Patent Publication Number: US-2021166898-A1

Title: Mechanical interlock with enhanced features

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This is a non-provisional of, and claims the benefit of the filing date of, pending U.S. provisional patent application No. 62/769,733, filed Nov. 20, 2018, entitled “Mechanical Interlock with Enhanced Features,” which application is incorporated in its entirety by reference herein. 
    
    
     FIELD OF THE DISCLOSURE 
     The present disclosure relates generally to electrical devices such as mechanical interlocks, disconnect switches, rotatably actuatable switches, etc., and more particularly to mechanical interlocks incorporating one or more enhanced features to provide a more robust locking mechanism, to facilitate easier assembly, and/or to provide additional capabilities. 
     BACKGROUND OF THE DISCLOSURE 
     Electrical switches such as, for example, disconnect switches, mechanical interlocks, rotatably actuatable switches, etc. (collectively referred to herein as a mechanical interlock or mechanical interlocks without the intent to limit) are used in a variety of commercial applications, both indoors and outdoors, for energizing and de-energizing electrical devices, such as machinery, motors, lights, fans, pumps, generators and the like. 
     Generally speaking, mechanical interlocks are arranged and configured to receive, for example, one or more pin and sleeve devices such as, for example, a plug to supply electrical power to downstream electrical devices. Mechanical interlocks are generally designed for use in harsh or high abuse environments such as, for example, wet, dusty, or corrosive environments. 
     As will be appreciated by one of ordinary skill in the art, mechanical interlocks include, inter alia, an electrical enclosure, an external handle assembly connected to an electrical load switch located within the electrical enclosure, and a connector (e.g., a female receptacle) for coupling to the plug. The mechanical interlock may also include a number of other electrical and mechanical components as well such as, for example, fuses, contactors, etc. 
     As will be appreciated by one of ordinary skill in the art, the mechanical interlock receives power through a plurality of power input lines and supplies power to, for example, a plug coupled to the connector. The external handle assembly mounted to the front of the enclosure may be connected to the load switch through, for example, a shaft to operate the actuating mechanism of the load switch. In use, the external handle assembly is rotationally locked to the load switch via the shaft. Thus arranged, rotational movement of the handle assembly causes the shaft to rotate, which in turn rotates the load switch to selectively supply and disconnect power from the connector, and hence the plug and the downstream electrical device. 
     That is, in use, the downstream electrical device can be energized or de-energized, depending on the direction of rotation of the handle assembly. That is, the mechanical interlock is “ON” (e.g., supplying power to the connected, downstream electrical device) when the plug is coupled to the connector and the handle assembly is in an “ON” position. When the handle assembly is moved to an “OFF” position, the actuating mechanism of the load switch will have been moved to open the contacts, so that power to the associated electrical device is disconnected. Generally speaking, the handle assembly is rotated ninety-degrees to transition the mechanical interlock between the ON and OFF positions. 
     In use, mechanical interlocks include a locking mechanism that prevents making and breaking of power under load. That is, in use, the mechanical interlock is arranged and configured so that the handle assembly cannot be moved to the “ON” position until a plug is coupled to the connector. Similarly, in use, the mechanical interlock is arranged and configured so that the plug cannot be removed or decoupled from the connector of the mechanical interlock until the handle assembly has been rotated or actuated to the OFF position. That is, for example, until the handle assembly has been rotated to the OFF position, the plug cannot be removed. In this manner, mechanical interlocks prevent making or breaking of power under load. This is a simplified explanation of the operation of the mechanical interlock for purposes of the present disclosure. 
     It would be desirable to provide mechanical interlocks with one or more enhanced features to provide a more robust locking mechanism, to facilitate easier assembly, and/or to provide additional capabilities. 
     SUMMARY OF THE DISCLOSURE 
     This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended as an aid in determining the scope of the claimed subject matter. 
     In one embodiment, disclosed herein is a mechanical interlock including an enclosure, a connector at least partially received within the enclosure for selectively receiving a plug, a load switch positioned within the enclosure, the load switch arranged and configured to selectively supply power to the connector, a handle assembly operatively associated with the enclosure, the handle assembly being selectively movable between an ON position and an OFF position to selectively energize and deenergize the load switch, a shaft for rotationally coupling the handle assembly to the load switch, and an interlock latch arranged and configured to be operatively associated with the connector and the handle assembly, the interlock latch movable between a first position and a second position, wherein, when in the first position, the interlock latch prevents rotation of the handle assembly, and when in the second position, the interlock latch enables rotation of the handle assembly so that the handle assembly can be moved from the OFF position to the ON position. 
