Abstract:
A terminal reversing block mounts to a standard electrical disconnect device such as a circuit breaker or a pullout switch. The disconnect device has a housing which defines a cavity that faces in one direction for receiving a cable. Front and rear contacts are in the housing, one of which extends into the cavity for engagement with a cable. A terminal reversing block has a housing with at least one pocket which faces in a direction other than the opposite of the direction in which the disconnect device&#39;s cavity faces. A terminal collar disposed in the terminal reversing block pocket is engageable with a cable inserted into the pocket. A terminal in the reversing block has a mating portion and a connecting portion. The connecting portion engages the terminal collar. The mating portion engages one of the front and rear contacts of the electrical disconnect device. The arrangement of the directions in which the cavity and pocket face permits routing of the cables to minimize space requirements in a confined area, such as an enclosure or a cabinet.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Application Ser. No. 61/288,805, filed Dec. 21, 2009, the disclosure of which is incorporated by reference herein. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to adapters for rerouting electrical wires or cables. In particular, the present invention relates to terminal reversing blocks for changing the direction of electrical cables extending out of an electrical disconnect device. As used herein the term “cable” will be used to describe electrical conductors including wires, cables, busbars or other conductors. 
     High current electrical disconnect devices, such as pull-out switches or circuit breakers for example, are typically connected to thick, heavy electrical cables. The cable connectors of such disconnect devices are commonly referred to as terminal collars. The terminal collars conventionally are located on opposite sides of the housing of the disconnect device. This arrangement arises from the fact that the disconnect device internally has a selectably bridgeable gap in its conductors so there are two naturally-defined, physically separate “sides” of the conductive path through the disconnect. Thus, it is most convenient to physically locate the cable connectors that terminate the two sides of the electrical path on separate sides of the disconnect device. This choice is reinforced by the space requirements of the large cables. It is convenient to route the incoming and outgoing cables on opposite sides of the disconnect device to keep them out of each other&#39;s way. 
     The electrical disconnect device is typically mounted inside an enclosure, such as a junction box or a cabinet. Heavy electrical input cables bring power into the electrical disconnect device and similarly large electrical output cables carry power out of the electrical disconnect device. The diameter of the electrical input and output cables is such that the cables do not bend easily. Consequently, if a linear, single-direction arrangement of the cables is unworkable in a particular situation large spaces are required to bend an electrical input or output cable around to effect a variation in a cable&#39;s direction. 
     As mentioned above, high current electrical disconnect devices have cable retaining structures such as terminal collars which include lugs with clamping screws. For example, the disconnect device can be a pullout fusible switch that is configured to have electrical input cables enter into the bottom of the switch and electrical output cables exit out of the top of the switch, as seen in U.S. Pat. No. 4,536,046 to Erickson, the disclosure of which is incorporated herein by reference. Another example of an electrical disconnect device is a load switch or circuit breaker, as seen in U.S. Pat. No. 4,363,063 to Erickson, the disclosure of which is incorporated herein by reference. 
     It is often desired to have the electrical input and output cables routed in directions other than the conventional opposite directions. For example, it is sometimes advantageous to have the output cables routed in the same direction as the input cables. That is, the input and output cables are essentially right next to each other. This may be due to limitations on space in the enclosure that contains the electrical disconnect device. The current method to accomplish this is to bend the electrical output cables around in an arc to route the output cables in the same direction as the input cables. Due to the large diameter of high power cables, the radius about which they will bend is large. This means the space required to bend the cables in a reversing arc may be larger than is available. In addition, the extra lengths of cables or cables required to make such an arc increases the cost. 
     This problem is illustrated in  FIG. 21 . A standard electrical disconnect device  2  (in this case a load switch or circuit breaker) has input cables  4  attached to the bottom side thereof and output cables  6  extending from the top side of the disconnect device  2 . A wide enclosure  8  is needed to bend output cables  6  around to be routed out the same side of the enclosure  8  from which input cables  4  enter the enclosure  8 . This Figure is merely illustrative of the problem, as in some situations even the somewhat large radius of curvature shown may not be achievable due to the stiffness of the output cables. 
