Shorting electrical connector assembly with positive lock

Abstract: An electrical connector assembly (1) includes a first connector (3) mateable with a second connector (4), with respective interengageable terminals (7,8,9,10). A shorting device (34) establishes a short circuit between at least two terminals (7,8) of at least one (4) of the connectors. A locking device (2) is movably mounted on one (3) of the connectors to lock the connectors in mated condition. An actuating device (35) separate from and independent of the locking device (2) is provided for opening the short circuit established by the shorting device (34).

Description: Field of the Invention This invention generally relates to the art of electrical connectors and, particularly, to an electrical connector assembly having a shorted circuit when a pair of connectors are mated. The invention is directed to independent means for positively locking the connectors in mated condition and for opening the short circuit. Background of the Invention Electrical connectors typically are used in pairs to form a mated electrical connector assembly. The two connectors may have dielectric housings mounting terminals which are interengaged when the two connectors are mated. In some applications, a shorting device may be employed in one of the connectors for establishing a short circuit between at least two of the terminals for safety reasons. For instance, automobiles or other vehicles may employ shorted connectors for airbags, belt tensioners or other devices which are provided with explosive actuators or detonators. It is highly desirable to prevent accidental or unintentional actuation or detonation of the devices during such activities as manufacturing or assembly operations or during repair or other maintenance work. In addition, in the case of high inductive peaks, such as during spot welding or electrical welding work on the vehicle body or other components, high and hazardous induced voltages can unintentionally be established on the feed lines to the airbag or other detonatable device which would cause unintentional activation thereof. Examples of such shorted electrical connector assemblies are shown in U.S. Patent Nos. 5,275,575; which is considered to represent the closest prior art 5,816,840 and 5,827,083. Each of these patents show a pair of connectors in which latching means are provided therebetween. A secondary safety device is used to reinforce or positively lock the latching means after the connectors are mated, and the safety device performs a dual function of opening the short circuit. In these examples, the systems disadvantageously couple the functions of the mechanical secondary locking operation as well as the electrical opening of the short circuit. In other words, the short circuit is opened only together with the mechanical lock. U.S. Patent No. 5,314,345 discloses a system wherein the short circuit is automatically opened when the two connectors of the assembly are mated. A safety device is used simply to reinforce locking arms on the connectors. Such systems may cause severe safety problems because the short circuit is opened before the connectors are completely or positively locked. The present invention is directed to solving these various problems or disadvantages of the prior art by providing a system wherein the positive locking function and the opening of the short circuit are made independent of each other. In other words, a secondary locking device is used to positively lock the connectors in mated condition and a separate actuating device is used for opening the short circuit of the assembly. Summary of the Invention An object, therefore, of the invention is to provide a new and improved shorted electrical connector assembly of the character described. According to the invention this is achived with an electical connector assembly according to claim 1. In the exemplary embodiment of the invention, the connector assembly includes a first connector having a dielectric housing mounting a plurality of first terminals. A second connector is mateable with the first connector in a given mating direction and has a dielectric housing mounting a plurality of second terminals engageable with the first terminals when the connectors are mated. A shorting device establishes a short circuit between at least two terminals of the second connector. Complementary interengaging latching means are provided between the first and second connectors engageable when the connectors are mated. A locking device is movable into operative association with the latching means to prevent disengagement of the latching means. An actuating device is provided for opening the short circuit established by the shorting device. The actuating device is separate from and independent of the locking device. A novel feature of the invention is that the separate actuating device automatically moves the separate locking device to an operative position. In particular, the actuating device is movably mounted in a given path onto the housing of the first connector. At least a portion of the locking device is located in that path of movement. Therefore, movement of the actuating device to open the short circuit automatically moves the locking device to its operative position. As disclosed herein, the locking device is movably mounted on the housing of the first connector for movement generally parallel to the mating direction into operative association with the latching means. The actuating device is movably mounted on the housing of the first connector also for movement generally parallel to the mating direction to open the short circuit. In the preferred embodiment, the latching means includes a pair of latch arms spaced laterally of the mating direction. The locking device is generally U-shaped to define a pair of locking arms movable into locking association backing-up the latch arms. The locking arms are configured to define a pre-locked position of the locking device on the housing of the first connector. Finally, complementary interengaging holding means are provided between the actuating device and the first connector to hold the actuating device in position opening the short circuit. Other objects, features 