     In one embodiment, the interlock latch includes a first end and a second end, the first end being arranged and configured to contact the plug upon insertion of the plug into the connector so that the interlock latch is moved from the first position to the second position via insertion of the plug into the connector. 
     In one embodiment, the second end of the interlock latch is selectively coupled to the shaft so that, when the interlock latch is in the first position, the second end of the interlock latch engages the shaft so that rotation of the shaft and the handle assembly is prevented, and, when the interlock latch is in the second position, the second end of the interlock latch is decoupled from the shaft so that rotation of the shaft and the handle assembly is permitted. 
     Additionally, and/or alternatively, in one embodiment, the mechanical interlock may include a plug connector arranged and configured to prevent the plug from being removed from the connector when the handle assembly is in the ON position. In one embodiment, the plug connector includes a slider plate and a latch spring, the slider plate movable from a first position to a second position via rotation of the handle assembly from the OFF position to the ON position, wherein, when the slider plate is in the second position, the latch spring engages the plug inserted into the connector so that removal of the plug is prevented. 
     Additionally, and/or alternatively, in one embodiment, the mechanical interlock may include a magnetic switch including a magnet and a sensor arranged and configured to determine a position of the handle assembly. In one embodiment, when the handle assembly is in the OFF position, the magnet is arranged and configured to interact with the sensor to provide an indication that the handle assembly is in the OFF position, and when the handle assembly is in the ON position, the magnet is positioned at a distance from the sensor such that the sensor does not sense the magnet. 
     Additionally, and/or alternatively, in one embodiment, the mechanical interlock may include a battery power supply for supplying backup power to the magnetic switch and/or a processor in case of mains power lost. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       By way of example, a specific embodiment of the disclosed device will now be described, with reference to the accompanying drawings, in which: 
         FIG. 1  is an exploded, perspective view of a mechanical interlock in accordance with one or more aspects of the present disclosure; 
         FIG. 2  is a detailed, partial, front, perspective view of the mechanical interlock shown in  FIG. 1 , the mechanical interlock including an interlock latch illustrated in a first position, the cover portion being omitted for clarity; 
         FIG. 3  is a detailed, partial, front, perspective view of the mechanical interlock shown in  FIG. 1 , the mechanical interlock including an interlock latch illustrated in a second position, the cover portion being omitted for clarity; 
         FIG. 4  is a detailed, partial, rear perspective view of the mechanical interlock shown in  FIG. 1 , the mechanical interlock including an interlock latch illustrated in a first position; 
         FIG. 5  is a detailed, partial, rear, perspective view of the mechanical interlock shown in  FIG. 1 , the mechanical interlock including an interlock latch illustrated in a second position; 
         FIG. 6A  is a front perspective view of an example embodiment of an interlock latch for use with the mechanical interlock shown in  FIG. 1 ; 
         FIG. 6B  is a rear perspective view of an example embodiment of an interlock latch for use with the mechanical interlock shown in  FIG. 1 ; 
         FIG. 7A  is a detailed, rear, elevational view of an example embodiment of an interlock latch, the interlock latch illustrated in a first position with the interlock latch coupled to a shaft associated with the handle assembly; 
         FIG. 7B  is a detailed, rear, elevational view of the interlock latch shown in  FIG. 7A , the interlock latch illustrated in a second position with the interlock latch decoupled from the shaft; 
         FIG. 8A  is a detailed, rear, elevational view of an alternate example embodiment of an interlock latch, the interlock latch illustrated in a first position with the interlock latch coupled to a shaft associated with the handle assembly; 
         FIG. 8B  is a detailed, rear, elevational view of the interlock latch shown in  FIG. 8A , the interlock latch illustrated in a second position with the interlock latch decoupled from the shaft; 
         FIG. 9  is a partial, rear, perspective view of an example embodiment of an interlock latch, a slider plate, and a latch spring assembly for use with the mechanical interlock shown in  FIG. 1 , the slider plate and the latch spring illustrated in a first position; 
         FIG. 10  is a partial, rear, perspective view of the slider plate and the latch spring shown in  FIG. 9 , the slider plate and the latch spring illustrated in a second position; 
         FIG. 11  is a detailed, cross-sectional view of the slider plate and the latch spring shown in  FIG. 10 , the slider plate and the latch spring illustrated in the second position; 
         FIG. 12  is a partial, rear perspective view of an example embodiment of a cam mechanism for movably coupling the slider plate and the latch spring between first and second positions; 
         FIG. 13A  is a rear perspective view of an example embodiment of a latch spring for use with the mechanical interlock shown in  FIG. 1 ; 
         FIG. 13B  is an alternate, rear perspective view of the latch spring shown in  FIG. 12A ; 
         FIG. 13C  is a partial, rear perspective view of the slider plate and the latch spring positioned in the enclosure; and 
         FIG. 14  is a partial, rear perspective view of an example embodiment of a magnetic switch for use with the mechanical interlock shown in  FIG. 1 . 
