CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This patent application is a continuation of and claims priority under U.S.C. §120 to U.S. patent application Ser. No. 12/772,419, entitled “Locking Device For Connectors,” filed May 3, 2010, the entirety of which is incorporated by reference herein. 
     
    
     TECHNICAL FIELD 
       [0002]    The present invention relates generally to a locking device. More particularly, the present invention is directed to an automatic locking device for single pole connectors. 
       BACKGROUND OF THE INVENTION 
       [0003]    Heavy duty connectors include receptacles and plugs for high power cable connections and may be used, for example, in oil drilling applications. For instance, heavy duty connectors can safely carry power from generators to switch gear, selective catalytic reduction (SCR) packages, or traction motors, including mud pumps, draw works, rotary tables, cement pumps and other offshore applications. Conventionally, once a high power plug is inserted into a receptacle, an external “U” shaped clevis pin may be used to lock the plug in place and eliminate the possibility of accidental disengagement. Typically, the clevis pin is vertically inserted into a set of holes in the upper and lower portion the receptacle and seated within a groove molded in the plug to positively lock the plug within the receptacle. However, the process of inserting the clevis pin into the receptacle to lock the plug in place may be cumbersome for the user because the clevis pin must be aligned with the set of holes in the upper and lower portion of the receptacle as well as the molded groove in the plug. 
         [0004]    Therefore, a need exists for a receptacle having an improved locking mechanism that is easier to use than conventional receptacles. 
       SUMMARY OF THE INVENTION 
       [0005]    The present invention attempts to satisfy the above-described need by providing a locking mechanism for automatically securing a plug within a receptacle. Generally, the locking mechanism is coupled to a plug receiving end of a connector receptacle. The locking mechanism includes a sleeve unit having openings configured to receive alignment members, and a control unit coupled to the sleeve unit by extension members. In certain aspects, the extension members are extension springs. 
         [0006]    The alignment members are configured to engage and lock the plug once inserted in the receptacle. The control unit biases the alignment members in a locked position. Upon rotation of the control unit, in an unlocked position, the alignment members are free to move into grooves in the control unit, thus allowing a user to connect and disconnect the plug from the receptacle. The extension members bias some of the alignment members towards the locked position, thus once the plug is inserted into the receptacle, the alignment members automatically lock the plug into place by shifting into the locked position. 
         [0007]    In certain aspects, the sleeve unit includes a push sleeve and a retainer. The retainer can include notches configured to engage a control unit when the locking mechanism is in the unlocked position. The retainer can be coupled to one end of the extension members. 
         [0008]    In certain aspects, the control unit includes a spinner, locking ring, and a control wheel. The spinner can be coupled a second end of the extension members. The locking ring includes protrusions that bias the alignment members to a locked position, and grooves that engage the alignment members when in the unlocked position. In certain aspects, the locking ring includes notches that engage the notches on the retainer in the unlocked position. Upon rotation of the control wheel, the locking ring engages the retainer. 
         [0009]    In certain aspects, the extension members are extension springs. In the unlocked position, the extension members are extended. Alternating alignment members may be exposed to tension from the extension members, and the tension forces the alignment members towards the locked position and allow the extension members to return to their original state. 
         [0010]    These and other aspects, objects, features and embodiments of the present invention will become apparent to those skilled in the art upon consideration of the following detailed description of illustrated embodiments exemplifying the best mode for carrying out the invention as presently perceived. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1A  is a perspective view of a receptacle, according to an exemplary embodiment 
           [0012]      FIG. 1B  is an exploded view of the receptacle shown in  FIG. 1A , according to an exemplary embodiment. 
           [0013]      FIG. 1C  is a side cross-sectional view of the receptacle shown in  FIG. 1A , according to an exemplary embodiment. 
           [0014]      FIG. 2  is a perspective view of a push sleeve, according to an exemplary embodiment. 
           [0015]      FIG. 3  is a perspective view of a bracket, according to an exemplary embodiment. 
           [0016]      FIG. 4  is a perspective view of a retainer, according to an exemplary embodiment. 
           [0017]      FIG. 5  is a perspective view of a spinner, according to an exemplary embodiment. 
