Abstract:
An interlock plate slidably affixed to a multi-bay connector header ensures a preordained connection sequence of multiple plug-in connectors. The interlock plate covers portions of the connector header, and can move with respect to the connector header to prevent access to selected bays of the header. When in a base position, the interlock plate allows insertion of one or more make-first/break-last connector plugs, but blocks insertion of one or more make-last/break-first connector plugs. When in a shifted position, the interlock plate prevents removal of the inserted make-first/break-last connector plug(s), and allows insertion of the make-last/break-first connector plug(s). Insertion of the make-last/break-first connector plug(s) locks the interlock plate in the shifted position, so that the make-last/break-first connector plug(s) must be removed prior to the make-first/break-last connector plug(s).

Description:
TECHNICAL FIELD 
     The present invention is directed to connection systems including multiple plug-in connectors, and more particularly to an interlock mechanism for ensuring that the plug-in connectors are inserted in a specified sequence and removed in the opposite sequence. 
     BACKGROUND OF THE INVENTION 
     In an electrical system including multiple components or modules that are interconnected with cables and plug-in connectors, separate sets of cables and connectors are generally used for power and signal, and the order or sequence in which the power and signal connectors are to be inserted and removed is sometimes specified in order to prevent component damage and/or ensure technician safety. For example, some high-voltage components include a multi-bay connector header for receiving both a high-voltage power connector and a low-voltage signal connector, and an interlock mechanism for ensuring that the power connector is inserted prior to insertion of the signal connector, and that the signal connector is removed prior to removal of the power connector. In other words, the interlock mechanism ensures that the power connector makes-first and breaks-last, relative to the signal connector. By way of example, the U.S. Pat. Nos. 7,084,361 and 7,402,068 show and describe connection-sequencing interlock mechanisms for high-voltage vehicle electrical systems. 
     The main drawback with known connection-sequencing interlock mechanisms is that they tend to be application specific and require custom-produced connectors, which can significantly increase system cost. Accordingly, what is needed is a connection system with an improved connection-sequencing interlock mechanism that works with conventional or inexpensive connector devices. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a connection system including a multi-bay connector header and an improved connection-sequencing interlock plate integrated into the connector header. The interlock plate covers portions of the connector header, and can move with respect to the connector header to prevent access to selected bays of the connector header. A detent lock feature retains the interlock plate in a base position that allows insertion of one or more make-first/break-last connectors, but blocks insertion of one or more make-last/break-first connectors. Once the make-first/break-last connector(s) is inserted, the detent lock is released, and the interlock plate is then moved from the base position to a shifted position that prevents removal of the inserted connector(s), and allows insertion of the make-last/break-first connector(s). Insertion of the make-last/break-first connector(s) locks the interlock plate in the shifted position, so that the make-last/break-first connector(s) must be removed prior to the make-first/break-last connector(s). Once the make-last/break-first connector(s) have been removed, the interlock plate is returned to the base position to permit removal of the make-first/break-last connector(s). 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded isometric view of the multi-connector apparatus of the present invention, including a multi-bay connector header and an interlock plate; 
         FIG. 2A  is an isometric view of an assembled multi-connector apparatus, with the interlock plate in a base position; 
         FIG. 2B  is a plan view of the multi-connector apparatus of  FIG. 2A  in the direction of the connector header bays; 
         FIG. 3A  is an isometric view of an assembled multi-connector apparatus, with the interlock plate in a shifted position; and 
         FIG. 3B  is a plan view of the multi-connector apparatus of  FIG. 3A  in the direction of the connector header bays. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The apparatus of the present invention is disclosed herein in the context of a connection system  10  for a high voltage vehicle electrical system, including a multi-bay male-pin connector header  12  configured to receive multiple plug-in female connectors. In the illustrated embodiment, the connector header  12  is mounted on a circuit board  13 , but it should be understood that the connector header  12  may alternatively be integrated into a larger component such as the housing of a battery pack, if desired. Moreover, the connection system  10  may be used in various other applications, both vehicular and non-vehicular. 
     Referring to the exploded view of  FIG. 1 , the illustrated connector header  12  includes a set of four high-voltage bays  14   a ,  14   b ,  14   c ,  14   d  configured to receive four high-voltage female power connectors  16   a ,  16   b,    16   c ,  16   d , and a set of four low-voltage bays  18   a ,  18   b ,  18   c ,  18   d  configured to receive four female signal connectors  20   a ,  20   b ,  20   c ,  20   d . The connector pins in each of the high-voltage bays  14   a ,  14   b ,  14   c ,  14   d  are connected to the terminals of a high voltage battery pack (not shown), so that the power connectors  16   a ,  16   b ,  16   c ,  16   d  can couple high-voltage power to various high-voltage components (not shown) of the electrical system via the associated cables  22   a ,  22   b ,  22   c ,  22   d . And the connector pins in each of the low-voltage bays  18   a ,  18   b ,  18   c ,  18   d  are connected to temperature sensors or to voltage taps used to measure battery pack cell voltages, which are fed to a signal processor (not shown) by the signal connectors  20   a ,  20   b ,  20   c ,  20   d  and the associated cables  24   a ,  24   b ,  24   c ,  24   d.    
     An interlock plate  30  slidably fastened to connector header  12  requires a servicing technician to remove the signal connectors  20   a - 20   d  from low-voltage header bays  18   a - 18   d  prior to removing the power connectors  16   a - 16   d  from high-voltage header bays  14   a - 14   d ; and after servicing, to insert the power connectors  16   a - 16   d  into high-voltage header bays  14   a - 14   d  prior to inserting the signal connectors  20   a - 20   d  into low-voltage header bays  18   a - 18   d.  The purpose of the signal-before-power removal sequence is to allow the signal processor to detect the impending power disconnect and prepare the system for safe removal of the power connectors  16   a - 16   d . And the purpose of the power-before signal insertion sequence is to surge-protect the temperature sensors and the signal processor. 
