Abstract:
Coupler has a safety lock and a latching hook. The safety lock pivots between an unlocked position in which it does not contact a first implement pin receivable within a pair of apertures, and a locked position in which it retains the first pin within the apertures. The latching hook pivots between an unlatched position in which it does not contact a second implement pin receivable within another pair of apertures, and a latched position in which it retains the second pin within the apertures. A spring biases the safety lock toward the locked position, maintaining engagement of the safety lock with the first pin and preventing its withdrawal from the apertures in the event of a hydraulic system failure. When the implement is released, the spring continues to bias the safety lock toward the locked position, preventing withdrawal of the first pin from the apertures in the event of a hydraulic system failure before completion of the release operation.

Description:
BACKROUND OF THE INVENTION 
   This disclosure pertains to a coupler for releasably and lockably coupling an implement such as a bucket to the end of a boom, with the coupler having a mechanism for inhibiting unintentional release of the implement. 
   BRIEF SUMMARY OF THE INVENTION 
   Powered digging or material-moving machines such as excavators and backhoes typically have an operator-manipulable boom to which one of a variety of implements can be coupled. Typical implements include buckets of various sizes and shapes, rakes, clamshells, grab-buckets, rippers, augers, grapples, hammers, etc. 
   The machine operator must sometimes interchange implements to perform different tasks. For example, an operator moving loose material with a bucket may encounter hard material which must be broken up before it may be moved with a bucket. In such a case, the operator may wish to remove the bucket from the machine&#39;s boom, mount a ripper on the boom, use the ripper to break up the hard material, then remove the ripper and remount the bucket in order to continue moving the broken material. 
   A coupler is commonly fixed at the end of the boom. The coupler includes a mechanism for coupling any one of the implements to the boom. The implements are adapted for such coupling by providing them with mounting pins which are engaged by the coupler in well known fashion. The coupler can be actuated by the operator in order to quickly and easily decouple an implement from the machine then recouple it to another implement, without requiring the operator to leave the machine&#39;s operating cab. 
   If the mounting pins of an implement are not properly engaged by the coupler it is possible for the implement to suddenly and unexpectedly decouple from the machine&#39;s boom. If this happens damage or injury may be caused to the coupler, to the implement or to nearby items or persons. This problem is addressed by the coupler described below. 
   The foregoing examples of the related art and limitations related thereto are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Exemplary embodiments are illustrated in referenced figures of the drawings. It is intended that the embodiments and figures disclosed herein are to be considered illustrative rather than restrictive. 
       FIGS. 1 and 20  are respectively right and left side oblique lower front isometric views of the coupler. 
       FIGS. 2 and 21  are respectively right and left side isometric views of one of the coupler&#39;s lock links. 
       FIGS. 3 and 22  are respectively right and left side isometric views of one of the coupler&#39;s safety locks. 
       FIGS. 4 and 23  are respectively right and left side isometric views of one of the coupler&#39;s torsion springs. 
       FIGS. 5 and 24  are respectively right and left side isometric views of one of the coupler&#39;s cylinder mount links. 
       FIGS. 6 and 25  are respectively right and left side isometric views of the coupler&#39;s latching hook. 
       FIGS. 7 and 26  are respectively right and left side isometric views of the coupler&#39;s hydraulic cylinder. 
       FIGS. 8 and 27  are respectively right and left side oblique lower front isometric views of the coupler, and depict a portion of an implement having forward and rearward pins respectively positioned within the coupler&#39;s forward and rearward coupling apertures before activation of the coupler&#39;s safety locks and latching hook. 
       FIGS. 9 and 28  are respectively right and left side front elevation views, on an enlarged scale, of the  FIG. 8  coupler. 
       FIGS. 10 and 29  are respectively right and left side section views, on an enlarged scale, taken ( FIG. 10 ) with respect to line  10 - 10  shown in  FIG. 9  and ( FIG. 29 ) with respect to line  29 - 29  shown in  FIG. 28 . 
