An anti-release mechanism of a pin-grabber coupler securing a work tool connected to a work machine is disclosed. The anti-release mechanism comprises an actuator, a wedge, a latch, a guide rod connecting the wedge and the latch, and a bias member on a first guide rod end of the guide rod biasing the latch and the wedge together. The wedge and the latch lock around a pin of the work tool and maintain the wedge against the pin of the work tool during a loss of engagement force of the wedge against the pin.

TECHNICAL FIELD

The present disclosure generally relates to locking mechanisms in a work machine, and more particularly, relates to anti-release mechanisms of quick couplers connecting to pin-on work tools.

BACKGROUND

Work machines such as excavators, backhoes, skid steers, wheel loaders, tractors, etc., are often provided with a quick coupler that is used to attach and detach various work tool attachments or implements to the work machine. More specifically, such work machines often include a hydraulically movable boom or arm with such implements being connected at an end of the boom. Generally, quick couplers are heavy-duty industrial components that allow for the fast and efficient changing of buckets, hammers, grapples, compactors, rakes, and other implements to the boom of the work machine. Without a quick coupler, workers are required to manually disconnect work tools or work implements from a standard coupler, necessarily making their work less efficient.

Pin-grabber couplers are a type of quick coupler that connects to pin-on work tools. Generally, pin-on work tools comprise pins that engage or integrate connection of the work tool to the quick coupler for operation with the work machine. Many pin-on work tools have different pin spreads, the distance between two pin centers of a pin-on work tool. Differing pin spreads are available for different work tools in the market and for work tools produced by different manufacturers.

Standard pin-grabber couplers only physically connect the work tool to the machine by using a primary or wedge locking element frictionally loaded against a work tool pin. A wedge style coupler utilizes a combination of wedge angle and friction coefficient to counteract the tendency of the working forces that would cause disengagement. The primary wedge in a standard coupler lacks an additional supplementary anti-release mechanism that aids in ensuring the wedge remains engaged with a pin of a work tool in the event of a loss of engagement force from the actuator.

Others have disclosed anti-release mechanisms, but fail to provide an anti-release mechanism on the primary wedge of a pin coupler. For example, US Publication No. 2018/0355579 discloses a locking device for a quick coupler for coupling the pin of an attachment to earth working machinery having a clamp device including a pivotable arm biased by a biasing means for preventing the wedge from becoming disengaged with the coupler. The clamp device requires a substantial arc shape and a spring on its end that provides a closing biasing force. The locking device and clamp device do not provide versatility to secure the wedge locking element to varying diameters of pins and pin spreads of work tools.

It can therefore be seen that a need exists for an improved anti-release mechanism which facilitates a supplementary locking mechanism for the primary wedge of a coupler to secure the work tool to the work machine in the event of a loss of engagement force.

SUMMARY OF THE DISCLOSURE

In accordance with one aspect of the disclosure, an anti-release mechanism of a pin-grabber coupler securing a work tool connected to a work machine is disclosed. The anti-release mechanism comprises an actuator, a wedge, a latch, a guide rod connecting the wedge and the latch, and a bias member on a first guide rod end of the guide rod biasing the latch and the wedge together. The wedge and the latch lock around a pin of the work tool and maintain the wedge against the pin of the work tool during a loss of engagement force.

In accordance with another aspect of the disclosure, a work machine is disclosed. The work machine comprises: a frame; a ground engaging element supporting the frame; an engine supported by the frame; a working mechanism extending from the frame; a pin-grabber coupler connected to the working mechanism; a work tool having a pin, the work tool being connected to the pin-grabber coupler; the pin-grabber coupler including a coupler frame, an anti-release mechanism, and an actuator. The anti-release mechanism includes: a wedge, a latch, a guide rod connecting the wedge and the latch, and a bias member on a first end of the guide rod biasing the latch and the wedge together. The wedge and the latch lock around the pin and maintain the wedge against the pin during a loss of engagement force.

In accordance with another aspect of the disclosure, a method of securing a work tool to a pin-grabber coupler of a work machine during a loss of engagement force is disclosed. The method comprising: providing the pin-grabber coupler including a pin grabber having an anti-release mechanism, a secondary engagement end, and an actuator connecting the anti-release mechanism and the secondary engagement end, the anti-release mechanism having a wedge, a latch, a guide rod connecting the wedge and the latch, and a bias member on the guide rod; actuating the actuator to extend the anti-release mechanism to a pin of the work tool; engaging the wedge against the pin and the latch around the opposite side of the pin; and maintaining a biasing force with the bias member keeping the wedge and latch engaged against the pin during a loss of engagement force.

