Patent Publication Number: US-9896817-B2

Title: Coupler assembly for releasably coupling a work machine to work tool and method thereof

Description:
FIELD OF THE DISCLOSURE 
     The present disclosure relates to a coupler assembly of a work machine, and in particular, a coupler assembly including a plurality of locking mechanisms for releasably coupling a work tool to a work machine. 
     BACKGROUND 
     Many conventional work machines, such as those in the construction and forestry industries, perform various tasks such as craning or digging functions. To perform some of these functions, machines may include a work tool removably coupled to a boom arm. The work tool may include a blade, bucket, etc. A coupler may be used for removably coupling one or more work tools to the boom arm. 
     SUMMARY 
     In one embodiment of the present disclosure, a coupler assembly is provided for coupling a work tool to a work machine. The coupler assembly includes a body having a front end and a rear end; a first locking mechanism pivotable about a pivot from a first position to a second position, the first locking mechanism configured to be coupled to the work tool in the first position and decoupled in the second position; and a second locking mechanism including a pin having a first end and a second end, a tab coupled to the pin proximate the second end, and a spring disposed between the first end and the second end, where the second locking mechanism is axially and pivotably movable about an axis; wherein, the second locking mechanism is movable between a locked position and an unlocked position; further wherein, as the first locking mechanism moves from the second position to the first position, the second locking mechanism automatically moves to the locked position. 
     In one example of this embodiment, the first locking mechanism is maintained in the first position in the locked position. In a second example, as the second locking mechanism is moved from the locked position to the unlocked position, the pin is axially moved to an outward position from its locked position and the tab is rotated to a position whereby at least one of the second end and the tab is in contact with the first locked mechanism to maintain the pin in the outward position. In a third example, the first locking mechanism is movable between the first and second positions in the unlocked position. In a fourth example, a second spring coupled to the first locking mechanism. 
     In a fifth example, the coupler assembly includes a spring support pivotably coupled to the first locking mechanism; and a retainer fixedly coupled to the body; wherein, the second spring is disposed between the spring support and retainer. In a sixth example, the body defines a longitudinal axis that passes through the pivot, and the second spring is disposed below the axis in the first position and above the axis in the second position. In a seventh example, the first locking mechanism remains in the second position when the second spring is disposed above the axis. In an eighth example, the second locking mechanism automatically moves to its locked position once a trailing edge of the first locking mechanism moves past the pin and the pin is releasably disengaged from contacting the first locking mechanism. 
     In another example of this embodiment, the spring biases the pin from its outward position to an inward position once the pin is no longer in contact with the first locking mechanism. In a further example, a hook portion is defined at the front end of the body, the hook portion being configured to be releasably coupled to the work tool. In a different example, in the second position, the hook portion is coupled to the work tool until the body is rotated to a position that releases the work tool from the hook portion. 
     In a further embodiment, a work machine includes a frame supported by at least one ground-engaging mechanism; a cab mounted to the frame, the cab including at least one control element for controlling a function of the machine; a work tool controllable for performing a work function; a coupler assembly for coupling the work tool to the work machine, the coupler assembly including a body having a front end and a rear end; a first locking mechanism pivotable about a pivot from a first position to a second position, the first locking mechanism configured to be coupled to the work tool in the first position and decoupled in the second position; and a second locking mechanism including a pin having a first end and a second end, a tab coupled to the pin proximate the second end, and a spring disposed between the first end and the second end, where the second locking mechanism is axially and pivotably movable about an axis; wherein, the second locking mechanism is movable between a locked position and an unlocked position; further wherein, as the first locking mechanism moves from the second position to the first position, the second locking mechanism automatically moves to the locked position. 
     In one example of this embodiment, in the second position, the coupler assembly is controllably rotated via a hydraulic cylinder to disengage the work tool from the coupler assembly. In a second example, in the locked position, the first locking mechanism is maintained in the first position; and in the unlocked position, the first locking mechanism is movable between the first and second positions. In a third example, as the second locking mechanism is moved from the locked position to the unlocked position, the pin is axially moved to an outward position from its locked position and the tab is rotated to a position whereby at least one of the second end and the tab is in contact with the first locked mechanism to maintain the pin in the outward position. 