     
    
    
     The drawings are not necessarily to scale. The drawings are merely representations, not intended to portray specific parameters of the disclosure. The drawings are intended to depict example embodiments of the disclosure, and therefore are not be considered as limiting in scope. In the drawings, like numbering represents like elements. 
     DETAILED DESCRIPTION 
     Numerous embodiments of improved mechanical interlocks in accordance with the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the present disclosure are presented. The mechanical interlock of the present disclosure may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will convey certain example aspects of the mechanical interlock to those skilled in the art. In the drawings, like numbers refer to like elements throughout unless otherwise noted. 
     As will be described in greater detail below, in various embodiments, a mechanical interlock according to the present disclosure may include one or more features to facilitate a more robust design, easier assembly, and/or enhanced capabilities as compared to prior devices. That is, for example, according to the present disclosure, a mechanical interlock may include an improved locking mechanism for ensuring that the external handle assembly can only be rotated to the ON position after proper insertion of a plug. For example, the mechanical interlock may include an interlock latch operatively associated with the external handle assembly and the internal connector. In one embodiment, the interlock latch is in direct contact with a plug inserted into the connector and a shaft coupled to the external handle assembly. By providing a direct coupling, a more robust locking/latching mechanism is provided that cannot be easily circumvented. In addition, a mechanical interlock may include one or more keys (e.g., a Poke-Yoke feature) to facilitate easier assembly and/or to prevent human errors caused by improper assembly. For example, in one embodiment, the mechanical interlock may include one or more keys between a latch spring and the enclosure to prevent improper insertion and/or orientation of the latch spring. Additionally, and/or alternatively, the mechanical interlock may include an integrated magnetic switch and monitoring system to ensure that the location of the external handle assembly is known so that the position of the handle assembly can be compared to the state of the device, and if necessary, one or more fault indications can be provided. 
     As will be described herein, the features according to the present disclosure may be used with any suitable mechanical interlock now known or hereafter developed. As such, details regarding construction and operation of the mechanical interlock are omitted for sake of brevity of the present disclosure. In this regard, the present disclosure should not be limited to the details of the mechanical interlock disclosed and illustrated herein unless specifically claimed and that any suitable mechanical interlock can be used in connection with the principles of the present disclosure. 
     As previously mentioned, mechanical interlocks can be used to supply power to connected devices via, for example, a pin and sleeve device such as, for example, a plug (not shown). That is, for example, a plug can be connected to the mechanical interlock for supplying power to a downstream electrical device. 
     Referring to  FIG. 1 , the mechanical interlock  100  includes a number of components including, inter alia, an enclosure  110 , a connector  120  for coupling to, for example, a plug  50  ( FIGS. 3 and 10 ), an internal load switch  130 , an external handle assembly  140 , and a shaft  150  for rotationally coupling the external handle assembly  140  to the internal load switch  130 . In the illustrated embodiment, the shaft  150  may be in the form of a two-piece shaft so that the external handle assembly  140  may be operatively coupled to a handle portion or shaft  152  and the load switch  130  may be coupled to a switch portion or shaft  154 , the handle portion or shaft  152  may be rotationally coupled to the switch portion or shaft  154  so that rotation of the external handle assembly  140  rotates the handle portion or shaft  152 , which rotates the switch portion or shaft  154 , which rotates/actuates the load switch  130  (portion and shaft used interchangeably herein without the intent to limit). 
