Patent Document

CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 61/143,031, filed on Jan. 7, 2009, the specification of which is incorporated by reference herein in its entirety for all purposes. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates generally to connecting connectors to coaxial cable. More particularly, the present invention relates to an installation tool for connecting a coaxial cable to a connector. 
         [0003]    It has long been known to use connectors to terminate coaxial cable so as to connect a cable to various electronic devices such as televisions, radios and the like. Prior art coaxial connectors generally include a connector body having an annular collar for accommodating a coaxial cable, an annular nut rotatably coupled to the collar for providing mechanical attachment of the connector to an external device and an annular post interposed between the collar and the nut. A resilient sealing O-ring may also be positioned between the collar and the nut at the rotatable juncture thereof to provide a water resistant seal thereat. The collar includes a cable receiving end for insertably receiving an inserted coaxial cable and, at the opposite end of the connector body, the nut includes an internally threaded end extent permitting screw threaded attachment of the body to an external device. 
         [0004]    This type of coaxial connector further typically includes a locking sleeve to secure the cable within the body of the coaxial connector. The locking sleeve, which is typically formed of a resilient plastic, is securable to the connector body to secure the coaxial connector thereto. In this regard, the connector body typically includes some form of structure to cooperatively engage the locking sleeve. Such structure may include one or more recesses or detents formed on an inner annular surface of the connector body, which engages cooperating structure formed on an outer surface of the sleeve. A coaxial cable connector of this type is shown and described in commonly owned U.S. Pat. No. 6,530,807. 
         [0005]    Conventional coaxial cables typically include a center conductor surrounded by an insulator. A conductive foil is disposed over the insulator and a braided conductive shield surrounds the foil covered insulator. An outer insulative jacket surrounds the shield. In order to prepare the coaxial cable for termination, the outer jacket is stripped back exposing an extent of the braided conductive shield which is folded back over the jacket. A portion of the insulator covered by the conductive foil extends outwardly from the jacket and an extent of the center conductor extends outwardly from within the insulator. 
         [0006]    Upon attachment with a connector, a coaxial cable is inserted into the cable receiving end of the connector body, wherein the annular post is forced between the foil covered insulator and the conductive shield of the cable. In this regard, the post is typically provided with a radially enlarged barb to facilitate expansion of the cable jacket. The locking sleeve is then moved axially into the connector body to clamp the cable jacket against the post barb providing both cable retention and a water-tight seal around the cable jacket. The connector can then be attached to an external device by tightening the internally threaded nut to an externally threaded terminal or port of the external device. 
         [0007]    Various installation tools to facilitate the assembly of a coaxial cable to a connector are known in the art. Commonly used prior art installation tools are typically hand-held devices resembling pliers that provide the necessary force for driving the locking sleeve in order to lock the cable to the connector. When the handles of such tools are squeezed together, a jaw mechanism of the tool typically pushes or inserts the locking sleeve of the connector into the connector body to secure the cable in the connector. However, this requires prior manual insertion of a prepared end of the cable into engagement with the tubular post contained within the connector body. Since the post expands the coaxial cable braid, some level of force is required on the part of the installer in order to fully insert the cable to its proper position within the connector body for proper connector compression/installation. Also, ensuring that the cable is inserted the precise required distance into the connector is further problematic with such manual assembly. 
         [0008]    Accordingly, it is desirable to provide an installation tool that simplifies the coaxial cable to connector assembly process. It is further desirable to provide a cable installation tool that exerts the necessary forces to both install the cable an exact distance into the connector and also to compress the locking sleeve in one application. 
       OBJECTS AND SUMMARY OF THE INVENTION 
       [0009]    It is an object of the present invention to provide a tool for assembling a coaxial cable to a connector. 
         [0010]    It is a further object of the present invention to provide a coaxial cable installation tool having structure to exert the necessary forces to both install the cable an exact distance into the connector and also to compress the locking sleeve of the connector in one application. 