     In a fourth example, the machine includes a spring support pivotably coupled to the first locking mechanism; a retainer fixedly coupled to the body; and a second spring coupled to the spring support and retainer to maintain a compressive force against the first locking mechanism. In a fifth example, the body defines a longitudinal axis that passes through the pivot; further wherein, the second spring is disposed below the axis in the first position and above the axis in the second position. In a sixth example, the first locking mechanism remains in the second position when the second spring is disposed above the axis. In a seventh example, the second locking mechanism automatically moves to its locked position once a trailing edge of the first locking mechanism moves past the pin and the pin and tab are releasably disengaged from contacting the first locking mechanism. In an eighth example, a hook portion is defined at the front end of the body, the hook portion being configured to be releasably coupled to the work tool. 
     In a different embodiment, a method is provided for decoupling a work tool from a work machine. The method includes providing a coupler assembly including a body, a spring, a first locking mechanism, and a second locking mechanism, the second locking mechanism including a pin having a first end and a second end, and a tab coupled to the pin at the second end; moving the pin axially outwardly from its locked position; rotating the pin until the second locking mechanism contacts the first locking mechanism; pivoting the first locking mechanism about a pivot; moving the first spring from a position below an axis passing through the pivot to a position above the axis; releasing a pin of the work tool from the first locking mechanism; and decoupling the work tool from the work machine. 
     In one example of this embodiment, the method includes unlocking the second locking mechanism after the rotating step. In a different example, the pin is rotated until the tab contacts a plug coupled to the first locking mechanism. In a third example, the method includes inserting a tool into an opening formed in the first locking mechanism; rotating the tool in a downward position; and moving the first locking mechanism from a first position to a second position; wherein, the pin is released from the first locking mechanism in the second position. In a fourth example, the method includes maintaining contact between the first and second locking mechanisms in the second position. 
     In a fifth example, the method includes compressing the first spring between the coupler assembly and the first locking mechanism. In a sixth example, the method includes maintaining a second pin of the work tool coupled to the coupler assembly at a front end of the body after the releasing step. In a seventh example, the method includes pivoting the coupler assembly to release the coupler assembly from the second pin before the decoupling step. 
     In another embodiment of the present disclosure, a method is provided for coupling a work tool to a work machine. The method includes providing a coupler assembly including a body, a spring, a first locking mechanism, and a second locking mechanism, the second locking mechanism including a pin having a first end and a second end, a tab coupled to the pin at the second end, and a second spring; positioning the first locking mechanism is an open position and the second locking mechanism in an unlocked position relative to the first locking mechanism; contacting the first locking mechanism with the work tool; triggering the first locking mechanism to rotate about a pivot; rotating the first locking mechanism about the pivot to couple the work tool to the first locking mechanism; automatically releasing the second locking mechanism from contact with the first locking mechanism; moving the second locking mechanism from its unlocked position to a locked position; and coupling the work tool to the work machine. 
     In one example, the moving step includes decompressing a second spring of the second locking mechanism after the releasing step. In a second example, the rotating step includes rotating the first locking mechanism from an open position to a closed position. In a third example, the method includes enabling the first locking mechanism to rotate about the pivot when the second locking mechanism is disposed in the unlocked position; and preventing the first locking mechanism from rotating about the pivot when the second locking mechanism is disposed in the locked position. In a fourth example, the method includes disposing the second locking mechanism outwardly from the body in the unlocked position; and disposing the second locking mechanism inwardly from the body in the locked position. 
     In a fifth example, the method includes positioning the spring above a longitudinal axis passing through the pivot before the rotating step. In a sixth example, the method includes moving the spring from above the axis to below the axis during the rotating step. In a seventh example, the method includes engaging a hooked portion of the coupler assembly with the work tool before the contacting step. In an eighth example, the method includes pivoting the coupler assembly about the work tool after the engaging step in order to perform the contacting step. In a ninth example, the method includes coupling the work tool at a first end of the body via the hooked portion and at a second end via the first locking mechanism, the first end and second end being spaced from one another. In another example, the method includes disposing the tab at a location behind the first locking mechanism in the locked position. 
