Abstract:
An electronic connector latch system provides safety via an internally hidden latch that requires a correctly sized pin to open. The described system is positive, in that it provides a “deadbolt” style latching wherein the pull out force is perpendicular to direction of opening the latch, and latching occurs on both sides of the locking post. The system is still user friendly in that mating the two connectors together can be accomplished without any tools. Mating is achieved with a simple insertion of the mating connector. The latch is captured inside the plastic unit housing, and a stamped sheet metal spring provides high cycle life.

Description:
FIELD 
       [0001]    This present invention relates to electrical connectors, and more particularly to a positive safety latch for making and unmaking a power connection. 
       BACKGROUND 
       [0002]    In many electrical power environments, components and conductors are typically provided and installed in a modular manner, such that the various parts must eventually be mated, or electrically connected, with suitable connectors. In high-power or critical applications, it is important that the connectors be positive and reliable, while also allowing for a connection to be unmade if necessary. 
         [0003]    By way of example, connectors used in the solar industry to connect photovoltaic (PV) modules in series utilize a latching system that require a tool to separate the mated connectors. This safety requirement is typical for single pole DC Solar connectors; however there is a need for a multi-pole AC Solar system that requires a tool for disconnection. This is especially true, for example, in applications involving micro-inverters. 
         [0004]    The latching system must be rugged to withstand the harsh environment of solar applications, provide high durability for many mating cycles, be cost effective, and be easy for installers to make and unmake connectors. 
         [0005]    Thus, it is an object underlying certain implementations of the described principles to provide a system for efficiently and effectively avoiding the above-noted problems where applicable. However, while this is an object underlying certain implementations of the invention, it will be appreciated that the invention is not limited to systems that solve the problems noted herein. Moreover, the inventors have created the above body of information for the convenience of the reader and expressly disclaim all of the foregoing as prior art; the foregoing is a discussion of problems discovered and/or appreciated by the inventors, and is not an attempt to review or catalog the prior art. 
       SUMMARY 
       [0006]    In an embodiment of the invention, a multi-pole AC Solar system latch system is provided that provides safety via an internally hidden latch that requires a special tool or correctly sized pin to open. The described system is positive, in that it provides a “deadbolt” style latching. Pull out force is perpendicular to direction of opening the latch, and latching occurs on both sides of the locking post. 
         [0007]    While unlatching the connection is made secure, the system is still very user friendly in that mating the two connectors does not require any tools. Mating is achieved with a simple straight forward insertion of the mating connector. The latch is captured inside the plastic unit housing, and a stamped sheet metal spring provides high cycle life. In an embodiment of the invention the lead-in construction provides a smooth surface for inserting the mating connector. Finally, the device is configurable, in that the spring thickness and width can be modified to optimize spring force in a given application. 
         [0008]    Although various embodiments of the invention are applicable to multi-pole AC Solar system connections, other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is an external perspective view of a latch and its usage environment according to an embodiment of the invention, including a mating connector or cable assembly, connector body, and unlocking pins; 
           [0010]      FIG. 2  is a schematic front elevation of the connector body; 
           [0011]      FIGS. 3A-3D  are enlarged images of a section of  FIG. 2  showing the latch during use in an embodiment of the invention; 
           [0012]      FIGS. 4A-4C  are perspective views of the connector assembly during use in an embodiment of the invention; 
           [0013]      FIG. 5  is a perspective view of the latched assembly of  FIG. 4C  with an unlocking tool inserted into matching guide holes in the connector body; 
           [0014]      FIG. 6  is a perspective view of the latching spring according to an embodiment of the invention; 
           [0015]      FIG. 7  shows a cross-sectional side view of the connector assembly according to an embodiment of the invention; 
           [0016]      FIG. 8  is a perspective view of a latch spring according to an embodiment of the invention; and 
           [0017]      FIG. 9  is an end view of the latch spring of  FIG. 8 . 
       
    
    