           [0018]      FIG. 6  is a perspective view of a springs, according to an exemplary embodiment. 
           [0019]      FIG. 7  is a perspective view of a locking ring, according to an exemplary embodiment. 
           [0020]      FIG. 8  is a perspective view of a control wheel, according to an exemplary embodiment. 
           [0021]      FIG. 9  is a perspective view of a connector, according to an exemplary embodiment. 
           [0022]      FIG. 10A  is a front cross-sectional view of a receptacle, prior to insertion of a plug and in a locked position, according to an exemplary embodiment. 
           [0023]      FIG. 10B  is a perspective view of the receptacle shown in  FIG. 10A , prior to insertion of a plug and in an unlocked position, according to an exemplary embodiment. 
           [0024]      FIG. 10C  is a perspective view of the receptacle shown in  FIG. 10A , during insertion of a plug and in an unlocked position, according to an exemplary embodiment. 
           [0025]      FIG. 10D  is a perspective view of the receptacle shown in  FIG. 10A , after insertion of a plug and in a locked position, according to an exemplary embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0026]    The present invention relates to connectors having an improved locking mechanism for securing a plug within a receptacle. The locking device described herein allows positive locking of a plug to a receptacle. The locking device can generally lock the plug in the same position each time with added strength over conventional locking devices. The locking device also can allow automatic positioning and locking of the plug to the receptacle. 
         [0027]    The invention may be better understood by reading the following description of non-limitative, exemplary embodiments with reference to the attached drawings wherein like parts of each of the figures are identified by the same reference characters. 
         [0028]      FIG. 1A  is a perspective view of a connector receptacle  100 , showing components visible from an exterior, according to an exemplary embodiment. The receptacle  100  includes a cylindrical housing  105  having a cavity  105   a  therein, and configured for receiving a connector plug (not shown). The receptacle  100  includes a flange  110  extending orthogonally from the housing  105 . The flange  110  includes holes  110   a  for receiving fasteners (not shown) for mounting the receptacle  100  to a wall or other surface (not shown). 
         [0029]    A bracket  115  is coupled to an exterior of the housing  105 . The bracket  115  includes an opening  115   a  configured to accept a securing mechanism (not shown), such as a lock. The bracket  115  prevents a user from accidentally unlocking the plug from the receptacle  100 . 
         [0030]    The receptacle  100  includes a push sleeve  120  partially positioned within the cavity  105   a  and coupled to an interior of the plug receiving end  105   b  of the housing  105 . The push sleeve  120  includes multiple alignment members  125   a ,  125   b  positioned within apertures  120   a  in the push sleeve  120 . The alignment members  125   a ,  125   b  align and hold the plug in a locked position. 
         [0031]    The receptacle  100  also includes an insert assembly housing  135  positioned within the cavity  105   a  of the housing  105 . The insert assembly housing  135  houses an insert assembly (not shown) configured to mate with a connector plug. The receptacle  100  further includes a control wheel  140  coupled to an exterior of the push sleeve  120 . The control wheel  140  is movable between a first position and a second position, and allows a user to disengage a plug from the receptacle  100  upon rotation. 
         [0032]      FIG. 1B  is an exploded view showing all of the components of the connector receptacle  100 , and  FIG. 1C  is a side cross-sectional view of the assembled connector receptacle  100 , according to an exemplary embodiment. The receptacle  100  includes the housing  105  having the cavity  105   a  therein, and the push sleeve  120  positioned within the cavity  105   a . The push sleeve  120  includes a cavity  120   b . The insert assembly housing  135  is positioned within the cavity  120   b  and extends into the cavity  105   a  of the receptacle housing  105 . 
         [0033]    The receptacle  100  includes a circular retainer  145  having a plurality of apertures  145   a  corresponding to and aligned with the apertures  120   a  on the push sleeve  120  when the retainer  145  is coupled to the push sleeve  120 . In certain embodiments, the retainer  145  may be coupled to the push sleeve  120  via screws  150  extending from holes  145   c  on the retainer  145  through holes  120   c  on the push sleeve  120 . The receptacle  100  also includes a circular spinner  160 . The spinner  160  is movably coupled to the retainer  145  by springs  170  extending from holes  145   d  on the retainer  145  to holes  160   d  on the spinner  160 . 
