Cable coupler having retained wedges

A cable coupler includes a body having a first end, a second end, and first and second passageways sized and shaped to receive a cable, with each passageway including a tapered portion. A wedge assembly is disposed in each tapered portion to secure a cable to the body. A clip assembly is attached to the body adjacent the tapered portion of each of the passageways and is shiftable between a closed position in which the clip assembly is positioned to prevent an adjacent one of the wedge assemblies from exiting the corresponding passageway and an open position in which the adjacent wedge assembly is insertable into the tapered portion of the corresponding passageway.

FIELD OF THE INVENTION

The invention relates generally to cable couplers for joining a pair of cables under tension and, more specifically, to a cable coupler having retained wedges.

BACKGROUND OF THE INVENTION

Cable couplers that couple two tensioned cables together are used in many applications. For example, in underground mining operations a cable roof truss is created in an underground mine passage generally consists of a tensioned cable extending between a pair of embedded roof anchors. Many times, the tensioned cable is made up of two sections which must be joined by a coupler. The construction industry also uses joined cables in a number of applications, such as in column wrapping, ring-tensioning applications, or with barrier cable installations often seen in parking garages.

A first design for a cable coupler is known as a spacer tube, often rectangular in section that has two barrels extending through the coupler. The cables are pulled through the barrels in opposite directions and tensioned. A set of wedge pieces are placed in the barrels adjacent the cables and the cables are released. The cables pull backward under their own tension, drawing the wedge pieces into the barrel. The wedge pieces grip the cables and lock the cables relative to the coupler.

A second design incorporates a curved path for each of the cables. This design, commonly known as the “dog bone” coupler due to the distinctive shape of the coupler, is different than the spacer tube in that the passages for the cables are curved to reduce sharp edges and to more evenly distribute the forces along the cable. Again, after the cables are tensioned and released, the cables and the retaining wedges are drawn into the tapered passageways of the coupler, drawing the wedge pieces into progressively greater contact with the cables so that the wedge pieces grip and lock the cables relative to the coupler.

In both of the aforementioned designs, the user must first insert both cables through the barrels of the coupler and then, using a tensioner, place the cables under tension. The wedge pieces must be manually placed adjacent the cables and in the tapered portion of the barrels. Unfortunately, these loose wedge pieces can easily fall to the ground during installation, and the wedge pieces may be lost in the darkness of a mine passage. Valuable time may be lost looking for and recovering any dropped or lost wedge pieces. To alleviate this often-encountered problem, suppliers generally provide extra wedges with the cable coupler. However, even if the wedge pieces are not lost, time and manual dexterity are required to insert the wedges into the coupler, which may have to be accomplished in a cold and/or dark setting.

DETAILED DESCRIPTION

Referring now to the drawings, and specifically toFIG. 5, a cable coupler10is depicted. The cable coupler10includes a body12that has a first end14and a second end16and has a first passageway18and a second passageway20that each extend from the first end14to the second end16. A clip22is disposed on the body12adjacent the first end14. A wedge assembly24is disposed in the first passageway18at the first end14and may be engaged by the retaining clip22as will be explained in greater detail below.

Referring back toFIG. 1, a cable truss system30incorporates the cable coupler10and is used to support a roof32of a mine passage34. A typical mine passage34may incorporate one or more of such cable truss systems30spaced along the length of the mine passage34to help support the roof32of the mine passage34. The cable truss system30includes a first cable36with a first end38and a second end40. A first bore42extends into the roof32at an angle outward from the mine passage34. The second end40of the first cable36is disposed in the first bore42. In this example, a resin cartridge44is also disposed in the first bore42and secures the second end40of the first cable36in the first bore42. Other known elements and methods can be used to secure the first cable36in the first bore42. The first cable36extends through a first ring eye plate46and presses the eye plate46upward against the roof32of the mine passage34.

The cable truss system30includes a second cable48with a first end50and a second end52. A second bore54extends into the mine roof32at an angle outward from the mine passage34. The second end52of the second cable48is disposed in the second bore54. In this example, a second resin cartridge56is also disposed in the second bore54and secures the second end52of the second cable48in the second bore54. Again, other known elements and methods can be used to secure the second cable48in the second bore54. The second cable48extends through a second ring eye plate58and presses the eye plate58upward against the roof32of the mine passage34.

The first end38of the first cable36and the first end50of the second cable48are both disposed in the cable coupler10, as will be detailed herein. The cable coupler10maintains both the first cable36and the second cable48in a state of tension so as to create a compressive force on the roof32in the mine passage34to help support the roof32.

Referring now toFIGS. 2 and 3, the cable coupler10is depicted in an assembled view (FIG. 2), and an exploded view (FIG. 3), prior to the insertion of either the first or second cables36,48. The cable coupler10includes the body12with the first end14, the second end16, and a sidewall60extending between the first end14and the second end16. In this example, the sidewall60takes a generally curved hour glass or dog bone shape.

The first passageway18and the second passageway20extend from the first end14to the second end16. Preferably, the passageways are disposed in a common plane. The first passageway18includes a tapered portion62which forms a seat for the wedges as would be common practice. The tapered portion62is generally conically shaped and is disposed adjacent the first passageway18near the first end14.

