Abstract:
Wire-untwisting tools and tool bits are disclosed. The wire-untwisting tool comprises a tool body, a movable member, and a spring. The tool body has a first channel extending inwardly from a first surface and a second channel extending inwardly from a second surface. The movable member includes a third channel, and is positioned within the second channel to move therein between an open position, in which the first and third channels are substantially aligned and contiguous, and a gripping position, in which they are not. The spring bears between the tool body and the movable member so and biases the movable member toward the gripping position. A pair of twisted wires inserted into the aligned channels of the tool body and the movable member when the movable member is pushed into the open position will be gripped for untwisting when the movable member moves back to the gripping position.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The invention relates generally to the field of wirework, and more specifically, to tools for untwisting wires. 
   2. Description of Related Art 
   Pairs of metal wires are often twisted together into a helical configuration. This sort of twisting can be used to join wires over long lengths, and has certain other uses and advantages. For example, when wires are used to carry electrical signals, helical twisting of pairs of wires reduces electromagnetic interference with the signals that the two wires are carrying. 
   Cables using metal wires for signal conduction are in wide and common use. One of the more common cables in use today is the standard Category-5 (CAT-5) Ethernet cable, which is used to connect computers and other computing hardware for networking purposes. Inside the CAT-5 Ethernet cable are four twisted pairs of wires, for a total of eight conductor wires. The ends of the cable may be capped with standard RJ-45 connectors, or the wires may simply be connected to appropriate terminal blocks without a connector, depending on the application. 
   When installing or otherwise manipulating cables that use twisted pair wires, it is often necessary to untwist the individual wires so that they can be fitted into connectors or terminal blocks. For example, to insert the end of the CAT-5 Ethernet cable into a connector, the four pairs of wires are untwisted a short distance, and the connector is crimped over the untwisted, straightened ends. An electrical connection is made by contacts within the connector that penetrate the insulation of the individual wires. 
   Ethernet cable is often installed in large volumes, for example, in a new office building. A large spool of the cable is usually brought in, and installers are left to cut whatever lengths of cable are necessary from the spool. In order to connect those pieces of cable, a short length of the twisted pairs of wires is untwisted, as was described above. The process of untwisting the pairs of wires during the installation can be laborious and difficult, and becomes more so as the user repeats the operation many times to make multiple cables. The installer may have difficulty grasping the wires, and after a number of such operations, his or her fingers may hurt. 
   SUMMARY OF THE INVENTION 
   One aspect of the invention relates to a wire-untwisting tool. The wire-untwisting tool comprises a tool body, a movable member, and a spring. The tool body has a first channel extending inwardly from a first surface and a second channel extending inwardly from a second surface. The movable member includes a third channel, and is adapted to be inserted into the second channel in the tool body and to move therein between an open position, in which the first and third channels are substantially aligned and contiguous, and a gripping position, in which the first and third channels are misaligned. The spring is arranged to bear between the tool body and the movable member so as to bias the movable member toward the gripping position. A pair of twisted wires inserted into the substantially aligned first and third channels when the movable member is in the open position will be gripped by the misaligned first and third channels when the movable member is in the gripping position. 
   Another aspect of the invention relates to a wire-untwisting tool. The wire untwisting tool comprises an elongate tool body with an end face, a movable member, and a spring. A first channel is formed in the tool body so as to extend inwardly from and generally perpendicular to the end face. A second channel is formed in the tool body proximate and generally parallel to the end face. The movable member has a third channel formed therein and is positioned within the second channel of the tool body for sliding movement in a direction generally parallel to the end face between an open position in which the first channel is aligned and contiguous with the third channel and a gripping position in which the first and third channels are misaligned. The spring is arranged to bear between the movable member and the tool body so as to bias the movable member toward the gripping position. 
   Yet another aspect of the invention relates to a wire-untwisting tool bit. The wire-untwisting tool bit comprises a wire-gripping and untwisting portion and a shank portion. The shank portion is constructed and arranged to be inserted into a handle or gripping device. The wire gripping and untwisting portion includes an end face. A first channel is formed in and extends inwardly from the end face. A second channel is formed in and extends inwardly from a second surface. A movable member has a third channel formed therein and is positioned within the second channel for sliding movement in a direction generally parallel to the end face between an open position in which the first channel is aligned and contiguous with the third channel and a gripping position in which the first and third channels are misaligned. A spring is arranged to bear between the movable member and the tool body so as to bias the movable member toward the gripping position. 
