Patent Publication Number: US-2006018461-A1

Title: Termination block

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention is directed generally to communication interface equipment and, more particularly, to termination blocks for connecting systems for telephone networks.  
      2. Description of the Related Art  
      Termination blocks are used to quickly connect telephonic devices, such as telephones, to telephone networks. A termination block provides a multi-wire connector jack, having multiple tines, to receive a multi-wire connector plug having multiple tines such that contact is made between the corresponding pairs of plug and jack tines when the connector plug is inserted into the connector jack. The jack tines are connected by wires to termination screws to which the wires of a telephone network are also connected.  
      The multi-wire connector plug is typically connected to a phone cord having two, four, or more wires by making connections between the corresponding pair or pairs of phone cord wires and plug tines. The phone cord wires are connected to a telephonic device such as a phone.  
      The termination block is typically mounted to a faceplate and positioned inside of a wall of a room. The faceplate has an opening to access the multi-wire connector jack from the room to allow the multi-wire connector plug of the telephonic device placed in the room to be inserted into the connector jack. Termination blocks allow telephonic devices to be quickly connected to and disconnected from the telephone network. Unfortunately, construction of conventional termination blocks is more expensive and less reliable than desired. Conventional termination blocks have numerous parts including multiple washers, wires, wire connectors, and other parts that are typically hand assembled. Also, since so many parts are involved, very extensive testing is required for each assembled termination block, which further adds to the inconvenience of construction resulting in undesirable costs being incurred.  
     BRIEF SUMMARY OF THE INVENTION  
      The present invention resides in a termination block. One disclosed embodiment include a rear face with a rear aperture; a front face with a front aperture, the front and rear faces being spaced apart; and a plurality of mounting surfaces on the rear face. A plurality of screw receiving portions are each positioned at one of the mounting surfaces and have an opening and a screw receiver extending from the rear face toward the front face. An interior recess is provided between the rear and front faces. The interior recess is accessible from the rear face through the rear aperture and accessible from the front face through the front aperture.  
      A plurality of screws are each extending through the opening of one of the screw receiving portions and threadably received in the screw receiver thereof.  
      A plurality of terminal connection pads are positioned at the rear face at one of the mounting surfaces. Each of the terminal connection pads has a screw aperture therethrough positioned in alignment with the opening of the screw receiving portion positioned at the mounting surface and one of the screws extends through the screw aperture. A plurality of tines extends through the rear aperture of the rear face and are positioned within the interior recess and positioned for access through the front aperture. Each tine has a contact end portion. The contact end portions of the tines are in spaced apart arrangement in position within the interior recess. A plurality of trace members are positioned at the rear face, with each trace member electrically coupling together one of the terminal connection pads and one of the tines.  
      The illustrated embodiment includes a plug extending through the rear aperture of the rear face and within the interior recess and holding the tines in spaced apart arrangement. The plug has a plurality of channels, each having one of the tines positioned therein. The plug has a cover portion extending over a portion of the rear face and covering at least a portion of the trace members.  
      The illustrated embodiment also has at least one rear raised portion positioned adjacent to each of the terminal connection pads and extending from the rear face rearward beyond the adjacent terminal connection pad.  
      The termination block may also include a plurality of forwardly projecting front support members. The front support members are positioned to engage at least a portion of the rear raised portions of another termination block when two termination blocks are positioned in engagement with the front face toward the rear face of the another termination block. The combined length of the front support members and the portions of the rear raised portions in engagement are sufficient to keep the front face from contacting the rear face of the another termination block, whereby damage to the screws is prevented during face to face shipment or storage of the termination blocks.  
      The illustrated embodiment includes rear raised portions positioned adjacent to the trace members and extending from the rear face rearward beyond the trace members with the trace members positioned therebetween.  
      A plurality of spaced apart channels are also provided in the illustrated embodiment at the rear face. Each channel receives a free end portion of one of the tines.  
      Each of the tines springably engage a portion of the rear face to generate a forwardly directed tension force on the tine. In the illustrated embodiment the free end portion of one of the tines is positioned in each of the channels.  
      The plug extending through the rear aperture of the rear face and within the interior recess in the illustrated embodiment applies a forward force to the tines to generate a forwardly directed tension force in the tine.  
      The contact end portion of each of the tines has a flat forward facing contact surface with a coating of conductive metal thereon and the other portions of the contact end portion are uncoated.  
      A screw retainer extends rearward from the rear face and is sized to removably retain a mounting screw used to mount a mounting member to which the termination block is attached. The screw retainer is sized to retain a wire cable having wires to be connected to the terminal connection pads when the mounting screw is removed therefrom to serve as a cable strain relief.  