     As illustrated, the enclosure  110  may be made up of a rear housing portion or base  112  and a front housing portion or cover  114 , although it is envisioned that the enclosure  110  may be manufactured from more or less portions. In addition, the enclosure  110  may be manufactured from any suitable material including, for example, plastic, metal, or the like. 
     In one example embodiment, the mechanical interlock  100  may also include an interlock latch  200 , a slider plate  220 , and a latch spring  240 . As will be described in greater detail, in use, the interlock latch  200  is selectively movable between a first position ( FIGS. 2 and 4 ) and a second position ( FIGS. 3 and 5 ). The interlock latch  200  is arranged and configured to be operatively associated with the connector  120  and the external handle assembly  140  so that when the interlock latch  200  is in the first position, the interlock latch  200  prevents rotation of the external handle assembly  140 , and when the interlock latch  200  is in the second position, the interlock latch  200  permits rotation of the external handle assembly  140 . In one embodiment, the interlock latch  200  is movable between the first position and the second position via insertion of the plug  50  ( FIG. 3 ) into the connector  120 . That is, insertion of the plug  50  into the connector  120  contacts and moves the interlock latch  200  from the first position ( FIGS. 2 and 4 ) to the second position ( FIGS. 3 and 5 ). 
     Referring to  FIGS. 6A and 6B , the interlock latch  200  includes a first end  202  and a second end  204 . In use, the first end  202  of the interlock latch  200  is arranged and configured to be contacted by the plug  50  ( FIG. 3 ) upon insertion of the plug  50  into the connector  120 . For example, the first end  202  may include a shelf  206  for contacting the plug  50 . In use, insertion of the plug  50  into the connector  120  of the mechanical interlock  100  causes the plug  50  to contact and move the interlock latch  200  from the first position ( FIGS. 2 and 4 ) to the second position ( FIGS. 3 and 5 ). In one embodiment, the interlock latch  200  moves axially (e.g., interlock latch  200  moves along a longitudinal axis of the latch) from the first position ( FIGS. 2 and 4 ) to the second position ( FIGS. 3 and 5 ). In use, the interlock latch  200  may be biased towards the first position so that when the plug  50  is not engaged with the connector  120 , the external handle assembly  140  is prevented from being rotated to the ON position. The interlock latch  200  may be biased by any suitable mechanism now known or hereafter developed including, for example, a spring  208  ( FIG. 2 ). 
     As illustrated in  FIGS. 2-5 , the second end  204  of the interlock latch  200  is arranged and configured to selectively engage the shaft  150  such as, for example, the handle shaft  152 . In this manner, when the interlock latch  200  is in the first position ( FIGS. 2 and 4 ), the second end  204  of the interlock latch  200  engages the shaft  150  (e.g., handle shaft  152 ) so that rotation of the shaft  150 , and hence the external handle assembly  140  coupled thereto, is prevented so that rotation of the handle assembly  140  from the OFF position to the ON position is prevented until a plug  50  has been fully inserted into the connector  120 . Meanwhile, when the interlock latch  200  is in the second position (e.g., when a plug  50  has been fully inserted into the connector  120 ) ( FIGS. 3 and 5 ), the second end  204  of the interlock latch  200  is arranged and configured to decouple from the shaft  150  (e.g., the second end  204  of the interlock latch  200  disengages from the handle shaft  152 ) so that rotation of the shaft  150 , and hence the external handle assembly  140  coupled thereto, is permitted so that rotation of the handle assembly  140  can be rotated from the OFF position to the ON position. 
     As illustrated, the second end  204  of the interlock latch  200  may include a bore or opening  210  so that the shaft  150  (e.g., handle shaft  152 ) may pass through the interlock latch  200 . In addition, the second end  204  of the interlock latch  200  may include a key  212  such as, for example, a projection, a hook, or the like, for engaging a recess or slot  156  formed in the shaft  150 . 