     In yet a further embodiment, a coupler assembly for coupling a work tool to a work machine is provided. The coupler assembly includes a pair of longitudinal bodies having a front end and a rear end; a plate coupled between the pair of bodies at the rear end thereof, wherein the plate includes a slot defined therein; a hook portion formed at the front end of the pair of bodies, the hook portion defining a first cavity adapted to receive to a first pin of the work tool; a first locking mechanism defining a plurality of openings and including a finger portion, the finger portion partially defining a second cavity adapted to receive a second pin of the work tool; a pivot pin disposable in one of the plurality of openings of the first locking mechanism, the pivot pin pivotably coupling the first locking mechanism to the pair of bodies to enable the first locking mechanism to pivot about a first pivot axis; a first spring having a first end and a second end, the first end being pivotably coupled to the first locking mechanism about a second pivot axis; and a second locking mechanism including a pin having a first end and a second end, a tab coupled to the pin proximate the second end, and a second spring disposed between the first and the second ends, where the second locking mechanism is axially and pivotably movable about an axis; wherein, the first locking mechanism is pivotable about the first pivot axis between a first position and a second position, and the second locking mechanism is movable between a locked position and an unlocked position; further wherein: in the first position, the first locking mechanism is configured to be coupled to the second pin of the work tool and the tab is disposed to the rear of the first locking mechanism to block the first locking mechanism from pivoting from its first position and the second locking mechanism is disposed in its locked position; and in the second position, the first locking mechanism is pivotably displaced from the first position such that the finger portion is configured to be at least partially disposed between the pair of bodies and the second pin, and the second locking mechanism is disposed axially outward in its unlocked position and in contact with the first locking mechanism. 
     In one example of this embodiment, the coupler assembly includes a spring support pivotably coupled to the first locking mechanism; and a retainer fixedly coupled to the pair of bodies; wherein, the first spring is disposed between the spring support and retainer. In a second example, one of the pair of bodies defines a longitudinal axis that passes through the first pivot axis; further wherein, the first spring is disposed below the longitudinal axis in the first position and above the longitudinal axis in the second position. In a third example, the second locking mechanism automatically moves to its locked position from its unlocked position once a trailing edge of the first locking mechanism moves past the pin, the pin is releasably disengaged from contacting the first locking mechanism, and the second spring biases the second locking mechanism inwardly such that the tab is disposed rearward of the first locking mechanism. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above-mentioned aspects of the present disclosure and the manner of obtaining them will become more apparent and the disclosure itself will be better understood by reference to the following description of the embodiments of the disclosure, taken in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is a side view of a machine; 
         FIG. 2  is a side perspective view of a portion of a boom assembly and a work tool; 
         FIG. 3  is a partial side view of a coupler assembly for coupling the boom assembly of  FIG. 2  with the work tool. 
         FIG. 4  is another partial side view of the coupler assembly of  FIG. 3 ; 
         FIG. 5  is another partial side view of the coupler assembly being decoupled from the work tool; 
         FIG. 6  is another partial side view of the coupler assembly being decoupled from a rear pin of the work tool; 
         FIG. 7  is another partial side view of the coupler assembly being decoupled from the work tool; 
         FIG. 8  is a partial side view of the coupler assembly being coupled to a front pin of the work tool; 
         FIG. 9  is a partial side view of the coupler assembly being coupled to a rear pin of the work tool; 
         FIG. 10  is another partial side view of the coupler assembly being partially coupled to the work tool; 
         FIG. 11  is a side perspective and cross-sectional view of the coupler assembly of  FIG. 3  in a coupled position; 
         FIG. 12  is a side perspective and cross-sectional view of the coupler assembly of  FIG. 3  in a decoupled position; 
         FIG. 13  is an exploded view of the coupler assembly of  FIG. 3 ; 
         FIG. 14  is a flowchart illustrating one example of decoupling a work tool from the coupler assembly of  FIG. 3 ; and 
         FIG. 15  is a flowchart illustrating one example of coupling a work tool to the coupler assembly of  FIG. 3 . 
     
    
    
     Corresponding reference numerals are used to indicate corresponding parts throughout the several views. 
     DETAILED DESCRIPTION 
     The embodiments of the present disclosure described below are not intended to be exhaustive or to limit the disclosure to the precise forms disclosed in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art may appreciate and understand the principles and practices of the present disclosure. 
     An example embodiment of a work machine is shown in  FIG. 1 . The machine is illustrated as a loader backhoe  100 . The present disclosure is not limited, however, to a loader backhoe and may extend to other work machines such as an excavator, crawler, harvester, skidder, motor grader, or any other work machine. As such, while the figures and forthcoming description may relate to a loader backhoe, it is to be understood that the scope of the present disclosure extends beyond a loader backhoe and, where applicable, the term “machine” or “work machine” will be used instead. The term “machine” or “work machine” is intended to be broader and encompass other vehicles besides a loader backhoe for purposes of this disclosure. 