      Other features and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)  
       FIG. 1  is an isometric schematic of a roll of lead frames.  
       FIG. 2  is a top plan view of a several lead frames of the lead frame roll of  FIG. 1  showing the front faces of the lead frames.  
       FIG. 3  is an isometric view of a frame of several of the lead frames of the lead frame roll of  FIG. 1  showing the rear faces of the lead frames.  
       FIG. 4  is an isometric rear view of one lead frame showing the tines after being bent for mounting to a termination block base.  
       FIG. 5  is an isometric front view of the lead frame of  FIG. 4 .  
       FIG. 6  is an isometric rear view of the lead frame of  FIG. 4  oriented for mounting to a termination block base.  
       FIG. 7  is an isometric rear view of the lead frame of  FIG. 6  mounted in the termination block base with a block plug oriented for insertion into the termination block base at the location of the bent tines.  FIG. 8  is an isometric rear view of the assembled lead frame, termination block base and block plug of  FIG. 7  with four screw oriented for being threadably received by the termination block base.  
       FIG. 9  is an isometric rear view of the fully assembled termination block.  
       FIG. 10  is an isometric front view of the termination block of  FIG. 9 .  
       FIG. 11  is a front view of the termination block of  FIG. 10 .  
       FIG. 12  is an isometric rear view of a single receptacle cover plate for use with the termination block of  FIG. 9 .  
       FIG. 13  is a cross-sectional side elevational view of the single receptacle cover plate of  FIG. 12  showing the termination block ready for snap fitting to the single receptacle cover plate.  
       FIG. 14  is a cross-sectional side elevational view of the single receptacle cover plate of  FIG. 12  showing the termination block fully inserted into the single receptacle cover plate.  
       FIG. 15  is an isometric rear view of the single receptacle cover plate of  FIG. 12  with the termination block fully inserted into the single receptacle cover plate.  
       FIG. 16  is an isometric front view of the single receptacle cover plate of  FIG. 12  with the termination block fully inserted into the single receptacle cover plate.  
       FIG. 17  is an isometric rear view of a dual block bracket.  
       FIG. 18  is a cross-sectional side elevational view of the dual block bracket of  FIG. 17  showing first and second termination blocks nested together and ready for snap fitting to the dual block bracket.  
       FIG. 19  is a cross-sectional side elevational view of the dual block bracket of  FIG. 17  showing the first and second termination blocks fully inserted into the dual block bracket.  
       FIG. 20  is an isometric rear view of the dual block bracket of  FIG. 17  with the first and second termination blocks fully inserted into the dual block bracket.  
       FIG. 21  is an isometric rear view of the dual block bracket of  FIG. 17  with the first and second termination blocks fully inserted into the dual block bracket shown with telephone network wires attached.  
       FIG. 22  is an isometric front view of the dual block bracket of  FIG. 17  with the first and second termination blocks fully inserted into the dual block bracket.  
       FIG. 23  is an isometric rear view of the dual block bracket of  FIG. 17  with the first and second termination blocks fully inserted into the dual block bracket shown with two mounting screws being held by the screw retainers on the second termination block for shipping.  
       FIG. 24  is an isometric rear view of a pair of termination blocks stacked for shipment or storage purposes. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      As will be discussed in greater detail herein, a termination block  2 , shown fully assembled in  FIG. 9 , is disclosed that greatly reduces the number of individual parts required with conventional termination blocks, thus reducing the manufacturing cost of the termination block and increasing reliability. Other advantages of the termination block  2  will be described.  
      The termination block  2  is manufactured using a stamped, thin, flat lead frame  4  detached from a roll  6  of continuous strip lead frames, shown in  FIG. 1  partially unrolled. Several of the unrolled lead frames  4  are shown with a flat front face surface  8  (facing downward in  FIG. 1 ) and a flat rear face surface  10  (facing upward in  FIG. 1 ). The individual lead frames  4  are positioned between and attached to left and right side edge strips  12  and  14 , respectively, of the roll  6 . Each of the left and right side edge strips  12  and  14  include a series of sprocket holes  16 .  
      As is conventional, the sprocket holes  16  are used in stamping for precise orientation and in other aspects of manufacturing the termination block  2  using the lead frame  4 . The sprocket holes  16  on the left and right side edge strips  12  and  14  are laterally aligned, except that there is no sprocket hole on the right side edge strip  14  corresponding to every other one of the sprocket holes of the left side edge strip  12  to prevent the inadvertent inversion of the otherwise symmetrical lead frames  4  of the roll  6 . As will be described below, in the illustrated embodiment only the flat front face surface  8  of a portion of each lead frame  4  is coated with a highly conductive metal such as gold so keeping the lead frame properly oriented is desirable.  