     Thus, there remains a need for a way to reroute electrical output cables from an electrical disconnect device in a minimum of space. There also remains a need for a way to adapt such electrical cable routing to industry standard electrical disconnect devices, such as pull out switches or circuit breakers for example. 
     SUMMARY OF THE INVENTION 
     The present invention provides a terminal reversing block that connects to a standard electrical disconnect device. The terminal reversing block has a dielectric housing that mounts therein one or more conductive terminals. Each terminal has a mating portion, a body portion, and a connecting portion. The mating portion is engageable with a conductor of the electrical disconnect device. The connecting portion is engageable with an output cable by means of a terminal collar. The body portion joins the mating and connecting portions. The connecting portion of the terminal is located remotely from the mating portion. 
     The terminal reversing block&#39;s housing can be sized and shaped to fit above or below the electrical disconnect device. The terminal reversing block is preferably sized and shaped to have the same or roughly the same length and width as the electrical disconnect device, thereby minimizing the length and width required for the completed assembly of the terminal reversing block and electrical disconnect device. The body portion of the terminal may include an offset section that separates the longitudinal axes of the mating portion and connecting portions thereby providing easy access to the terminal collars on the electrical disconnect device and the terminal reversing block. Alternatively, the terminal reversing block can be sized and shaped to extend out from at least one side of the electrical disconnect device so as not to increase the height of the electrical disconnect device, thereby minimizing the height required for the enclosure of the terminal reversing block and electrical disconnect device. 
     These and other desired benefits of the invention, including combinations of features thereof, will become apparent from the following description. It will be understood, however, that a device could still appropriate the claimed invention without accomplishing each and every one of these desired benefits, including those gleaned from the following description. The appended claims, not these desired benefits, define the subject matter of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a top plan view of a terminal reversing block in accordance with the present invention. 
         FIG. 2  is a front elevation view, on an enlarged scale, of the terminal reversing block. 
         FIG. 3  is a rear elevation view, on an enlarged scale, of the terminal reversing block. 
         FIG. 4  is a side elevation view of the terminal reversing block. 
         FIG. 5  is a section of the terminal reversing block, taken generally along line  5 - 5  of  FIG. 1 . 
         FIG. 6  is a section, on an enlarged scale, of the terminal reversing block housing, taken generally along line  6 - 6  of  FIG. 1 . 
         FIG. 7  is a section, on an enlarged scale, of the terminal reversing block housing, taken generally along line  7 - 7  of  FIG. 1 . 
         FIG. 8  is a side elevation view of a terminal. 
         FIG. 9  is a top plan view of a terminal. 
         FIG. 10  is a top plan view of an electrical disconnect device, in this instance a pullout switch, assembled on the terminal reversing block of the present invention. 
         FIG. 11  is a front elevation view of the assembly of  FIG. 10 . 
         FIG. 12  is a rear elevation view of the assembly of  FIG. 10 . 
         FIG. 13  is a side elevation view of the assembly of  FIG. 10 . 
         FIG. 14  is a section, similar to  FIG. 5 , of the assembly of  FIG. 10 . 
         FIG. 15  is a top plan view of an electrical disconnect device, in this instance a pullout switch, assembled on a terminal reversing block, mounted in an enclosure and with cables connected to the electrical disconnect device and terminal reversing block. 
         FIG. 16  is a cross sectional side elevation view of the electrical disconnect device assembly of  FIG. 15 . 
         FIG. 17  is a top plan view of two electrical disconnect devices mounted on alternate embodiments of reversing blocks, illustrating a configuration of dual reversing blocks to create a manual transfer switch. 
         FIG. 18  is a cross sectional side elevation view of the assembly of  FIG. 17 . 
         FIG. 19  is a top plan view of an alternate electrical disconnect device, in this instance a load switch, assembled on a terminal reversing block of the present invention. 
         FIG. 20  is a top plan view of the electrical disconnect device assembly of  FIG. 19  in an enclosure. 
