Abstract:
A socket and wedge assembly that securely holds wire rope and is easy to release includes a collapsible wedge. The wedge collapses at the front, narrowed end to utilize the high pressures at the front end of the wedge in effecting the collapse and releasing the rope. The wedge includes a movable element that pivots and/or translates to facilitate a quick and reliable collapse of the wedge and release of the wire rope. The wedge includes a cavity to at least partially exhaust the fumes created from cutting the support with a torch for release of the wire rope.

Description:
FIELD OF THE INVENTION 
     The present invention pertains to a wedge and socket assembly for securing a wire rope, which is particularly useful in heavy load applications such as found in certain excavating machines. 
     BACKGROUND OF THE INVENTION 
     Wire ropes are used in certain excavating machines and other machines where heavy lifting or pulling is required. In excavating machines (such as dragline excavating systems and cable shovels), wedge and socket assemblies are commonly used to secure an end of a wire rope. The socket in these assemblies includes a tapered passage or cavity that is adapted to receive the wedge. A wire rope is passed through the tapered passage in the socket, looped about the larger end of a wedge, and then fed back into the passage with the wedge. As the wire rope is tightened, the wedge is firmly fit into the passage so as to securely hold the wire rope against the sidewalls of the tapered passage in the socket. The socket also includes a clevis or other fastening arrangement that is coupled to a component of the machine, chain, etc. While such assemblies are effective in securing the wire rope, they can be difficult to release. 
     SUMMARY OF THE INVENTION 
     The present invention pertains to an improved socket and wedge assembly that securely holds wire rope but which also enables an easy release, and in particular, to a collapsible wedge usable in such an assembly. 
     In one aspect of the invention, the wedge is collapsible to facilitate an easy release of the wire rope. The wedge collapses at the front, narrowed end to utilize the high pressures at the front end of the wedge in effecting the collapse and releasing the rope. 
     In another aspect of the invention, the wedge includes a pivotal element attached to a larger base to facilitate a quick and reliable collapse of the wedge and release of the wire rope. In the initial state, the elements comprising the wedge are in a fixed condition to securely hold the wire rope in the socket. In the release state, the pivotal element rotates to a collapsed position for a quick, sure and easy release of the wire rope. 
     In another aspect of the invention, the collapsible element of the wedge holding the wire rope is subject to pivotal and translational movement to release the rope quickly, easily and efficiently. 
     In another aspect of the invention, the pivotal element of the wedge has a support that is cut to cause collapse of the wedge and release of the wire rope. The support preferably includes a stop or brace to engage the base and better resist the high pressures that can be experienced in holding the wire rope in the socket. 
     In another aspect of the invention, the wedge includes a cavity to at least partially exhaust the fumes created from cutting the support with a torch for release of the wire rope. 
     In another aspect of the invention, the wedge grips the wire rope along only a part of the wedge&#39;s periphery. In one construction, the wedge grips the wire rope along only the front portion of the tapered passage, where the highest pressure is experienced, along one side of the wedge, i.e., the portion adapted to collapse when the rope is released. This arrangement focuses the pressure on the wire rope where it best secures it and enables an easier release. 
     In another aspect of the invention, the wedge collapses and releases the tension contained in secured wire ropes with increased safety to workers. In preferred embodiments of the invention, the components of the wedge remain interconnected during collapse to minimize any risk of parts being forcibly ejected during release of the tension and energy contained in the secured wire rope. Also, even if a portion of the wedge was designed to disconnect or became disconnected from the remaining wedge during collapse, the collapse tends to be inward to further reduce the risk of injury. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a socket and wedge assembly of the present invention. 
         FIG. 2  is a side view of a wedge and socket assembly with the socket shown partially and in cross section. 
         FIG. 3  is a side view of a collapsible wedge of the present invention. 
         FIG. 4  is a perspective view of the wedge. 
         FIG. 5  is a top view of the wedge. 
         FIG. 6  is a rear end view of the wedge. 
         FIG. 7  is a perspective view of a base component of the wedge. 
         FIG. 8  is a side view of the base component. 
         FIG. 9  is a cross-sectional view taken along line  9 - 9  in  FIG. 8 . 
         FIG. 10  is a cross-sectional view taken along line  10 - 10  in  FIG. 9 . 