      The roll  6  includes a cross members  18  associated with each lead frame  4 , and extending between and attached to the left and right edge strips  12   15  and  14 . Each of the lead frames  4  is attached to one of the cross members  18 , as will be describe below.  
      The lead frames  4  each include four terminal connection pads  22  with apertures therethrough, four parallel tines  24  and four trace members  26 . The trace members  26  each electrically couples one of the terminal connection pads  22  to a corresponding one of the tines  24 . Before the lead frame  4  is detached from the roll  6 , the terminal connection pads  22  located toward the left side edge strip  12  are attached thereto, and the two of the terminal connection pads located toward the right side edge strip  14  are attached thereto. Similarly, before the lead frame  4  is detached from the roll  6 , an end of each of the tines  24  is attached to the cross member  18  associated with the lead frame. The cross member  18  holds what will become the free ends of the tines  24  properly spaced apart until the tines are detached therefrom.  
      The lead frame  4  is shown in  FIGS. 4 and 5  detached from the roll  6  with the tines  24  thereof bent in preparation for mounting of the lead frame to a termination block base  28  shown in  FIG. 6 . When detached from the roll  6 , and ready for use, each lead frame  4  comprises four separate circuit portions, each circuit portion having one terminal connection pad  22  with one aperture therethrough, one tine  24  and one trace member  26  electrically couples the terminal connection pad and tine together. Each circuit portion is a unitary conductor with the terminal connection pad  22 , the tine  24  and the trace member  26  thereof being of one-piece construction.  
      As best illustrated in  FIG. 2 , the flat front face surface  8  of the tines  24  of the lead frame  4  have an end portion  56  coated with a highly conductive metal such as gold. The coated end portions  56  of the tines  24  of the lead frame  4  will be positioned when mounted to the termination block base  28  in generally parallel and planar alignment with each other for contact with the tines of a connector plug (not shown) when inserted into the termination block  2 . As illustrated in  FIG. 3 , the rear face surface  10  of the tines does not require such a coating since it will not be positioned to contact with the tines of the connector plug, thus saving on material and processing costs.  
      As illustrated in  FIGS. 4 and 5 , the tines  24  are bent to form a first bend  58  at about the location of their connection to the trace members  26 , and a second bend  59  spaced away from the coated end portions  56  of the tines. The  20  orientation of the tines  24  of the lead frame  4  with respect to the termination block base  28  is shown in  FIG. 6  prior to mounting of the lead frame to the termination block base.  
      As illustrated in  FIGS. 6,10  and  11 , the termination block base  28  has a rear face surface  60 , a front face surface  62 , and four side surfaces  64 ,  66 ,  68  and  70 . The rear face surface  60  of the termination block base  28  has coplanar mounting surface portions shaped similar to the terminal connection pads  22  and trace members  26  of the lead frame  4 . The mounting surface portions of the rear face surface  60  of the termination block base  28  corresponding to the terminal connection pads  22  are identified in  FIG. 6  by reference numeral  74 .  
      In  FIG. 7  the lead frame  4  is shown mounted to the termination block base  28 , with the front face surface  8  of the coplanar terminal connection pads  22  and trace members  26  of the lead frame engaging the correspondingly shaped coplanar mounting surface portions of the rear face surface  60  of the termination block base. The termination block base  28  has an aperture  71  opening in the rear face surface  60  positioned to receive therein the bent tines  24  of the lead frame  4  when mounted to the termination block base.  
      A termination block plug  50  is shown in  FIG. 7  in position for insertion into the aperture  71  of termination block base  28  after the bent tines  24  of the lead frame  4  are first inserted into the aperture. The plug  50  is shown fully inserted into the aperture  71  in  FIG. 8 . The plug  50  has a cover flange  94  arranged such that when the plug is inserted into the aperture  71 , the cover flange projects outward and covers portions of the trace members  26  extending away from the tines  24  toward the terminal connection pads  22 . The plug  50  also has four spaced apart tine channels  96  that each receives therein a portion of a different one of the tines  24  when the plug is inserted into the aperture  71 . When inserted, the plug  50  engages the tines  24  and presses them forward, which causes the free end portions thereof to engage a portion of the rear face surface  60  of the termination block base  28  adjacent to the aperture  71  and place the tine under a forwardly directed tension force.  