         [0011]    In the efficient attainment of these and other objects, the present invention provides a coaxial cable installation tool. The installation tool of the present invention generally includes a front jaw assembly adapted to retain a cable connector and a back jaw assembly movably coupled to the front jaw assembly. The cable connector includes a connector body and a compression sleeve and the back jaw assembly is adapted to insert an end of the cable into the cable connector upon movement of the back jaw assembly toward the front jaw assembly and subsequently press the compression sleeve into the connector body upon further movement of the back jaw assembly toward the front jaw assembly. 
         [0012]    In a preferred embodiment, the front jaw assembly of the cable installation tool includes an actuator shaft extending in a rearward direction toward the back jaw assembly, wherein the back jaw assembly is traversable along the actuator shaft. The actuator shaft preferably includes a shaft body and a radially enlarged cam portion, wherein the cam portion causes the back jaw assembly to grip the cable as the back jaw assembly traverses over the cam portion, and wherein the back jaw assembly releases the cable as the back jaw assembly traverses over the shaft body toward the front jaw assembly. 
         [0013]    The actuator shaft further preferably includes a ramped surface between the shaft body and the cam portion for facilitating smooth engagement of the cam portion with the back jaw assembly as the back jaw assembly traverses over the cam portion. Also, the shaft body and the enlarged cam portion are preferably circular in cross-section. 
         [0014]    The front jaw assembly further preferably includes a U-shaped pocket for receiving the connector body and a flange extending into the pocket for engaging the connector body to prevent axial movement of the connector body in the tool. 
         [0015]    The back jaw assembly preferably includes a gripper mechanism movably engaged with the actuator shaft. The gripper mechanism closes to grip the cable when the gripper mechanism is engaged with the cam portion of the actuator shaft, and opens to release the cable when the gripper mechanism is not engaged with the cam portion of said actuator shaft. 
         [0016]    The gripper mechanism preferably includes a pair of gripper arms pivotably connected to the back jaw assembly. The gripper arms form a closable cable gripping mouth at one end thereof for gripping the cable and a closable actuator shaft opening at an opposite end thereof for engagement with the cam portion of the actuator shaft. The gripper arms are preferably spring-biased and the actuator shaft opening is preferably at least partially surrounded by a chamfered surface for facilitating smooth engagement with the cam portion of the actuator shaft. The closable actuator shaft opening of the gripper arms has an axial depth, which, together with the axial length of the radially enlarged cam portion of the actuator shaft, matches the desired depth of cable insertion into the connector. 
         [0017]    The back jaw assembly further preferably includes a cable receiving pocket for receiving the cable and an actuator shaft aperture for receiving the actuator shaft. In addition, the back jaw assembly further preferably includes a forward face facing the front jaw assembly for pressing the compression sleeve into the connector body. 
         [0018]    The cable installation tool of the present invention further preferably includes a pair of pivotably connected handles connected to the front jaw assembly and the back jaw assembly for moving the front jaw assembly and the back jaw assembly together and apart. 
         [0019]    The present invention further involves a method for installing an end of a cable into a connector. The method generally includes the steps of retaining a cable connector in a front jaw assembly of a cable installation tool, inserting the end of the cable into the connector body, gripping the cable with a back jaw assembly of the cable installation tool upon initial movement of the back jaw assembly toward the front jaw assembly, further inserting the cable into the connector body upon further movement of the back jaw assembly toward the front jaw assembly, releasing the cable from the back jaw assembly upon further movement of the back jaw assembly toward the front jaw assembly and pressing the compression sleeve into the connector body with the back jaw assembly by further moving the back jaw assembly toward the front jaw assembly thereby securing the cable in the connector. 
         [0020]    A preferred form of the coaxial cable installation tool, as well as other embodiments, objects, features and advantages of this invention, will be apparent from the following detailed description of illustrative embodiments thereof, which is to be read in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0021]      FIG. 1  is a top front perspective view of a preferred embodiment of the coaxial cable installation tool formed in accordance with the present invention. 