         FIG. 11  is a perspective view of a pivoting component of the wedge. 
         FIG. 12  is a side view of the pivoting component. 
         FIG. 13  is a cross-sectional view taken along line  13 - 13  in  FIG. 12 . 
         FIG. 14  is a cross-sectional view taken along line  14 - 14  in  FIG. 12 . 
         FIG. 15  is a perspective view of an alternative embodiment of a collapsible wedge in accordance with the present invention. 
         FIG. 16  is a side view of the alternative wedge. 
         FIG. 17  is a top view of the alternative wedge. 
         FIG. 18  is a rear view of the alternative wedge. 
         FIG. 19  is a cross-sectional view taken along line  19 - 19  in  FIG. 17 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention pertains to a socket and wedge assembly  10  for holding a wire rope  11 , which comprises a socket  12  and a wedge  14 . Assembly  10  can be used to securely hold a wire rope under heavy loading such as may be experienced in excavating machines (such as dragline operations and cable shovels). Nevertheless, assembly  10  could be used in other environments where a wire rope needs to be securely held. 
     Socket  12  has a conventional design and could have the form of a wide variety of different constructions. In one example, as seen in  FIG. 1 , socket  12  is an elongate member that includes a tapered passage  16  at a front end  18 , a clevis  20  at a rear end  22  to facilitate connection with another component, chain, etc, and a generally hollow intermediate portion  24 . Tapered passage  16  includes a rear opening  26  through which wedge  14  is inserted for use, and a narrowed front opening  28  through which the length of wire rope  11  passes. 
     Wedge  14  includes a base  30  and a movable arm  32  that are coupled together for use in socket  12  to hold a wire rope  11 . In use, base  30  and arm  32  are in a fixed condition for mating receipt within the tapered passage  16  of socket  12 . Arm  32  grips the wire rope against one sidewall  33  of the tapered passage  16  in socket  12 , while base  30  grips the wire rope against the opposite sidewall  35  of the tapered passage  16 . Arm  32  is subject to collapse toward base  30  when a support  37  is cut to facilitate removal of the wedge from socket  12  and release of the wire rope  11 . 
     Base  30  includes a first side  34  and an opposite second side  36  that generally converge toward a front narrowed end  38 . While first side  34  extends generally the entire length of wedge  14 , second side  36  extends only part of the length. In a preferred construction, the second side stops well short of front end  38  to define an open space  39  into which arm  32  is placed. The rear end  40  of base  30  has a convex, curved configuration that joins the first and second sides  34 ,  36 . One or two notches  60  are provided along rear end  40  to facilitate cutting of the wire rope  11  when release is desired. A couple of eyes  62  are preferably provided along rear end  40  near second side  36  to accommodate handling of the wedge in larger assemblies and to ensure proper insertion of the wedge into the socket. 
     A channel  42  extends along first side  34 , second side  36  and rear end  40  for receipt of the wire rope  11 . In a preferred embodiment, channel  42  is a trough that extends continuously around nearly the entire perimeter of base  30  excluding the open space  39 . First side  34  extends forward farther than second side  36  to define a front projection  44  beneath open space  39 . An upstanding brace  46  is preferably formed at the end of projection  44  to provide additional support for arm  32  as discussed below. A mount  48  is provided at the base of front projection  44  for attaching arm  32 . In a preferred construction, mount  48  includes an upstanding web  52  positioned between a pair of support surfaces  54 . The support surfaces  54  are concave and curved to receive a portion of arm  32 . Support surfaces are preferably uniformly curved to define a segment of a circle, though other curvatures are possible. A hole  58  extends through web  52  at the origin of the radius of curvature for support surfaces  54 . 
     Arm  32  includes a support  37  engaging the front end  38  of base  30  and a hub  56  for connecting to mount  48 . In use, support  37  holds arm  32  in a fixed condition to tightly hold the wire rope against release. When release of the rope is desired, support  37  is cut so that arm  32  collapses toward base  30  and releases the wire rope. In a preferred construction, hub  56  is secured to mount  48  to facilitate the pivotal movement of arm  32 . Arm  32  has a generally U-shaped configuration with part of the open space  39  being a clearance gap  39   a  to permit collapse of arm  32  when release of the wire rope is desired. The clearance gap  39   a  may be filled with an elastomeric foam or other elastomer, or left as a void. The use of an elastomer that burns away with the use of the torch to cut support  37 , as discussed below, would be preferred. 