      The termination block base  28  has four screw holes  72  located at the mounting surface portions of the rear face surface  60  thereof with shapes similar to the terminal connection pads  22  of the lead frame  4 . The screw holes  72  coincide with the apertures of the terminal connection pads  22  and are sized to threadably receive screws  52  with screw heads  54  (shown in  FIG. 8  in position for insertion into the screw holes and in  FIG. 9  fully inserted). The screws  52  are used to secure wires from a telephone network (not shown) to the terminal connection pads  22  of the lead frame  4  in electrical connection therewith. The screw holes  72  extend through four tubular body portions  75  of the termination block base  28 .  
      The rear face surface  60  of the termination block base  28  further includes four raised supports  76 , one to an outward side of each mounting surface portion  74  corresponding to one of the terminal connection pads  22 , and a raised pad wall  78  to an inward side of each mounting surface portion corresponding to one of the terminal connection pads spaced apart to receive the terminal connection pad therebetween. The raised support  76  and the raised pad wall  78  protect the terminal connection pad  22  from contact by wires other than the one to be connected thereto.  
      The termination block base  28  also has indicia  80  at the rear face surface  60  adjacent to the terminal connection pads  22  to identify various colors of wire to be connected thereto according to telecommunication convention (e.g., red, yellow, green, and black). The screw heads  54  are also painted with different colors according to the telecommunication convention (e.g., red, yellow, green, and black) to facilitate proper identification of the wires to be connected to the terminal connection pads  22  by an installer of the termination block  2 .  
      The rear face surface  60  of the termination block base  28  also has raised wall portions  82  which extend along adjacent to the mounting surface portions of the rear face surface that correspond to the trace members  26  of the lead frame  4  to protect the trace members. When the plug  50  is inserted into the aperture  71 , the cover flange  94  of the plug extends over and above the portions of the raised wall portions  82  adjacent to the trace members  26  extending away from the tines  24  toward the terminal connection pads  22 .  
      The rear face surface  60  of the termination block base  28  also includes five parallel raised wall portions  86  defining four receiving areas therebetween. The raised wall portions  86  are positioned inward of the aperture  71  of termination block base  28  such that when the bent tines  24  of the lead frame  4  are inserted into the aperture each tine has a free end portion thereof positioned in the receiving area between a different pair of the adjacent raised wall portions  86 .  
      As noted above, the fully assembled termination block  2  is shown in  FIG. 9  from the rear. Front views of the fully assembled termination block  2  are shown in  FIGS. 10 and 11 . The front face surface  62  of the termination block base  28  includes an aperture  88  within which the coated end portions  56  of the tines  24  of the lead frame  4  will be positioned for contact with the tines of a connector plug (not shown) when inserted into the aperture  88 .  
      The termination block  2  will now be discussed with respect to its mounting to cover plates and brackets, and as to other aspects of its design. As shown in  FIGS. 9-11 , the termination block base  28  has a side wall  102  and a side wall  104  at opposite sides thereof. Each of the side walls  102  and  104  has an exterior surface  107  which in part defines the side surfaces  64  and  66 , respectively, of the termination block base  28 , and interior surface  108 . As shown in  FIG. 9 , the termination block base  28  has a pair of spaced apart, laterally extending block latch tabs  90  projecting outward from the exterior surface  107  of the side wall  102 , at locations toward the front face surface  62 , which are provided for mounting of the termination block  2  to a cover plate such as shown in  FIG. 12  or a bracket such as shown in  FIG. 17 , as will be described in greater detail below. The termination block base  28  has a recess  91  located between the block tabs  90 . As shown in  FIG. 10 , the termination block base  28  has a centrally positioned, laterally extending single block latch tab  98  projecting outward from the exterior surface  107  of the side wall  104 , at a location toward the front face surface  62 , and a pair of block latch recesses  100  in the exterior surface  107  of the side wall  104 , at a location toward the front face surface  62  with the block tab  98  positioned therebetween. The block tab  98  is also provided to mount the termination block  2  to a cover plate or bracket. The block recesses  100  are spaced apart by the same distance as the block tabs  90  and used when two termination block bases  28  are mounted side by side to a cover plate or bracket, as will be described below.  
      The side walls  102  and  104  of the termination block base  28  each terminate in an end wall surface  106  which in part defines the front face surface  62  of the termination block base  28  and are the most forward portions of the front face surface. The end wall surfaces  106  of the side walls  102  and  104  are coplanar and, as will be described below, engage the rear face of the cover plate or bracket to which the termination block  2  is mounted.  
      A single receptacle cover plate  110  is shown from its rear face in  FIG. 12  as having wall screw holes  112  for receiving screws to secure the single receptacle cover plate to a wall box (not shown). The receptacle cover plate  110  also includes a receptacle hole  114 , which when a termination block  2  is mounted to the receptacle cover plate, aligns with the aperture  88  of the termination block base  28  and permits insertion of a connector plug into the aperture  88  from the front face of the receptacle cover plate for contact with the tines  24  of the lead frame  4 .  