     DETAILED DESCRIPTION 
       [0018]    As noted above, in an embodiment of the invention, a latch system is provided that operates via an internally hidden latch that gives a “deadbolt” type latching, wherein the pull out force is perpendicular to direction of opening the latch, and latching occurs on both sides of a locking post. Other features will be appreciated from the following detailed description and figures. In an embodiment, the referenced connectors are specifically configured for a multi-pole AC Solar system, and the type and number of connections and conductors in such systems will be familiar to those of skill in the art. 
         [0019]    Referring now to  FIG. 1 , this figure shows an external perspective view of the latch in its usage environment. As shown, a mating connector or cable assembly  100  latches into a connector body  101 . In a further embodiment, unlocking pins  102  are provided within the connector body  101 . 
         [0020]      FIG. 2  is a schematic front elevation of the connector body  101  ( 201 ). The connector body  201  includes internal locking springs  202  for latching onto locking pins of the mating connector assembly  100  ( FIG. 1 ). The connector body  201  also includes guides  203  for the locking pins, as well as guides  204  for the disconnect pins or tool, which requires access to the locking springs  202  to open them. 
         [0021]      FIGS. 3A-3D  are enlarged images of section  205  of  FIG. 2 . Renumbered  305 , the enlarged section shows the internal locking spring  302  at rest ( FIG. 3A ), being spread open upon insertion of a locking pin  301  of the mating connector assembly  100  ( FIG. 3B ), latched around the barb end of the latching pins  301  ( FIG. 3C ), and being forced open by unlocking pins  304  ( FIG. 3D ). 
         [0022]      FIGS. 4A-4C  show the connector assembly  400  including locking pins  402  being inserted into the connector body (not shown except for locking springs  403 ). In  FIG. 4A , the locking pins  402  are not yet in contact with the locking springs  403 . In  FIG. 4B , the locking pins  402  are in contact with and are spreading open the locking springs  403 . Finally, in  FIG. 4C , the barb portions  404  of the locking pins  402  have passed through the locking springs  403 , and the locking springs  403  have reclosed behind the barb portions  404 . 
         [0023]      FIG. 5  shows the latched assembly of  FIG. 4C  with the unlocking tool  500  being inserted into the matching guide holes in the connector body  101  (not shown in  FIG. 5 ). As can be seen, the pins  501  of the tool  500  are inserted to spread the latching springs  502 , so that they release the barb portions  503  of the latching pins. This allows the connector assembly  504  to be removed from the connector body. 
         [0024]      FIG. 6  is a perspective view of the latching spring  600 . The latching spring  600  in the illustrated embodiment includes a formed lip  601  on both top and bottom to ease insertion of the locking pins of the mating connector (not shown), and to simplify insertion of the unlocking tool (not shown). A second formed lip  602  on top and bottom of the opposite side of spring  600  allows for easy insertion of the unlocking tool from this side alternatively. The flat bearing surface of the spring  600  interface with the locking pins of a mated connector (not shown). 
         [0025]      FIG. 7  shows a cross-sectional side view of the connector assembly  100 , renumbered  700 . The cross-section is taken vertically through one of the latch pins. The connector assembly  700  includes a main body portion  701  and a pin portion  702 . The pin portion  703  further includes a barb portion  703  for interfering with and being locked by the prongs  704  of the locking springs. 
         [0026]      FIGS. 8 and 9  show optional features that may be implemented within various embodiments of the invention. In particular,  FIG. 8  is a perspective view of a latch spring  800  including rounded lead-ins  801 - 802  in place of all lips  601 - 602 , to avoid gouging of the connector housing wall. The perspective view of latch spring  800  also shows an optional cut-out  803 , configured to engage with a key, e.g., a molded plastic key, in the connector housing to ensure that the spring  800  will not rotate inside housing.  FIG. 9  shows the same structure as  FIG. 8 , albeit in an end view taken along direction A of  FIG. 8 .  FIG. 9  also shows the connector housing walls  804 . 
         [0027]    Although the foregoing examples illustrate locking springs and pins at opposite sides of the assembly, it will be appreciated that the pair of locking elements may instead be located above and below the assembly, and/or that a single such locking element (latch spring and pin with barb) may be used, or that three or more such elements may be used. Although not specifically reiterated above, it will be appreciated that the described connection system is used to lock connector body and connector assembly together such that conductors in each are fixed into contact with one another. There may be one or more such conductors within each of the connector body and connector assembly, and each such conductor may carry power, signal, or both. 
         [0028]    While the springs are preferably a metallic or other flexible material, the connector assembly and conductor body may be made of any suitable material having sufficient rigidity, moldability or formability and, if required by the application, sufficient insulating properties. Example materials for constructing these elements include plastic, e.g., thermo set or other plastic, resin, fiber-reinforced resins and plastics, and similar materials. 
         [0029]    It will be appreciated that the foregoing description provides examples of a connection structure that is secure and user friendly, while maintaining a high cycle life and customizability through the size and strength of the included spring elements. However, it will be appreciated that other implementations of the disclosure may differ in detail from the foregoing examples. As such, all references to the disclosure or examples thereof are intended to reference the particular example being discussed at that point and are not intended to imply any limitation as to the scope of the disclosure more generally. All language of distinction and disparagement with respect to certain features is intended to indicate a lack of preference for those features, but not to exclude such from the scope of the disclosure entirely unless otherwise indicated. 
         [0030]    Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. 
         [0031]    Accordingly, this disclosure includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the disclosure unless otherwise indicated herein or otherwise clearly contradicted by context.