Patent Publication Number: US-9903095-B2

Title: Tool coupler

Description:
TECHNICAL FIELD 
     The present disclosure relates generally to a tool coupler and, more particularly, to a coupler for removably connecting a tool system to a mobile machine. 
     BACKGROUND 
     A typical worksite requires machines to perform a variety of different functions, including digging, leveling, grading, hauling lifting, trenching, etc. These functions are most efficiently conducted with tool systems specifically designed for each of the different functions. A tool coupler can be used to increase the functionality and versatility of the machine by allowing different tool systems to be quickly and interchangeably connected to the machine. 
     An exemplary tool coupler is disclosed in U.S. Patent Publication No. 2012/0027551 (the &#39;551 publication) by Rohou that published on Feb. 2, 2012. In particular, the &#39;551 publication discloses a tool coupler for an agricultural vehicle. The tool coupler includes a bracket connected to the vehicle, and a mast arrangement connected to a front loader. The mast arrangement comprises a pin configured to be received within a hook-shaped bearing point of the bracket, and a locking element that is movable by the operator. To perform the coupling, the operator drives the vehicle toward the front loader, until the pin of the mast arrangement is placed inside the bearing point of the bracket. The operator then exits the vehicle to make a hydraulic connection, and then re-enters the vehicle. The operator uses lift cylinders of the front loader to rotate the mast arrangement about the pin until openings in the mast align with corresponding openings in the bracket. The operator again exits the cabin and moves the locking element into the aligned openings, thereby completing the coupling. The operator enters the cabin again to control the vehicle and the newly connected front loader. 
     While the tool coupler of the &#39;551 publication may adequately couple a front loader to an agricultural vehicle, it may still be less than optimal. In particular, the tool coupler of the &#39;551 application requires the operator to leave the cabin multiple times in order to properly engage the coupler. And if the holes in the bracket and mast are not properly aligned when the operator exits the cabin to move the locking element, the locking element will not be able to pass through the openings. It may be difficult using the tool coupler of the &#39;551 publication to properly align the holes, as the operator&#39;s view of the holes may be obstructed. As a result, the operator will have to repeat the process multiple times, until the holes are properly aligned. This inconvenience could reduce efficiency, increase operating costs, and open the door to user error. 
     The tool coupler of the present disclosure addresses one or more of the needs set forth above and/or other problems of the prior art. 
     SUMMARY 
     One aspect of the present disclosure is directed to a base for a tool coupler. The base may include spaced-apart plates each having an upper end and a bottom end. The bottom end may have a leading edge and a trailing edge. The base may further include a female engagement feature located at the leading edge, and a male engagement feature located between the female engagement feature and the trailing edge of the spaced-apart plates. 
     Another aspect of the present disclosure is directed to an anchor for a tool coupler. The anchor may include a monolithic structure having an inside surface, an outside surface, a top surface, a bottom surface, a leading surface, and a trailing surface. The anchor may also include a primary engagement feature protruding outward from an intersection of the top and leading surfaces, and a secondary engagement feature formed within the top surface. 
     Yet another aspect of the present disclosure is directed to a tool coupler. The tool coupler may include a base configured to connect to the tool system and have spaced-apart plates each with an upper end and a bottom end, the bottom end having a leading edge and a trailing edge. The base may also have hooks located at the leading edge, and a first pin located between the hooks and the trailing edge of the spaced-apart plates. The first pin may extend transversely between the spaced-apart plates. The base may also have at least one web connecting the spaced-apart plates. The tool coupler may further include an anchor configured to connect to the machine and having a monolithic structure with an inside surface, an outside surface, a top surface, a bottom surface, a leading surface, and a trailing surface. The anchor may also have a rounded primary engagement feature protruding outward from an intersection of the top and leading surfaces to engage the hooks, a transverse slot formed within the top surface and configured to receive the first pin, and an elongated pocket formed inside the monolithic structure that is open to the transverse slot. The anchor may further have a wedge, and a linear actuator disposed inside the pocket and connected to the wedge. The linear actuator may be configured to selectively push the wedge into the transverse slot over the first pin to inhibit removal of the first pin from the transverse slot. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a pictorial illustration of an exemplary disclosed machine and tool system; and 
         FIGS. 2-4  are cutaway view illustrations of an exemplary disclosed tool coupler that may be used to connect the tool machine of  FIG. 1  with the machine of  FIG. 1 , each of  FIGS. 2-4  showing a different operating position of the tool coupler. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  illustrates an exemplary machine  10 . Machine  10  is a mobile machine that performs some type of operation associated with an industry, such as mining, construction, farming, transportation, or any other industry known in the art. In the disclosed example, machine  10  is a general track-type-tractor capable of accepting any number of different tool systems  12  by way of a coupler  14 , thereby becoming an application-specific machine. It should be noted, however, that machine  10  could be another type of machine, if desired. For example, machine  10  could be a wheeled machine and/or may have a fixed or integrated tool system in addition to tool system  12  that is removable. For example, machine  10  could be a haul truck having an integrated bed, a dozer having an integrated blade, or a backhoe having an integrated shovel. In any of these examples, machine  10  could still be configured to selectively connect with another tool system  12  by way of coupler  14 , if desired. 