       FIGS. 11 and 30  are respectively right and left side section views, on an enlarged scale, taken ( FIG. 11 ) with respect to line  11 - 11  shown in  FIG. 9  and ( FIG. 30 ) with respect to line  30 - 30  shown in  FIG. 28 . 
       FIGS. 12 and 31  are similar to  FIGS. 8 and 27  respectively, but show the coupler after activation of the safety locks and before activation of the latching hook. 
       FIGS. 13 and 32  are respectively front elevation views, on an enlarged scale, of the coupler shown in  FIGS. 12 and 31  respectively. 
       FIGS. 14 and 33  are respectively right and left side section views, on an enlarged scale, taken ( FIG. 14 ) with respect to line  14 - 14  shown in  FIG. 13  and ( FIG. 33 ) with respect to line  33 - 33  shown in  FIG. 32 . 
       FIGS. 15 and 34  are respectively right and left side section views, on an enlarged scale, taken ( FIG. 15 ) with respect to line  15 - 15  shown in  FIG. 13  and ( FIG. 34 ) with respect to line  34 - 34  shown in  FIG. 32 . 
       FIGS. 16 and 35  are similar to  FIGS. 8 and 27 ; and to  FIGS. 12 and 31  respectively, but show the coupler after activation of both the safety locks and the latching hook. 
       FIGS. 17 and 36  are respectively front elevation views, on an enlarged scale, of the coupler shown in  FIGS. 16  coupler and  35  respectively. 
       FIGS. 18 and 37  are respectively right and left side section views, on an enlarged scale, taken ( FIG. 18 ) section view taken with respect to line  18 - 18  shown in  FIG. 17  and ( FIG. 37 ) with respect to line  37 - 37  shown in  FIG. 36 . 
       FIGS. 19 and 38  are respectively right and left side section views, on an enlarged scale, taken ( FIG. 19 ) with respect to line  19 - 19  shown in  FIG. 17  and ( FIG. 38 ) with respect to line  38 - 38  shown in  FIG. 36 . 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Throughout the following description specific details are set forth in order to provide a more thorough understanding to persons skilled in the art. However, well known elements may not have been shown or described in detail to avoid unnecessarily obscuring the disclosure. Accordingly, the description and drawings are to be regarded in an illustrative, rather than a restrictive, sense. 
   Coupler  10  includes right and left upper side plates  12 ,  14  which transversely locate pins  16 ,  18 . Plates  12 ,  14  are fixed in spaced-apart, substantially parallel relationship by right and left lower side plates  20 ,  22 . Plates  20 ,  22  are in turn fixed in spaced-apart, substantially parallel relationship by flanges  24 ,  26 ,  28 . More particularly, the right and left outward ends of rearward flange  24  bridge across and are welded to the inward sides of side plates  12 ,  14 ,  20 ,  22 . The right and left outward ends of upper and lower forward flanges  26 ,  28  are welded to the inward sides of lower side plates  20 ,  22 . The opposed ends of pin  16  are journalled for rotation in bearings  19 ,  21  which are mounted in the upper forward ends of right and left upper side plates  12 ,  14  respectively. The opposed ends of pin  18  are journalled and fixed in bearings  23 ,  25  which are mounted toward the rearward ends of right and left upper side plates  12 ,  14  respectively. 
   Transversely aligned forward pin-receiving apertures  30  are formed in the forward ends of lower side plates  20 ,  22 . Transversely aligned rearward pin-receiving apertures  32  are formed in the rearward ends of lower side plates  20 ,  22 . Forward pin-receiving apertures  30  have upward and forward-facing openings  34 . Rearward pin-receiving apertures  32  have downward-facing openings  36 . 
   Latching hook  38  (best seen in  FIGS. 6 and 25 ) is pivotally mounted on pin  40  which extends through latching hook  38 &#39;s upper aperture  41 . The right end of pin  40  is journalled for rotation in bearing  42  ( FIG. 1 ) which is mounted in the lower rearward end of upper side plate  12  and in the upper rearward end of lower side plate  20 . The left end of pin  40  is journalled for rotation in bearing  44  ( FIG. 20 ) which is mounted opposite bearing  42  in the lower rearward end of upper side plate  14  and in the upper rearward end of lower side plate  22 . 