      The receptacle cover plate  110  has projecting outward from the rear face thereof a pair of spaced apart, laterally extending cover latch tabs  115 , each for releasably coupling with one of the pair of block tabs  90  of the termination block base  28  of the termination block  2  to be mounted to the receptacle cover plate, and a single laterally extending cover latch tab  116  for releasably coupling with the  20  single block tab  98  of the termination block base  28 . When snap fitted into place at the rear face of the receptacle cover plate  110 , with the block tabs  90  and  98  longitudinally inward of and lockably engaging the corresponding cover tabs  115  and  116 , engagement lips of the block tabs are positioned under opposing engagement lips of the corresponding cover tabs to hold the termination block base  28  in place against the rear face of the receptacle cover plate. The termination block base  28  of the termination block  2  is shown in  FIG. 13  positioned to be snap fitted into place at the rear face of the receptacle cover plate  110 , and is shown in  FIGS. 14 and 15  snap fitted into place. When the termination block base  28  is fully snap fitted into place with the cover tabs  115  engaging the block tabs  90  and the cover tab  116  engaging the block tab  98 , the end wall surfaces  106  of the side walls  102  and  104  of the termination block base engage the rear face of the receptacle cover plate. The front face of the receptacle cover plate  110  is shown in  FIG. 16  with the termination block base  28  fully snap fitted into place with the receptacle hole  114  of the receptacle cover plate aligned with the aperture  88  of the termination block base  28  of the termination block  2  mounted to the receptacle cover plate ready for insertion of a connector plug into the aperture  88  for contact with the tines  24  of the lead frame  4  of the termination block.  
      Also projecting outward from the rear face of the receptacle cover plate  110  are a pair of tab retainers  117 , each positioned laterally outward of one of the cover tabs  115  for securing the coupled connection of the cover tabs  115  with the block tabs  90 . The tab retainers  117  each have an L-shape with a longitudinally extending wall  117   a  and a laterally extending wall  117   b.    
      The longitudinally extending walls  117   a  of the tab retainers  117  are spaced apart to receive the side wall  102  of the termination block base  28  therebetween. When the termination block base  28  is mounted at the rear face of the receptacle cover plate by the cover tabs  115  coupling with the block tabs  90 , the longitudinally extending walls  117   a  trap the side wall  102  therebetween and thereby prevent laterally outward movement of the termination block base relative to the receptacle cover plate.  
      The laterally extending walls  117   b  are positioned to engage the interior surface  108  of the side wall  102  and prevent longitudinal inward movement of the block tabs  90  away from the cover tabs  115  should the receptacle cover plate  110  be longitudinally flexed. This prevents disengagement of the block tabs  90  from the corresponding cover tabs  115  should flexing occur that could otherwise longitudinally separate the block tabs  90  from the cover tabs  115  and cause the termination block base  28  to unintentionally be disconnected from the receptacle cover plate  110 .  
      The receptacle cover plate  110  also has projecting outward from its rear face a pair of tab retainers  118 , each positioned laterally outward of the single cover tab  116  for securing the coupled connection of the cover tab  116  with the single block tab  98 . The tab retainers  118  each have an L-shape with a longitudinally extending wall  118   a  and a laterally extending wall  118   b.    
      The longitudinally extending walls  118   a  of the tab retainers  117  are spaced apart to receive the side wall  104  of the termination block base  28  therebetween. When the termination block base  28  is mounted at the rear face of the receptacle cover plate by the cover tab  116  coupling with the block tab  98 , the longitudinally extending walls  118   a  trap the side wall  104  therebetween and thereby prevent laterally outward movement of the termination block base relative to the receptacle cover plate.  
      The laterally extending walls  118   b  are positioned to engage the interior surface  108  of the side wall  104  and prevent longitudinal inward movement of the block tab  98  away from the cover tab  116  should the receptacle cover plate  110  be longitudinally flexed. This prevents disengagement of the block tab  98  from the cover tab  116  should flexing occur that could otherwise longitudinally separate the block tab  98  from the cover tab  116  and cause the termination block base  28  to unintentionally be disconnected from the receptacle cover plate  110 .  
      In the past, the possibility of flexure of a receptacle cover plate causing disconnection of a termination block base often resulted in the welding or cementing of the termination block base to the receptacle cover, or use of a metal strap surrounding the termination block, and thereby increased manufacturing cost. The flexure can result from a blow to a connector plug inserted into the aperture of the termination block base.  