   Other aspects, features, and advantages of the invention will become apparent from the description that follows. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be described with respect to the following drawing figures, in which like numerals represent like structures throughout the figures, and in which: 
       FIG. 1  is a perspective view of a wire-untwisting tool according to one embodiment of the invention; 
       FIG. 2  is a front elevational view of the wire-untwisting tool of  FIG. 1 ; 
       FIG. 3  is a side elevational view of the wire-untwisting tool of  FIG. 1 ; 
       FIG. 4  is a top plan view of the wire-untwisting tool of  FIG. 1 ; 
       FIG. 5  is a sectional view of the wire-untwisting tool of  FIG. 1  taken through Line  5 — 5  of  FIG. 2 ; 
       FIG. 6  is a sectional view of the wire-untwisting tool similar to the view of  FIG. 5 , showing the movable member of the tool in the open position; 
       FIG. 7  is a sectional view of the wire-untwisting tool similar to the view of  FIG. 6  showing the tool gripping a pair of twisted wires with the movable member in the gripping position; 
       FIG. 8  is a perspective view of a wire-untwisting tool bit according to another embodiment of the invention; and 
       FIG. 9  is a perspective view of a wire-untwisting tool bit according to yet another embodiment of the invention. 
   

   DETAILED DESCRIPTION 
     FIG. 1  is a perspective view of a wire-untwisting tool, generally indicated at  10 , according to one embodiment of the invention. The wire-untwisting tool  10  of the illustrated embodiment includes an elongate tool body  12  that is generally cylindrical and is sized to fit comfortably in the hand of a user. The tool body  12  includes knurled portions  14  to make it easier to grip and hold. In addition to the knurled portions, the tool body  12  may have any shape or any features that make it easier to grip and hold. 
     FIG. 2  is a front elevational view of the tool  10 . As shown in  FIGS. 1 and 2 , at one end of the tool body  12 , a first channel  16  is bored into an end face  18 . In the illustrated embodiment, the channel is countersunk, i.e., the end of the first channel  16  that joins the end face  16  is enlarged and beveled. The first channel  16  is of sufficient size to admit a twisted pair of wires. (The use of the first channel  16  and the tool  10  will be described in more detail below.) In the illustrated embodiment, the first channel  16  is round and of generally constant diameter inwardly of the countersunk portion, although this need not be the case in all embodiments. 
     FIGS. 3 and 4  are side elevational and top plan views, respectively, of the tool  10 , and  FIG. 5  is a sectional view of the tool  10 , taken through Line  5 — 5  of  FIG. 2 . As is shown particularly in  FIGS. 1 ,  3 , and  5 , a second channel  20  of greater diameter is formed in the side surface of the tool body  12  proximate to the end face  18  and extends through the tool body  12  parallel to the end face  18 . 
   A movable member  22  in the form of a plunger is inserted into the second channel  20  and is constructed and arranged to move within the second channel  20 . The movable member  22  has a channel  24  formed within it. The channel  24  of the movable member  22  extends parallel to the first channel  16  in the end face  18  of the tool body  12  and has generally the same diameter as the first channel  16 . 
   The movable member  22  is adapted to move between an open position, in which the first channel  16  is substantially aligned with the channel  24  of the movable member  24  and a gripping position, in which the channel  24  of the movable member  22  is not aligned with the first channel  16 . (In the position depicted in  FIGS. 1–5 , the channel  24  of the movable member  22  is not aligned with the first channel  16 .) 
   In order to constrain the motion of the movable member  22  and retain it within the second channel  20  in the tool body, a recessed portion  26 , visible in the sectional view of  FIG. 5 , is formed in the movable member  22 , in this case, just below the channel  24  in the movable member  22 . Below the first channel  16  in the end face  18  of the tool body  12 , a threaded hole  28  is formed and extends inwardly, opening into the second channel  20  of the tool body  12 . A set screw  30  is inserted into the threaded hole  28  and extends into the recessed portion  26  of the movable member  22 , thus constraining the movement of the movable member  22  and preventing it from rotating. The end of the set screw  30  that contacts the recessed portion  26  may be made of plastic or another material that will perform the function without undue wear on the recessed portion  26 . The head of the set screw  30  is typically adapted to engage an Allen (hex) key or another type of fastener driver. 
   Although illustrated as being on the end face  18  of the tool body  12  in this embodiment, the set screw  30  and corresponding recessed portion  26  in the movable member  22  could be in any position. For example, they could be on the side of the tool body  12 , away from the opening of the first channel  16 . Additionally, other mechanisms for constraining the movement of the movable member may be used in other embodiments. For example, the movable member could be keyed (i.e., given a protrusion of a specific shape) and then used with a channel in the tool body of a corresponding and interengaging shape in order to prevent rotation. An enlarged bottom end, like that of a rivet, would prevent the movable member from leaving the tool body. 