   Right side safety lock  46  (best seen in  FIG. 3 ) has a ratchet face  55  and upper and lower apertures  56 ,  58 . Left side safety lock  48  (best seen in  FIG. 22 ) has a corresponding ratchet face  59  and upper and lower apertures  60 ,  62 . Right side torsion spring  108  (best seen in  FIG. 4 ) is positioned on the inward side of right side safety lock  46  to transversely align the coiled portion of spring  108  with aperture  56 . Left side torsion spring  110  (best seen in  FIG. 23 ) is positioned on the inward side of left side safety lock  48  to transversely align the coiled portion of spring  110  with aperture  60 . Upper apertures  56 ,  60  are transversely aligned with one another and with the coiled portions of torsion springs  108 ,  110 . Safety lock upper pivot pin  50  extends through apertures  56 ,  60  and through the coiled portions of right and left torsion springs  108 ,  110  as shown in  FIGS. 1 and 20 . The opposed ends of pin  50  are journalled for rotation in bearings  52 ,  54  which are mounted in the upper forward ends of lower side plates  20 ,  22  as shown in  FIGS. 1 and 20  respectively. Safety locks  46 ,  48  are thus spaced apart and pivotally mounted on safety lock upper pivot pin  50 . 
   Right side cylinder mount link  64  (best seen in  FIG. 5 ) has an engagement face  67  for engaging ratchet face  55  of right side safety lock  46  as explained below, and has upper forward and lower rearward apertures  68 ,  70 . Left side cylinder mount link  66  (best seen in  FIG. 24 ) has a corresponding engagement face  71  and upper forward and lower rearward apertures  72 ,  74 . Lower rearward apertures  70 ,  74  are transversely aligned with one another; and upper forward apertures  68 ,  72  are transversely aligned with one another. Cylinder mount link pivot pin  76  extends through lower rearward apertures  70 ,  74  as shown, for example, in  FIGS. 10 and 29 . The opposed ends of pin  76  are journalled for rotation in bearings  78 ,  80  which are mounted in the lower forward ends of lower side plates  20 ,  22  respectively as shown in  FIGS. 1  and  20  respectively. Cylinder mount links  64 ,  66  are thus spaced apart and pivotally mounted on cylinder mount link pivot pin  76 . 
   As best seen in  FIGS. 6 and 25 , latching hook  38  has right and left halves which are transversely aligned and joined by sleeve  83  and spacer  87 . Latching hook  38 &#39;s upper aperture  41  extends transversely through sleeve  83 . Transversely aligned central apertures  88  extend through latching hook  38 &#39;s right and left halves between sleeve  83  and spacer  87 . Sleeve  86  is fixed on the rod end of hydraulic cylinder  82  (best seen in  FIGS. 7 and 26 ). Sleeve  86  is positioned between latching hook  38 &#39;s right and left halves to transversely align sleeve  86 &#39;s aperture  89  with and between apertures  88 . Cylinder rod end pivot pin  84  extends through apertures  88 ,  89  as shown, for example, in  FIGS. 10 and 29 . The rod end of hydraulic cylinder  82  is thus pivotally coupled to latching hook  38 . 
   Right side lock link  94  (best seen in  FIG. 2 ) has upper and lower apertures  98 ,  100 . Left side lock link  96  (best seen in  FIG. 21 ) has corresponding upper and lower apertures  102 ,  104 . As previously explained, cylinder mount links  64 ,  66  are spaced apart on cylinder mount link pivot pin  76 . Right side lock link  94  is positioned on the right side of right side cylinder mount link  64  to transversely align apertures  68 ,  98 . Left side lock link  96  is positioned on the left side of left side cylinder mount link  66  to transversely align apertures  72 ,  102 . The cylinder end of hydraulic cylinder  82  is positioned between cylinder mount links  64 ,  66  to transversely align cylinder end aperture  90  (best seen in  FIGS. 7 and 26 ) with apertures  68 ,  72 ,  98 ,  102 . Cylinder end pivot pin  92  extends through the aligned apertures  68 ,  72 ,  98 ,  102 ,  90  as shown, for example, in  FIGS. 11 and 30 . The cylinder end of hydraulic cylinder  82  is thus pivotally coupled to cylinder mount links  64 ,  66  and to lock links  94 ,  96 . 