         [0034]    The receptacle  100  further includes a locking ring  165  coupled to the control wheel  140 . The locking ring  165  includes notches  165   a  on an exterior and configured to receive protrusions  140   a  positioned on an interior of the control wheel  140 . The spinner  160  is also coupled to the control wheel  140 . The spinner  160  is positioned within the control wheel  140 , and includes protrusions  160   b  configured to engage grooves  140   b  of the control wheel  140 . As a result, the control wheel  140 , the spinner  160 , and the locking ring  165  are partially rotatable about the remaining components of the receptacle  100  by way of the springs  170 . 
         [0035]    The receptacle  100  also includes a gasket  175  positioned between the control wheel  140  and the plug receiving end  105   b  of the housing  105 . The receptacle  100  further includes the bracket  115  coupled to an exterior of the housing  105  via screw  180 . The bracket  115  includes an opening  115   a  configured to accept a securing mechanism (not shown). 
         [0036]      FIG. 2  is a perspective view of a bell-shaped push sleeve  200 , according to an exemplary embodiment. The push sleeve  200  may be constructed from a rigid material, such as stainless steel. In certain exemplary embodiments, the material is corrosion-resistant. The push sleeve  200  includes four free-moving alignment members  205  and four alignment members  210  under spring tension (when assembled with remaining components of the receptacle  100 ). The alignment members  205 ,  210  are positioned within apertures  215  in the push sleeve  200 . The alignment members  205 ,  210  are spherical-shaped and constructed from any conductive material. In certain embodiments, the alignment members  205 ,  210  are fabricated from a corrosion-resistant material. In certain exemplary embodiments, alignment members  205 ,  210  are constructed from stainless steel. In certain alternative embodiments, three free-moving alignment members  205  and three alignment members  210  under spring tension may be included. In certain alternative embodiments, free-moving alignment members  205  may not be included. The number of alignment members  205 ,  210  present in the push sleeve  200  may vary from connector to connector and one having ordinary skill in the art can recognize a suitable number of alignment members  205 ,  210  to include. 
         [0037]    The push sleeve  200  also includes four holes  220  configured to receive fastening means (not shown) for coupling to a retainer (not shown), and four holes  225  configured to receive fastening means (not shown) for coupling to a receptacle housing  105 . 
         [0038]      FIG. 3  is a perspective view of a bracket  300  and a fastening screw  305 , according to an exemplary embodiment. The bracket  300  is L-shaped and includes an aperture  310  configured to receive a lockout device, such as a lock (not shown), and an aperture  315  configured to receive the screw  305 . The bracket  300  may be mounted to an exterior of a connector housing (not shown). 
         [0039]      FIG. 4  is a perspective view of a retainer  400 , according to an exemplary embodiment. The retainer  400  is configured to fit over an exterior of the push sleeve  200  ( FIG. 2 ). The retainer  400  may be coupled to the push sleeve  200  using fastening means (not shown) extending through holes  405  and holes  220  ( FIG. 2 ) of the push sleeve  200 . The retainer  400  also includes eight apertures  410  configured to receive alignment members  205 ,  210  ( FIG. 2 ). 
         [0040]    The retainer  400  includes four notches  415  located on alternating apertures  410 . The notches  415  are configured to engage corresponding notches on a locking ring (not shown). The retainer  400  also includes four protrusions  420 , each having a spring attachment member  425  extending therefrom. 
         [0041]      FIG. 5  is a perspective view of a circular spinner  500 , according to an exemplary embodiment. The spinner  500  includes four protrusions  505 , each having a spring attachment member  510  extending therefrom. When the spinner  500  is coupled to the retainer  400  ( FIG. 4 ), each protrusion  505  is positioned in a space between adjacent protrusions  420  ( FIG. 4 ) on the retainer  400 . The spinner  500  also includes eight rectangular notches  520  configured to engage a control wheel (not shown). 