The cable coupler10includes a cable lock64disposed adjacent the first end14of the first passageway18. The cable lock64includes the wedge assembly24, the clip22, and a plug66.

The retaining clip22may be positioned to engage the wedge assembly24as shown inFIG. 2, or it may be shifted away from the wedge assembly24as is shown at the right side of each ofFIGS. 5 and 6, as well as on both sides ofFIG. 7. The wedge assembly24includes at least a first wedge piece68and a second wedge piece70that combine to substantially form a truncated cone with a base72and a tip74. Three-piece wedge assemblies or other suitable wedge assemblies may also be employed.

Each of the first wedge piece68and the second wedge piece70have an engaging face76a,76bsuch that when the wedge pieces68,70are assembled to form the wedge assembly24, the engaging faces76a,76bare in confronting relationship. Each of the first and second wedge pieces68,70also include an internal cylindrical section78a,78b. When the wedge pieces68,70are assembled to form the wedge assembly24, the internal cylindrical sections78a,78bform a generally circular passage way80within the wedge assembly24. A set of teeth82is disposed on the internal cylindrical sections78a,78band is formed in a known way such that an object in the circular passage way80may be slid from the tip74of the wedge assembly24towards the base72, but locked with respect to sliding from the base72toward the tip74. A groove or recess84is disposed on the outside surface of each of the wedge pieces6870, generally adjacent to the base72. The groove84encircles the wedge assembly24at a generally constant distant from the base72.

The clip22includes a first end86disposed in a first recess88in the sidewall60near the first end14of the first passageway18. The clip22further includes a second end90disposed in a second recess90(obstructed in the FIG.) and formed opposite the first recess88. The clip22includes a pair of lateral portions92a,92bextending away from the first and second ends86,90, and a pair of side portions94a,94bextending towards each other from the lateral portions92a, and92b. As can be seen inFIG. 3, the clip22is generally C-shaped, and may be formed of spring steel or other material, and preferably may be flexible or resilient enough to be detached from the body12by withdrawing the ends86,90from their corresponding recesses88.

A ring96is sized to be seated in the groove84of the wedge assembly24, and may serve to assist in retaining the wedge assembly24within the tapered portion62, and may also generally maintain the wedge pieces68,70together as the first cable36is pushed through the first passageway18and through the wedge assembly24. The ring96is preferably a resilient O-ring formed from, for example, rubber or other suitable material. The ring96can also be made from plastic or a suitable metal, and is preferably flexible facilitate easy installation of the ring96into the groove84around the wedge assembly24.

The plug66of the cable coupler10is disposed in the circular passage way80in the wedge assembly24. The plug66maintains the wedge pieces68,70slightly apart from each other, and the ring96maintains the wedge pieces68,70against the plug66. The plug66assists in holding the wedge assembly24in a position to receive the first cable36when the cable is inserted as shown inFIG. 5.

As can be best seen inFIG. 5, a second cable lock100is disposed adjacent a second tapered portion102in the second passageway20on the second end16. The second cable lock100can include the same elements as the first cable lock64, such as a second wedge assembly104with individual wedge pieces104a,104b, a second clip22, a second ring96, and a second plug66. It will be appreciated that inFIG. 5, the retaining clip22shown to the right of the Figure is shown in an open position as will be explained in greater detail below.

Referring back toFIG. 4, the cable coupler10is shown with first and second cables36,48disposed in the first and second passageways18,20, respectively. The first end38of the first cable36extends through the first passageway18and the wedge assembly24and out the first end14of the first passageway18. Likewise, the first end50of the second cable48extends into through the second passageway20. As will be described herein, when each of the first and second cables36,48are under tension, the wedge assemblies24, by being pulled into the corresponding tapered portion of the passageways, will apply a gripping force to the cables and thus secure the first and second cables36,48relative to the coupler10and each other.

Referring now toFIG. 5, the configuration of the first and second passageway18,20is shown. The first and second passageway18,20are each curved to generally follow the hour glass shape of the body12and extend generally in the same plane. The second end16of the first passageway18defines a first axis A1and the first end14of the second passageway20defines a second axis A2that is generally aligned with the first axis A1. The second end16of the first passageway18includes a relief110in which the cross section of the first passageway18is enlarged. This eases the insertion of the first cable36into the first passageway18. It further removes sharp corners that may abrade or damage the first cable36when it is under tension. The second passageway20includes a similar relief112at the first end14.

The process of inserting the cables36,48into the cable coupler10and locking the cables36,48in the cable coupler10will now be described. Referring again toFIG. 5, the first cable36is shown as it is being inserted into the first passageway18, and the second cable48is shown already inserted through the second passageway20almost to the plug66. As will be understood, due to the symmetry of the anchor10, the process of the insertion and locking of the second cable48is the same process as for the first cable36.

The first cable36is shown inserted partially into the first passageway18. In general, this step is performed by hand as a user simply holds the anchor10in one hand and the first end38of the first cable36in the other hand and inserts the first cable36into the first passageway18. It will be appreciated that in accordance with the disclosed example the clip22and the ring96cooperate to maintain both wedge pieces of the wedge assembly24in the tapered portion of the passageway, thus preventing or minimizing the chances that one or more wedge pieces will be dropped and/or lost.