     Machine  10  includes, among other things, a frame  16 , a power source (e.g., an engine)  18  mounted to frame  16 , one or more traction devices  20 , and an operator station  22  supported by frame  16 . Operator station  22  may house any number and type of input devices  24  for use by the operator in controlling tool system  12 , coupler  14 , power source  18 , and/or traction devices  20 . 
     Tool system  12  includes any type of tool  26 , linkage that physically supports tools  26 , and one or more actuators that are connected to move the linkage and tool  26 . In the disclosed embodiment, tool system  12  is a front loader, tool  26  is a loader bucket, and four different actuators are connected to lift and tilt tool  26 . Specifically, the depicted tool system  12  includes parallel spaced-apart lift arms  28  that are pivotally connected to tool  26  at distal ends. One lift cylinder  30  is associated with each lift arm  28  (e.g., pivotally connected at a rod-end to a mid-portion of each lift arm  28 ), and two tilt cylinders  32  pivotally connect the mid-portions of lift arms  28  to tool  26 . With this arrangement, extensions and retractions of lift cylinders  30  cause raising and lowering of tool system  12 , while extensions and retractions of tilt cylinders  32  cause dumping and racking of tool  26 . It should be noted that the disclosed tool system  12  is exemplary only, and many other types and configurations of tool system  12  may be selectively coupled to machine  10  via coupler  14 . 
     Coupler  14  is essentially comprised of three different parts, including a tool system base (“base”)  34 , a machine anchor (“anchor”)  36 , and a lock  38  (shown only in  FIGS. 2-4 ). Base  34  is connected to tool system  12 ; anchor  36  is connected to machine  10 ; and lock  38  is used to selectively connect base  34  to anchor  36 . Lock  38 , as will be described in more detail below, can be selectively activated by the operator of machine  10  from inside station  22 . 
     As shown in  FIG. 1 , each base  34  is fabricated primarily from two separate plates  40  that are spaced apart from each other. Plates  40  sandwich the base end of the corresponding lift arm  28 , and a pin  42  passes between plates  40  and through the base end of lift arm  28 . During lifting of lift arm  28 , tool system  12  pivots about pin  42 . Plates  40  may together also function as a housing that substantially encloses and protects lift cylinder  30 . In particular, lift cylinder  30  may be disposed between plates  40 , and connect at a head end to a pin  44  that also passes between plates  40 . With this arrangement, reaction forces generated by lift cylinder  30  during lifting of tool system  12  are received and countered by base  34 . Pins  42  and  44  may be connected to plates  40  in any manner known in the art. One or more webs  46  may interconnect plates  40  to provide structural integrity to base  34 . 
     Base  34  has an upper end  48  that receives pin  42 , and a bottom end  50  that receives pin  44 . Bottom end  50  is larger than upper end  48 , and includes features intended to mate with corresponding features in anchor  36 . For example, bottom end  50  may extend forward toward tool  26  more than upper end  48 , such that a length of bottom end  50  in the fore/aft direction is about three to five-times greater than the same dimension of upper end  48 . 
     Bottom end  50  of base  34  has a leading edge (i.e., an edge facing tool  26 )  52  and a trailing edge  54  located opposite each other in the fore/aft direction. As shown in  FIGS. 2-4 , one or more primary engagement features (“primary features”)  56  are located at leading edge  52 . In the disclosed example, primary features  56  are female features (e.g., identical hooks) formed within or otherwise connected to (e.g., welded to an inside surface of) each of plates  40 , these hooks together being configured to engage a corresponding male feature of anchor  36 . In another example, primary features  56  may additionally or alternatively include a pin that passes transversely between plates  40  at the same location as where the hooks (e.g., where tips of the hooks) are shown. Other types and/or shapes of engagement features may also be possible. 