      A duplex or dual block bracket  120  is shown from its rear face in  FIG. 17  as having wall screw holes  122  for receiving screws to secure the dual block bracket to a wall box (not shown). The dual block bracket  120  is designed to have two of the termination blocks  2  described above mounted thereto. For clarity of description the two termination blocks will be referred to as first and second termination blocks  140  and  142  which are shown in  FIG. 20  mounted to the dual block bracket  120 . The dual block bracket  120  has first and second receptacle holes  124  and  125  which align with the apertures  88  of the termination block bases  28  of the first and second termination blocks  140  and  142  to permit insertion of a connector plug into each of the apertures  88  from the front face of the dual block bracket for contact with the tines  24  of the lead frame  4  of the termination block.  
      The termination block bases  28  of the first and second termination blocks  140  and  142  are shown in  FIG. 18  nested together end-to-end, as will be described in greater detail below, and positioned to be simultaneously snap fitted into place at the rear face of the dual block bracket  120 , and are shown in  FIGS. 19-22  snap fitted into place.  
      The first and second termination blocks  140  and  142  are brought into the nested end-to-end position by placing the side wall  102  of the termination block base  28  of the second termination block  142  against the side wall  104  of the termination block base  28  of the first termination block  140  as shown in  FIG. 18 . When in this position, the block tabs  90  of the termination block base  28  of the second termination block  142  project into the block latch recesses  100  in the exterior surface  107  of the side wall  104  of the termination block base  28  of the first termination block  140  such that the side wall  102  of the termination block base of the second termination block is positioned immediately adjacent to the side wall  104  of the termination block base of the first termination block. Also when in this position, engagement lips of the block tabs  90  of the termination block base  28  of the second termination block  142  are positioned under opposing engagement lips of the corresponding block latch recesses  100  of the termination block base  28  of the first termination block  140 . As will be described below, when the termination block bases  28  of the first and second termination blocks  140  and  142  are simultaneously snap fitted into place at the rear face of the dual block bracket  120 , the block tabs  90  of the termination block base  28  of the second termination block  142  are in latching engagement with the block latch recesses  100  of the termination block base  28  of the first termination block  140  to hold the termination block base of the second termination block, at the location of the side wall  102  thereof, in place against the rear face of the dual block bracket  120 . While the first and second termination blocks  140  and  142  are simultaneously snap fitted into place at the rear face of the dual block bracket  120 , the connection of each to the dual block bracket will now be separately described starting with the manner of mounting of the termination block base  28  of the first termination block to the dual block bracket.  
      As best seen in  FIG. 17 , the rear face of the dual block bracket  120  has a perimeter wall  123  projecting outward with spaced apart, longitudinally extending side walls  123   a  and  123   b  extending the length of the dual block bracket. A pair of spaced apart, laterally extending bracket tabs  126  projects outward from the rear face of the dual block bracket  120  toward one end of the dual block bracket, each for releasably coupling with one of the pair of block tabs  90  of the termination block base  28  of the first termination block  140 . A single laterally extending bracket tab  128  projects outward from the rear face of the dual block bracket  120  toward the middle of the dual block bracket for releasably coupling with the single block tab  98  of the termination block base  28  of the first termination block  140 . When the first termination block  140  is snap fitted into place at the rear face of the dual block bracket  120 , with the block tabs  90  and  98  longitudinally inward of and lockably engaging the corresponding bracket tabs  126  and  128 , engagement lips of the block tabs are positioned under opposing engagement lips of the corresponding bracket tabs to hold the termination block base  28  of the first termination block  140  in place against the rear face of the dual block bracket.  
      When the termination block base  28  of the first termination block  140  is snap fitted into place with the bracket tabs  126  engaging the block tabs  90  and the bracket tab  128  engaging the block tab  98 , the end wall surfaces  106  of the side walls  102  and  104  of the termination block base engage the rear face of the dual block bracket  120 .  
      Also projecting outward from the rear face of the receptacle cover plate  110  are a pair of laterally extending tab retainers  132 , each positioned laterally outward of one of the bracket tabs  126  for securing the coupled connection of the bracket tabs  126  with the block tabs  90 . The longitudinally extending side walls  123   a  and  123   b  of the dual block bracket  120 , in the vicinity of the tab retainers  132 , are spaced apart to receive the side wall  102  of the termination block base  28  of the first termination block  140  therebetween. When the termination block base  28  of the first termination block  140  is mounted at the rear face of the dual block bracket  120  by the bracket tabs  126  coupling with the block tabs  90 , the longitudinally extending side walls  123   a  and  123   b  trap the side wall  102  therebetween and thereby prevent laterally outward movement of the termination block base relative to the dual block bracket.  