     In a preferred construction, hub  56  includes a pair of spaced flanges  64  that define a gap  66  into which web  52  is received. Flanges  64  include convex, uniformly curved support surfaces  68  that set against support surfaces  54  of base  30 . Support surfaces  54 ,  68  preferably have the same radius of curvature to provide ample support for arm  32  and ease its rotation though support surfaces  54  could have a wider curvature. A hole  70  is provided in each flange  64  to align with hole  58  in web  52  when support surfaces  54 ,  68  are in contact. A pin  72  is fit through the aligned holes  58 ,  70  to couple arm  32  to base  30 . Pin  72  can be secured by any known means for retaining pivot pins including, for example, the use of a bolt and nut as the pivot pin. Pin  72  is preferably loosely received into holes  58 ,  70  so that support surfaces  54 ,  68  support the loads applied to the arm and direct the preferred pivotal movement of the arm. The pin keeps the arm coupled to the base particularly during rope installation and during removal of the wedge from the socket. Nevertheless, the pin or other arrangements (e.g. slots) could be used to support the loads and direct the movement of the arm. In addition, while a pivotal movement for arm  32  is preferred, it is possible for the arm to move toward base  30  (i.e., to collapse) in a non-pivoting manner e.g., through the use of slots and followers. 
     Arm  32  includes an outer side  74  that defines a channel  76  for receiving wire rope  11 . Outer side  74  converges toward first side  34  of base  30  in a forward direction (i.e., towards front end  38 ). While outer side  74  of arm  32  is generally axially aligned with second side  36  of base  30 , they are not in actual alignment. Outer side  74  is inclined at a slightly greater angle to first side  34  as compared to second side  36  so that only the arm  32  (and not second side  36 ) grips the wire rope  11  between wedge  14  and a sidewall  33  of tapered passage  16  in socket  12 . The length of wire rope  11  passing over second side  36  is laterally retained and directed along second side  36  by channel  42 , but it does not grip the wire rope  11  against the passage wall  33 . 
     Support  37  is provided at the front end  80  of arm  32  to retain the arm in a fixed holding position relative to the base  30 , i.e., in a position to hold the wire rope against sidewall  33  during use. Support  37  extends away from outer side  74  to engage the front end  38  of base  30 . A stop  82  is preferably provided at the distal end  84  of support  37  to engage brace  46 . When the wedge  14  is tightly fit into the tapered passage  16  of socket  12  to hold the wire rope  11 , substantial pressure can be applied to the arm along channel  76 . In the holding position, this pressure is resisted by support  37  and hub  56 . When high loads are applied to arm  32 , pressure mounts to bow arm  32  and bend support  37  outward. The engagement of stop  82  against brace  46  resists such bowing of arm  32  and outward flexing of support  37 . 
     In use, a wire rope  11  is fed into tapered passage  16  of socket  12  through front opening  28  and wrapped about wedge  14  such that it lay in channels  42 ,  76 . Wedge  14  with the wire rope  11  wrapped about it is then placed into the tapered passage through rear opening  26 . The application of force on the wire rope pulls the wedge tightly into the tapered passage  16  so that the wire rope is securely held in channels  42 ,  76 , i.e., between first side  34  of base  30  and channel  42  of tapered passage  16  in socket  12  and between channel  76  of arm  32  and sidewall  33 . Second side  36  of the base is spaced from sidewall  33  a greater distance than outer side  74  of arm  32  so that the wire rope is not gripped between the wedge and the socket at this location. Even though the wire rope is gripped only at the front of the tapered passage  16  on the arm side of the wedge, the rope is still securely supported against loss. The highest pressures on the arm side of the wedge occur at its front end, and can be used alone to hold the rope in place. Wedge  14 , despite gripping the wire rope with only the arm on the one side of the wedge, applies a similar grip and load as compared to a conventional wedge that includes a gripping surface along the entire length of each side of the wedge. 