     Referring to  FIG. 1 , the machine  100  includes a chassis  102  forming a frame structure. A power source or engine  104  can provide power to a plurality of traction devices, illustratively front wheels  106  and rear wheels  108 . It is also within the scope of the present disclosure that the traction devices of vehicle  100  may include belts or steel tracks, for example. In use, engine  104  drives the front and/or rear wheels  106  and  108  via a transmission (not shown), causing vehicle  100  to propel across the ground. 
     The machine  100  of  FIG. 1  may also include an operator cab  110  supported by the chassis  102  to house and protect the operator of the machine  100 . The operator cab  110  may include a plurality of controls for operating the machine. In  FIG. 1 , a steering wheel  112  may be used to manipulate a direction of travel of the machine  100 . In addition, other controls  114  such as joysticks, pedals, switches, buttons, and the like may be used for controlling one or more work functions of the machine  100 . 
     The machine  100  may include a loader assembly  116  disposed at a front end and a backhoe assembly  118  at a rear end thereof. The machine  100  may further include at least one work tool, illustratively a first work tool  120  (i.e., a loader bucket) coupled to the loader assembly  116  and a second work tool  138  (i.e., a backhoe bucket) coupled to the backhoe assembly  118 . Other suitable work tools may be used such as, for example, blades, forks, tillers, and mowers. Work tools  120  and  138  are moveably coupled to chassis  102  for scooping, carrying, and dumping dirt and other materials. 
     As shown in  FIG. 1 , the first work tool  120  is moveably coupled to the front end of chassis  102  via a first boom assembly  122 , which includes a plurality of hydraulic actuators for moving the first work tool  120  relative to chassis  102 . The illustrative first boom assembly  122  includes hydraulic lift cylinders  124  for raising and lowering the first boom assembly  122  and a hydraulic tilt cylinder  126  for tilting (e.g. digging and dumping) the first work tool  120 . 
     The second work tool  138  is moveably coupled to the rear end of chassis  102  via a second boom assembly  128 , which includes a dipper arm  140 , a boom arm  142 , a linkage assembly  144 , and a plurality of hydraulic actuators for moving the second work tool  138  relative to chassis  102 . The illustrative second boom assembly  128  may include a plurality of hydraulic swing cylinders  130  for swinging the second boom assembly  128  side to side, a hydraulic lift cylinder  132  for raising and lowering the second boom assembly  128 , a hydraulic crowd cylinder  134  for bending the second boom assembly  128 , and a hydraulic tilt cylinder  136  for tilting (e.g. digging and dumping) the second work tool  138 . The operator may control movement of the first and second work tools using controls  114  located within operator cab  110 . 
     Referring to  FIG. 2 , a portion of a work machine  200  is shown. In particular, a dipper arm  204  is shown extending downwardly from a boom arm (not shown). A linkage assembly  206  is pivotably coupled to the dipper arm  204 , and a coupler assembly  210  is coupled to the linkage assembly  206 . A hydraulic actuator  208  similar to the hydraulic tilt actuator  136  of  FIG. 1  is also shown. The hydraulic actuator  208  can be actuated via one or more controls  114  from the operator&#39;s cab  110 . By actuating the hydraulic actuator  208 , the linkage assembly  206  and coupler assembly  210  can be operably controlled for performing a work function. 
     In one example, a work tool  202  such as a bucket may be removably coupled to the coupler assembly  210 . The work tool  202  may include a first pin  212  and a second pin  214 . The first pin  212  may be disposed towards a front end of the work tool  202 , whereas the second pin  214  may be disposed towards a rear end thereof. In any event, an operator may operate the controls  114  in order to couple the coupler assembly  210  to the work tool  202 . This will be further described in this disclosure. 
     In conventional work machines such as a backhoe, there may be two mechanisms for locking or coupling a work tool to the machine. The machine can be controlled to couple one mechanism to the work tool, but the second mechanism usually requires the operator to exit the machine and manually manipulate the second mechanism for coupling to the work tool. Government safety regulations may require both mechanisms to be coupled to the work tool before the machine is operated. However, there is often no means to prevent the machine from being operated without both mechanism disposed in their respective locked conditions. In other words, if an operator does not want to exit the machine after locking the first mechanism to the work tool, there is nothing in place to prevent the machine from being operated. 
     Given that it is inefficient and unproductive to require the operator to exit the machine each time a new work tool is coupled thereto, a need exists to be able to automatically actuate the second mechanism to couple or lock the machine to the work tool. As will be described herein, the coupler assembly  210  is a spring-based assembly that provides an automatic locking mechanism for securing the work tool to the machine without requiring a machine operator to exit the machine and manually couple or lock the machine to the tool. In addition, the coupler assembly  210  further provides visual confirmation to the operator that the coupler assembly is disposed in either its unlocked or locked configuration. 