These and other aspects and features of the present disclosure will be better understood upon reading the following detailed description when read in conjunction with the accompanying drawings.

DETAILED DESCRIPTION

Referring now to the drawings, and with specific reference toFIG.1, an exemplary work machine100is shown, illustrated as an excavator. Excavators are heavy equipment designed to move earth material from the ground or landscape at a dig site in the construction and agricultural industries. While the following detailed description describes an exemplary aspect in connection with the excavator, it should be appreciated that the description applies equally to the use of the present disclosure in other work machines including but not limited to backhoes, front-end loaders, skid steers, wheel loaders, tractors, and the like.

The work machine100comprises a frame102supporting an engine104. The frame102is supported on ground engaging elements106illustrated as continuous tracks. It should be contemplated that the ground engaging elements106may be any other type of ground engaging elements106such as, for example, wheels, etc. The work machine100further includes a working mechanism108extending from the frame102for conducting work, such as, for example, excavating landscapes or otherwise moving earth, soil, or other material at a dig site. The frame102may be an upper swiveling body common with excavators and work machines in the agricultural and construction industries.

As illustrated in one embodiment, the working mechanism108includes a boom110, an arm112, a pin-grabber coupler114, and a work tool116used to remove earth, soil, and other material from a landscape site. The work tool116, also referred to as an implement, may be a bucket, dipper, hammer, thumb, hydromechanical tool, or other attachment that couples to the pin-grabber coupler114for operation by the work machine100. The work tool116may also be a pin-on work tool that engages connection with the pin-grabber coupler114.

The work machine100may utilize the pin-grabber coupler114to attach and detach the work tool116to the work machine100. The work machine100can quickly actuate attachment and detachment of the work tool116to and from the pin-grabber coupler114by a hydraulic circuit, electrical circuit, and/or a computer-controller system provided on the work machine100.

Referring now toFIG.2, in one embodiment, the pin-grabber coupler114is illustrated unlocked and partially engaged with the work tool116. The pin-grabber coupler114may include a coupler frame200and a pin grabber202having a primary engagement end204, an actuator206, and a secondary engagement end208. The pin grabber202is integrated in the coupler frame200. The primary engagement end204is connected to one end of the actuator206and the secondary engagement end208is connected to the other end of the actuator206. The primary engagement end204engages a first pin210of a work tool116and the secondary engagement end208engages a second pin212of a work tool116. The first pin210may also be referred as the “attachment pin” of a pin-on work tool. As shown inFIG.2, the secondary engagement end208grabs the second pin212in side known as the “jaw” of the pin-grabber coupler114.

Referring now toFIG.3, in one illustrated embodiment, the primary engagement end204may comprise a wedge300and a latch302connected to the actuator206. The primary engagement end204further includes a guide rod304that connects the wedge300to the latch302and is secured by a bias member306at one end of the guide rod304. The guide rod304may be a bolt, a tie rod, an all thread, or the like. The bias member306may be secured on the guide rod304by a fastener308. The fastener308may be a nut, or the like.

Referring now toFIG.4, in one illustrated embodiment, the wedge300may include a first wedge end400, a wedge slot402, a pair of first coupling slots404for connecting to the actuator206and/or the latch302, and a second wedge end406. The first wedge end400may be shaped like a flat or concave wedge, or have a sloping wedge surface, so that it maintains a load or engagement force against the first pin210. The second wedge end406may be a U-shaped body that provides clearance for movement of the pin grabber202during attaching and detaching the pin-grabber coupler114to and from the work tool116. The second wedge end406allows the wedge300to move around the actuator206. The first wedge end400of the wedge300is shaped in a way to lock and engage into position against the first pin210when there is an engagement force maintained on the wedge300. The secondary engagement end208may act as an anchor for maintaining the load on the wedge300and may be anchored on the second pin212of the work tool116.

However, during operation of the work machine100significant load cases exerted on the pin-grabber coupler114may momentarily remove the load on the wedge300causing a loss of engagement force by the wedge300from the first pin210. For example, a sudden event when the work tool116unexpectedly impacts an extremely hard or rock-like surface may be one such instance. As described herein, the primary engagement end204remains attached to the first pin210during a loss of engagement force. The latch302keeps the wedge300in place for situations where there is a loss of engagement from the wedge300. Causes for a loss of engagement force could include a loss of work machine100electrical or engine power or a partial/total failure to key components within the work machine100. When the wedge300loses its engagement force, the wedge300relies on a frictional force for remaining in place. There may be situations when the operator of a work machine100creates hard impacts or rattles which momentarily removes the load from the wedge300allowing for the wedge300to lose its frictional holding force. With the addition of the latch302, the wedge300has a supplementary holding force to keep the wedge300engaged.