     Referring to  FIGS. 7A and 7B , in one non-limiting example embodiment, the key  212  may be in the form of a blunt projection. That is, for example, the key  212  may include perpendicular sides and/or sharp corners for interacting with the slot  156  formed in the shaft  150  (e.g., handle shaft  152 ). Alternatively, referring to  FIGS. 8A and 8B , the key  212 ′ may include sloped sides and/or rounded corners for interacting with the slot  156  formed in the shaft  150  (e.g., handle shaft  152 ). By providing the key  156  with rounded corners, it has been discovered that machining of the slot  156  in the shaft  150  (e.g., handle shaft  152 ) is simplified as the tolerances are not as critical to ensuring desired engagement between the interlock latch  200  and the shaft  150 . In addition, by providing the key  212  with rounded corners, the key  212  can center itself as it engages the slot  156  formed in the shaft  150 . However, it is envisioned that the key  212  and the slot  156  may have any other suitable shapes, configurations, etc., to facilitate inter-engagement between the interlock latch  200  and the shaft  150 . 
     In accordance with one aspect of the present disclosure, by directly coupling the interlock latch  200  to the shaft  150  (e.g., handle shaft  152 ), which directly connects to the external handle assembly  140 , and by arranging and configuring the interlock latch  200  so that inserting a plug  50  into the connector  120  causes the plug  50  to directly contact the interlock latch  200 , an improved robust rotational locking mechanism is provided that allows rotation of the external handle assembly  140  only when the plug  50  is properly inserted into the connector  120 , and that locks the handle assembly  140  in the OFF position when the plug  50  is not inserted into the connector  120 . Directing coupling the interlock latch  200  to the rotational drive mechanism of the mechanical interlock  100  (e.g., external handle assembly  140  and the shaft  150 ) provides numerous advantages over current devices including, for example, maintaining the locking or latching feature at the rotating elements where rotational torque is applied. This is in contrast to known devices where the locking or latching feature is located at more remote locations from the rotating elements, which allows for excessive slop that can lead to the locking feature being overridden due to the application of excessive forces and/or distortion or deflection of the interconnecting parts. 
     As previously mentioned, the mechanical interlock  100  may also include a slider plate  220  and a latch spring  240 . In use, the slide plate  220  and the latch spring  240  act as a plug connector arranged and configured to prevent the plug  50  from being removed from the connector  120  when the handle assembly  140  is in the ON position. That is, in accordance with another aspect of the present disclosure, and as will be described in greater detail, in use, the slider plate  220  and the latch spring  240  are selectively movable between a first position ( FIG. 9 ) and a second position ( FIG. 10 ). In use, the latch spring  240  is arranged and configured to contact the plug  50  inserted into the connector  120  when the slider plate  220  and/or latch spring  240  is in the second position ( FIG. 10 ) so that the plug  50  cannot be removed from the connector  120  when the external handle assembly  140  is in the ON position. In one embodiment, the slider plate  220  and the latch spring  240  are movable between the first position ( FIG. 9 ) and the second position ( FIG. 10 ) via rotation of the external handle assembly  140 . 
     In this manner, and as previously mentioned, in use, insertion of the plug  50  into the connector  120  of the mechanical interlock  100  causes the interlock latch  200  to move from its respective first position ( FIGS. 2 and 4 ) to its respective second position ( FIGS. 3 and 5 ) thus enabling rotation of the external handle assembly  140  from the OFF position to the ON position. In addition, rotation of the external handle assembly  140  from the OFF position to the ON position causes the slider plate  220  and the latch spring  240  to move. In one example embodiment, the slider plate  220  and the latch spring  240  move axially downwards (e.g., the slider plate  220  and the latch spring  240  move along a longitudinal axis of the slider plate  220  (e.g., the slider plate  220  and the latch spring  240  move in the opposite direction of the interlock latch  200 )). Movement of the slider plate  220  and the latch spring  240  from their respective first positions ( FIG. 9 ) to their respective second positions ( FIG. 10 ) causes the latch spring  240  to operatively couple to the inserted plug  50 . That is, referring to  FIG. 11 , when the latch spring  240  is in its second position ( FIG. 10 ), the latch spring  240  engages or otherwise interacts with the inserted plug  50  in the connector  120  to prevent removal of the plug  50  when the external handle assembly  140  is in the ON position. 