As shown inFIG. 5, the first cable36has been inserted to the point where it is in confronting relationship with the plug66. As the user pushes the first cable36further, the first end38of the first cable36contacts the plug66. The plug66maintains the wedge assembly24outwardly such that the wedge assembly24is in a first position to receive the first cable36. The plug66can have a diameter slightly larger than the diameter of the first cable36to ensure that the wedge assembly24is held outwardly far enough to ease the entrance of the first cable36into the circular passage80of the wedge assembly24. The tip of the first cable36may be sized to ensure that it slides easily into the wedge assembly24.

Referring now toFIG. 6, the first cable36is pushed further through the first passageway18and pushes the plug66through the wedge assembly24until the first end38of the first cable36has been pushed through the wedge assembly24and extends out past the first end14of the first passageway18. The teeth82of the wedge assembly24are oriented to allow the plug66and the first cable36to slide from the second end16to the first end14of the first passageway18, but to grip and hold the first cable36fast as it is placed under tension and tends to slide toward the second end16of the first passageway18. Again, the second cable48can be inserted in the same way either before or after the insertion of the first cable36.

The user can tighten the first and second cables36,48by hand by pulling each of them until they are taut or by suitable machine tensioning. Referring again to the first cable36, the clip22maintains the wedge assembly24in position generally in the tapered portion62as the first cable36is inserted through the wedge assembly24and the plug66is pushed out. After the first cable36has been pulled through the body and the cable has been tensioned, the wedge assembly24has been pulled into the tapered portion62. The ring96is preferably resilient enough so as not to interfere with the motion of the wedge pieces into the tapered portion62such that the ring96does not interfere with the stressing of the first cable24.

At this point a tensioner is generally employed to pull the first cable36through the anchor10. When a predetermined tension has been reached and the first cable36has been stretched a predetermined distance, the tensioner releases the first cable36. Referring now toFIG. 7, after the first cable36is released, the tension is distributed over both the first cable36and the second cable48, and the cables36,48pull back through the body12in directions A3, A4. The teeth82of the wedge assemblies24,104engage the first and second cables36,48as the cables36,48pull back. The wedge assemblies24,104are pulled back into the body12until they engage their respective tapered portions62,102. As the wedge assemblies24,104are pulled back into their tapered portion62,102, the wedges assemblies24,104are forced by the tapered portions62,102to close progressively tighter around the first and second cables36,48to a second position where the cables36,48are locked in place.

The tension in the first cable36creates a force F1along the first axis A1and the tension in the second cable48creates a force F2along the second axis A2. Because the first axis A1and the second axis A2are generally aligned, the force F1and the force F2are opposite one another. This may serve to minimize any torque that would be created if the forces F1and F2were skew. Accordingly, the cable coupler10does not twist or twists only at a minimum, and the cables36,48are not forced against the edges of the passageways18,20.

In accordance with the disclosed example, the clip22holding the wedge pieces68,70in the wedge seat allows the user to simply insert the first cable36through the first passageway18with perhaps less manipulation of the wedge pieces68,70. The user may not have to manually insert the wedge pieces68,70into the tapered portion62after the cable36is placed in the first passageway18, as in the prior art. The disclosed example further alleviates the problem associated with dark working conditions of a mine passage in which the small wedges may become lost. The manufacturer may find the disclosed example lessens or eliminates the need to include extra wedge pieces. As can be understood, the present design may be faster and easier to use relative to the prior art.

Referring now toFIG. 5, the wedge assembly24can be installed in the tapered portion62as follows. The plug66is positioned between the individual wedge pieces68,70of the wedge assembly24, and the ring96is positioned into the groove84formed adjacent the ends of the wedge pieces68,70. As is shown in the right hand side ofFIG. 5, the retaining clip22(as well as the retaining clip22at the left of the FIG.) may be pivoted to an open position by pivoting the retaining clip22in the direction B about an axis C (extending into the plane of the FIG.) formed by the recesses88. In the open position, such as is shown to the right ofFIG. 5, a central portion23of the clip22is moved away from the opening of the tapered portion, such that the tapered portion is unobstructed by the clip22. In the open position, a wedge assembly24, plug, and ring, assembled as discussed above, may be freely inserted into the corresponding tapered portion of the corresponding passaway. The wedge pieces68,70and the plug66, held together by the ring96, may then be inserted as a single unit into the tapered portion62of the passageway.

Once the wedge assembly, the plug, and the ring are inserted into the tapered portion as discussed above, the clip22may be shifted to a closed position, such as is shown to the left ofFIG. 5. The clip22may pivot in the direction D about the axis C (the axis C extends into the plane of the FIG.). In the closed position, the central portion23of the clip22is positioned to obstruct a portion of the passageway, such that the wedge assembly24in the tapered portion is retained in the passage by the clip22.

The foregoing description is not intended to limit the scope of the invention to the form disclosed. It is contemplated that various changes and modifications may be those skilled in the art without departing from the spirit and scope of the invention.