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 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 an exploded, top perspective view of an electrical connector assembly embodying the concepts of the invention; FIGURE 2 is a view similar to that of Figure 1, rotated 180° with respect to the position shown in Figure 1; FIGURE 3 is another exploded perspective view of the assembly looking more toward the side thereof; FIGURE 4 is a side elevational view of the assembly with the connectors mated, with the locking device in its pre-latched position and with the actuating device in its inoperative position; FIGURE 5 is a top plan view of the assembly of Figure 4, with the actuating device moved partially toward its operative position; FIGURE 6 is an enlarged end elevational view looking toward the left-hand end of Figure 4; FIGURE 7 is a vertical section taken generally along line 7-7 of Figure 5; FIGURE 8 is an enlarged section similar to that of Figure 7, but with the actuating device moved to a pre-latched position over the locking device; FIGURE 9 is an enlarged vertical section taken generally along line 9-9 of Figure 5, but showing the actuating device in the position of Figure 8; FIGURE 10 is a top plan view of the assembly, with the locking device and the actuating device in their final operative positions; FIGURE 11 is an enlarged vertical section taken generally along line 11-11 of Figure 10; FIGURE 12 is an enlarged vertical section taken generally along line 12-12 of Figures 10 and 11; and FIGURE 13 is a bottom perspective view of the dielectric housing of the first connector. Detailed Description of the Preferred Embodiment Referring to the drawings in greater detail, and first to Figures 1-3, the invention is embodied in an electrical connector assembly, generally designated 1, which employs a secondary locking device 2. The connector assembly includes a first connector, generally designated 3, and a second connector, generally designed 4. The first connector is mateable with the second connector in a mating direction "X". During mating, a column-like mounting post 5 (Fig. 3) of the first connector is inserted into a receptacle 6 of the second connector. The receptacle and the mounting post (see Fig. 13) have non-circular cross-sections to provide polarization and ensure that the connectors are mated in correct angular orientations. Second connector 4 of connector assembly 1 includes a dielectric housing 4a which mounts a pair of pin terminals 7 and 8 (Fig. 3) which project upwardly into receptacle 6. The pin terminals are mateable with a pair of socket terminals 9 and 10 of first connector 3. The socket terminals project downwardly into mounting post 5 of the first connector when the connectors are mated. The socket terminals have crimp sections 11 and 12 for connection to appropriate conductors of a feed line 13. In essence, feed line 13 connects terminals 9 and 10 of first connector 3 to the electronic circuits of an airbag unit. Second connector 4 can be permanently mounted on an airbag (not shown) or pin terminals 6 and 7 can be connected to a detonator of the airbag. First connector 3 of connector assembly 1 includes a two-part dielectric housing 14 and 15 which are snapped together and include strain relief portions 16 for embracing feed line 13. Strain relief portion 16 of housing part 14 includes a plurality of teeth 16a which grip the feed line. An inductor, a ferrite or a ferrite-core coil 17 is connected to terminals 9 and 10 to discharge static potential. Alternatively or additionally, a capacitor or other circuits (not shown) may be provided to assist optimum signal transmission. For purposes described hereinafter, secondary locking device 2 is generally U-shaped as best seen in Figure 3. The U-shaped device defines a pair of generally parallel locking arms 18 which terminate in a pair of outwardly projecting locking hooks 20. The secondary locking device is mountable on first connector 3 generally parallel to mating direction "X" by inserting locking arms 18 and their locking hooks 20 first through a pair of channels 24 in housing part 15 and then through a pair of aligned channels 26 in housing part 14. In other words, channels 26 in housing part 14 form continuations of channels 24 in housing part 15. Turning to Figure 13, it can be seen that channels 26 exit out of the bottom of housing part 14. Still referring to Figure 13, a pair of latch arms 28 project from the bottom of housing part 14 and terminate in a pair of outwardly projecting latch hooks 29. The housing part may be unitarily molded of plastic material, and latch arms 28 are molded integrally therewith. The latch arms are located immediately outside channels 26, and cutout areas 30 are formed in latch hooks 29 of the latch arms. Cutout areas 30 are aligned with channels 26. Figure 9 shows first connector 3 mated with second connector 4. When mated, not only does mounting post 5 of the first connector enter receptacle 6 of the second connector, but latch arms 28 and latch hooks 29 also enter the receptacle adjacent the inside walls thereof. When fully mated, latch hooks 29 of integrally molded plastic latch arms 28 snap into latching engagement within latch recesses 32 (Fig. 9) formed in the inside walls of the receptacle of second connector 4. The interengagement of latch hooks 29 within latch recesses 32 is a "latching" function and not a positive locking function. In other words, the connectors still can be unmated by snapping latch hooks 29 back out of latch recesses 32. Figures 4, 5, 7 and 9 show secondary locking device 2 in its pre-latched position. In this position, locking arms 18 have entered channels 24 and 26 of housing parts 15 and 14, respectively, but the locking arms have not moved into locking engagement behind or backing-up latch arms 28 of the first connector. In other words, with secondary locking device in its pre-latched position, the connectors can be unmated as described above. In order to positively lock connectors 3 and 4 in their mated positions or condition, secondary locking device 2 is moved in the mating direction to its final locking or operative position shown best in Figure 12. When the locking device is pressed into the top of first connector 3, locking arms 18 