Referring now toFIG.5, in one illustrated embodiment, the latch302is responsible for keeping the wedge300engaged on the first pin210at all times allowing the wedge300to be able to frictionally lock up whenever the wedge300becomes loaded. The latch302is responsible for latching onto the first pin210of the work tool116during the engagement process of the wedge300. The latch302is responsible for keeping the wedge300of the pin-grabber coupler114engaged to the first pin210of the work tool116in the event of a loss of engagement force by the actuator206. The latch302comprises an elongated body500having a pair of second coupling slots502that integrates connection with the actuator206and the pair of first coupling slots404which may create a pivot point for the latch302. The latch302may be connected to the wedge300and the actuator206by a fastener, retaining pin, press fitting pin, or other method generally known in the arts. The wedge300and the latch302may be pivotally coupled to allow the latch302to pivotally move the latch head506radially open or closed relative to the wedge300. The latch also comprises a latch slot504in the elongated body500and a latch head506.

The guide rod304connects the wedge300to the latch302via the wedge slot402and the latch slot504. As illustrated, the bias member306is secured on the guide rod304on the side of the latch302away from the wedge300. It will be recognized by one having ordinary skills in the arts that the bias member306may be situated on the guide rod304on the side of the wedge300away from the latch302.

The bias member306provides a biasing force against the latch302towards the wedge300, or vice versa. The fastener308which secures the bias member306onto the guide rod304controls the biasing force of the bias member306against the latch302. The bias member306forces movement of the latch302towards the wedge300, or vice versa. The bias member306is depicted as a coil spring, but any other type of spring or biasing member may be used such as a strut isolator, strut, shock, or the like.

The latch302may further comprise a toe geometry feature508that supports preventing the latch302from closing too far from the biasing force. The toe geometry feature508helps prevent the latch302from over-pivoting which may result in the latch302not being able to clear the first pin210.

Now turning toFIGS.6-7, in an illustrated embodiment, the actuator206actuates engagement of the pin grabber202to the first pin210of the work tool116. When actuated, the actuator206extends or retracts a rod600from within the actuator206. The actuator206may be controlled by a hydraulic circuit, electric pneumatic, or other actuator generally known in the arts. The actuator206may be controlled by an operator, generally in the cab of a work machine100, utilizing a switch connected to a hydraulic circuit, electrical circuit, or computer-controller provided on the work machine100. The actuator206may comprise a check valve for regulating, or checking the pressure of, the load of the engagement force applied against the wedge300. The check valve holds the resulting retraction force applied to the wedge300. The actuator206may control the retraction and extension of the rod600inside the actuator206, which can increase or decrease the load applied.

As illustrated inFIG.2and inFIGS.6-9, in one embodiment of engaging the work tool116, the engagement of the pin grabber202to the first pin210may occur when the actuator206is actuated to extend the rod600outwardly, thereby extending the latch head506of the latch302over the first pin210of the work tool116. As shown inFIG.6, the first pin210is engaged within the pin-grabber coupler114near the primary engagement end204to engage the first pin210. The secondary engagement end208is illustrated engaged onto the second pin212of the work tool116. The secondary engagement end208may act as an anchor by supporting the engagement force required for locking the wedge300against the first pin210. The secondary engagement end208may include a rocker that is formed to integrate onto the second pin212. The rocker may be triangular in shape to engage the second pin212and provide an anchor support to maintain the frictional load of the wedge300on the first pin210.FIG.7illustrates the pin grabber202, wedge300, and latch302in locked position and extending towards the first pin210.FIG.8shows the wedge300extending towards the first pin210and the latch302engaging the first pin210once the actuator206has been actuated. The wedge300is illustrated extending with the latch302to engage the first pin210.FIG.9illustrates the wedge300and the latch302fully locked onto the first pin210of the work tool116.

As illustrated inFIGS.6-9, the wedge300and latch302are in position to lock and engage the first pin210as the rod600is extended from within the actuator206towards the first pin210. InFIGS.6-7, the latch head506rolls over the first pin210when the rod600is actuated to extend outward from within the actuator206. The bias member306provides a closing biasing force against the latch302towards the wedge300. The closing biasing force is maintained while the rod600extends the wedge300to engage the first pin210. The latch head506has a hook geometry feature that allows the latch302to act against force of the bias member306to pivot away from the wedge300and roll over the first pin210during attachment. The hook geometry may be triangular in shape with concave sides to facilitate the rolling or sliding over of the first pin210, as generally known by a person having ordinary skill in the arts. This occurs when the latch head506contacts the first pin210with the hook geometry of the latch head506.