     In use, the slider plate  220  and the latch spring  240  may be movably coupled relative to the enclosure  110  and/or the shaft  150  (e.g., handle shaft  152 ) by any suitable mechanism now known or hereafter developed. Referring to  FIG. 12 , in one embodiment, the slider plate  220  may be coupled to the shaft  150  via a cam mechanism  400  including a pin and bushing  410  coupled to the shaft  150  so that rotation of the external handle assembly  140  rotates the pin and bushing  410  along an arc with the pin and bushing  410  riding in a slot  420  formed within the slider plate  220 . As the pin and bushing  410  moves through its arc, the slider plate  220  moves down (e.g., when the external handle assembly  140  is rotated from the OFF position to the ON position). As the slider plate  220  moves down, the latch spring  240  is deformed or flexes causing the latch spring  240  (e.g., base  242 ) to contact or otherwise interact with the inserted plug  50 , thereby preventing the plug  50  from being withdrawn from the connector  120 . That is, referring to  FIG. 11 , as the slider plate  220  moves down, the latch spring  240  deflects towards the front housing portion or cover  114  so that the plug  50  can be coupled to the connector  120 . Thereafter, once the plug  50  has been properly inserted within the connector  120 , the latch spring  240  flexes back (e.g., away from the front housing portion or cover  114 ) so that, for example, the base  242  of the latch spring  240  can be received within a space, groove, recess, or the like  52  of the plug  50  to prevent the plug  50  from being withdrawn from the connector  120 . Thus, rotating the external handle assembly  140  from the OFF position to the ON position simultaneously activates the switch and locks the plug  50  to the connector  120 . 
     Referring to  FIGS. 13A, 13B, and 13C , in one example embodiment, the latch spring  240  may include a base  242  and first and second arms  244 ,  246  extending therefrom. In use, the first and second arms  244 ,  246  may be spaced from one another sufficiently to enable positioning of the interlock latch  200  therebetween. As illustrated, the first and second arms  244 ,  246  may lie in a plane offset from the base  242 . In one non-limiting example embodiment, the base  242  is oriented perpendicular to the first and second arms  244 ,  246 , and may also lie in a plane that is perpendicular to the plane of the first and second arms  244 ,  246 . In order to ensure that the latch spring  240  is properly orientated when inserted into the mechanical interlock  200 , the latch spring  240  and the enclosure  110  may include an alignment, key or keying feature (e.g., a Poke-Yoke mechanism)  250  incorporated therebetween (alignment, key and keying are used interchangeably herein without the intent to limit). That is, for example, to prevent incorrect or “flipped” installation of the latch spring  240  and to ensure proper operation (e.g., engagement and release), the latch spring  240  may incorporate a key  250  to ensure that the latch spring  240  can only be inserted in a proper orientation relative to the enclosure  110 . 
     In use, the key  250  may be any suitable feature now known or hereafter developed to ensure proper installation of the latch spring  240  within the enclosure  110 . For example, referring to  FIG. 13C , the enclosure  110  may include one or more male features, bosses, projections, or the like  252  (used interchangeably herein without the intent to limit) and the latch spring  240  may include one or more female features, openings, holes, or the like  254  (used interchangeably herein without the intent to limit), arranged and configured to receive the boss  252  formed on the enclosure  110 , or vice-versa. In this manner, the boss  252  extending from the enclosure  110  can only be received within the hole  254  formed in the latch spring  240  when the latch spring  240  is properly positioned within the enclosure  110 , thus ensuring easy and failsafe assembly. That is, in this manner, the latch spring  240  can only be installed in a single orientation (e.g., cannot be accidentally or unintentionally rotated or flipped), thus, ensuring proper orientation and/or positioning of the latch spring  240  relative to the enclosure  110 . 