           [0022]      FIG. 1   a  is a side view of the coaxial cable installation tool shown in  FIG. 1  in a hand-tool configuration. 
           [0023]      FIG. 1   b  is a side view of the coaxial cable installation tool shown in  FIG. 1  in a bench-top tool configuration. 
           [0024]      FIG. 2  is a front plan view of the tool shown in  FIG. 1  with the cable and connector ready for installation. 
           [0025]      FIG. 3  is a cross-sectional view of the tool shown in  FIG. 2 . 
           [0026]      FIG. 4  is a front plan view of the tool shown in  FIG. 1  with the cable inserted half way into the connector. 
           [0027]      FIG. 5  is a cross-sectional view of the tool shown in  FIG. 4 . 
           [0028]      FIG. 6  is a front plan view of the tool shown in  FIG. 1  with the cable fully inserted into the connector. 
           [0029]      FIG. 7  is a cross-sectional view of the tool shown in  FIG. 6 . 
           [0030]      FIG. 8  is a front plan view of the tool shown in  FIG. 1  with the connector sleeve compressed and the connector installation complete. 
           [0031]      FIG. 9  is a cross-sectional view of the tool shown in  FIG. 8 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0032]    Referring to the drawings, a preferred embodiment of the coaxial cable installation tool  10  of the present invention is shown. The tool  10  generally includes a front jaw assembly  12  movably coupled to a back jaw assembly  14 . It is to be noted that the drawings show only the front jaw assembly  12  and the back jaw assembly  14  of the tool  10 . The actuating mechanism for driving the jaw assemblies  12  and  14  together and apart is not shown in the detailed drawings of  FIGS. 1-9 . Such actuating mechanism can include conventional handles  60  for a hand-tool configuration, as shown in  FIG. 1   a , or a lever or a powered source  62 , (such as a hydraulic cylinder or an electromechanical drive), for a bench-top tool configuration, as shown in  FIG. 1   b.    
         [0033]    The front jaw assembly  12  includes a front jaw member  16  and an actuator shaft  18  fixed to the front jaw member. The front jaw member  16  is formed with a U-shaped pocket or receptacle  20  sized to receive the connector body  100  of a coaxial cable connector  102 . The front jaw member  16  is further formed with an inwardly directed flange  22  surrounding the forward periphery of the connector pocket  20 . The inwardly directed flange  22  is received within a groove  104  formed in the connector body  100  during use. Specifically, when the connector  102  is placed in the connector pocket  20  of the front jaw member  16 , the flange  22  engages the groove  104  to prevent any axial movement of the connector body  100  with respect to the front jaw assembly  12 . 
         [0034]    The actuator shaft  18  extends from a rear face  24  of the front jaw member  16  and is received in an actuator shaft aperture  26  formed in the back jaw assembly  14 . The actuator shaft  18  can be an integral part of the front jaw member  16 , or it can be a separate part fixed to the front jaw member in a conventional manner. In either case, the actuator shaft  18  remains stationary with respect to the front jaw member  16  during use. 
         [0035]    As shown in  FIGS. 2-9 , the actuator shaft  18  includes a shaft body  27  and a radially enlarged cam portion  28  disposed adjacent the rearward end of the actuator shaft, the function of which will be discussed in further detail below. The radially enlarged cam portion  28  has a diameter or width larger than the shaft body  27  and preferably includes ramped surfaces  29  at its forward and rearward extents. The ramped surfaces  29  provide a smooth transition between the outer surface of the actuator shaft body  27  and the radially enlarged cam portion  28 , as will be described in further detail below. The shaft body  27  and the cam portion  28  shown in the drawings have circular cross-sections, but other cross-sectional shapes are conceivable. 
