Abstract:
An isolating ground switch includes an enclosure with a frontal surface. A slide channel opens through the top of the enclosure. A conductive switch plate is received in the channel and is bi-directionally slidably positionable between the first position and the second position. A plurality of terminal studs project forwardly from the frontal surface of the enclosure and rearwardly conductively communicate with a conductive portion. When the switch plate is in the first position, the conductive portion engages the switch plate. When the switch plate is in the second position, the conductive portion is isolated from the switch plate.

Description:
BACKGROUND 
     This disclosure relates generally to devices for bonding and grounding various terminals. More particularly, this disclosure relates generally to devices and methods for grounding multiple harnesses and isolating the harnesses for testing. 
     It is common to bond harnesses for an electrically conductive line at a terminal and to provide a ground connection. Such terminals are located at or in utility marker posts, pedestals, cabinets, manholes, vaults and enclosures. The lines may serve as communication lines or markers for water lines, gas lines and power lines. Numerous devices and techniques have been advanced for implementing the required bonding and grounding. 
     When a specific line is to be tested, it is necessary to isolate the line. Conventional isolation of the lines typically requires that the connections be removed for the various lines to be tested and for the connections to be reattached after the testing to ensure the proper bonding and grounding. The conventional methods are inefficient and furthermore are often problematic when the bonding is not properly connected after the testing is complete. If each of the lines or multiple lines are to be tested, then each of the harnesses must be disconnected and properly reconnected. 
     SUMMARY 
     Briefly stated, an isolating ground switch in a preferred form comprises an enclosure having a frontal surface and a top. A side channel opens through the top. A conductive switch plate is received in the channel. The switch plate is bi-directionally slidably positioned between first and second positions. Terminal assemblies are mounted to the enclosure. Each terminal assembly includes a terminal stud projecting forwardly from the frontal surface. Each terminal stud also rearwardly conductively communicates with a conductive portion. When the switch plate is in a first position, each conductive portion conductively engages the switch plate. When the switch plate is in a second position, each conductive portion is conductively isolated from the switch plate. A ground connector conductively connects a terminal stud. 
     In one embodiment, the switch plate is bent forwardly to form a handle. The enclosure and the switch plate further have mounting openings at laterally spaced locations. The switch plate further has an array of openings located to correspond to the location of the terminal studs. The openings of the array are substantially identical and include an enlarged portion and a reduced portion. 
     In the second position, each conductive portion does not engage portions of the switch plate defining the openings, and in the first position, the conductive portion engages portions surrounding the reduced portion of the opening. Each terminal stud preferably comprises a threaded locate stud and a hex collar. The enclosure frontal surface defines an array of hex sockets which receive each hex collar. The conductive portion further comprises a screw which threads into the terminal stud. The enclosure is affixed with indicia indicating a direction for isolating and a direction for grounding. A mounting structure and a pair of fasteners extend through the mounting openings to mount the switch to a mounting structure. 
     The isolating ground switch preferably comprises an enclosure having a frontal surface and a side and a slide channel opening through the side. A conductive switch plate is received in the channel and slidably positionable between a first position and a second position. The switch plate has a plurality of plate openings. Terminal studs are mounted to the enclosure and project forwardly from the frontal surface. Each of the terminal studs rearwardly conductively communicates with a conductive unit. When the switch plate is in the first position, each conductive unit conductively engages the switch plate. When the switch plate is in a second position, each conductive unit is fully located in an opening and conductively isolated from the switch plate. A ground connector is conductively communicable with the slide plate. 
     The switch plate is preferably bent forwardly to form a handle. The enclosure and the switch plate further have mounting through openings at laterally spaced locations. A mounting structure and a pair of fasteners extend through the mounting openings to mount the switch to a mounting structure. The switch plate openings are substantially identical and include enlarged and reduced portions. In the second position, each conductive unit does not engage portions of the switch plate which define the plate openings. In the first position, the conductive assembly engages portions surrounding the reduced portions of the openings. The enclosure is preferably affixed with indicia indicating a direction for isolating and a direction for grounding. 
