Abstract:
A terminal block allows wires to be connected to the block by insertion at a front portion of the block and along a direction parallel to the length of the block. The block includes a securing feature to retain the electrical conductor securely in the block while also allowing simplified connection and disconnection of the wire.

Description:
PRIORITY APPLICATION 
       [0001]    This application claims the benefit of priority under 35 U.S.C. §119 of U.S. Provisional Application Ser. No. 61/896,960, filed on Oct. 29, 2013, the content of which is relied upon and incorporated herein by reference in its entirety. 
     
    
     BACKGROUND 
       [0002]    The disclosure relates to electrical terminal blocks, and more particularly to methods and hardware adapted to efficient connection of electrical conductors with electrical terminal blocks. 
         [0003]      FIG. 1  illustrates a conventional terminal block having front connection access. In this terminal block, an electrical conductor terminated by a ring lug is secured to the block by a screw. The terminal electrical conductor is held securely because the screw passes through the ring lug and actually threads into the block. Drawbacks to this solution are that the screws are loose and may become lost, and that the loose screws must be held and manually aligned with the ring lug while threading into the block. Another drawback is that the electrical conductor is difficult to connect in tight spaces because the electrical conductors extend perpendicular to the face of the terminal block. It is therefore difficult for a technician to hold the electrical conductor while at the same time holding a screwdriver and advancing a screw into the block. 
         [0004]      FIG. 2  illustrates another conventional terminal block having front attachment access and in which the electrical conductor is aligned with the direction of insertion. In this example, the electrical conductor is inserted into an aperture, and a thread is advanced to press a plate against the exposed metallic conductor of the electrical conductor. The plate, however, holds the electrical conductor in the block by friction and the electrical conductor may disengage the block when the electrical conductor is in tension. 
       SUMMARY 
       [0005]    One embodiment is addressed to a terminal block, comprising a housing having a front face, a receiving aperture at the front face adapted to receive a connection portion of a metallic conductor, an actuator member mounted in the housing so as to be translatable therein, a cam member mounted within the housing and configured to be pivoted about a pivot in response to translation of the actuator member, and a resilient member mounted within the housing and having a bias arm positioned to be moved toward and away from the connection portion of the conductor positioned within the receiving aperture. The resilient member may include a projection mounted on the bias arm configured to engage an aperture on the conductor positioned within the housing. 
         [0006]    A further embodiment includes a method of connecting an electrical conductor having a connection portion to a terminal block comprising a housing, a receiving aperture adapted to receive the connection portion, an actuator member mounted in the housing so as to be translatable therein, a cam member configured to be pivoted about a pivot in response to translation of the actuator member, and a resilient member mounted within the housing and having a bias arm with a projection thereon. The conductor is inserted into the receiving aperture, and the actuator member is advanced through the housing, wherein the actuator pivots the cam member as the actuator advances, and the cam member moves the resilient member so that the projection engages an aperture in the connection portion to secure the electrical conductor in the terminal block. 
         [0007]    Additional features and advantages will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the embodiments as described herein, including the detailed description which follows, the claims, as well as the appended drawings. 
         [0008]    It is to be understood that both the foregoing general description and the following detailed description are merely exemplary, and are intended to provide an overview or framework to understanding the nature and character of the claims. The accompanying drawings are included to provide a further understanding, and are incorporated in and constitute a part of this specification. The drawings illustrate one or more embodiment(s), and together with the description serve to explain principles and operation of the various embodiments. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  illustrates a conventional terminal block having front connection access. 
           [0010]      FIG. 2  illustrates a conventional terminal block having front connection access. 
           [0011]      FIG. 3A  illustrates a terminal block having front connection access according to a first embodiment in which an electrical conductor is not yet secured in the block. 
           [0012]      FIG. 3B  illustrates the terminal block of  FIG. 3A  in which the electrical conductor is secured in the block. 
           [0013]      FIG. 4A  is a section view of the terminal block of  FIG. 3A  taken on line  4 A- 4 A. 