         [0036]    The back jaw assembly  14  includes a back jaw member  30  and a gripper mechanism  31  attached thereto for alternately gripping and releasing a cable  106  during installation in a connector  100 . The gripper mechanism  31  can take various forms, but preferably includes a pair of opposing gripper arms  32  pivotably attached to a rear face  34  of the back jaw member. The back jaw member  30  is formed with a U-shaped cable receiving pocket  36 , as well as the actuator shaft aperture  26  mentioned above. The cable receiving pocket  36  is sized to receive a coaxial cable  106  and the actuator shaft aperture  26  is positioned below the cable receiving pocket and is sized to receive the cam portion  28  of the actuator shaft  18 . Sufficient clearance is provided between the cable receiving pocket  36  and the cable  106  and between the actuator shaft aperture  26  and the cam portion  28  of the actuator shaft  18  to permit the back jaw assembly  14  to translate forward along the cable and the actuator shaft toward the front jaw assembly  12  during use, as will be described in further detail below. 
         [0037]    The gripper arms  32  may be pivotably attached to the rear face  34  of the back jaw member  30  via pins  38  fixed in the back jaw member. Each gripper arm  32  includes a cable engagement end  40  and an opposite cam engagement end  42  with a pin  38  disposed therebetween. As a result, when the gripper arm  32  pivots about the pin  38 , the cable engagement end  40  moves in one of an inward or outward direction and the opposite cam engagement end  42  moves in the opposite inward or outward direction. 
         [0038]    The inner surface of the cable engagement end  40  of each gripper arm  32  is formed with a notch  43  to grip one side of the cable  106  during use. The notches  43  of each gripper arm  32  are preferably provided with a serrated or other textured surface  44  to enhance gripping of the cable  106 . The gripper arms  32  are attached to the back jaw member  30  such that the notches  43  at the cable engagement ends  40  are positioned facing each other on opposite sides of the cable receiving pocket  36  of the back jaw member. In this manner, the notches  43  together form a closable mouth  46  to grip the cable  106 . 
         [0039]    The gripper arms  32  are further preferably spring-biased about the pivot pins  38  to urge the cable engagement ends  40  apart, whereby the closable mouth  46  is normally maintained in an open position to receive a cable  106  during use. Such biasing force can be provided, for example, by a tension spring  64  connected between the gripper arms  32 , as shown in  FIG. 2 . 
         [0040]    The inner face of the opposite cam engagement end  42  of each gripper arm  32  is formed with a semi-circular recess  48  that engages the actuator shaft  18 . The recesses  48  of the gripper arms  32  face each other to form a circular opening  50  through which the actuator shaft traverses during use. The recesses  48  are preferably surrounded by chamfered surfaces  52  formed in the forward and rearward faces of the gripper arms  32 , which, together with the ramped surfaces  29  of the actuator shaft cam portion  28 , facilitate smooth transition between the cam portion and the shaft body  27  as the actuator shaft  18  traverses through the circular opening  50  during use, as will be discussed in further detail below. 
         [0041]    Having thus far described the structural components of the tool  10 , use of the tool will now be sequentially described with reference to  FIGS. 2-9 . First, the end of a coaxial cable  106  is prepared in a conventional manner by stripping the cable jacket and folding back the braid. Next, with the tool  10  in the open position, whereby the front and back jaw assemblies  12  and  14  are separated to their fullest extent, as shown in  FIGS. 2 and 3 , a coaxial cable connector  102  is placed in the connector pocket  20  of the front jaw assembly  12  and a cable  106  is loosely placed in the cable receiving pocket  36  of the back jaw assembly  14 . At this point, the prepared end of the cable  106  can be manually inserted through the locking sleeve  108  of the connector  102  until it engages with the annular post  110  of the connector. This initial insertion requires only minimal force by the installer. 
         [0042]    With the tool  10  in the open position, as shown in  FIGS. 2 and 3 , only the rearward-most end of the shaft body  27  is received in the actuator shaft opening  50  of the gripper arms  32 . The reduced diameter of the rearward end of the shaft body  27  keeps the cam engagement ends  42  of the gripper arms  32  close together, whereby the opposite cable engagement ends  40  are separated. 