of the locking device move further in the mating direction until locking hooks 20 snap around the bottom of latch arms 28 which are latched within recesses 32 of second connector 4. In other words, locking arms 18 of locking device 2 provide a secondary or positive locking means for latch arms 28. Referring to Figure 13 in conjunction with Figure 12, it can be understood that locking hooks 20 at the distal ends of locking arms 18 of secondary locking device 2 snap into locking engagement within cut-out areas 30 (Fig. 13) in latch hooks 29 of latch arms 28. In essence, there is insufficient space between mounting post 5 and locking arms 18 to permit both the latch arms 28 and the locking arms to move out of the locked position. The connectors now can be unmated only if secondary locking device 2 is moved back to its pre-latched position or totally removed. From the foregoing, it can be understood that the operation and function of secondary locking device 2 is totally independent of any electrical function of the connector assembly. In particular, a shorting device 34 (Figs. 2, 7, 8 and 11) includes a pair of coupled contact elements 36 and 37 which respectively bear against pin terminals 7 and 8 under a mechanical or spring action. The shorting device preferably is stamped and formed of conductive spring sheet metal material to electrically connect the two pin terminals and establish a short circuit therebetween. In order to open the short circuit established by shorting device 34, an actuating device 35 is provided with an elongated finger 39 which is insertable into a channel 40 in first connector 3. Actuating device 35 is integrally connected to housing part 14 by a plastic strip 42 integrally molded between the housing part and the actuating device. In other words, plastic strip 42 acts as sort a "living hinge" between the actuating device and first connector 3. A pair of integrally molded latches 44 are formed at opposite sides of the actuating device. Figures 1-7 show actuating device 35 in a completely inoperative position. Plastic strip 42 is quite flexible and, therefore, Figures 1-3 and 5-7 show the flexible strip bent upwardly, while Figure 4 shows the flexible strip generally horizontal. Figures 8 and 9 show actuating device 35 having been moved or pivoted in a path "Y" to a pre-locked position. In this position, it can be seen that the actuating device overlies secondary locking device 2. In other words, the secondary locking device is in the path of movement "Y", of the actuating device. It also can be seen particularly in Figure 8 that finger 34 has been inserted into channel 40 completely into the interior of receptacle 6 of second connector 4. The finger is immediately adjacent contact elements 36 and 37 of shorting device 34. However, it should be noted that, in this pre-locked position of the actuating device, the contact elements still are in engagement with pin terminals 7 and 8 to maintain the short circuit established therebetween by the shorting device. Figure 11 shows actuating device 35 having been moved from its pre-locked position of Figure 8 to its final operative locking position wherein the short circuit established by shorting device 34 has been opened. In particularly, it can be seen that finger 39 of the actuating device has engaged contact element 36 of shorting device 34 to move the contact element out of conductive engagement with its respective pin terminal 7 or 8. Alternatively, finger 39 could engage both contact elements 36 and 37 to move the contact elements completely away from conductive engagement with the two pin terminals. In the final locked position of actuating device 34, latches 44 (Fig. 4) at opposite sides of the actuating device engage appropriate latch shoulders in the areas indicated at 46 of housing part 15 of first connector 3. This interengagement forms a holding means between the actuating device and the first connector to hold the actuating device in its final operative position opening the short circuit established by shorting device 34. Finally, as stated above, in the illustrated embodiment of the invention the secondary locking device 2 is located in the path of movement of actuating device 35. Therefore, when the actuating device is moved to its final operative and locked position as described immediately above, the actuating device engages the top of the secondary locking device as seen best in Figure 12 and drives the locking device into its final locked position. Therefore, movement of actuating device 35 to open the short circuit established by shorting device 34 automatically moves locking device 2 to its final locked position. Therefore, unintentional detonation of an airbag, a belt tensioner or the like without positively locking the connectors in mated condition can be safely avoided. By providing an independent secondary locking device 2 which is separate from actuating device 35 the process of opening the short circuit is de-coupled from the mechanical locking of the connector assembly. It now is possible to fabricate, transport and incorporate already pre-assembled systems with mated connectors in a pre-mated and locked condition without opening the short circuit. Maintenance of the short circuit can reliably prevent voltages applied to or induced on the system from causing unintentional detonation of the airbag. The same is also advantageously true in case of installation or repair work, because it now is possible to remake the short circuit without having to totally dismantle the electrical subassemblies, i.e., even after an accident in which lines have been severed. It is possible, for example, for an airbag to be shortcircuited again safely or deactivated from time to time by simply operating actuating device 35 with which the short circuit is opened, completely independently of the operation of secondary locking device 2. This is completely contrary to the prior art wherein simultaneous closure of the mechanical secondary lock with the opening of the short circuit provided the only safety. It will be understood that the invention may be embodied in other specific forms without departing from the scope as defined by the appended claims 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.