     In one example embodiment, the enclosure  110  may include first and second bosses  252   a,    252   b  protruding therefrom and the latch spring  240  (e.g., first and second arms  244 ,  246  of the latch spring  240 ) may include first and second holes  254   a,    254   b  for receiving the first and second bosses  252   a,    252   b,  respectively, extending from the enclosure  110 . The bosses  252   a,    252   b  and the holes  254   a,    254   b  may be arranged and configured so that the first boss  252   a  is only receivable by the first hole  254   a  in the first arm  244  and the second boss  252   b  is only receivable in the second hole  254   b  in the second arm  246  when the latch spring  240  is properly positioned and/or orientated within the enclosure  110 . By providing one feature or key different from the other, the latch spring  240  cannot be incorrectly inserted into the enclosure  110 . In use, the key  250  may include different sized bosses  252  and holes  254 . For example, the first boss  252   a  may be sized for receipt within the first hole  254   a  only and the second boss  252   b  may be sized for receipt within the second hole  254   b  only (e.g., the first and second holes  254   a,    254   b  may be sized or shaped to be different from each other, while the first and second bosses  252   a,    252   b  may likewise be shaped to be different from each other). Alternatively, the bosses  252  and the holes  254  may be arranged and configured so that if the latch spring  240  is inserted into the enclosure  110  in a rotated or flipped orientation, the first and second bosses  252   a,    252   b  will not align with the first and second holes  254   a,    254   b.  It should be appreciated that numerous variations of keys may be utilized to ensure that the latch spring  240  can only be inserted into the enclosure  110  in a single, proper orientation. 
     As should be appreciated, the key  250  may be any suitable mechanism or keying feature now known or hereafter developed so long as improper coupling and/or orientation of the latch spring  240  relative to the enclosure  110  is prevented. As such, the present disclosure should not be limited to the particular bosses and holes described and illustrated herein unless specifically claimed. 
     Referring to  FIG. 14 , in accordance with another aspect of the present disclosure, the mechanical interlock  100  may include an integrated magnetic switch  300  to ensure that the position of the handle assembly  140  is known with certainty and so that the position of the handle assembly  140  relative to the electrical state of the load switch  130  (e.g., ON versus OFF) can be compared, monitored, etc., and, if necessary, one or more fault indications can be provided. 
     In one example embodiment, the mechanical interlock  100  may incorporate a magnet  310  such as, for example, a permanent magnet or the like, that may be affixed to a moving element that directly translates with the external handle assembly  140  so that, in use, the magnet  310  can be moved into and out of range relative to a sensor such as, for example, a hall-effect sensor  320 . For example, in one embodiment, the magnet  310  may be coupled to the slider plate  220  so that movement of the slider plate  220  between the first and second positions moves the magnet  310  into and out of range relative to the sensor  320  located on, for example, a PCB board  330  coupled to an inside surface of the enclosure  100 . Alternatively, the sensor  320  may be located on the slider plate  220  and the magnet  310  may be located on the PCB board  330 . In use, the magnet  310  and sensor  320  may be coupled to the slider plate  220  and PCB  330  by any suitable mechanism now known or hereafter developed. 
     As will be appreciated by one of ordinary skill in the art, when the magnet  310  is located a certain distance away from the sensor  320 , the magnet  310  will be out of a sensing range of the sensor  320 , thus the magnetic flux from the magnet  310  will be out of range from the sensor  320  and the sensor  320  will not be triggered. Alternatively, when the magnet  310  moves towards the sensor  320 , the magnetic flux from the magnet  310  will be within a certain distance or range of the sensor  320  to trigger the sensor  320 . 
     As illustrated, with the slider plate  220  in the first position (e.g., corresponding to the OFF position of the handle assembly  140 ), the magnet  310  positioned on the slider plate  220  will be within range of the sensor  320  so that the magnet  310  interacts with the sensor  320  to provide a signal that the external handle assembly  140  is in the OFF position. Meanwhile, with the slider plate  220  in the second position (e.g., corresponding to the ON position of the handle assembly  140 ), the magnet  310  positioned on the slider plate  220  is moved axially so that the magnet  310  is no longer within range of the sensor  320  so that the magnet  310  no longer interacts with the sensor  320  thus providing no signal. Alternatively, it is envisioned that the magnet  310  may be arranged and configured to interact with the sensor  320  when in the ON position but not in the OFF position. 
     In use, the signal generated by the magnetic flux created when the magnet  310  is positioned within range of the sensor  320  is transmitted to a processor (not shown) located on, for example, the printed circuit board or PCB  330 . The processor may also be communicatively coupled to the load switch  130  so that the processor receives a signal corresponding to the state of the load switch  130  (e.g., ON or OFF). In this manner, the magnetic switch  300  in combination with the processor compares the actual position of the external handle assembly  140  relative to the state of the load switch  130  (e.g., ON or OFF), and, if desired, provides one or more fault indications. That is, in one example embodiment, the magnetic switch  300  can be used to verify the position of the external handle assembly  140 , and this information can be provided to, for example, a processor. In addition, using one or more sensors, the processor can receive data concerning the state of the load switch  130  such as, for example, whether power is being supplied. Thereafter, the processor can compare the position of the handle assembly  140  to the electrical state of the load switch  130  to determine if one or more fault conditions exists, and if so, to provide an indication of fault. 