When the wedge300and latch302are secured around the first pin210, the latch302will act as a supplemental anti-release mechanism so that the pin-grabber coupler114does not disconnect from the work tool116in the event of a loss of engagement force.

Referring now toFIGS.10-14, in one embodiment, the pin-grabber coupler114is illustrated unlocking/disconnecting from the work tool116.FIG.10illustrates the wedge300and the latch302fully engaged onto the first pin210prior to retraction by the actuator206.FIG.11illustrates the wedge300retracting and the latch302disengaging the first pin210.FIG.12illustrates the wedge300fully disengaged from the first pin210.FIG.13illustrates the pin-grabber coupler114fully unlocked.FIG.14illustrates the secondary engagement end208disengaging from the second pin212from a slot of the pin-grabber coupler114. When the rod600is retracted by actuating the actuator206, the wedge300retracts and disengages the first pin210. The latch head506rolls over the first pin210and against the force of the bias member306when the rod600retracts into the actuator206, as shown inFIG.12.

As shown inFIGS.13-14, the latch302is illustrated disengaged from the first pin210, and the pin-grabber coupler114is unlocked from the work tool116. The first pin210can be removed from the jaw of the pin-grabber coupler114. The secondary engagement end208can then be removed from the second pin212of the pin-grabber coupler114.

Referring now toFIGS.15-16, in another illustrated embodiment, the guide rod304may comprise a retaining pin700installed in a retaining hole in the guide rod304. The location of the retaining hole on the guide rod304ensures a desired or pre-determined closing force by the bias member306during assembly of the retaining pin700in the guide rod304.FIG.15illustrates the primary engagement end204including with the retaining pin700installed on the guide rod304.FIG.16illustrates the primary engagement end204from another side view with the retaining pin700installed on the guide rod304. The retaining pin700may be a cotter pin, a cotter hair, a lynch pin, a roll pin, a hand ring, a detent ball pin, a wire snap, or other retaining pin generally known in the arts.

The retaining pin700supports controlling the desired biasing force from the bias member306when installed on the guide rod304. The through-hole for the retaining pin700may be positioned on the guide rod304so that the fastener308is installed at a pre-determined length securing the pre-loaded/pre-determined biasing force of the bias member306with the retaining pin700. The retaining pin700ensures the required force of the bias member306is properly installed on the guide rod304for the proper work machine100application. The retaining pin700also ensure that the fastener308remains in place and the fastener308is prevented from loosening to prevent the biasing force of the bias member306from weakening.

As shown inFIGS.17-21, additional embodiments of the latch302are illustrated. As illustrated inFIG.17, the latch302may comprise a heel geometry feature800that provides a lifting force of the latch head506to pivotally open up the latch302for clearing the first pin210when actuated by the actuator206. When actuating the actuator206, a position at an extension or retraction of the actuator206causes the heel geometry feature800to provide a lifting force when the rod600is extended or retracted from the actuator206. The heel geometry feature800supports opening up the latch302so that the latch head506can clear the first pin210during locking and/or unlocking of the pin-grabber coupler114from the work tool116. The heel geometry feature800may comprise a geometric feature that prevents over-rotating of the latch302and/or limits the closing of the latch302. The toe geometry feature508may also comprise a geometric shaped feature that prevents over-rotating of the latch302and/or limits the closing of the latch302.

As illustrated inFIG.18, the heel geometry feature800provides a lifting force for the latch302at a position when the latch302is extended towards the first pin210. When the latch302reaches the position the latch head506is lifted above the first pin210to create space between the latch head506and the first pin210so that the latch302can clear the first pin210to form a lock around the first pin210.

Now referring toFIG.19, in one embodiment, the latch302is illustrated with a pair of elongated coupling slots900that replace the pair of second coupling slots502, which are more circular in geometry. The pair of elongated coupling slots900allows movement of the latch302relative to the wedge300, while remaining pivotally connected to the wedge300, as shown inFIGS.19-20. The pair of elongated coupling slots900provides the latch302with more clearance operability so that the latch head506can surround and lock to the first pin210with varying diameters. The latch302may be integrally connected to the rod600of the actuator206with the wedge300creating a pivot point for the latch302so that the latch head506may move radially to open or close relative towards the wedge300. As shown inFIG.18, the pair of elongated coupling slots900allow movement of the latch302at the pivot point with the wedge300and the rod600. The latch slot504may be provided or positioned at an angle which causes the latch to retract from the force of the bias member306. The latch slot504may also be elongated to provide for clearance for movement of the guide rod304.

