Abstract:
A switch extension device comprises an elongate extension member and an actuation member. The elongate extension member has a distal end shaped to couple with an electrical switch and a proximal end for positioning remote from the electrical switch. The actuation member is coupleable to the proximal end of the elongate extension member. The actuation member is movable to move the extension member to actuate the electrical switch. Methods of operation are also described.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Patent Application No. 62/075,791, filed Nov. 5, 2014, which is hereby incorporated by reference. 
    
    
     BACKGROUND 
     Accessing high voltage environments, including the controls to a transformer within a transformer cabinet, requires specialized equipment and procedures to ensure the safety of all personnel. 
     According to one known approach, an electrical switch, such as a rotary switch mounted to the interior of the cabinet, is adapted for operation outside of the cabinet by fitting the switch with a switch extension shaft. The switch extension shaft can be locked with a padlock, e.g., to keep the switch off, at a location outside the cabinet. In this way, such a switch extension shaft can be used in conjunction with a load break switch compliant with governing safety standards, including operability of the switch when the cabinet is open and the ability to lock the switch in an off position. 
     There still is a need, however, to provide increased flexibility and convenience in enabling switching operations from outside of a cabinet, while still maintaining safety, that are not addressed by the known approach. 
     SUMMARY 
     Described below is a switch extension device and mounting assembly for mounting the switch extension device in a supported arrangement. The supported arrangement, including, e.g., a suspended arrangement, ensures that the extension device maintains alignment with the switch when a door to a secured area where the switch is located, or other surface to which an outer switch handle is mounted, is moved between open and closed positions. Conveniently, the new approach allows for personnel to comply with Lock-out/Tag-out requirements in place at many installations. 
     According to a first implementation, a switch extension device comprises an elongate extension member and an actuation member. The elongate extension member, e.g., a shaft, has a distal end shaped to couple with an electrical switch and a proximal end for positioning remote from the electrical switch. The actuation member is coupleable to the proximal end of the elongate extension member. The actuation member is movable to move the extension member to actuate the electrical switch. 
     The actuation member can be lockable to prevent unauthorized movement of the actuation member. A switch extension device can comprise a plate for mounting to a surface, the plate having an opening sized to receive the proximal end of the extension member such that the actuation member is lockable in place relative to the plate. The plate can define at least a first locking position and a second locking position in which the actuation member can be locked to prevent the distal end of the actuation member from actuating the electrical switch. The actuation member can be rotatable to actuate the electrical switch. 
     The extension member can be supported in a generally horizontal orientation. The extension member can be suspended in a generally horizontal orientation. In some embodiments, the switch extension device comprises at least one support member, and the support member is positioned along the extension member between the proximal end and the distal end. The support member is mountable to a surface to support the extension member. 
     The switch extension device can comprise a support assembly having a first end for mounting to a first surface, a second end for mounting to a second surface and a hanger assembly adjustably positioned between the first end and the second end. The hanger member has an opening sized to receive the extension member. In an alternative implementation, the support assembly can comprise a support rod for positioning in a generally horizontal orientation and wall plates at the first and second ends for mounting the support assembly to adjacent surfaces. 
     The extension member can be sized such that the proximal end is positionable outside of a securable enclosure for the electrical switch when the distal end is engaged with the electrical switch. The switch extension device can comprise a plate for mounting to a surface of the securable enclosure. The plate can have an opening shaped to receive a proximal end of the extension member and define at least a first locking position and a second locking position at which the actuation member can be locked to prevent unauthorized movement of the extension member. The actuation device can be removably coupled to the proximal end of the extension member to allow the plate to be moved proximally past the proximal end of the extension member, with the support member continuing to support the extension member. 
     The actuation device can be adapted for coupling with a hot stick device manipulated by an operator. 
     The extension member can comprise at least two extension member sections that are adjustably connected to each other. 
     According to a method, remotely actuating an electrical switch positioned within a secured area comprises coupling an elongate extension member to the electrical switch with a distal end of the extension member contacting the electrical switch and a proximal end of the extension member positioned to extend outside of the secured area, coupling an actuation member to the proximal end of the extension member, configuring the secured area in a secured state, and actuating the actuation member from outside the secured area to move the extension member and in turn actuate the electrical switch. 