           [0014]      FIG. 4B  is a section view of the terminal block of  FIG. 3B  taken on line  4 B- 4 B. 
       
    
    
     DETAILED DESCRIPTION 
       [0015]    Reference will now be made in detail to the present preferred embodiment(s), examples of which are illustrated in the accompanying drawings. Whenever possible, the same reference numerals will be used throughout the drawings to refer to the same or like parts. 
         [0016]      FIG. 3A  illustrates a terminal block  10  having front connection access according to a first embodiment. In  FIG. 3A , an electrical conductor  14  is not yet secured in the block. The electrical conductor  14  is terminated at a connection portion  20  in the form of a ring lug having a lug aperture  22 . The terminal block  10  has a housing  30  having a front face formed by a wall  34 , a top wall  38 , a first side wall  42 , a second side wall  44  spaced from the first side wall  42 , and a bottom wall  48 . The walls  34 ,  38 ,  42 ,  44 ,  48  are illustrated as forming five sides of a parallelepipedal, generally rectangular six-sided solid, but one or more faces of the terminal block  10  may be oriented at relative angles of other than 90 degrees. A receiving aperture  50  in the front wall  34  receives the connection portion  20  for physically and electrically connecting the electrical conductor  14  to the terminal block  10 . 
         [0017]    A connection lug  54  is disposed within the housing  30  and serves to secure the ring lug  20  to the connection block  10 . Referring to  FIG. 3B , the connection lug  54  (shown in in  FIG. 3A ), is connected to a resilient spring arm  58  that deflects so as to position the connection lug  54  within the lug aperture  22 . The spring arm  58  is deflected by turning a threaded actuator member  60  that is accessible at the front wall  34 . The details of the terminal block  10  and the manner in which the electrical conductor  14  is connected to the block  10  are described in further detail below with reference to  FIGS. 4A and 4B . 
         [0018]      FIG. 4A  is a section view of the terminal block  10  of  FIG. 3A  taken on line  4 A- 4 A, before the electrical conductor  14  is secured in the block  10 . The threaded actuator member  60  is accommodated within a passage  64  in the terminal block  10 , at an orientation generally parallel to a long axis  66  of the terminal block  10 , generally perpendicular to the front wall  34 , and parallel to the top wall  38 , the side walls  42 ,  44 , and the bottom wall  48 . The actuator member  60  threads into a female threaded section  68  that is secured within the housing  30 . 
         [0019]    In  FIG. 4A , the connection lug  54  is not engaged with the aperture  22  in the ring lug  20 , so that the electrical conductor  14  is not connected to the terminal block  10 . In the unconnected state the actuator member  60  has not been advanced into the housing  30  so as to pivot the cam member  70  and thus move the connection lug  54  into the aperture  22 . As the actuator member  60  is threaded into the aperture  68  to secure the conductor  14  in the connection block  10 , the end of the actuator member  60  translates along the long axis  66  of the housing  30  and comes into engagement with the cam member  70 . The cam member  70  is pivotable about a pivot  72  so that as the actuator member  60  translates along the axis  66 , the cam member  70  pivots away from the front wall  34  and downward toward the bottom wall  48 . The spring arm  58  has a bias arm  74  that contacts and biases the cam member  70  to remain in contact with the actuator member  60 . Threading the actuator member  60  into the aperture  68  opposes the spring arm  58  bias so as to force the connection lug  54  into the lug aperture  22 . The bias arm  74  also supports the connection lug  54 . 
         [0020]      FIG. 4B  is a section view of the terminal block of  FIG. 3B  taken on line  4 B- 4 B.  FIG. 4B  illustrates the terminal block in its connected state, where the electrical conductor  14  is secured in place due to the connection lug  54  extending through the ring lug aperture  22 , as well as by friction between the spring arm  58  and the ring lug  20 . 