         FIG. 21  is a top plan view of an electrical disconnect device in an enclosure, illustrating the prior art method of reversing the cables. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A terminal reversing block  10  in accordance with the present invention is shown in  FIG. 1 . Terminal reversing block  10  is adapted for heavy duty power transmission applications. For example and not by way of limitation, the illustrated terminal reversing block  10  is rated at 240 volts AC/125 volts DC and 400 amps. Terminal reversing block includes three main components, a housing or base  12 , one or more terminals or blades  14 , and a terminal collar  72  associated with each terminal. For clarity in illustrating the housing  12  and terminals  14 , the terminal collars  72  are not shown in  FIGS. 2-7 . The terminal collars are shown and described below in connection with  FIGS. 11 and 14 . Also, references herein to front, side, top, bottom and the like are from the point of view of a terminal reversing block mounted on a horizontal surface. Obviously the terminal reversing block could be mounted on a vertical surface such as a wall or a rack. Accordingly, directional references to the block&#39;s front, side, top or bottom are for reference purposes only and are not to be interpreted as limiting the orientations in which the terminal reversing block could be mounted. 
     In this embodiment the terminal reversing block is a three-pole device. Accordingly, it has three terminals  14 . It will be understood that different numbers of poles and terminals therefor could be provided depending on the needs of a particular application. Housing  12  and terminal  14  can be made from any industry standard dielectric and conductive materials, respectively. By way of example only, housing  12  may be molded of an insulator resin, usually a phenolic resin, and the terminals  14  are made of copper with a finish of silver plate and protective dip. 
     Details of the housing&#39;s construction are illustrated in  FIGS. 1 through 7 . The housing  12  has two sections, a terminal-receiving shell and a collar-receiving case. The shell has two side walls  16 ,  18  joined by a transverse end wall  20 . The side walls  16 ,  18  each have an angled portion  16 A,  18 A, respectively. Front extensions  16 B,  18 B join the angled portions. At the junction of the angled portions with the straight main portions of the side walls the wall thickness is somewhat enlarged at  16 C,  18 C ( FIGS. 1 and 7 ). Similar enlargements are found at  16 D,  18 D where the side walls join the end wall  20 . The top lands of these enlargements serve as resting surfaces for the feet of an electrical disconnect device mounted on top of the shell. 
     The housing&#39;s shell section further includes a bed or floor  22  which extends between the side walls  16 ,  18  and end wall  20 . To accommodate the angled portions  16 A,  18 A of the side walls the floor  22  has an angled front portion  22 A. The floor is located somewhat above the bottom edges of the side and end walls, as seen in  FIGS. 5-7 . Those figures best illustrate that the floor has six terminal-mounting bores through it. Three of these bores  24 A ( FIG. 5 ) are in the angled front portion  22 A of the floor. Three more of the bores  24 B ( FIGS. 5 and 7 ) are aligned with the enlargements  16 C,  18 C of the side walls. Although the bores themselves are covered in  FIG. 1  it can be understood that bores  24 A are aligned with and receive the terminal-mounting bolts  26 A and bores  24 B are aligned with and receive terminal-mounting bolts  26 B. Each bore  24 A,  24 B is surrounded on the top surface of the floor by an upper boss  28 . The upper bosses engage the underside of a terminal  14 , as seen in  FIGS. 2 and 5 , to create an air gap between the terminal and the floor, which aids in heat dissipation. Each bore  24 A,  24 B is also surrounded on the bottom surface of the floor by a lower boss  30 . The lower boss receives a nut  32  ( FIG. 5 ) which is engageable with one of the terminal mounting bolts  26 A or  26 B. 
     In this three-pole embodiment the shell is subdivided into three terminal-receiving chambers  34 A,  34 B,  34 C by two partitions  36 ,  38 . The partitions extend generally parallel to the side walls  16 ,  18 . Thus, the partitions also include angled portions  36 A,  38 A. Each partition  36 ,  38  also has a pair of enlarged or thickened portions  36 B,  38 B, respectively. The enlarged portions each accommodate a threaded bore  40  therein. The threaded bores receive mounting screws (not shown) which extend through an electrical disconnect device to retain the device on the shell. Cylindrical protrusions  42  surround the bores  40  and extend a short distance above the top land of the partitions  36 ,  38 . These protrusions fit into small depressions (not shown) in the underside of an electrical disconnect device mounted on the shell to serve as locators for the disconnect device. 