FIG.20illustrates the wedge300and the latch302engaging the first pin210with a larger diameter, whereasFIG.21illustrates the wedge300and the latch302engaging the first pin210with a smaller diameter. The pair of elongated coupling slots900provided at the pivot point with the wedge300allows the latch302to “reach out” or contract in order to support locking on different diameters of the first pin210of the work tool116.

INDUSTRIAL APPLICABILITY

In operation, the present disclosure may find applicability in many industries including, but not limited to, the construction, earth-moving, and agricultural industries. Specifically, the technology of the present disclosure may be used for work tool securement to work machines including, but not limited to, excavators, backhoes, skid steers, wheel loaders, tractors, and the like. For example, the teaching of this disclosure can be advantageously employed with a quick coupler for easily connecting and disconnecting work tools such as hammers, buckets, dippers, dig tools, and the like. While the foregoing detailed description is made with specific reference to excavators, it is to be understood that its teachings may also be applied onto the other work machines such as backhoes, skid steers, wheel loaders, tractors, mulchers, and the like that utilize a coupler for connecting to work tools.

It may also be recognized to a person skilled in the arts that the foregoing anti-release system may be provided as a kit for an anti-release mechanism for installing onto a wedge locking element utilized by a wide range of machine sizes and machine types. This anti-release mechanism disclosed herein will allow the operator of the work machine100to be able to maintain the wedge300of a pin-grabber coupler114engaged to the first pin210of the work tool116during a loss of engagement force. The actuating of the actuator206of the pin grabber202can be operated from the comfort of the cab with a minimal amount of effort by using a hydraulic circuit, electric pneumatic, or a computer-controller system provided in the work machine100, as generally known in the arts. The anti-release mechanism consists of configuring the primary engagement end204of the pin grabber202with the wedge300, the latch302, the guide rod304, and the bias member306.

Referring now toFIG.22, in one embodiment, a method1000of securing a work tool116to a pin-grabber coupler114of a work machine100during a loss of engagement force is disclosed. The method1000comprises, first in a step1010, providing the pin-grabber coupler114including the pin grabber202having the anti-release mechanism, a secondary engagement end208, and the actuator206connecting the anti-release mechanism and the secondary engagement end208, the anti-release mechanism having the wedge300, the latch302, the guide rod304connecting the wedge300and the latch302, and the bias member306on the guide rod304. The guide rod304may be installed in the wedge slot402and latch slot504to connect the wedge300and the latch302so that the bias member306provided on the guide rod304provides a closing force of the latch302towards the wedge300. The bias member306may be secured on the guide rod304with a fastener308. The guide rod304may also be provided with a through-hole proximate to a first end of the guide rod304. The through-hole is positioned on the guide rod304so that after installing the bias member306, a retaining pin700may be inserted in the through-hole to meet a pre-determined or required biasing force of the bias member306for securing the wedge300and the latch302against the first pin210.

In a step1020, the actuator206is actuated to extend the anti-release mechanism to the first pin210of the work tool116. In a step1030, the wedge300engages the first pin210and the latch302engages around the opposite side of the first pin210. Next, in step1040, the bias member306maintains a biasing force to keep the wedge300and latch302against the first pin210during a loss of engagement force. The closing biasing force is maintained around the first pin210by the bias member306forcing closure of the latch302and the wedge300around the first pin210during a momentarily unlocking of the wedge300against the first pin210.

The wedge300and the latch302may be connected with the guide rod304via the wedge slot402and latch slot504. Further, the method1000may further include providing a latch head506having a hook geometry that allows the latch head506to roll over the first pin210and exert a force against the bias member306when the latch302engages or disengages the first pin210, and actuating the actuator206to extend or retract the anti-release mechanism to engage or disengage the first pin210.

The latch302may be provided with the toe geometry feature508on the latch302to prevent over-rotation or over-pivoting of the latch302when the actuator206is actuated to engage the anti-release mechanism with the first pin210. The latch302may be further provided with the heel geometry feature800on the latch302to facilitate a pivotable locking clearance of the first pin210when the actuator206is actuated to engage the anti-release mechanism with the first pin210.

The anti-release mechanism of the pin grabber202of the pin-grabber coupler114provides an added advantage of protecting the longevity of a work tool in the event of a loss of engagement force occurring to the actuator206of the pin-grabber coupler114during operation by the work machine. It is desirable that a coupling and uncoupling anti-release function be provided onto existing work machines utilizing pin-grabber couplers to protect pin-type work tools from disengaging from the pin-grabber coupler during a loss of engagement.

From the foregoing, it can be seen that the technology disclosed herein has industrial applicability in a variety of settings such as, but not limited to work machines in the construction and agricultural industries that utilize a coupler for connecting to various work tools.