     For example, due to one or more fault conditions, the mechanical interlock  100  could be supplying power even though the external handle assembly  140  is in the OFF position, or vice versa. During such an event, it would be advantageous to provide one or more fault indicators. For example, due to an overload condition, the electrical contacts in the mechanical interlock  100  could be heated to the point that they are welded closed so that the mechanical interlock  100  is constantly supplying power even though the external handle assembly  140  may be in the OFF position. In such an event, the processor can detect that the mechanical interlock  100  is supplying power (e.g., the load switch  130  is in the ON position) while detecting that the external handle assembly  140  is in the OFF position, and as a result could provide one or more fault indicators. 
     In use, the one or more fault indicators could be any suitable indication now known or hereafter developed. For example, the indication could be one or more LEDs on the enclosure  110 , could be one or more wireless signals, texts, emails, or the like transmitted by the mechanical interlock  100 , etc. 
     Referring to  FIG. 14 , the mechanical interlock  100  may also incorporate one or more battery backups  350  to, for example, supply power to the processor, PCB, fault indicator, etc. so that if a loss of neutral or ground occurs, the mechanical interlock  100  can still provide one or more fault indicators as desired. That is, the mechanical interlock  100  may include a battery power supply for supplying backup power to the magnetic switch  300  and the processor in case where mains power is lost. 
     While the present disclosure refers to certain embodiments, numerous modifications, alterations, and changes to the described embodiments are possible without departing from the sphere and scope of the present disclosure, as defined in the appended claim(s). Accordingly, it is intended that the present disclosure not be limited to the described embodiments, but that it has the full scope defined by the language of the following claims, and equivalents thereof. The discussion of any embodiment is meant only to be explanatory and is not intended to suggest that the scope of the disclosure, including the claims, is limited to these embodiments. In other words, while illustrative embodiments of the disclosure have been described in detail herein, it is to be understood that the inventive concepts may be otherwise variously embodied and employed, and that the appended claims are intended to be construed to include such variations, except as limited by the prior art. 
     The foregoing discussion has been presented for purposes of illustration and description and is not intended to limit the disclosure to the form or forms disclosed herein. For example, various features of the disclosure are grouped together in one or more aspects, embodiments, or configurations for the purpose of streamlining the disclosure. However, it should be understood that various features of the certain aspects, embodiments, or configurations of the disclosure may be combined in alternate aspects, embodiments, or configurations. Moreover, the following claims are hereby incorporated into this Detailed Description by this reference, with each claim standing on its own as a separate embodiment of the present disclosure. 
     As used herein, an element or step recited in the singular and proceeded with the word “a” or “an” should be understood as not excluding plural elements or steps, unless such exclusion is explicitly recited. Furthermore, references to “one embodiment” of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. 
     The phrases “at least one”, “one or more”, and “and/or”, as used herein, are open-ended expressions that are both conjunctive and disjunctive in operation. The terms “a” (or “an”), “one or more” and “at least one” can be used interchangeably herein. All directional references (e.g., proximal, distal, upper, lower, upward, downward, left, right, lateral, longitudinal, front, back, top, bottom, above, below, vertical, horizontal, radial, axial, clockwise, and counterclockwise) are only used for identification purposes to aid the reader&#39;s understanding of the present disclosure, and do not create limitations, particularly as to the position, orientation, or use of this disclosure. Connection references (e.g., engaged, attached, coupled, connected, and joined) are to be construed broadly and may include intermediate members between a collection of elements and relative to movement between elements unless otherwise indicated. As such, connection references do not necessarily infer that two elements are directly connected and in fixed relation to each other. All rotational references describe relative movement between the various elements. Identification references (e.g., primary, secondary, first, second, third, fourth, etc.) are not intended to connote importance or priority but are used to distinguish one feature from another. The drawings are for purposes of illustration only and the dimensions, positions, order and relative to sizes reflected in the drawings attached hereto may vary.