     Referring to  FIGS. 3 and 13 , one illustrated embodiment of the coupler assembly  210  is shown. The coupler assembly  210  includes a pair of elongated bodies  302  spaced from one another. A first plate  304  may be coupled between the pair of bodies  302  at a rear of the coupler assembly  210 , whereas a second plate  1300  may be coupled therebetween at a front of the assembly  210 . Each plate may be welded, for example, to the pair of elongated bodies  302 . As shown in  FIG. 2 , the first plate  304  may include a defined slot  306  therein. The slot  306  may be substantially U-shaped. The shape of the defined slot  306 , however, may be oval, rectangle, square, or the like. 
     The coupler assembly  210  includes a front end defined by a pair of hook arms  344 . The hooks arms  344  form a cavity  342  for receiving the second pin  214  of the work tool  202 . The assembly  210  may include a rear end that includes a first locking mechanism  308  and a second locking mechanism  310 . The first locking mechanism  308  is pivotably coupled to the bodies  302  via a pivot pin  322 . The pivot pin  322  may be an elongated pin that is positioned within an opening formed in each body  302 , and the first locking mechanism  308  may pivot about a first pivot axis  328 . The pivot pin  322  may include an enlarged head at one end and a retaining ring  1318  may be used to fasten the pin  322  at an opposite end thereof. Between the enlarged head and retaining ring, a pair of washers  1312 , a pair of bearings  1314 , and a spacer bearing  1316  may be disposed between the first locking mechanism  308  and pivot pin  322 . 
     The second locking mechanism  310  may be formed by an elongate pin  312  that passes through an opening formed in one of the bodies  302 . The opening for the pin  312  of the second locking mechanism  310  may be spaced from the opening for the pivot pin  322 , but the location of each is generally towards the rear of the coupler assembly  210 . The second locking mechanism  310  may further include a tab  314  that is coupled thereto. For instance, the tab  314  may be welded to the pin  312 . The tab  314  may extend at a direction that is at least partially perpendicular to a longitudinal axis defined by the pin  312 . The tab  314  may be coupled at one end of the pin  312 , whereas a handle is coupled at the opposite end thereof. The pin  312  therefore is pivotably and axially movable relative to the pair of bodies  302 . 
     In addition, the second locking mechanism  310  may include a spring  1302  that biases the pin  312  towards a position defined inwardly of the bodies  302 . This will be described in greater detail below. The spring  1302  is disposed between a first ring  1304  and a first retaining ring  1310  at one end and a second ring  1306  and a second retaining ring  1308  at an opposite end thereof. For example, the first ring  1304  and first retaining ring  1310  may be disposed nearest the handle, whereas the second ring  1306  and second retaining ring  1308  may be disposed nearest the tab  314 . As previously described, the spring  1302  is disposed between the rings and retaining rings and is compressed when the pin  1312  is moved axially outward and away from the coupler assembly  210 . In some aspects, the spring  1302  may constantly be compressed when assembled with the pin  312 , and when the pin  312  is pulled outwardly it further compresses the spring  1302 . 
     The first locking mechanism  308  may be formed by a pair of bodies as shown in  FIG. 13 . Each body includes a plurality of openings defined therein, one of which is for the pivot pin  322  as previously described. Each body of the first locking mechanism  308  includes a crescent-shaped finger  316  that has a curvature for defining a cavity  318 . The cavity  318 , as shown in  FIG. 3 , is formed partially by the inner surface of the finger  316  along one side and an inner surface  320  of the body along an opposite side. The cavity  318  may be defined as a longitudinal channel having a width that is approximately the diameter of the second pin  214 . In some embodiments, the width may be slightly larger than the diameter of the second pin  214  for a secure engagement. In other embodiments, the width may be much larger than the diameter of the pin  214 . In any event, when coupling the coupler assembly  210  to the work tool  202 , the second pin  214  is received within the cavity  318 . As will be described below, the finger  316  may be pivoted to further secure the second pin  214  of the work tool  202  within the cavity  316  in the coupled position. 
     A plug  326  formed by an elongate pin may also be coupled to an opening defined in one of the bodies of the first locking mechanism  308 . When assembled, a portion of the plug  326  may extend out of the opening. This will be further described below. 