     When release of the wire rope is desired, support  37  is cut by a torch or other means. As an alternative, a cut-away or removable block may be provided in lieu of all or part of support  37 . Once the support (or block) has been cut or otherwise removed, the pressure on arm  32  caused by tightly gripping the wire rope causes the arm to pivot inward toward front projection  44  of base  30 . All surfaces gripping the cable experience and inward pressure when loaded so that the arm will automatically collapse when the support  37  is removed. Since all the gripping pressure of the wedge on the wire rope against sidewall  33  is applied by the arm, the collapse of arm  32  is immediate upon cutting support  37 . Moreover, with the shortened length of arm  32  (as compared to the overall wedge length) the arm rotates about a shorter radius. A shorter turning radius, in turn, leads to greater collapse (i.e., movement of the arm away from sidewall  33 ), and surer release of the wire rope. A clearance section  84  is provided at the rear end of arm  32  to permit rotation of the arm without this portion of the arm rising up with the pivotal motion and gripping or applying unwanted pressure to the wire rope. In a preferred construction, clearance section  84  is a segment that extends rearward at a different inclination than channel  76  so that it does not rise above second side  36  of base  30  when arm  32  is collapsed, though other formations are possible. 
     A torch is a preferred tool for cutting support  37 . In a preferred embodiment, wedge  14  is formed with cavities  86 ,  88  in one or both of arm  32  and base  30 . Cavity  86  in arm  32  is an internal space or passage extending between clearance space  39   a  and the rear end of the arm  32 . Cavity  86  is generally positioned between of hub  56  and channel  76 . Cavities  88  are defined by external recessed formed in base  30  rearward of mount  48 . Cavity  86  communicates with cavities  88  at the rear end of arm  32  between mount  48  and channel  76 . Cavities  86 ,  88  receive and exhaust fumes from the cutting process. Additional passage for exhausting the fumes to cavities  88  can also be provided by forming gap  66  to be wider than web  52 . In any event, cavities  86 ,  88  are optional irrespective of whether a torch is to be used to cut support  37 . It is noted that cavities  86 ,  88  may each be formed internally or externally of arm  32 . 
     In an alternative embodiment ( FIGS. 15-19 ), a collapsible wedge  114 , like wedge  14 , includes a base  130  and a movable arm  132  that collapses in a forward direction to release the wire rope. The base  130  and arm  132  collectively define a front end  133 , a rounded rear end  135  about which the wire rope is wrapped, and pair of generally linear, rearwardly diverging sides  141 ,  143 . In contrast to wedge  14 , arm  132  contacts and grips the wire rope along substantially the entire length of side  143  of the wedge. The use of a longer arm to grip the wire rope reduces the risk that the wire rope will be crushed during use, which may cause the diameter of the rope to lessen and, in some cases, loosen the wedge&#39;s grip on the wire rope. Accordingly, wedge  114  provides an enhanced level of security in the holding the wire rope. Nevertheless, even with the longer arm  132 , both wedges  14 ,  114  preferably use a construction where the wedge is formed by a larger base and a smaller arm effecting the desired collapse. 
     The base  130  and arm  132  collectively define a channel  142  about the outer periphery of the wedge for containing the wire rope. The channel is formed by base  130  along side  141  and rear end  135 , and by arm  132  along side  143  to form a substantially continuous channel, preferably U-shaped, for receiving the wire rope. 
     A coupling  147  is provided to join arm  132  to base  130  and hold the components together for installation while still permitting forward collapse of the arm when removal is desired. In the illustrated embodiment, arm  132  and base  130  are loosely joined to permit pivoting and translational movement of the arm when release is desired. However, the arm may be moved by way of a pivoting or translational motion. The benefits gained by a forward collapse of the wedge is not dependent on the way the arm moves or whether the wedge uses a larger base-smaller arm construction as is set forth in the preferred embodiment. Accordingly, the wedge could have an arm that collapses in a pivotal motion, translation motion, or in a combination of pivot and translation movement. Further, these various movements are possible with short arms (e.g., less than half of the overall length of a side of the wedge), longer arms (e.g., extending more than half the length of a side of the wedge), or the use of an arm that is essentially the mirror image of the base (i.e, using two co-equal components). Also, benefits gained in releasing the wire rope can be realized through the use of a base and arm construction, i.e., where the base is larger than the arm, irrespective of whether the collapse is forward or rearward. However, in the preferred construction, the collapse is forward and the collapse is effected by an arm which is smaller than the base. 