     One or more secondary engagement features (“secondary features”)  58  are located between primary features  56  and trailing edge  54 . In the disclosed embodiment, a single secondary feature  58  is included in each base  34 , and shown as being located between primary features  56  and pin  44 . Secondary feature  58  may be a secondary engagement feature, as it is configured to engage anchor  36  after primary features  56  have already been engaged with anchor  36 . In the depicted example, secondary feature  58  is a pin that passes transversely between plates  40 . 
     Returning to  FIG. 1 , anchor  36  is received between plates  40  at bottom end  50  of base  34 . Anchor  36  is a monolithic structure having an inside surface  60 , an outside surface  62 , a bottom surface  64 , a top surface  66 , a leading surface  68 , and a trailing surface  70 . Inside and outside surfaces  60 ,  62  are generally planar, oriented generally orthogonal to a ground surface under machine  10 , aligned in the fore-aft direction of machine  10 , and mirror images of each other. Bottom surface  64  is generally perpendicular to inside and outside surfaces  60 ,  62 , and parallel with the ground surface. Top surface  66  is generally perpendicular to inside and outside surfaces  60 ,  62 , and tilted downward in the forward direction relative to bottom surface  64 . The tilting of top surface  66  may allow for material buildup on top of anchor  36 , without the buildup interfering with the coupling of base  34  to anchor  36 . Leading and trailing end surfaces  68 ,  70  are both generally perpendicular to inside and outside surfaces  60 ,  62  and also to bottom surface  64 . 
     A primary engagement feature (“primary feature”)  72  (i.e., the male feature discussed above) protrudes forward and upward from an intersection of top and leading surfaces  66 ,  68 . Primary feature  72  is rounded at a distal end that engages primary features  56 , thereby creating a smooth surface about which the hooks pivot. Primary feature  72  protrudes away from leading surface  68  far enough to avoid contact of feature  56  (i.e., of the tips of the hooks) with leading surface  68 . An outer radius of primary feature  72  may be about equal to or smaller than an inner radius of feature  56 . 
     A secondary or female engagement feature (“secondary feature”)  74  is formed within top surface  66  and configured to receive secondary feature  58 . In the disclosed embodiment, secondary feature  74  is a recess or transverse slot, in which the pin of secondary feature  58  is seated during connection of base  34  to anchor  36 . As shown in  FIGS. 2-4 , secondary feature  74  may have a depth that is at least as big as a diameter of the pin, and a length in the fore-aft direction that is 1.5-2.5 times the diameter of the pin. A leading side of secondary feature  74  is tilted backward and downward relative to leading and trailing surfaces  68 ,  70 , such that, as secondary feature  58  is pressed down into secondary feature  74 , base  34  is pulled rearward and further onto anchor  36 . A bottom surface of secondary feature  74  is generally parallel to top surface  66  of anchor  36 . The location and size of secondary feature  74  creates a lip  76  at the intersection of top and trailing surfaces  66 ,  70  that functions as an end stop for secondary feature  58 . It is contemplated that, in some embodiments, lip  76  may be omitted (i.e., that secondary feature  74  may continue through trailing surface  70 ), if desired. 
     A pocket  78  is formed inside anchor  36  to house lock  38 . Pocket  78  is elongated, generally aligned in the fore/aft direction, and open at one end to secondary feature  74 . In this configuration, lock  38  (i.e., at least a portion thereof) is configured to selectively extend from pocket  78  into the open space of secondary feature  74 , thereby inhibiting the pin of secondary feature  58  from inadvertently exiting the space. Pocket  78  may have any shape and size necessary to properly house lock  38 . In the disclosed embodiment, pocket  78  has a generally square cross-section. In this embodiment, one or more planar side surfaces of pocket  78  function as guides for the moving elements of lock  38 . For example, an upper surface of pocket  78  may function as a guide for lock  38 , and be generally parallel with top surface  66  and the bottom surface of secondary feature  74 . It is contemplated that holes and/or passages (not shown) may be formed within anchor  36  that allow for electrical, mechanical, and/or hydraulic communication with lock  38  while lock  38  is inside pocket  78 . 
     Lock  38  may be any device known in the art that can be remotely activated by the operator to inhibit disengagement of secondary feature  58  from secondary feature  74 . In the disclosed embodiment, lock  38  includes a mechanical wedge  80  and an actuator  82  that is connected to move wedge  80 . Wedge  80  has a generally flat back that slides against the planar upper surface of pocket  78 , and a tapered front that is configured to engage and secure secondary feature  58  inside secondary feature  74 . Actuator  82  is a linear actuator, for example an electrical screw or hydraulic cylinder that, when actuated, causes wedge  80  to advance into the open space of secondary feature  74 . In one example, wedge  80  is spring-biased to retract back into pocket  78  when actuator  82  is deactivated. In another example, wedge  80  is powered back into pocket  78  by actuator  82 . 