     The coupler assembly  210  may be referred to as a spring-type coupler assembly. As shown in  FIGS. 3-13 , the coupler assembly  210  may include a spring  330 . The spring  330  may be a coil spring, toroidal spring, bevel spring, or any other known type of spring. The spring may apply a continuous spring force against the first locking mechanism  308 . This spring force may vary based on the position of the first locking mechanism  308  and spring  330 . 
     The spring  330  includes a first end and a second end. The first end may be coupled to a spring support  332  and the second end may be coupled to a retainer  334 . The spring support  332  forms a body that may include an extended portion  1330  that fits within the spring  330 . The body of the spring support  332  may further define an opening  1328  for receiving a pin  336 . The pin  336  defines a second pivot axis  338  and is further received in openings formed in the first locking mechanism  308 . The pin  336  may be secured or coupled to the first locking mechanism  308  via a retaining ring  1320 . Thus, the spring support  332  and first end of the spring  330  is pivotably coupled to the first locking mechanism  308  about the second pivot axis  338 . As such, pivotal movement of the spring  300  and spring support  332  can enable a proper alignment of the spring  330 . 
     The retainer  334 , or spring retainer, may be coupled to the side plate  1300  of  FIG. 13 . The side plate may include a pair of holes for fastening the retainer  334  thereto. As shown in  FIG. 13 , the retainer  334  may be received within a larger opening defined in the side plate  1300 , and a washer  1324 , retainer plate  1322 , and fasteners  1326  may further be used for coupling the retainer  334  to the side plate  1300 . In the illustrated embodiments, the retainer  334  may be fixedly coupled to the side plate  1300 . However, in other embodiments, the retainer  334  may be pivotably or otherwise movably coupled to the side plate  1300 . 
     As shown best in  FIG. 3 , a cap screw  340  or other fastener may be threadedly coupled to the retainer  334 . During the assembly process, the spring  330  may be under significant strain. Thus, to enable the assembly and disassembly thereof, the cap screw  340  may be used to collapse the spring  330 . The retainer  330  may therefore be drilled and tapped to support the use of a cap screw in the assembly and disassembly processes. 
     Referring to  FIG. 3 , the coupler assembly  210  is shown in its coupled or locked position  300 . In this position, the coupler assembly  210  is coupled to the second pin  214  of the work tool  202 . The first locking mechanism  308  is in a first or coupled position and the second locking mechanism  310  is in its locked position. In the locked position, the tab  314  of the second locking mechanism  310  may be disposed behind or to the rear of the first locking mechanism  308 . As such, the first locking mechanism  308  is unable or blocked from pivoting about the first pivot axis  328 . Moreover, the pin  312  of the second locking mechanism  310  is disposed axially inward (i.e., the axial inward position being into the page of  FIG. 3 ). Thus, the first locking mechanism  308  remains coupled to the second pin  214 . 
     Also in the coupled position  300  of  FIG. 3 , the spring  330  is positioned below a first axis  324 . The first axis  324  is shown passing through the first pivot axis  328  and the second end of the spring  330 . As will be described below, the position of the spring  330  relative to this first axis  324  will change as the coupler assembly  210  is coupled to and decoupled from the work tool  202 . 
     In the coupled position  300  of  FIG. 3 , the first pin  212  of the work tool  202  is disposed within the second cavity  342  formed by the hook arm  344  of the coupler assembly  210 . The orientation of the coupler assembly  210  may be such that it is disposed at an acute angle relative to a horizontal axis (not shown) passing through the pivot axis  328 . This provides sufficient support for coupling the work tool  202  to the machine. 
     In order to release the work tool  202  from the coupler assembly  210 , one example of a method  1400  for doing so is shown in  FIG. 14 . This example provides a number of blocks for executing the method. One skilled in the art will appreciate that some of these steps may not be required in other examples, whereas additional steps may be executed in further examples. Thus,  FIG. 14  is intended to be a non-limiting example of how to release or decouple the work tool  202  from the coupler assembly  210 . 
     In block  1402 , the handle on the second locking mechanism  310  may be pulled axially outward so that the pin  312  and tab  314  are no longer positioned directly behind or to the rear of the first locking mechanism  308 . For instance, in  FIG. 11 , the pin  312  and tab  314  are shown disposed in an axially inward position  1100 . In this position  1100 , the tab  314  and at least part of the pin  312  is disposed rearward or behind a rear surface  1102  (i.e., trailing edge  902  of  FIG. 9 ) of the first locking mechanism  308 . This axially inward position  1100  of the pin  312  and tab  314  is referred to as the locked position of the second locking mechanism  310 . In effect, the second locking mechanism  310  at least partially obstructs or prevents the first locking mechanism  308  from rotating from its position in  FIG. 11  to its position in  FIG. 5 , which is described in further detail below. 