         [0021]    Referring to  FIGS. 4A and 4B , a method for connecting the electrical conductor  14  to the connection block  10  will be described. Referring to  FIG. 4A , the electrical conductor  14  is inserted into the receiving aperture  50 , along a direction generally parallel to the axis  66 , so that the lug aperture  22  is in position to receive the connection lug  54 . The receiving aperture  50  can terminate in a stop  76  against which the ring lug  20  abuts when the electrical conductor  14  is in its connection position. In this position, the cam member  70  is biased against a cam stop  78  by the bias arm  74 , and the connection lug  54  is out of the path of the ring lug  20  so that the connection ring lug  20  can be introduced fully into the receiving aperture  50 . 
         [0022]    Referring to  FIG. 4B , the actuator member  60  is threaded into the female threaded section  68  until it contacts and acts to pivot the cam member  70  about the pivot  72 . As the cam member  70  pivots, it in turn causes the bias arm  74  to pivot towards a fixed, base portion  82  of the spring arm  58 . The bias arm  74  pivots about a resilient bend  86  connecting the two portions  74 ,  82 . The travel of the actuator member  60  and the cam member  70  may be configured to not only move the connection lug  54  through the ring lug aperture  22 , but to also press the bias arm  74  down tightly onto the ring lug  20  so that it is securely fixed between the bias arm  74  and the base portion  82  of the spring arm  58 . As shown in  FIG. 4B , the connection lug  54  extends down into the base portion  82 . The base portion  82  can include, for example, a recessed portion, or an aperture, that allows the connection lug  54  to extend partially into or wholly through the base portion  82 . The base portion  82  can be fixed to, for example, the bottom wall  48 , or fixed relative to some other section of the housing  30 . 
         [0023]    To disconnect the electrical conductor from the terminal block  10 , the actuator member  60  is withdrawn out of the passage  64  so that the cam member  70  pivots away from the ring lug  20  under action of the spring arm  58  bias, causing the connection lug  54  to disengage from the ring lug aperture  22 . The electrical conductor  14  can then be pulled from the receiving aperture  50  in a direction generally parallel to the long axis  66  of the connection block  10 . 
         [0024]    According to one aspect of the the present embodiments, the connection block  10  may be an electrical connection device intended to electrically connect the electrical conductor  14  to another component, system, hardware, or other electrically conductive infrastructure. In this embodiment, the electrical conductor  14  may be an insulated electrical conductor, and the spring arm  58  can be formed from a resilient and/or deformable electrical conductor such as a metal. Examples of suitable metallic materials include, copper, steel, aluminum, other metals, and alloys thereof. 
         [0025]    The spring arm  58  can terminate at a connection pin  90  configured to plug into a larger component, system, or hardware, so as to be electrically connected to the conductor  14  through the connection block  10 . A second pin  92  may be included and may or may not be electrically coupled to the spring arm  58 . One or both of the pins  90 ,  92  may protrude from the bottom wall  48 , or another wall of the housing  30 . The housing  30 , as well as the cam member  70 , may be formed from electrically insulative materials such as plastics or other polymers so as to prevent current flow through the housing. The housing  30  has a generally rectangular parallelepipedal shape, but other geometric forms may be used. 
         [0026]    In this specification, the term “pivot” is not to be construed to mean only circular motion. Other forms of rotational motion, including general curvilinear motions, are encompassed by the term. For example, the bias arm  74  pivots in response to the bias of the cam member  70 , but its motion will not describe a perfect circular arc, and will instead undergo a general curvilinear motion. 
         [0027]    Unless otherwise expressly stated, it is in no way intended that any method set forth herein be construed as requiring that its steps be performed in a specific order. Accordingly, where a method claim does not actually recite an order to be followed by its steps or it is not otherwise specifically stated in the claims or descriptions that the steps are to be limited to a specific order, it is no way intended that any particular order be inferred. 
         [0028]    It will be apparent to those skilled in the art that various modifications and variations can be made without departing from the spirit or scope of the invention. Since modifications combinations, sub-combinations and variations of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and their equivalents.