     An isolating ground switch comprises an enclosure with a frontal surface and a top and a slide channel opening through the top. A conductive switch plate is received in the channel and is slidably positionable from a first position to a second position. The switch plate has an upper handle. Threaded terminal studs are mounted to the enclosure and project forwardly from the frontal surface. Each of the terminal studs rearwardly conductively communicates with a conductive unit. When the switch plate is in the first position, each conductive unit conductively engages the switch plate. When the switch plate is in the second position, each conductive assembly is conductively isolated from the switch plate. A ground connector conductively communicates with each terminal stud. The switch plate further has an array of openings which are located to correspond to the location of the terminal studs. The openings are preferably substantially identical and include an enlarged portion and a reduced portion. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a generally front perspective view of an isolating ground switch; 
         FIG. 2  is a generally front view of another embodiment of an isolating ground switch; 
         FIG. 3  is a front view of the isolating ground switch of  FIG. 1  together with connected bonding harnesses and illustrated in a grounding mode and mounted to a utility marker post; 
         FIG. 4  is a front view of the isolating ground switch, marker post and harnesses of  FIG. 3  configured in an isolated mode; 
         FIG. 5  is a front view of the isolating ground switch, marker post and harnesses of  FIG. 4  together with a test transmitter clip; 
         FIG. 6  is a partially exploded perspective view of the isolating ground switch of  FIG. 1 ; 
         FIG. 7  is a perspective view of the isolating ground switch of  FIG. 1  in a partially assembled state; 
         FIG. 8  is an exploded perspective view of the isolating ground switch of  FIG. 7 ; 
         FIG. 9  is a reversed bottom exploded view of the isolating ground switch of  FIG. 7  in a partially assembled state; 
         FIG. 10  is a perspective exploded view of the isolating ground switch of  FIG. 2  in a partially assembled state; and 
         FIGS. 11A, 11B and 11C  are perspective views of the isolating ground switch of  FIG. 1  mounted to a displaceable arm mount, such as may be employed in a below ground location, and illustrating retracted, intermediate and elevated positions, respectively. 
     
    
    
     DETAILED DESCRIPTION 
     With reference to the drawings wherein like numerals represent like parts throughout the several figures, an isolating ground switch is generally designated by the numeral  10  for a six-position isolating ground plate ( FIG. 1 ), and by the numeral  12  for a three-position isolating ground plate ( FIG. 2 ). With reference to  FIGS. 3-5 , the isolating ground switches  10  and  12  are adapted to mount to marker posts  14  or other structures and to provide an efficient bi-stable ground switch which permits multiple lines  16  each having a bonding harness  18  to be either concurrently isolated ( FIG. 4 ) or to be concurrently connected to ground ( FIG. 3 ) in an efficient, user-friendly process while maintaining the bonding harnesses in a connected state. 
     The isolating ground switches  10  and  12  are adapted to connect with multiple bonding harnesses  18  and provide a ground connection via a ground lug  20 . The ground lug  20  has an opening  22  which receives a #6 to #24 AWG ground wire  24  secured in position by a set screw  26 . 
     The isolating ground switch  10  preferably comprises a compact, substantially rectangular enclosure  30  having a base  40  and a snap-fit cover  60 . The enclosure  30  is formed from a rugged non-conductive material. An intermediate sliding switch plate  50  ( FIG. 8 ) is received between the base  40  and the cover  60  and is manually reciprocated to provide the bonding and isolating functions. An array of parallel terminal connectors  32  preferably comprise threaded locate studs  34  having hex collars  36 . The studs  34  extend forwardly from the enclosure for bonding via a nut  38  with a bonding harness  18 . 
     The base  40  is preferably a substantially rectangular molded member formed of 10% glass filled polycarbonate Lexan™ material. The base  40  has a pair of laterally spaced slots  42  adjacent opposed sides and a bottom slot  44 . For isolating switch  10 , six shallow circular wells  46  are formed in the base for receiving terminal hardware, as will be described below. The base  40  also includes a pair of opposed openings  48  which function as a part of a throughbore for securing the base to a mounting post or other structure. 
     The ground switch plate  50  is preferably a brass member which is bent forwardly at an upper end to form a substantially L-shaped section. The upper end  52  functions as a handle. The plate  50  includes a pair of laterally spaced oblong slots  54  which generally align with the openings  48  in the base, as will be further described. The plate  50  includes substantially identical quasi-keyhole-type openings  55  having an enlarged portion  56  and an upper reduced portion  57 . The openings  55  generally align with the wells  46  of the base, as will be further described. In one form, a rubber material  58  covers the handle portion to provide an enhanced grip of the handle. In this regard, a pair of rectangular openings  53  may be formed to anchor the grip. The upper surface of the handle may be affixed with indicia  59  ( FIG. 6 ) which briefly indicates the switch plate  50  operation. 
     The cover  60  is preferably a substantially rectangular molded member formed from 10% glass filled polycarbonate Lexan™ material. The cover  60  has a frontal face  62  which includes laterally spaced hex-shaped openings  64  that generally align with the plate oblong slots  54  (to accommodate the sliding of the plate  50 ) and the base openings  48  to provide continuous throughbores. The throughbores receive fasteners ( FIGS. 3-6 ) secured by nuts  65  for mounting the isolating ground switch to a structure. The cover also includes hex sockets  70  (partially illustrated), as will be further described. The hex sockets  70  generally align with the keyhole openings  55  of the grounding plate and the wells  46  in the base. The hex sockets  70  each closely receive a hex collar  36  of a locate stud  34 . 