     Interlock plate  32  comprises a peripheral frame  31  that surrounds the connector header  12  and a top surface  32  that selectively and partially overlaps the bays  14   a - 14   d  and  18   a - 18   d  of connector header  12 . The top surface  32  is provided with a set of four central openings  34   a ,  34   b ,  34   c ,  34   d  configured to receive the four power connectors  16   a - 16   d , and a set of four laterally outboard openings  36   a ,  36   b ,  36   c ,  36   d  configured to receive the four signal connectors  20   a - 20   d . In a base position of the interlock plate  30 , depicted in  FIGS. 2A-2B , the four central openings  34   a - 34   d  align with the four high-voltage bays  14   a - 14   d  of connector header  12 , but the four laterally outboard openings  36   a - 36   d  are laterally offset with respect to the four low-voltage bays  18   a - 18   d  of connector header  12 . Thus, with interlock plate  30  in its base position, the four power connectors  16   a - 16   d  can be freely inserted into (or removed from) the four high-voltage bays  14   a - 14   d , but the four signal connectors  20   a - 20   d  cannot be inserted into the low-voltage bays  18   a - 18   b.  And as best seen in  FIGS. 1 and 2A , the sidewalls of power connectors  16   a - 16   d  are undercut laterally outboard of the cables  22   a - 22   d  as indicated by the reference numerals  38  so that once the power connectors  16   a - 16   d  are inserted into the four high-voltage bays  14   a - 14   d , the interlock plate  30  can be slid laterally to the shifted position depicted in  FIGS. 3A-3B . In the shifted position, the four laterally outboard openings  36   a - 36   d  align with the four low-voltage bays  18   a - 18   d  to permit insertion (and removal) of the signal connectors  20   a - 20   d , and portions of the interlock plate top surface  32  adjacent the openings  34   a - 34   b  overlap the marginal portions of the inserted power connectors  16   a - 16   d  to prevent them from being removed. And when the four signal connectors  20   a - 20   d  are inserted into the low-voltage bays  18   a - 18   d,  interference between the installed signal connectors  20   a - 20   d  and the portions of the interlock plate top surface  32  adjacent the openings  36   a - 36   d  prevent the interlock plate  30  from being moved back to the base position. 
     Finally, the connection system  10  includes a detent lock feature for retaining the interlock plate  30  in the base position prior to insertion of the power connectors  16   a - 16   d . The detent lock feature is formed by a set of tabs  40  on interlock plate  30  and a corresponding set of slots  42  formed in the sidewalls of connector header  12 . A domed projection is formed on the inboard face of each tab  40 , and the domed projections seat in the connector header slots  42  when the interlock plate  30  is in the base position depicted in  FIGS. 2A-2B . Each of the power connectors  16   a - 16   d  include a similar projection  44  formed on the sidewall adjacent to the sidewall of the connector header  12 , so that when a given power connector is inserted into a high-voltage bay of connector header  12 , the outwardly depending projection  44  on the side of the power connector engages the inwardly depending projection on the respective tab  40  of interlock plate  30 , pushing the tab projection out of the respective slot  42 . When the power connectors  16   a - 16   d  have all been inserted into the high-voltage bays  14   a - 14   d , the interlock plate tabs  40  are no longer seated in the connector header slots  42 , leaving the interlock plate  30  free for lateral movement with respect to the connector header  12 . Thus, the detent lock feature serves to both initially retain the interlock plate  30  in the base position, and to prevent lateral movement of the interlock plate  30  with respect to the connector header  12  until the power connectors  16   a - 16   d  have all been inserted into the high-voltage bays  14   a - 14   d  of connector header  12 . 
     In summary, the multi-connector apparatus of the present invention provides a reliable way of ensuring a preordained connector make-and-break sequence any time the connectors  16   a - 16   d  and  20   a - 20   d  are inserted or removed, whether at initial factory installation or during subsequent maintenance or servicing. At factory installation, the detect lock feature holds the interlock plate  30  in the base position of  FIGS. 2A-2B  so that only the power connectors  16   a - 16   d  can be inserted into the connector header  12 . And all of the power connectors  16   a - 16   d  have to properly inserted before the detent lock feature releases the interlock plate  30 . Then the installer slides the interlock plate  30  to the shifted position of  FIGS. 3A-3B  so that the signal connectors  20   a - 20   d  can be inserted into the connector header  12 . At that point, the interlock plate  30  cannot be moved due to interference between it and the installed signal connectors  20   a - 20   d . At subsequent maintenance or servicing, the signal connectors  20   a - 20   d  must be removed first due to the shifted position of the interlock plate  30 . Then the technician can shift the interlock plate  30  to the base position of  FIGS. 2A-2B , and remove the power connectors  16   a - 16   d . And after at least one of the power connectors  16   a - 16   d  have been removed, the detent lock feature re-engages to retain the interlock plate  30  in the base position. It will also be apparent that the multi-connector apparatus of the present invention provides a cost-effective way ensuring a preordained connector make-and-break sequence because the interlock plate  30  is obviously inexpensive to produce, and the connectors  16   a - 16   d  and  20   a - 20   d  are either conventional or only slightly modified. 
     While the multi-connector apparatus of the present invention has been described in reference to the illustrated embodiment, it should be understood that various modifications in addition to those mentioned above will occur to persons skilled in the art. For example, the connector header  12  may be configured to accommodate a greater or lesser number of connectors, the connector header  12  may be molded as part of a larger component or assembly, and so forth. Accordingly, it is intended that the invention not be limited to the disclosed embodiment, but that it have the full scope permitted by the language of the following claims.