         [0042]      FIG. 6  is a perspective view of four springs  600 , according to an exemplary embodiment. The springs  600  include a first end  605  for attaching to spring attachment members  425  on the retainer  400  ( FIG. 4 ), and a second end  610  for attaching to spring attachment member  510  on the spinner  500  ( FIG. 5 ). The springs  600  are extension springs. In certain alternative embodiments, the springs  600  may be an elastic device. 
         [0043]      FIG. 7  is a perspective view of a cylindrical locking ring  700 , according to an exemplary embodiment. The locking ring  700  may be constructed from plastic, or any other material suitable for flexing service. Suitable materials include, but are not limited to, stainless steel, aluminum, and spring steel. In certain embodiments, non-metallic compounds and metallic materials can be combined to provide the function of the locking ring  700 . The locking ring  700  includes four protrusions  705  extending inwardly from an interior surface  710 . Each protrusion  705  includes a notch  710  configured to engage notches  415  on the retainer  400  ( FIG. 4 ). The locking ring  700  also includes four protrusions  715 , each positioned between two protrusions  705 . The protrusions  705 ,  715  prevent alignment members  205 ,  210  ( FIG. 2 ) from moving outward from an interior of a receptacle. When the locking ring  700  is rotated, the alignment members  205  are movable into notches  720  positioned between protrusions  705 ,  715 . 
         [0044]    The locking ring  700  further includes eight rectangular notches  725  spaced apart along an exterior surface  730 . The notches  725  are configured to receive corresponding rectangular protrusions on an interior surface of a control wheel (not shown). One having ordinary skill in the art will recognize that the notches  725  can have any shape for engaging corresponding protrusions on the control wheel. One having ordinary skill in the art also will recognize that any number of notches  725  may be included in the locking ring  700 , and corresponding to the number of protrusions on the control wheel. 
         [0045]      FIG. 8  is a perspective view of a cylindrical control wheel  800 , according to an exemplary embodiment. The control wheel  800  can be nonmetallic so as to prevent a user from accidentally being exposed to an electrical spark when engaging the control wheel  800 . The control wheel  800  includes eight rectangular protrusions  805  on an interior surface  810 . Each protrusion  805  is configured to engage a corresponding notch  725  on the locking ring  700  ( FIG. 7 ). One having ordinary skill in the art will recognize that the protrusions  805  can have any shape for engaging corresponding notches  725  on the locking ring  700 . One having ordinary skill in the art also will recognize that any number of protrusions  805  may be included in the control wheel  800 , and corresponding to the number of notches  725  on the locking ring  700 . 
         [0046]    The control wheel  800  further includes eight rectangular protrusions  820  extending inwardly from and orthogonal to the interior surface  810 . The protrusions  820  are configured to engage the rectangular notches  520  on the spinner  500  ( FIG. 5 ). One having ordinary skill in the art will recognize that the protrusions  820  can have any shape for engaging corresponding notches  520  on the spinner  500 . One having ordinary skill in the art also will recognize that any number of protrusions  820  may be included in the control wheel  800 , and corresponding to the number of notches  520  on the spinner  500 . 
         [0047]    The control wheel  800  also includes eight notches  825  positioned on an end of an exterior surface  830 . At least one of the notches  825  align with the bracket  300  ( FIG. 3 ) and engage a lock (not shown) or other device that prevents a user from accidentally rotating the control wheel  800  and unlocking the plug from the receptacle. 
         [0048]      FIG. 9  is a perspective view of a connector  900 . The connector  900  includes a plug  905  and a receptacle  910 . The receptacle  910  includes a housing  915  having a cavity  920  configured to receive the plug  905 . The receptacle  910  includes eight alignment members  915  positioned within the cavity  920  and in communication with a control wheel  920 . The plug  905  includes a groove  930  configured to engage the alignment members  915  when the plug  905  is inserted into the cavity  920  of the receptacle  910 . The control wheel  920  locks and unlocks the receptacle  910  to allow insertion and removal of the plug  905 , as further described with respect to  FIG. 10  below. 