     In block  1402 , the pin  312  and tab  314  of the second locking mechanism  310  are pulled axially outward in a direction indicated by arrow  1104  in  FIG. 11 . This releases the first locking mechanism  308  from being disposed in a locked position in block  1406 . In other words, with the second locking mechanism  310  moved axially outwardly, a path by which the first locking mechanism  308  may pivot in a counterclockwise direction is vacated and thus unobstructed. 
     In this embodiment, however, the spring  1302  of the second locking mechanism  308  biases the pin  312  to return to its position of  FIG. 3 . Thus, in block  1404 , the second locking mechanism  310  is rotated in a clockwise direction as shown by arrow  400  in  FIG. 4 . The second locking mechanism  310  may be rotated until the tab  314  comes into contact with a surface  1202  of the plug  326  as best illustrated in  FIGS. 4 and 12 . In this position, the second locking mechanism  310  is disposed in its unlocked position  1200  because the spring  1302  is compressed and forces the pin  312  and tab  314  axially inward and into contact with the first locking mechanism  308 . 
     In its unlocked position of  FIG. 4 , the second locking mechanism  310  is also at least partially protruding outwardly further than it does in its locked position of  FIG. 3 . For example, the pin  312  may be displaced by one or more inches outward from the body  302  of the coupler assembly  210 . The displacement may be more less in other examples, but the displacement of the second locking mechanism  310  provides a visual indication or confirmation to the machine operator that the second locking mechanism  310  has been unlocked. Similarly, when the second locking mechanism  310  is disposed in its locked position of  FIG. 3 , the second locking mechanism  310  is not displaced axially outward and this provides a visual indicator of the locked position. 
     Once the second locking mechanism  310  is moved to its unlocked position, the method  1400  may advance to block  1408  where the first locking mechanism  308  may be unlocked. To do so, a rod or other tool  402  may be inserted through the slot  306  in the first side plate  304  to engage the first locking mechanism  308 . Once engaged, block  1410  may be executed such that the rod or tool  402  may be pivoted in a clockwise direction as indicated by arrow  502  in  FIG. 5 . The rotational movement of the rod or tool  402  induces a similar clockwise pivotal movement of the first locking mechanism  308  about the first pivot axis  328  to its unlocked position  500 . 
     In the unlocked position  500  of  FIG. 5 , the cavity  318  is oriented at least partially towards the ground (i.e., downwardly). In some aspects, the cavity  318  may be disposed at an angle relative to a vertical axis (not shown) passing through the first pivot axis  328 . In any event, the first locking mechanism  308  is pivoted to a position where the second pin  214  may be released therefrom. Given the weight of the work tool  202 , the second pin  214  may slide or otherwise move out of the cavity  318 . This is further possible because the first pin  212  is still coupled to the front end of the coupler assembly  210 , and the work tool  202  may be hanging or disposed therefrom off the ground by several inches or more. 
     In addition, in block  1412  the position of the spring  330  changes from the coupled or locked position of  FIG. 3  to the decoupled or unlocked position of  FIG. 5 . In  FIG. 5 , the spring  330  is now positioned above the first axis  324 . In the position of  FIG. 5 , the spring  330  may act like a detent to maintain the first locking mechanism  308  in its unlocked or open position. 
     Although not shown in detail, the pin  312  of the second locking mechanism  310  may include a chamfer at its end. In addition, the first locking mechanism  308  may include a chamfer or ramp formed therein to facilitate a smooth movement of the pin  312  and first locking mechanism  308  during pivotal movement of the first locking mechanism  308 . The chamfer and ramp may not be included in other embodiments. Moreover, this pivotal movement may induce movement in the second locking mechanism  310 , and in particular, the pin  312 . The pin  312 , for example, may be further pushed outwardly as the plug  326  moves. In some instances, this repositions the second locking mechanism  310  in an intermediate position or “ready to lock” position. Thus, as will be described, the second locking mechanism  310  is moved to a position to be triggered or released to its locked position. 