   As previously explained, safety locks  46 ,  48  are spaced apart on safety lock upper pivot pin  50 . More particularly, right side lock link  94  is positioned on the right side of right side safety lock  46  to transversely align apertures  58 ,  100 ; and left side lock link  96  is positioned on the left side of left side safety lock  48  to transversely align apertures  62 ,  104 . Safety lock lower pivot pin  106  extends through aligned apertures  58 ,  62 ,  100 ,  104  as shown, for example, in  FIGS. 11 and 30 . Lock links  94 ,  96  are thus pivotally coupled between safety locks  46 ,  48  and cylinder mount links  64 ,  66 . 
   Right and left side torsion springs  108 ,  110  are coiled around safety lock upper pivot pin  50  as previously explained. The springs&#39; upwardly extending ing ends  112 ,  114  bear against upper forward flange  26 . The springs&#39; transversely inwardly extending lower ends  116 ,  118  are seated within transverse recesses (not shown) in safety locks  46 ,  48  respectively. Springs  108 ,  110  thus bias safety locks  46 ,  48  clockwise with respect to safety lock upper pivot pin  50 , as shown, for example, in  FIGS. 10 ,  11 ,  14 ,  15 ,  18  and  19 . 
   In operation, pins  16 ,  18  are coupled to a machine&#39;s boom (not shown) in well known fashion to mount coupler  10  on the end of the boom. The machine operator initially actuates a cab-mounted control mechanism (not shown) to fully retract hydraulic cylinder  82  into the retracted position best seen in  FIGS. 10-11  and  29 - 30 . Such retraction pivots latching hook  38  forwardly (i.e. clockwise about pivot pin  40 , as viewed in  FIGS. 10-11 ; and counterclockwise about pivot pin  40 , as viewed in  FIGS. 29-30 ) such that latching hook  38  is clear of rearward aperture  32 ; and pivots cylinder mount links  64 ,  66  rearwardly (i.e. clockwise about pivot pin  76 , as viewed in  FIGS. 10-11 ; and counterclockwise about pivot pin  76 , as viewed in  FIGS. 29-30 ). Such pivotal movement of cylinder mount links  64 ,  66  draws lock links  94 ,  96  rearwardly (i.e. toward the right, as viewed in  FIGS. 10-11 ; and toward the left, as viewed in  FIGS. 29-30 ) on cylinder end pivot pin  92 . Since lock links  94 ,  96  are coupled between cylinder mount links  64 ,  66  and safety locks  46 ,  48  on pivot pins  76 ,  106  respectively, safety locks  46 ,  48  are also drawn rearwardly (i.e. pivoted counterclockwise about safety lock upper pivot pin  50  as viewed in  FIGS. 10-11 ; and clockwise about pin  50  as viewed in  FIGS. 29-30 ), such that safety locks  46 ,  48  are clear of aperture  30  as shown in  FIGS. 8-11  and  27 - 30 . 
   The operator then manoeuvres the machine&#39;s boom to position forward mounting pin  120  of implement  124  within coupler  10 &#39;s forward pin-receiving receiving aperture  30  and to position implement  124 &#39;s rearward mounting pin  122  within coupler  10 &#39;s rearward pin-receiving aperture  32  as shown in  FIGS. 8 and 27 . 