     In one example of a coupling  147 , a projection  149  extends forward from base  130  along side  143  to define an inner shoulder  151 . As seen in  FIG. 17 , projection  149  has a thinner width than the channel  142  and the main portion of base  130 . Arm  132  includes a complementary groove  153  along its rear end  155  that is configured to receive projection  149 . As seen in  FIG. 19 , groove  153  extends the entire depth of arm  132 . A pin  157  is received through aligned holes in arm  132  to set just beneath shoulder  151 ; pin  157  could be in contact with or spaced from the shoulder. Shoulder  151  could be linear, curved, angular or have another configuration. Nevertheless, other kinds of coupling arrangements permitting collapse of arm  132  could also be used. In addition, the arm and base could be coupled with means other than a pin such as, for example, a collapsible foam within cavity  186 . 
     Arm  132  preferably includes a front support  137  that projects downward to rest against a front base bearing surface  159 . A brace or rim  146  extends around the outside of support  137  along the front and both sides. This brace limits movement of the support in a forward or lateral direction. A rear bearing surface  161  of arm  132  abuts against a rear base bearing surface  163  on base  130 . Although support  137  is preferably an integral part of arm  132  it could be an integral portion of the base or a separate component that is attached to either the arm or the base. Moreover, the support could be formed by a plurality of components if desired so long as they can be readily cut or otherwise removed when release of the wire rope is desired. If the support is a separate component attached to the base, the front and lateral support provided by brace  146  may be provided by the support. The construction or position of the support could vary considerably and encompasses the portion of the wedge that is removed to cause the desired collapse. 
     The abutment of support  137  against brace  146  and of rear bearing surface  161  against rear base bearing face  163  hold the arm from moving axially relative to the base. The receipt of projection  149  in groove  153  along with the receipt of support  137  between the side portions of brace  146  prevent the arm from moving laterally relative to the base. The insertion of pin  157  beneath shoulder  151  prevents disconnection of the arm from the base. In this way, wedge  114  can be easily inserted into socket  12  as a single unit. 
     When release of the wire rope is desired, support  137  is cut by a torch or other means. Although removal of support  137  by a torch is preferred, removal of the support does not require complete removal of the element. Rather, removal of the support means that the support is moved out of its supporting position even if it continues to exist and remains a part of the collapsed wedge. In any event, the surfaces gripping the wire rope in use experience considerable inward pressure on account of the tight grip on the rope. As a result, arm  132  automatically collapses when support  137  is removed, i.e. arm  132  will pivot such that the front end  165  of the arm drops toward front base bearing surface  159 . The pressure also will tend to move arm  132  inward in a translation motion as the fit of the arm loosens with the removal of support  137 . Pin  157  does not impede this motion because it is unencumbered in the inward direction, i.e., it is free to move inward along groove  153  away from shoulder  151 . The pin does not move inward in the operating condition because of the abutment of support  137  against front base bearing surface  159  and rear bearing surface  163  against rear base bearing surface  163 . This inward translation in combination with the forward pivoting motion of arm  132  results in a sure release of the wire rope for removal of the wedge. 
     As with wedge  10 , wedge  110  includes a cavity  186  between arm  132  and base  130 . Cavity  186  not only provides clearance for movement of arm  132 , but also preferably exhausts fumes from the cutting process. 
     In both wedges designs, the wedge is able to collapse and release the tension contained in secured wire ropes with minimal risk to workers&#39; safety. In wedges  14 ,  114 , the components of the wedge remain interconnected during collapse to lessen the risk of parts being forcibly ejected during release of the tension and energy contained in the secured wire rope. In wedge  14 , the arm  32  remains pinned to the base  30 . While pin  157  in wedge  114  is not fixed in the same way, the fit and position of arm  132  causes the arm to remain with the base, i.e., the arm tends to collapse against the base due to cutting the wire ropes as opposed to being forced away from the assembly. Similarly, if the support or other portion of the wedge were designed to disconnect or became disconnected from the remaining wedge portion during collapse, the collapse tends to be inward as noted above to minimize the risk of injury to workers.