     The method may also comprise supporting the extension member in a generally horizontal position using a support assembly attached to at least one surface of the secured area. 
     The method can also comprise positioning a plate with an opening dimension to receive a proximal end of the extension member on an exterior surface of the secured area. The plate can define at least a first locking position and a second locking position at which the actuation member can be locked to prevent rotation relative to the plate. 
     The extension member can be positioned to extend through a door providing access to the secured area. The plate can be positioned on an exterior surface of the door such that when the actuation member is removed from the proximal end, the door can be opened and the extension member remain supported by the support assembly. Actuating the actuation member from outside the secured area can comprise contacting the actuation member with a hot stick device and rotating the actuation member to in turn rotate the extension member and the electrical switch. 
     The foregoing and other objects, features, and advantages will become more apparent from the following detailed description, which proceeds with reference to the accompanying figures. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a new switch extension device and a related mounting assembly. 
         FIG. 2A  is an enlarged perspective view of a portion of the new switch extension device and mounting assembly of  FIG. 1 . 
         FIG. 2B  is a perspective view of the new switch extension device of  FIG. 2A  from a different perspective. 
         FIG. 3  is a perspective view showing the mounting assembly. 
         FIGS. 4A, 4B, 4C and 4D  are top plan, side elevation, front elevation and perspective views, respectively, of the new switch extension device. 
         FIG. 5  is a top plan view of the new switch extension device showing a junction between sections of the device. 
         FIG. 6  is an elevation view of a portion of an electrical panel having a switch with which the new switch extension device can be used. 
         FIG. 7  is a perspective view showing the switch extension device engaged with the switch of  FIG. 6 . 
         FIG. 8  is an expanded elevation view of the electrical panel of  FIGS. 6 and 7  showing the mounting assembly as mounted to support the switch extension device. 
         FIG. 9  is an elevation view of a portion of a door to a secured area on which a plate for use with the switch extension device is mounted. 
         FIG. 10  is an elevation view of the plate showing the actuation member or handle locked in a closed position to prevent rotation of the actuation member relative to the plate. 
         FIG. 11  is an enlarged elevation view of a portion of the door showing a hot stick device being used to engage the actuation member of the switch extension device. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , a new mounting assembly  100  for one or more switch extension shafts is shown. A representative first switch extension member or shaft  102 A has a switch socket  104  at its distal end for engaging an electrical switch and a proximal exposed end  110  ( FIG. 4A ) with an actuation member or switch handle  112 . A representative switch S is shown in  FIG. 6  mounted on a panel and shown with other associated electrical equipment. The switch socket  104  and the switch handle  112  can be connected together by one or more shaft sections, such as a distal shaft section  106  and a proximal shaft section  108  ( FIG. 2A ). Such separate shaft sections can be secured together by fasteners  111  or other mechanical fastening arrangement, as described in further detail below. 
     As shown in  FIG. 1 , the assembly  100  can include multiple switch extension shafts, such as second and third switch extension shafts  102 B and  102 C as shown, in addition to the first switch extension shaft  102 A. Each switch extension shaft can be positioned to operate a separate switch, which provides for greater convenience and safety. 
     Referring to  FIGS. 2A and 2B , the switch extension shaft  102 A extends through a plate  116  that is typically affixed to a vertical surface, e.g., a door, which is movable relative to the switch. The plate  116  can have identifying indicia, such as “TX” as shown, to indicate the switch to which the corresponding switch extension shaft can be coupled. The switch handle  112  can have a loop  114  or other similar structure configured to allow coupling with a hot stick H ( FIG. 11 ) or other implement allowing remote actuation/operation of the switch handle. The switch handle  112  is removably coupled to the proximal end  110  of the shaft, such as with a pin  140  ( FIG. 4B ). 
     The switch handle  112  can also have a locking member  115  engageable with a padlock shackle P ( FIG. 10 ). The plate  116  can have one or more lock openings, such as the lock openings  118 A,  118 B, also configured to receive the padlock shackle P. In this way, the switch handle  112  can be locked in a desired one of several possible positions to prevent it from being rotated to change the position of the corresponding switch, i.e., the TX switch in this example. In operation, when it is desired to open the door, any padlocks must be unlocked and removed, the switch S must be in a predetermined position, and the switch handle  112  must be uncoupled from the shaft. The shaft remains supported at the proper position to allow the door to be closed after work within the cabinet is complete, with the aligned opening in the plate  116  and door passing over the proximal end  110  of the shaft. 