       FIGS. 2-4  depict different stages of a coupling operation.  FIGS. 2-4  will be discussed in more detail in the following section to further illustrate the disclosed concepts. 
     INDUSTRIAL APPLICABILITY 
     The presently disclosed tool coupler is applicable to any mobile machine to increase the functionality of the machine. For example, a general-use machine may utilize the disclosed coupler to selectively connect a front loader, a backhoe, a trencher, a crane, or another tool system to the machine, such that the machine can be used for many different purposes. In another example, a specific-use machine may utilize the disclosed coupler to connect with a tool system different from the one already connected to the machine. This increase in functionality lowers capital costs for the machine owner, and/or allows for increased business opportunities. Operation of coupler  14  will now be described in detail with respect to  FIGS. 2-4 . 
     As shown in  FIG. 2 , the first step in connecting tool system  12  to machine  10  is to drive machine  10  forward toward tool system  12 , until primary feature  72  is received within feature  56  (i.e., until the male protrusion of anchor  36  rests within the hooks of base  34 ). Base  34  naturally tilts forward as shown in  FIG. 2  when tool system  12  is resting on the ground surface and not connected to machine  10 , due to the kinematics of tool system  12 . Accordingly, during the forward movement of machine  10  described above, the operator is able to observe the engagement of features  72  and  56 , and to selectively adjust the trajectory of machine  10  so that features  72 ,  56  align and engage properly. 
     After engagement of primary feature  72  with primary features  56 , the operator connects hydraulic supply lines (not shown) located onboard machine  10  with corresponding lines of tool system  12 . It should be noted that each tool system  12  attachable to machine  10  may have different fluid supply needs and, accordingly, different connection requirements. For example, some tool systems  12  may need a single hose connection to be made, while other tool systems  12  may require multiple hoses to be connected. It is also possible, that some tool systems  12  may not require any fluid connections. 
     In the disclosed embodiment, at least two supply and two drain connections must be made (i.e., one supply and one drain for each set of lift and tilt cylinders  30 ,  32 ). In this example, these connections are made manually by the operator of machine  10 . In some applications, the manual connections may require the operator to exit station  22 . In other applications, however, the operator may be able to reach the corresponding hoses and perform the required connections while remaining in station  22 . In yet other embodiments, the connections may be made automatically during the mechanical coupling of base  34  with anchor  36 . 
     Once the appropriate hydraulic connections are made, the operator manipulates one or more input devices  24  inside station  22  to cause a pivoting motion of base  34  about primary feature  72 . For example, the operator may cause lift cylinders  30  to retract, such that base  34  (when viewed from the perspective of  FIG. 1 ) rotates in a clockwise direction. At this point in time, wedge  80  is fully retracted into pocket  78 . The operator causes pivoting of base  34  in this direction until secondary feature  58  is placed within secondary feature  74  (shown in  FIG. 3 ). 
     Once the operator visually confirms that secondary feature  58  is properly located inside secondary feature  74 , and without having to exit station  22 , the operator locks secondary feature  58  in place. In particular, as shown in  FIG. 4 , the operator causes actuator  82  to force wedge  80  out of pocket  78  and over the top of secondary feature  58 . The operator initiates this operation via manipulation of input device  24 . As the tapered surface of wedge  80  engages secondary feature  58 , the tapered surface functions to force secondary feature  58  further into secondary feature  74 . Once wedge  80  is fully extended, coupling of tool system  12  to machine  10  is complete. To decouple tool system  12  from machine  10 , the operator performs the above-described operations in a reverse order. 
     Several advantages are associated with the disclosed tool coupler. In particular, the operator is required to exit station  22  a reduced number of times (if at all) to complete the coupling. In addition, the location and configuration of anchor  36  allows clear view to the operator of the disclosed coupling process. 
     It will be apparent to those skilled in the art that various modifications and variations can be made to the tool coupler of the present disclosure without departing from the scope of the disclosure. Other embodiments will be apparent to those skilled in the art from consideration of the specification and practice of the tool coupler disclosed herein. For example, although machine  10  is shown as having only a single set of couplers  14  located at one end of machine  10 , it is contemplated that multiple sets may be used and located at opposing ends such that two or more tool systems  12  may be simultaneously connected to machine  10 . It is intended that the specification and examples be considered as exemplary only, with a true scope of the disclosure being indicated by the following claims and their equivalent.