   The top end of the movable member  22  has an enlarged pressure application portion  32  that is sized and shaped to be depressed by a user&#39;s thumb. A coil-type compression spring  34  bears between the underside of the pressure application portion  32  and the tool body  12 , biasing the movable member into an upward, gripping position. 
   The use of the tool  10  and the other positions of the movable member  22  are shown with more particularity in  FIGS. 6 and 7 , which are sectional views of the tool similar to the view of  FIG. 5  with the movable member in an open and a gripping position, respectively. Specifically, in the position of  FIG. 6 , the pressure application portion  32  of the movable member  22  has been depressed, causing the spring  34  to compress and the movable member  22  to move downwardly into a position in which the first channel  16  formed in the end face  18  of the tool  10  is aligned and contiguous with the channel  24  in the movable member  22 . In that position, the set screw  30  has also contacted the upward end of the recess  26 ; therefore, the movable member  22  cannot be moved downwardly any farther. 
   With the movable member  22  in the position illustrated in  FIG. 6 , the user can insert a twisted pair of wires  36  into the aligned and contiguous channels  16 ,  24  while holding the movable member  22  in the illustrated position. When the movable member  22  is released, the spring  34  will move it upwardly, until the movable member  22  is in the gripping position shown in  FIG. 7 . As shown in  FIG. 7 , with the first channel  16  and the channel  24  of the movable member  22  misaligned, the pair of wires  36  is caught and gripped between the top of the first channel  16  and the bottom of the channel  24  of the movable member  22 . 
   Once the wires  36  are gripped by the tool  10  as shown in  FIG. 7 , the user is free to rotate the tool  10  clockwise or counterclockwise as much as necessary to untwist the two wires  36 . Once a sufficient length of the wires  36  is untwisted, the user again depresses the pressure application portion  32  to move the movable member  22  into the open position illustrated in  FIG. 6 , this releasing the untwisted wires. 
   The two channels  16 ,  24  and the tool  10  as a whole may be sized for any size or diameter of wires. Additionally, the two channels  16 ,  24  may have different sizes or lengths. For example, the channel  24  of the movable member  22  may be made slightly larger in diameter than the first channel  16  so as to prevent wires from being caught between the two channels  16 ,  24  if a misalignment occurs in the open position of the movable member  22 . 
   The channel  24  of the movable member  22  may also be bored through only a portion of the movable member  22 , instead of being bored through its entire thickness. There may be certain advantages to doing so. Specifically, it is generally desirable to grip the shortest possible length of wire in most untwisting applications. If a relatively long length of wire is inserted into the two channels,  16 ,  24 , the clamped end of the wire may remain twisted, even though the rest of the wire is untwisted. However, if the length of the channel  24  in the movable member  22  is shorter, it is less likely that the clamped end of the wire will remain twisted. The length of the channel  24  in the movable member  22  may also be modified by inserting a plug of appropriate dimensions. 
   The amount of force necessary to successfully grip the wires for untwisting may increase as the size of the wire increases. In general, the properties of the spring  34  and the amount of force imparted by it may vary from embodiment to embodiment, but the spring force should be sufficient to retain the wires without unduly fatiguing the user. Moreover, if the wires to be untwisted are relatively small in diameter, it may be advantageous to use a relatively weak spring, so that the gripping action does not accidentally sever the wires. 
   The tool  10  can be made using a number of fabrication processes and a number of materials. Metal is believed to be the most durable of the materials from which tool  10  may be made. However, the tool  10  may also be made out of a plastic or composite material, if desired. In many applications, the wires that are to be untwisted will be electrically insulated, and thus, there will be little or no concern about the possibility of an electrical short. If the wires are uninsulated or there is concern about the possibility of an electrical short, the tool  10  could be made of a nonconductive material, such as plastic, or the channels  16 ,  24  could be lined with such a material. 
   The fabrication process will depend on the material of which the tool  10  is made, although, in general, the parts may be molded, cast, or machined, depending on the material. As one example, a steel rod 5.25 inches in length and 0.450 inches in diameter was used to make a tool  10 . Appropriate holes were drilled and countersunk in the end face for the first channel  16  and drilled and tapped for the set screw hole  28 . The diameter of the first channel  16  was 0.113 inches, drilled with a No. 33 drill bit. The set screw hole was drilled with a No. 43 drill bit (0.089 inches) and tapped for a 4-40 set screw. The diameter of the second channel  20  was 0.250 inches. The movable member  22  was 0.940 inches in overall length, with a recessed portion 0.400 inches in length. The resulting tool was found to work well for untwisting the conductors of Ethernet cables, including CAT-5 cables. The resulting tool should also work well with other twisted pair cables, including CAT-3 and CAT-3A Ethernet cables. 