      The laterally extending tab retainers  132  are positioned to engage the interior surface  108  of the side wall  102  of the termination block base  28  of the first termination block  140  and prevent longitudinal inward movement of the block tabs  90  away from the bracket tabs  126  should the dual block bracket  120  be longitudinally flexed. This prevents disengagement of the block tabs  90  from the corresponding bracket tabs  126  should flexing occur that could otherwise longitudinally separate the block tabs  90  from the bracket tabs  126  and cause the termination block base  28  to unintentionally be disconnected from the dual block bracket  120 .  
      The dual block bracket  120  also has projecting outward from its rear face a pair of tab retainers  133 , each positioned laterally outward of the single bracket tab  128  toward the middle of the dual block bracket for securing the coupled connection of the bracket tab  128  with the single block tab  98  of the termination block base  28  of the first termination block  140 , and as will be described below, also for securing the coupled connection of the block tabs  90  of the termination block base  28  of the second termination block  142  with the block latch recesses  100  of the termination block base of the first termination block  140 . The tab retainers  133  each have a U-shape oriented opening laterally inward with a pair of spaced apart, laterally extending walls  134  and  136 , and a longitudinally extending wall  135 .  
      The longitudinally extending walls  135  of the tab retainers  133  are spaced apart to receive the side wall  104  of the termination block base  28  of the first termination block  140  therebetween. When the termination block base  28  of the first termination block  140  is mounted at the rear face of the dual block bracket  120  by the bracket tab  128  coupling with the block tab  98 , the longitudinally extending walls  135  trap the side wall  104  therebetween and thereby prevent laterally outward movement of the termination block base relative to the dual block bracket.  
      The laterally extending walls  134  of the tab retainers  133  are positioned to engage the interior surface  108  of the side wall  104  of the termination block base  28  of the first termination block  140  and prevent longitudinal movement of the block tab  98  away from the bracket tab  128  should the dual block bracket  120  be longitudinally flexed. This prevents disengagement of the block tab  98  from the bracket tab  128  should flexing occur that could otherwise longitudinally separate the block tab  98  from the bracket tab  128  and cause the termination block base  28  of the first termination block  140  to unintentionally be disconnected from the dual block bracket  120 .  
      The manner of mounting of the termination block base  28  of the second termination block  142  to the dual block bracket  120  will now be described. A single laterally extending bracket tab  130  projects outward from the rear face of the dual block bracket  120  toward the end of the dual block bracket away from the bracket tabs  126  for releasably coupling with the block tab  98  of the termination block base  28  of the second termination block  142 . As previously described, when the first and second termination blocks  140  and  142  are brought into the nested end-to-end position for simultaneous snap fitting into place at the rear face of the dual block bracket  120 , the block tabs  90  of the termination block base  28  of the second termination block  142  project into the block latch recesses  100  in the exterior surface  107  of the side wall  104  of the termination block base  28  of the first termination block  140 . The block tabs  90  of the termination block base  28  of the second termination block  142  are in latching engagement with the block latch recesses  100  in the exterior surface  107  of the side wall  104  of the termination block base  28  of the first termination block  140  for releasably coupling with the block tabs  90  of the termination block base of the second termination block to the block latch recesses  100  of the termination block base of the first termination block. As such, the termination block base  28  of the first termination block  140  is held in place against the rear face of the dual block bracket  120  by the bracket tabs  126  and  128 , and the termination block base  28  of the second termination block  142  is held in place against the rear face of the dual block bracket  120  by the bracket tab  130  and the block latch recesses  100 .  
      The recess  91  in the termination block base  28  of the second termination block  142 , located between the block tabs  90  thereof, is sufficiently large to receive therein the bracket tab  128  and thereby allow the side wall  102  of the termination block base  28  of the second termination block  142  to be positioned immediately adjacent to the side wall  104  of the termination block base  28  of the first termination block  140 , as can be seen in  FIG. 19 . This flush mounting of the two termination block bases without space therebetween is also facilitated by utilizing the block latch recesses  100  in the first termination block  140  to lockably receive the block tabs  90  of the second terminal block  142  rather than utilizing a set of bracket tabs, such as the bracket tabs  126  used to engage the block tabs  90  of the first terminal block. The resulting dual block bracket  120  has a shortened length than prior dual block bracket designs.  
      When the second termination block  142  is snap fitted into place at the rear face of the dual block bracket  120 , with the block tabs  90  and  98  lockably engaging the corresponding block latch recesses  100  of the first termination block  142  and the bracket tab  130 , respectively, engagement lips of the block tabs are positioned under opposing engagement lips of the corresponding block latch recesses of the first termination block and the bracket tab  130  to hold the termination block base  28  of the second termination block  142  in place against the rear face of the dual block bracket.  