     The shell portion of the housing  12  has a series of ribs  44  on the underside of the floor  22 , some of which are seen in FIGS.  2  and  5 - 7 . Some of the ribs carry small feet  46 , which lift most of the housing off a surface to which it is mounted to facilitate air flow around the underside of the housing. The shell is completed by four mounting tabs  47  which extend from the bottom edges of the side walls  16 ,  18 . The tabs have holes therein for receiving a mounting screw (not shown). It will be noted that the bottom surfaces of the mounting tabs are coplanar with the bottom edges of the feet  46 . 
     Attention is now directed to the case section of the housing. The case section is a box-like portion attached to the front of the shell section. In fact, the extensions  16 B,  18 B of the side walls define the sides of the case. The case further includes a transverse rear wall  48  and a top wall  50 . Depending from the top wall  50  and attached at the rear wall  48  are four vertical interior walls  52 A,  52 B,  52 C and  52 D. At the front edge of the interior walls and adjoining the underside of the top walls is a retention ledge  53  ( FIGS. 2 and 5 ). A similar retention ledge  53  is formed on the inner surfaces of the side wall extensions  16 B,  18 B. Together the extensions  16 B,  18 B, rear wall  48 , top wall  50 , interior walls  52 A-D and retention ledges  53  define three collar-receiving pockets  54 A,  54 B,  54 C, as best seen in  FIG. 2 . These pockets are open to the bottom and are largely open to the front except for the retention ledges  53 . Access to each pocket through the top wall  50  is provided by openings  56  in the top wall. The collar-receiving pockets are sized to receive one terminal collar in each pocket, as will be explained below. The pockets can be considered to face in a direction generally perpendicular to the rear wall  48  and toward the open front of the pocket. Thus, for example, the pocket  54 A in  FIG. 5  faces in the direction of arrow X. 
       FIGS. 8 and 9  illustrate details of the terminal or blade  14 . Each terminal is an integral part that has a mating portion  58 , a connecting portion  60  and a body portion  62 . In this embodiment the body portion includes a planar, straight trunk  64 , an upstanding neck  66  extending out of the plane of the trunk, and an offset portion  68 . The mating portion  58  adjoins the neck  66  while the connecting portion  60  adjoins the offset portion  68 . Both the trunk  64  and offset portion  68  have mounting apertures  69  therethrough for receiving the terminal mounting bolts  26 A,  26 B. There is also a bore  70  in the mating portion  58  and connecting portion  60 . It will be noted that the trunk  64  defines a longitudinal main axis A and connecting portion  60  defines a longitudinal offset axis B. Due to the presence of the offset portion  68  of the terminal, the main axis A and offset axis B are spaced from one another. 
       FIGS. 11 and 14  show the terminal collar generally at  72 . In the illustrated three-pole disconnect device and terminal reversing block, there are three terminals  14  in the reversing block, one in each terminal-receiving chamber  34 . These terminals are each connected to one of the three terminal collars in the disconnect device, one collar in each of the collar-receiving pockets  54 A,  54 B,  54 C. Only one of the terminal collars will be described since the others have the same construction. The terminal collar is made of a conductive material such as a suitable aluminum alloy. It includes a main body or lug  74 . The lug is a generally rectangular block with a central passage  76  through it that defines a roof  78  and a floor  80  in the lug  74 . The floor&#39;s upper surface has a small protrusion  82 . A C-shaped clip  84  is engageable with the floor as will be explained. The roof  78  has a threaded aperture through it that receives a threaded clamping screw  86 . The clamping screw can be threadedly advanced into and retracted from the central passage  76  to selectably retain or release a cable. 
