitarily molded of dielectric plastic material, "joining" edges 24 define elongated living hinges for flexing of the latch walls transversely of the longitudinal axes of terminal-receiving passageways 16a and 16b. Lastly, each latch wall 22a and 22b of connector housing 10 in FIG. 1 includes a latch boss 28 defining a latch shoulder 28a for purposes described hereinafter. The latch bosses project into the terminal-receiving passageways.

Turning next to FIG. 2, each terminal-receiving passageway includes a lower cavity wall portion 29a and a stop shoulder 29b. FIG. 2 best shows the shape of latch bosses 28 and latch shoulders 28a. The flexing direction of the latch walls is indicated by double-headed arrow "A".

Referring now to FIGS. 1 and 3, each terminal 14 is elongated and is stamped and formed from sheet metal material. The terminal defines a longitudinal axis 33. The terminal includes a front blade-like male mating end 32, a rear terminating end 34 and an intermediate body portion 36 between the ends. Terminating end 34 includes two pairs of crimp arms 38 and 40, crimp arms 38 being adapted for crimping onto the outside insulation or cladding of an insulated electrical wire "W" (FIG. 1), and crimp arms 40 being adapted for crimping onto and terminating the electrical conductive core "C" of the wire, all of which is well known in the art. Lastly, intermediate body portion 36 is generally U-shaped to define a bottom wall 36a and a pair of side walls 36b. Each side wall has a latch shoulder 42 stamped in the upper edge thereof. Therefore, the remainder of side walls 36b and bottom wall 36a provide a substantial massive body portion of the terminal of excellent current flow characteristics.

The insertion of one of the terminals 14 into one of the passageways in connector housing 10, and the operation of the latching system of the invention, now will be described in relation to FIG. 4 which shows a terminal 14 inserted into passageway 16b of connector housing 10. Specifically, terminal 14 is inserted into passageway 16b of housing 10 in the direction of arrow "B". It can be seen that front male end 32 of the terminal is narrower than body portion 36 and is joined thereto by a tapered transition section 46. As the terminal is inserted into the passageway, the tapered transition section engages the rear sides of latch bosses 28 which, themselves, are tapered as seen in FIGS. 2 and 8. As the terminal is inserted further into the passageway, latch bosses 28 of latch walls 22a and 22b will engage side walls 36b of the intermediate body portion 36 of the terminal, whereupon the latch walls will flex transversely outwardly of the longitudinal axis of the terminal and passageway. In essence, latch walls 22a and 22b will flex outwardly about their living hinges defined by edges 24 integrally joined to the generally rigid wall means 18 and 20 of the housing.

When the terminal reaches its fully inserted position, with front male end 32 positioned forwardly in passageway 16b for mating with a complementary female terminal inserted into the passageway, flexible latch walls 22a and 22b will snap back inwardly as latch shoulders 42 on the terminal pass latch shoulders 28a of latch bosses 28 on the flexible latch walls. The forwardly facing latch shoulders 28a of the housing latch walls and the rearwardly facing latch shoulders 42 of the terminal prevent removal of the terminal from passageway 16c. When fully inserted, the tops of a pair of tangs 50 of terminal 14 engage the upper cavity wall, bottom wall 36a of the terminal engages lower cavity wall portion 29a and a forwardly facing shoulder 52 of the terminal engages stop shoulder 29b.

Terminal position assurance device 12 (FIG. 1), shown in detail in FIGS. 5-7, is mountable in the housing 10 for movement between first and second positions only when the terminal 14 is properly positioned in the passageway. More particularly, the device includes a generally planar, rectangular top wall 54 having a pair of longitudinal side walls or flanges 56 depending therefrom on opposite sides or edges thereof. A boss 58 depends from the underside of top wall 54 generally at the center thereof and includes a forwardly projecting head portion 58a. Forwardly projecting head portion 58a has laterally extending lock shoulders 58b adapted to lock behind housing wall latch shoulders 28a when the terminal position assurance device 12 is fully inserted in the housing 10 in the second position preventing the device from being inadvertently removed from the housing.

Side walls 56 and boss 58 define channels 60 therebetween on opposite sides of the boss. Lastly, a lip 62 projects slightly outwardly of the device at an end thereof, for purposes described below. The device is molded of rigid dielectric material such as plastic or the like. Hole 63 in top wall 54 simply is a molding core-out hole.

In operation of terminal position assurance device 12, reference is made to FIGS. 8-10, wherein it can be seen that the terminal position assurance device has been inserted into the rear of passageway 16b in the direction of arrow "X" (FIGS. 8 and 9). When so inserted, side walls 56 of the terminal position assurance device slide in slots 59 (FIG. 8) between generally rigid walls 18 of housing 10 and flexible latch walls 22a and 22b of the housing. As best seen in FIG. 8, side walls 56 of the terminal position assurance device are positioned immediately outside the flexible latch walls whereby the latch walls cannot move laterally outwardly away from their latched condition with terminal 14.

When terminal position assurance device is moved to the second position shown in FIGS. 8-10, it also can be seen particularly in FIG. 8, that boss 58 is positioned between and in engagement with latch bosses 28, and head portion 58a of the boss is positioned between and in engagement with tangs 50 of terminal 14 to prevent lateral movement inwardly of side walls 36b of the terminal. Therefore, latch shoulders 42 of the terminal cannot move laterally inwardly away from their latched engagement with latch bosses 28 of flexible latch walls 22a and 22b. In essence, channels 60 (FIGS. 6 and 7) between side walls 56 and boss 58/head portion 58a are effective to sandwich the flexible latch walls of the housing and the side walls of the terminal within the channels so that the walls cannot separate and disengage the latch bosses and latch shoulders. It can also be seen in FIGS. 8 and 9 that lip 62 at the rear end of the terminal position assurance device engages the outside of housing 10 about the periphery or mouth of passageway 16b to prevent over-insertion of the terminal position assurance device beyond its proper position as shown. Lastly, laterally extending lock shoulders 58b lock behind housing wall latch shoulders 28a to prevent the device from being inadvertently removed from the housing.

If terminal 14 is not fully inserted into passageway 16b (i.e. latch shoulders 42 of the terminal have not snapped behind latch shoulders 28a of latch bosses 28), head portion 58a of boss 58 of terminal position assurance device 12 cannot pass between the latch bosses because of the thicknesses of tangs 50 of the terminal. In other words, channels 60 of the terminal position assurance device are too narrow to accept the combined thickness of the flexible latch walls, latch bosses and the metal of the terminal.

It will be understood that the invention may be embodied in other specific forms without departing from the spirit or central characteristics thereof. 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.