       FIG. 9  shows the plate  116  mounted to a representative door D and after the switch handle  112  has been removed, such that the exposed end  110  of the shaft projecting through an opening in the plate  116  is visible.  FIG. 10  is similar to  FIG. 9 , but shows the switch handle  112  coupled to the exposed end  110  and locked in the switch “CLOSED” position with the padlock shackle P extending through the aligned locking member  115  and lock opening  118 A. 
     The switch extension shaft  102 A can be supported, such as in a generally horizontal orientation as shown, by a hanger support  120 A. As best shown in  FIG. 3 , the hanger support  120 A can have a shaft receiving section  122  configured to receive the switch extension shaft  102 A and an opposite support end, such as a hanger section  124 . In the illustrated embodiment, the hanger section  124  is also adjustably positioned, such as by coupling it at a desired position along a horizontal support rod  134 . In this way, the switch extension shaft  102 A can be supported in a desired orientation, including when the door to which the plate  116  is affixed is moved from a closed position to an open position, which desirably keeps the switch socket  104  aligned so that it can be repositioned over the switch when the door is returned from the open position to the closed position. 
     The switch socket  104  is shown engaged with the switch S in  FIG. 7 . In some implementations, the switch socket  104  is secured to the switch S. For example, the socket  104  can be fastened to the switch S with a ¼ inch bolt or other suitable fastening arrangement. 
     The support rod  134  can be mounted by any suitable arrangement, including between wall plates  136  so as to extend approximately horizontally, such as is shown in  FIG. 8 . The hanger support  120 A can be comprised of one or more sections, such as an upper section  130  and a lower section  132  as shown. The sections  130 ,  132  may be removably coupled together, such as by using fasteners  138 . The support rod  134  and hanger supports, such as the hanger support  120 A, provide great adjustability for installing the assembly in a variety of different environments. 
     The support rod  134  can have any suitable cross-section, such as a square cross section as shown. The hanger section  124  can have a configuration adapted to correspond to the support rod  134 , such as a square tubing cross section as shown. The hanger section  124  can have a fastener  126  or other element to adjustably lock the hanger section  124  in a desired lateral position along the support rod  134 . 
     The shaft receiving section  122  can be configured as shown to permit the switch extension shaft  102 A to be rotated while it is being supported. For example, the shaft receiving section  122  can be formed from a section of tubing. 
       FIGS. 4A, 4B, 4C and 4D  are top plan, side elevation, front elevation and perspective views, respectively, of the switch extension shaft  102 A and plate  116 . As described above, the switch extension shaft  102 A can have the pin  140  or other similar element to removably couple the switch handle  112  to the proximal exposed end  110 . For greater security and safety, the pinned connection can be configured such that if a padlock shackle is locked through the locking member  115  on the handle  112  and one of the lock openings  118 A,  118 B, such as the lock opening  118 A as shown, then the handle  112  cannot be removed even if the pin  140  is removed. 
     In some implementations, the proximal shaft section  108  can be formed from ¾ inch solid metal round bar stock, and the distal shaft section  106  can be formed of 1 inch metal tubing dimensioned to receive the ¾ inch bar stock. The shaft sections  106 ,  108  can be removably secured together, such as with fasteners  111 . In another implementation as shown in  FIG. 5 , the distal shaft section  106  and the proximal shaft section  108  are attached together at a pinned connection  142  to provide a more robust connection once the precise positioning for best operation has been determined. 
     As shown in  FIG. 11 , in some implementations, an operator uses a hot stick device H for added safety when actuating the switch S via the switch extension shaft  120 A. The operator fits the hot stick device over the switch handle  112  and rotates the device, which in turn rotates the switch handle  112  and the switch S. In this way, the operator can safely move the switch to the desired position. 
     In view of the many possible embodiments to which the disclosed principles may be applied, it should be recognized that the illustrated embodiments are only preferred examples and should not be taken as limiting the scope of protection. Rather, the scope of protection is defined by the following claims. We therefore claim all that comes within the scope and spirit of these claims.