     Assembly of the terminal reversing block is as follows. First, a terminal  14  is placed in each of the housing&#39;s terminal-receiving chambers  34 A-C with the terminal&#39;s mounting apertures  69  aligned with the bores  24 A,  24 B in the housing floor  22 . Then the terminal mounting bolts  26 A,  26 B are installed to fix the terminal in place. It will be evident that the terminal&#39;s offset portion  68  lies above the angled portion  22 A of the floor and the terminal&#39;s connecting portion  60  extends into the one of the collar-receiving pockets MA-C. Next the terminal collars  72  are placed in the pockets MA-C. With the C-shaped clip removed, the lug  74  is inserted into the pocket from the front but with the roof  78  lower than its ultimate position so the roof will clear the lower edges of the retention ledges  53 . At this point the connecting portion  60  of the terminal will extend into the central passage  76  of the lug but somewhat above the floor  80 . Once the lug is far enough into the pocket to clear the retention ledges  53 , the lug is pushed upwardly so it fits in behind the retention ledges. This upward movement of the lug carries the foot&#39;s protrusion  82  into engagement with the bore  70  in the terminal&#39;s connecting portion  60  and places the connecting portion in engagement with the top surface of the floor  80 . Then the C-shaped clip  84  is placed over the connecting portion  60  and bottom of the floor  80 . The C-shaped clip has sufficient spring force to retain it in place on the lug&#39;s floor. The clip  84  holds the terminal collar  72  on the terminal&#39;s connecting portion  60  and prevents the terminal collar  72  from falling out the bottom of the pocket  54 . It can be seen that once a cable is placed in the central passage, a driver tool, e.g., a hex driver, can be placed through one of top wall openings  56  to engage the clamping screw  86  and advance it into the central passage, thereby clamping the cable between the screw and the top surface of the C-shaped clip  84 . 
     Having described the terminal reversing block  10 , we can now turn to the electrical disconnect device. One embodiment of an electrical disconnect device  88  is shown installed on a terminal reversing block  10  in  FIGS. 10-14  In this example the device  88  is a standard pullout switch. One of the advantages of the present invention is that no alteration in the construction of the pullout switch is required. It may be advantageous to remove the terminal collars on the output side of the disconnect device but this is not absolutely necessary. The pullout switch  88  is mounted on the shell of the terminal reversing block and held by screws (not shown) that extend through the switch and into bores  40 . 
     The pullout switch  88  has a housing  90  that has front and rear case sections similar to that of the terminal reversing block. The front case section has three cavities  91  which are generally similar to the pockets  54  in the terminal reversing block. Terminal collars  92  similar to collars  72  are disposed in the cavities  91  (the rear case section is shown with its collars removed). C-shaped clips  93  ( FIG. 14 ) connect the collars  92  to front contacts  94 , which are mounted on the floor of the housing  90 . Rear contacts  96  are also mounted on the floor. As can be seen in  FIG. 14  the front and rear contacts  94 ,  96  in this embodiment are laminated plates fastened to the housing  90  by bolts. Each contact includes an upstanding member  94 A,  96 A, as seen in  FIG. 14 . A dividing wall  98  mechanically and electrically separates the front and rear contacts. A removable insert section  100  fits into a well formed in the center of the housing  90 . The insert section has a handle  102  by which it can be lifted out of the housing. It will be understood that the interior of the insert section includes bridging members  103 , i.e., electrical conductors that will engage the upstanding members  94 A,  96 A of the front and rear contacts when the insert section is installed in housing  90 , thereby providing a conductive path between the contacts. 
     As seen in  FIG. 14 , the neck  66  of the terminal  14  extends into the rear case section of the housing  90 , placing the terminal mating portion  58  adjacent the end of the rear contact  96 . A connecting bolt  104  is threaded into the threaded bore  70  to bond the mating portion  58  tightly to the rear contact  96 . 
       FIGS. 15 and 16  illustrate the assembly of an electrical disconnect device  88  and a terminal reversing block  10  mounted in an enclosure  106 . The enclosure could be any sort of cabinet, load center or the like for protecting the equipment therein. The cabinet may have a door or cover  108 . Conduits  110 A, B may join the enclosure through suitable junctions  112 . Input cables  114  installed in conduit  110 A enter the bottom of the cabinet and are connected to the disconnect device  88  at its terminal collars  92 . Output cables  116  installed in conduit  110 B are connected to the terminal reversing block  10  in the manner described above. As  FIGS. 15 and 16  show, both the input and output cables extend through the bottom of the enclosure, in a compact space because the terminal reversing block reverses the direction of the output terminal collars. 