         [0043]    As the front jaw assembly  12  and the back jaw assembly  14  begin to move together as shown in  FIGS. 4 and 5 , the cam portion  28  of the actuator shaft  18  engages the circular opening  50  of the gripper arms  32  causing the cam engagement ends  42  of the gripper arms to move apart. Separation of the cam engagements ends  42  of the gripper arms  32  causes the cable engagement ends  40  to move closer together to grip the cable  106 . With the cable  106  thus gripped, further forward movement of the back jaw assembly  14  forces the cable further into the connector  102  to secure the cable to the post of the connector. 
         [0044]    As the back jaw assembly  14  moves further forward toward the front jaw assembly  12 , the cam portion  28  of the actuator shaft  18  slides through the circular opening  50  of the gripper arms  32  and eventually moves out of engagement with the circular opening  50  of the gripper arms  32 . As the cam portion  28  of the actuator shaft  18  exits the actuator shaft opening  50 , the reduced diameter of the shaft body portion  27  allows the spring force applied to the gripper arms  32  to cause the cam engagement ends  42  to return together. The resultant pivoting of the gripper arms  32  separates the opposite cable engagement ends  40  of the gripper arms, thereby releasing the cable  106 . 
         [0045]    Further forward movement of the back jaw assembly  14  toward the front jaw assembly  12  causes a forward face  54  of the back jaw member  30  to come into contact with a rearward face of the compression sleeve  108  of the connector  102 , as shown in  FIGS. 6 and 7 . The back jaw assembly  14  is then driven still further to press the compression sleeve  108  into the connector body  100  as shown in  FIGS. 8 and 9 . Once the cable is fully inserted as shown in  FIGS. 8 and 9 , the installed connector and cable can be removed from the tool  10  by slightly releasing the front and back jaw assemblies  12  and  14 . 
         [0046]    In this regard, the axial length of the cam portion  28  of the actuator shaft  18  together with the axial depth of the closable actuator shaft opening  50  of the gripper arms  32  preferably has a length A that matches the desired depth A of cable insertion into the connector, as shown in  FIG. 3 . In most coaxial cable installation applications, the dimension A is between about 0.375 and 0.625 inches, and is preferably about 0.430 inches. 
         [0047]    It is also desirable to ensure that the body portion  27  of the actuator shaft  18  has a length sufficient to enable the back jaw assembly  14  to traverse the actuator shaft a distance at least as much as the dimension A before engaging the locking sleeve  108  of the connector. In other words, the body portion  27  of the actuator shaft  18  preferably has a length that will ensure that the front face  54  of the back jaw member  30  does not make contact with the locking sleeve  108  until the cable  106  has been inserted the desired depth A. In a preferred embodiment, the front face  54  of the back jaw member  30  makes contact with the locking sleeve  108  at the moment that the cable  106  has been inserted the desired depth A. To accomplish this, the length of the body portion  27  of the actuator shaft  18  is chosen taking into account the dimension A, the depth of the back jaw member  30 , the depth of the connector receiving pocket  20  and the axial dimensions of the connector components. As can be appreciated, the length of the body portion  27  of the actuator shaft  18  will vary depending on all of these factors. 
         [0048]    The diameter or width of the cam portion  28  is also chosen to provide the desired gripping force on the cable  106  by the gripping arms  32  without damaging the cable. The gripping force of the gripping arms  32  is also determined by the depth of the notches  42  and the recesses  48  of the gripping arms, as well as the length of the gripper arms and the spacing of the gripper arm pivot pins  38 . 
         [0049]    As a result of the present invention, an installation tool is provided that performs both the cable insertion operation, in addition to the subsequent step of connector compression. The benefit of the present invention is an installation process that is faster and easier. 
         [0050]    Although the illustrative embodiments of the present invention have been described herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various other changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention. 
         [0051]    Various changes to the foregoing described and shown structures will now be evident to those skilled in the art. Accordingly, the particularly disclosed scope of the invention is set forth in the following claims.

Technology Category: y