     The cover includes side skirts  66  having rearwardly projecting resilient tabs  67  which engage in the side slots  42  of the base. In addition, there is a bottom tab  69  which resiliently engages in the bottom slot  44  of the base. One or both of the side skirts may be affixed with an arrow and indicia  68  indicating the ground and isolating directions for the slidably received switch plate  50 . 
     Substantially identical locate backing screws  80  each have a head  82  with a diametric dimension which is less than that of the wells  46 . The heads  82  are received in corresponding wells  46 . The forward portion  84  of the backing screw is threaded and extends from an enlarged intermediate portion  85  which receives a floating washer  86  and an O-ring  88 . The forward threaded portion  84  threads into the rear of a locate stud  34 . Each hex collar  36  is closely received in a hex socket  70  of the cover and is fixed against rotation therewith. The threaded portion  84  of the locate backing screw threads into the locate stud to complete a conductive path. It will be appreciated that the locate studs  34  each connect to a bonding harness  18  and includes and typically mounts a lock washer  37  and a hex nut  38  for securing the harness connection. 
     The cover  60  snaps over the base  40  to form the enclosure  30  and a channel to capture the intermediately received sliding switch plate  50 . Upon normal force applied to the upper end or handle  52 , the switch plate  50  selectively reciprocates upwardly and downwardly between an isolated and a grounded position, as indicated in the drawings. The back of the plate  50  slides above the heads  82 . In a fully upward locate mode for the ground plate relative to the cover and base, the heads  82  of the locate backing screw are received in the wells  46 , and the carried floating washers  86  and O-rings  88  remain in a non-contact electrically isolated position within the corresponding enlarged portions  56  of the keyhole slots  55  of the switch plate  50 . Therefore, there is no electrical connection between the locate studs  32  and the locate screws  80 , washer  86  or O-rings  88 . When the ground plate  50  is forced downwardly to the grounding mode, the plate portion defining the reduced portions  57  of the slots engage the floating washer  86  and the O-rings  88  to establish conductive or electrical communication with the locate studs  34  and essentially provide a grounding function for the bonded harnesses  18 . 
     For the three terminal isolated ground plate  12  ( FIGS. 2 and 10 ), the cover plate  60 A is modified to define three hex sockets  70  and accept three terminal connectors  32 . 
     It will be appreciated that the position of the switch plate  50  will either isolate the various lines, which connect via the bonding harnesses, or will ground each of the lines. Consequently, when it is desired to test a line, the line may be isolated in an efficient manner without disconnecting the corresponding harness. A test clip  17  ( FIG. 5 ) may be attached to the terminal  32 . Typically, a distinctive tone is transmitted along the line  16 . After testing, the line along with the other lines may be restored to the grounding function by manually forcing the switch plate  50  downwardly. The ground lug  20  is typically connected to one of the locate studs  34 . Other ground connectors are also possible. In addition, the isolating ground switch  10  or  12  provides a well-defined, easily observed indication of whether the terminal is in a bi-stable isolated or a grounded mode. 
     In one preferred application as indicated in  FIGS. 11A-11C , isolated grounding plate  10  is mounted to a displaceable bracket  90 . An access cover may cover a below ground terminal assembly. The cover is not illustrated. When the cover is opened, the grounding plate  10  is upwardly pulled and simultaneously transformed from the grounding position ( FIG. 11A ) to the isolated position ( FIG. 11C ) so that testing may be accomplished. When the cover is returned, the grounding plate  10  is forced downwardly to ensure both a proper below ground position and the grounding of the various lines. 
     It will be appreciated that various conductive lines may be provided to provide a waterline mark, a gas line mark and various communication or power line indicators. In preferred embodiments, the tints of the base  40  and the cover  60  indicate the preferred application, such as yellow for a gas line, blue for a water line, orange for communication lines and red for a power line. Naturally, the number of actual terminals  32  or locate studs  34  may be varied from, for example, a six locate stud configuration and a three locate stud configuration illustrated in  FIGS. 1 and 2 , respectively. 
     While preferred embodiments of the foregoing have been set forth for purposes of illustration, the foregoing description should not be deemed a limitation of the invention herein. Accordingly, various modifications, adaptations and alternatives may occur to one skilled in the art without departing from the spirit and the scope of the invention.