       FIGS. 17 and 18  illustrate how two terminal reversing blocks could be adapted to create a manual transfer switch. This embodiment has a terminal reversing block  118  with a pullout switch housing  120  mounted thereon as shown above. Input cables  122  are connected to the reversing block. Output cables  124  are connected to the switch housing  120  but the pullout switch housing  120  is shown without an insert section, such as that shown previously at  100 . A second terminal reversing block housing  126  is provided with another pullout switch  128  mounted on it. Switch  128  does have an insert section  130  for shorting the contacts in the switch. Switch  128  also has output terminal collars  132  which connect to output cables  134 . Terminal reversing block housing  126  lacks terminals and terminal collars. It simply provides a base for matching the height of pullout switch  128  with that of pullout switch housing  120 . This enables the terminals  14  of reversing block  118  to be joined to the front contact of switch  128  by conductive straps or jumpers  136 . With this arrangement the input cables  122  are electrically connected to one or the other of the sets of output cables  124  or  134 , depending on the location of the one insert section  130 . That is, if insert section  130  is placed as shown in switch  128  a connection is made between cables  122  and  134  via terminals  14 , straps  136 , and insert section  130  shorting the contacts in switch  128 . No connection exists to output cables  124  due to the absence of an insert section to short the contacts in switch housing  120 . If the insert section  130  is taken out of switch  128 , doing so breaks the circuit to cables  134 . If the insert section  130  is then placed in switch housing  120  it closes the circuit from the input cables  122  to the output cables  124 . 
       FIG. 19  illustrates another type of electrical disconnect device, in this case a load switch  138 , mounted on a terminal reversing block  10 .  FIG. 20  shows load switch  138  and terminal reversing block  10  in an enclosure  106 . Input and output cables both extend through the same end of the enclosure. 
     It is pointed out that the offset portion  68  of the terminal  14  results in the centerline of the terminal collars in the reversing block being laterally spaced from the centerline of the terminal collars in the disconnect device  88 . This is best seen in  FIG. 11  where the vertical centerline of a disconnect collar is indicated at plane C while the vertical centerline of a reversing block collar is indicated at plane D. This staggering of the terminal collars into individual, separate planes facilitates attaching cables to the assembly of a terminal reversing block and a disconnect device. The cables are more readily packed together with the offset arrangement of the reversing block&#39;s terminal collars compared to those of the disconnect device. 
     It will be understood that there are numerous modifications of the illustrated embodiments described above which will be readily apparent to one skilled in the art, such as many variations and modifications of the terminal reversing block and/or its components, including combinations of features disclosed herein that are individually disclosed or claimed herein, explicitly including additional combinations of such features. Also, there are many possible variations in the materials and configurations. These modifications and/or combinations fall within the art to which this invention relates and are intended to be within the scope of the claims, which follow. For example, instead of routing the output cables in the same direction as the input cables, in some instances it may be desirable to route the output cables perpendicular to the input cables. In this case the terminal reversing block would be configured to have its output terminal collars facing to one side of the housing. Also, while the terminal collar is a preferred device for maintaining a cable in contact with the connecting portion of the terminal, other arrangements could be used to hold the cable against the terminal. For example, an internally-threaded sleeve for receiving the clamping screw  86  could be mounted in the case portion of the housing and aligned with the collar-receiving pocket such that the clamping screw is engageable with a cable lying above the terminal&#39;s connecting portion  60 . Finally, it will be understood that references to input and output cables are for purposes of distinguishing between two sets of cables and not for implying what the cables are connected to in the rest of the circuit. Thus, depending on the needs of a particular circuit, either an input or output cable could be connected to the line side of the circuit and either an input or output cable could be connected to the load side of the circuit.