      When the termination block base  28  of the second termination block  142  is snap fitted into place with the block tabs  90  engaging the block latch recesses  100  of the first termination block  140  and the bracket tab  128  engaging the block tab  98 , the end wall surfaces  106  of the side walls  102  and  104  of the termination block base engage the rear face of the dual block bracket  120 . In  FIG. 21 , the first and second termination blocks  140  and  142  are shown with wires  200  of telephone network cables  202  and  204 , respectively, attached to the terminal connection pads  22  of the lead frames  4  of the termination blocks using the screws  52 .  
      As noted above, the tab retainers  133  of the dual block bracket  120  are provided for also securing the coupled connection of the block tabs  90  of the termination block base  28  of the second termination block  142  with the block latch recesses  100  of the termination block base of the first termination block  140 . The longitudinally extending walls  135  of the tab retainers  133  are spaced apart to receive the side wall  102  of the termination block base  28  of the second termination block  142  therebetween. When the termination block base  28  of the second termination block  142  is mounted at the rear face of the dual block bracket  120  by the block tab  98  coupling with the block latch recesses  100  of the first termination block  140 , the longitudinally extending walls  135  trap the side wall  102  therebetween and thereby prevent laterally outward movement of the termination block base relative to the dual block bracket.  
      The laterally extending walls  136  of the tab retainers  133  are positioned to engage the interior surface  108  of the side wall  102  of the termination block base  28  of the second termination block  142  and prevent longitudinal movement of the block tabs  90  away from the block latch recesses  100  of the first termination block  140  should the dual block bracket  120  be longitudinally flexed. This prevents disengagement of the block tabs  90  from the block latch recesses  100  of the first termination block  140  should flexing occur that could otherwise longitudinally separate the block tabs from the block latch recesses of the first termination block and cause the termination block base  28  of the second termination block  142  to unintentionally be disconnected from the dual block bracket  120 .  
      As for the receptacle cover plate  110  discussed above, in the past the possibility of flexure of a dual block bracket causing disconnection of the termination block bases of the termination blocks often resulted in the welding or cementing of the termination block bases to the dual block bracket, or use of a metal strap surrounding the termination blocks, and thereby increased manufacturing cost.  
      The front face of the dual block bracket  120  is shown in  FIG. 22  with the termination block bases  28  of the first and second termination blocks  140  and  142  fully snap fitted into place with the receptacle holes  124  and  125  of the dual block bracket aligned with the apertures  88  of the termination block bases of the first and second termination blocks mounted to the dual block bracket ready for insertion of a connector plug into each of the apertures  88  for contact with the tines  24  of the lead frame  4  of the termination block.  
      The termination block  2  includes a pair of hooked shaped screw retainers  92  projecting rearward from the rear face surface  60  of the termination block base  28  which, during shipment of the termination block, each may hold a screw  146  as illustrated in  FIG. 23 . For the dual block bracket  120  shown in  FIG. 23  with the first and second termination blocks  140  and  142  attached thereto, only the second termination block is provided with the two screws  146  needed for insertion through the wall screw holes  122  to secure the dual block bracket  120  to a wall box (not shown). The screw retainers  92  of the first termination block  140  remain empty. While not illustrated for a single receptacle cover plate  110 , the two screw retainers  92  of the single termination block  2  shown in  FIG. 12  may hold the two screws  146  needed for insertion through the wall screw holes  112  to secure the single receptacle cover plate to a wall box (not shown).  
      The screws  146  may be easily removed at the time of installation of the termination block  2  and, as noted above, used to fasten the receptacle cover plate  110  or dual block bracket  120  to a wall box. After the screws  146  are removed from the screw retainers  92 , the telephone network cables  202  and  204  can be pushed under and retained by the screw retainers  92  as shown in  FIG. 21  for the dual block bracket  120 . Thus, the screw retainers  92  can serve a second purpose as cable strain reliefs upon installation of the termination blocks  2 .  
      As illustrated in  FIG. 24 , the termination blocks  2  may be stacked one above the other for shipment and storage without damage. This is accomplished because the four raised supports  76  of the rear face surface  60  of the termination block base  28  of each termination block  2  are positioned to engage and support the end wall surfaces  106  of the side walls  102  and  104  of another termination block base stacked thereabove. Their combined lengths provide sufficient standoff to prevent the screws  52  of the bottom one from contacting the termination block above it. This prevents the color marking paint applied to the screw heads  54  of the screw  52  from being damaged.  
      From the foregoing it will be appreciated that, although specific embodiments of the invention have been described herein for purposes of illustration, various modifications may be made without deviating from the spirit and scope of the invention. Accordingly, the invention is not limited except as by the appended claims.