   The operator next actuates the aforementioned control system to extend the cylinder end of hydraulic cylinder  82  to the left, as viewed in  FIGS. 14-15  (i.e. to the right, as viewed in  FIGS. 33-34 ). Such extension pivots cylinder mount links  64 ,  66  forwardly (i.e. counterclockwise about pivot pin  76 , as viewed in  FIGS. 14-15 ; and clockwise about pivot pin  76 , as viewed in  FIGS. 33-34 ). Such pivotal movement of cylinder mount links  64 ,  66  moves lock links  94 ,  96  forwardly on cylinder end pivot pin  92 . Since lock links  94 ,  96  are coupled between cylinder mount links  64 ,  66  and safety locks  46 ,  48  on pivot pins  76 ,  106  respectively, safety locks  46 ,  48  are also drawn forwardly (i.e. pivoted clockwise about safety lock upper pivot pin  50  as viewed in  FIGS. 14-15 ; and counterclockwise about pin  50  as viewed in  FIGS. 33-34 ), such that safety locks  46 ,  48  extend within aperture  30  atop implement  124 &#39;s forward mounting pin  120 . The ratchet faces  55 ,  59  of safety locks  46 ,  48  engage the locking faces  67 ,  71  of cylinder mount links  64 ,  66  preventing withdrawal of pin  120  from aperture  30  as shown in  FIGS. 12-15  and  31 - 34 . Springs  108 ,  110  bias safety locks  46 ,  48  clockwise with respect to safety lock upper pivot pin  50  as viewed in  FIGS. 14-15  (i.e. counterclockwise as viewed in  FIGS. 33-34 ) maintaining engagement of safety locks  46 ,  48  atop pin  120  and preventing withdrawal of pin  120  from aperture  30  in the event of a hydraulic system failure. 
   The operator continues to extend the rod end of hydraulic cylinder  82  to the right, as viewed in  FIGS. 18-19  (i.e. to the left, as viewed in  FIGS. 37-38 ), thereby pivoting latching hook  38  counterclockwise about pivot pin  40  as viewed in  FIGS. 18-19  (i.e. clockwise about pivot pin  40  as viewed in  FIGS. 37-38 ) to extend latching hook  38  into rearward aperture  32  beneath implement  124 &#39;s rearward mounting pin  122 , preventing withdrawal of pin  122  from aperture  32  as shown in  FIGS. 16-19  and  35 - 38 . 
   To release implement  124  from coupler  10 , the operator first actuates the aforementioned control system to retract hydraulic cylinder  82 &#39;s rod end to the left as viewed in  FIGS. 14-15  (i.e. to the right as viewed in  FIGS. 33-34 ). Such retraction pivots latching hook  38  forwardly (i.e. clockwise about pivot pin  40  as viewed in  FIGS. 14-15 ; and counterclockwise about pivot pin  40  as viewed in  FIGS. 33-34 ) into the position shown in  FIGS. 12-15  and  31 - 34  in which latching hook  38  is clear of rearward aperture  32 . The operator continues to retract hydraulic cylinder  82 &#39;s cylinder end to the right as viewed in  FIGS. 10-11  (i.e. to the left as viewed in  FIGS. 29-30 ). Such retraction pivots cylinder mount links  64 ,  66  rearwardly, drawing lock links  94 ,  96  rearwardly on cylinder end pivot pin  92  thereby overcoming the biasing of springs  108 ,  110  and drawing safety locks  46 ,  48  rearwardly such that safety locks  46 ,  48  are clear of aperture  30  as shown in  FIGS. 8-11  and  27 - 30 . It will be noted that springs  108 ,  110  maintain engagement of safety locks  46 ,  48  atop pin  120  during release of implement  124  from coupler  10  until the final phase of the release operation in which the springs&#39;biasing is overcome as aforesaid, thus preventing withdrawal of pin  120  from aperture  30  in the event of a hydraulic system failure before completion of the release operation. 
   While a number of exemplary aspects and embodiments have been discussed above, those of skill in the art will recognize certain modifications, permutations, additions and sub-combinations thereof. It is therefore intended that the following appended claims and claims hereafter introduced are interpreted to include all such modifications, permutations, additions and sub-combinations as are within their true spirit and scope.