         [0049]      FIG. 10A  is a front cross-sectional view of a receptacle  1000 , prior to insertion of a plug (not shown) and in a locked position, according to an exemplary embodiment. The receptacle  1000  includes a push sleeve  1020  coupled to a retainer  1045 . The push sleeve  1020  includes multiple alignment members  1025   a ,  1025   b  positioned within apertures (not shown) in the push sleeve  1020 . The alignment members  1025   b  are under spring tension from springs  1070 . The receptacle  1000  further includes a control wheel  1040  coupled to an exterior of the push sleeve  1020 . The control wheel  1040  is coupled to a spinner (not shown) and a locking ring  1065 . The control wheel  1040 , spinner, and locking ring  1065  rotate at least partially about the push sleeve  1020  and retainer  1045  via springs  1070 . The control wheel  1040  is movable between a first position ( FIGS. 10A ,  10 D) and a second position ( FIGS. 10B ,  10 C). In the first position, notches  1075  on the locking ring  1065  are disconnected from notches  1080  on the retainer  1045 , and protrusions  1085 ,  1090  prevent alignment members  1025   a ,  1025   b  from moving outward. In the first position, the alignment members  1025   a ,  1025   b  are biased towards an interior cavity of the receptacle, and prevent a plug from being fully inserted into the receptacle  1000 . 
         [0050]      FIGS. 10B and 10C  are front cross-sectional views of the receptacle  1000 , prior to insertion or removal of a plug (not shown) and in an unlocked position, according to an exemplary embodiment. The control wheel  1040  (which is coupled to the spinner (not shown) and the locking ring  1065 ) is rotated clockwise one-eighth of a turn and in the second position. In the second position, the notches  1075  on the locking ring  1065  engage notches  1080  on the retainer  1045 . The engagement of notches  1075  with notches  1080  aligns notches  1095  on the locking ring  1065  with the alignment members  1025   a  ( FIG. 10B ). The alignment of notches  1095  with alignment members  1025  allow the alignment members  1025   a ,  1025   b  to shift outward and retract into the notches  1095  upon insertion of a plug ( FIG. 10C ). 
         [0051]      FIG. 10D  is a front cross-sectional view of the receptacle  1000 , after insertion of a plug (not shown) and in a locked position, according to an exemplary embodiment. Upon insertion of the plug, the alignment members  1025   b  (which are under spring tension) are automatically pushed towards the plug to engage a groove in the plug and lock the plug in place. 
         [0052]    Generally, the components of the locking mechanism on the receptacles of the present invention may be fabricated from any material that is corrosion-resistant. Suitable materials include, but are not limited to, stainless steel, and corrosion-resistant aluminum. The locking mechanisms of the present invention are capable of preventing accidental disengagement of a plug from the receptacle. The inclusion of alignment members in communication with a locking ring and a control wheel allow a user to safely and easily engage and disengage a plug from a receptacle. 
         [0053]    Any spatial references herein, such as, for example, “top,” “bottom,” “upper,” “lower,” “above”, “below,” “rear,” “between,” “vertical,” “angular,” “beneath,” etc., are for purpose of illustration only and do not limit the specific orientation or location of the described structure. 
         [0054]    Therefore, the invention is well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. The particular embodiments disclosed above are illustrative only, as the invention may be modified and practiced in different but equivalent manners apparent to those having ordinary skill in the art and having the benefit of the teachings herein. For instance, the features of the locking ring may be integrated into the control wheel to form a single control unit. Also, the features of the retainer may be integrated into the push sleeve to form a single sleeve unit. While numerous changes may be made by those having ordinary skill in the art, such changes are encompassed within the spirit and scope of this invention as defined by the appended claims. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular illustrative embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the present invention as defined by the claims below. The terms in the claims have their plain, ordinary meaning unless otherwise explicitly and clearly defined by the patentee.
A connector for high amperage, AC or DC connection includes a plug and a receptacle configured to securely mate and lock with each other. Connector receptacles include a locking mechanism having a sleeve unit having a plurality of openings configured to receive a plurality of alignment members, a control unit in communication with the alignment members, and at least one extension member coupling the sleeve unit to the control unit. The control unit is configured to bias the alignment members to engage a groove in a plug in a locked position. Upon rotation of the control unit, the control unit engages the sleeve unit and allows the alignment members to freely move, thus allowing a user to connect or disconnect the plug from the receptacle.