Claims: An electrical connector assembly (1), comprising: a first connector (3) having a dielectric housing (14,15) mounting a plurality of first terminals; a second connector (4) mateable with the first connector in a given mating direction (X) and having a dielectric housing (4a) mounting a plurality of second terminals (7,8) engageable with the first terminals when the connectors are mated; a shorting device (34) for establishing a short circuit between at least two terminals (7,8) of at least one (4) of the connectors characterized by a locking device (2) movably mounted on the first connector (3) to lock the connectors in mated condition; and an actuating device (35) separate from and independent of the locking device (2) for opening the short circuit established by the shorting device (34). The electrical connector assembly of claim 1 comprises complementary interengaging latching means (28,29,32) between the first and second connectors engageable when the connectors are mated. The electrical connector assembly of claim 2 wherein the locking device (2) is movable into operative association with the latching means (28,29,32) to prevent disengagement of the latching means. The electrical connector assembly according to one of the preceding claims wherein said actuating device (35) is movably mountable in a given path (Y) onto the housing of the first connector (3), and at least a portion of said locking device (2) is located in said path, whereby movement of the actuating device (34) to open the short circuit automatically moves the locking device (2) to an operative position. The electrical connector assembly according to one of preceding claims 2 to 4 wherein said locking device (2) is movably mounted on the housing of the first connector (3) for movement generally parallel to said mating direction (X) into operative association with the latching means (28,29,32). The electrical connector assembly according to one of preceding claims wherein said actuating device (35) is movably mountable on the housing of the first connector (3) for movement generally parallel to said mating direction (X) to open the short circuit. The electrical connector assembly according to one of preceding claims 2 to 6 wherein said locking device (2) is movably mounted on the housing of the first connector (3) for movement generally parallel to said mating direction (X) into operative association with the latching means (28,29,32). The electrical connector assembly of claim 1 wherein the actuating device (35) is mounted on the first connector (3) for movement in a given path (Y) to open the short circuit established by the shorting device (34). The electrical connector assembly of claim 8 wherein at least a portion of the locking device (2) is being located in said path (Y) of movement of the actuating device (35), whereby movement of the actuating device to open the short circuit automatically moves the locking device to an operative position. The electrical connector assembly of claims 8 or 9 wherein said path (Y) of movement of the actuating device (35) is generally parallel to said mating direction (X). The electrical connector assembly according to one of claims 8,9 or 10 wherein said locking device (2) is movably mounted on the first connector (3) for movement generally parallel to said mating direction (X) into operative association with the latching means (28,29,32). The electrical connector assembly according to one of the claims 8 to 11 wherein said path (Y) of movement of the actuating device (35) is generally parallel to said mating direction (X). The electrical connector assembly according to one of the claims 2 to 12 wherein said latching means (28,29,32) comprise a pair of latch arms (28) spaced laterally of the mating direction (X) and said locking device (2) is generally U-shaped to define a pair of locking arms (18) movable into locking association backing-up the latch arms (28). The electrical connector assembly according to claim 13 wherein said locking arms are configured to define a pre-locked position of the locking device (2) on the housing of the first connector (3). The electrical connector assembly according to one of the preceding claims, including complementary interengaging holding means (44) between the actuating device (35) and the first connector (3) to hold the actuating device in position opening the short circuit. The electrical connector assembly according to one of the preceding claims, including means (20) on the locking device (2) to define a pre-locked position of the locking device on the housing of the first connector (3).

Inventors: MASEK VIT, MASEK, VIT
Applicants: MOLEX INC, MOLEX INCORPORATED
Application year: 2001
Main classification: H01R13
IPC codes: H01R13