   In order to reduce the weight of the tool  10 , the majority of the tool body  12  may be bored out or otherwise formed without a solid central portion, as is shown in  FIGS. 5–7 . This may be particularly useful if the tool  10  is made of metal. 
   Other adaptations and changes to the tool  10  may be made without altering its basic function and manner of operation. For example, in the tool  10  of  FIGS. 1–7 , the movable member  22  translates vertically, biased by a compression spring  34 . In other embodiments, the spring could be a torsional spring, and the movable member could rotate, rather than translating, to move into a gripping position. In that case, the user would twist the top of the movable member to move it. Certain changes would be made for a torsional spring embodiment; for example, the recess that constrains the movement of the movable member would be cut circumferentially, instead of longitudinally. 
   Additionally, features may be added to the tool body  12  to facilitate handling. For example, a pocket clip, similar to those used with pens, could be added to the tool body  12 , as could a clip, ring, or other structure to engage a tool belt. 
   In the embodiment illustrated in  FIGS. 1–7 , the tool  10  includes an elongate tool body  12  that is suitable for use as a handle. However, in other embodiments, the functional features and components of the tool  10  could be made in the form of a tool bit, to be inserted into any one of a number of standard handles. 
     FIG. 8  is a perspective view of a wire-untwisting tool bit  100  according to another embodiment of the invention. The tool bit  100  has the same functional, wire-untwisting components as the tool  10 ; therefore, the description above will suffice for those components. However, instead of a tool body  12  that is suitable for use as a handle, the tool bit  100  includes a round shank  102  that is sized and shaped for insertion into a variety of standard handles  104 ,  106  and chucks. If the tool bit  100  is inserted into a handle  104 ,  106 , it may be held in place with a set screw or any other compatible mechanism. 
   In some embodiments, the tool bit  100  could be inserted into the chuck of, for example, a power drill, and used with the power drill. However, for most wire untwisting jobs, the use of a power tool may be excessive, because the wire would likely untwist and then begin re-twisting before the user could stop the power tool. Of course, there may be some applications in which use with a power tool has advantages, for example, if a particularly long length of wire is to be untwisted. 
   Even without a power tool, the tool bit  100  has advantages. One advantage is that the user can pick whichever handle feels most comfortable in his or her hand. Users who are arthritic, for example, may pick a larger or more easily gripped handle. Another advantage is that if a user has multiple tools that fit a standard handle  104 ,  106 , the overall weight and number of tools that the user carries can be reduced. 
   While a round tool bit  100  may be convenient for some applications and some handles  104 ,  106 , it is by no means the only shape in which a wire untwisting tool bit may be made.  FIG. 9  is a perspective view of a tool bit  200  according to yet another embodiment of the invention. 
   The tool bit  200  has the same functional, wire-untwisting components as the other embodiments of the tool  10  and the tool bit  100 . However, the shank  202  of the tool bit  200  has a hexagonal shape, and is particularly of the type that includes a circumferential channel  204  in a rearward portion. The circumferential channel  204  helps the standard hex-bit handles  206 ,  208  to grip the shank  202 . 
   Most tool bits that are used with standard handles rely, at least in part, on compressive forces on the tool bit during use to retain the tool bit within the handle. Some handles use a relatively weak retaining mechanism, such as a magnet, to keep the tool bit within the handle at other times. However, as the wire-untwisting tools and tool bits  10 ,  100 ,  200  are used to untwist wire, some axial tension may be placed on the tool  10  or tool bit  100 ,  200 . Therefore, it is advantageous if the engagement of the tool bit  100 ,  200  with the handle  104 ,  106 ,  206 ,  208  is by a mechanism that is able to resist at least some axial tension without allowing the tool bit  100 ,  200  to slip out of the handle  206 ,  208 . In the case of the tool bit  200 , the circumferential channel  204 , in cooperation with structure inside the handles  206 ,  208  performs this function. 
   Other shapes for wire untwisting tool bits according to embodiments of the invention may also be used. Shapes that prevent rotation of the tool bit within the handle are particularly advantageous. 
   Additionally, although the tool bits  100 ,  200  were described above as being interchangeable by the user, a tool bit  100 ,  200  could be press-fit by a manufacturer into a particular handle so that it is not removable by the user. This is one way in which a manufacturer might make a number of wire-untwisting tools with different types of handles. 
   While the invention has been described with respect to certain exemplary embodiments, the description is meant to be illuminating, rather than limiting. Certain modifications and changes may be made without departing from the scope of the invention, which is defined by the claims.