     As illustrated in  FIG. 6 , the first locking mechanism  308  is disposed in a second position  600  (i.e., unlocked or open position) such that the second pin  214  is released therefrom. In this position  600 , the finger portion  316  of the first locking mechanism  308  is disposed between the body  302  and the second pin  214  so that the second pin  214  cannot be simply re-engaged. Also in this position, the first pin  212 , however, remains engaged in the second cavity  342  and in contact with the hook arm  344 . The hook arm  344  may form a lower lip  602  that has a concave-like shape in this position  600 . In block  1414 , this concave-like shape can prevent the first pin  212  from sliding or otherwise moving out of the cavity  342 . This partial coupling is further maintained as the weight of the work tool  202  causes the second pin  214  to release from the rear end of the coupler assembly  210  and travel along an arc-shaped path  604 . 
     To decouple the first pin  212  from the coupler assembly  210 , the method  1400  can advance to block  1416  whereby the entire coupler assembly  210  is rotated in a counterclockwise direction indicated by arrow  700  in  FIG. 7 . As such, the coupler assembly  210  is oriented such that its front end  702  is disposed downwardly and its rear end  704  is disposed upwardly. In the illustrated embodiment of  FIG. 7 , the work tool  202  is disengaged from the coupler assembly  210 . 
     Referring now to  FIG. 15 , one example of a method  1500  for coupling a work tool to a machine is illustrated. Here, the work tool  202  and coupler assembly  210  are illustrated in  FIG. 8  as well. The method  1500  may include a number of executable blocks for coupling the work tool  202  and coupler assembly  210 . In a first block  1502  of the method  1500 , the first pin  212  of the work tool  202  may be engaged to the front end  702  of the coupler assembly  210 . To do so, the coupler assembly  210  may be controllably moved via the hydraulic actuator  208 , which is controlled by the machine operator. The hook arm  344  may be oriented in a position  800  of  FIG. 8  such that the first pin  212  is received within the cavity  342  formed in the front end  702  of the coupler assembly  210 . Once the pin is received in the cavity, block  1504  may be executed to rotate the coupler assembly  210  in a clockwise direction indicated by arrow  802 . 
     As the coupler assembly  210  is rotated in the clockwise direction  802 , block  1506  may be executed whereby an inner cavity surface  320  of the first locking mechanism  308  comes into contact with the second pin  214 . Once the first locking mechanism  308  contacts the second pin  214 , further movement of the second pin  214  into the cavity  318  urges the first locking mechanism  308  to pivot about the first pivot axis  328  in a counterclockwise direction indicated by arrow  900  of  FIG. 9 . 
     The coupling method  1500  may advance to block  1510  where the first locking mechanism  308  continues to pivot about the first pivot axis  328  until a trailing edge  902  thereof passes by the second locking mechanism  310 . As it passes the second locking mechanism, the pin  312  or tab  314  release from contact with the first locking mechanism  308  in block  1512  to thereby trigger the second locking mechanism  310  to automatically move from its unlocked position to its locked position of  FIG. 3 . In other words, the spring  1312  of the second locking mechanism  310  is released in block  1512  and automatically biases the pin  312  and tab  314  axially inward to their respective locked positions. In the locked position  1000  of  FIG. 10 , the tab  312  is now disposed directly behind or rearward of the first locking mechanism  308  so that the first locking mechanism  308  is prevented from pivoting to its unlocked position. 
     In  FIG. 10 , the second pin  214  is again engaged by the first locking mechanism  308  and disposed within the cavity  318 . In this position, the method executes block  1516  such that the spring  330  again is moved to a position from above the first axis  324  to a position below the first axis  324  to further lock or secure the second pin  214  to the coupler assembly  210 . In this method  1500 , it is noteworthy that no operator intervention is required to lock the second locking mechanism  310 . In other words, in the aforementioned method and design, the second locking mechanism  310  can automatically be released from its unlocked position to its locked position. The only intervention in this embodiment is when the second locking mechanism  310  is moved from its locked position to its unlocked position. 
     The aforementioned methods are intended only to be examples for coupling and decoupling the coupler assembly  210  to a work tool. The work tool  202  is shown and described as being a bucket, but it may be a blade or any other form of work tool. Moreover, the coupler assembly  210  may be coupled to any type of work machine. While a backhoe loader is shown and described herein, this is only intended to be one example of a work machine that incorporates the structure and function of the coupler assembly  210 . 
     While embodiments incorporating the principles of the present disclosure have been disclosed hereinabove, the present disclosure is not limited to the disclosed embodiments. Instead, this application is intended to cover any variations, uses, or adaptations of the disclosure using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this disclosure pertains and which fall within the limits of the appended claims.