Connector

Abstract

A coupler for connecting a tool having first and second parallel pins to the arm of a vehicle or machine, the coupler comprising a body for mounting on the arm of a vehicle or machine, a front first jaw fixed to the body for receiving the first tool pin, a movable rear second jaw facing away from the first jaw for receiving the second tool pin, an actuator for moving the second jaw toward and away from the first jaw, and a locking member, the first jaw having a distinct lip forward of a seat for each pin, the locking member being pivotable about a pivot located forward of the lip of the first jaw between a locked position in which a portion of the locking member projects into an opening in the first jaw, and an unlocked, retracted position.

Description

[Technical field]

[0001] The present disclosure relates to a coupler for connecting a work implement to the arm of an excavator, mining machine, or other earthmoving machine or vehicle, and in particular, to a hydraulic coupler with safety features to prevent uncoupling in the event of a hydraulic failure or due to incomplete coupling of the implement during the coupling process. [Background technology]

[0002] Hitches (commonly referred to as "couplers" or "hitches") are used to releasably connect an implement (e.g., a digging bucket or other earth moving implement) to the arm of a machine (e.g., an excavator, mining machine, or backhoe). These couplers are typically mounted to the free end of the arm and are configured to engage a pair of parallel pins typically provided on the implement to connect the implement to the arm.

[0003] Modern hitches are operated using hydraulic actuators. This allows the vehicle operator to quickly and remotely exchange multiple implements from the end of the excavator arm by releasing one implement from the hitch and engaging the pin of another. In use, the implements are held securely by the hitch under hydraulic pressure. However, failure due to loss of hydraulic pressure, or failure to correctly engage both pins, runs the risk of the implement coming loose or falling off the arm. If the implement comes loose or falls, it poses a safety hazard and can result in serious injury.

[0004] To mitigate the risk of hydraulic failure, hydraulic couplers are typically equipped with one or more safety locking features to ensure that in the event of a hydraulic failure causing a loss of hydraulic pressure, one or both of the tool pins remain engaged with the coupler. In some existing couplers, a spring-loaded latch is used as a safety latch on at least one of the coupler jaws. However, these spring-loaded safety latches can fail under certain loading conditions. One such condition is when there is a loss of hydraulic pressure and the coupler is in or moves to a vertical or near vertical orientation such that the tool pins are vertically aligned. In this vertical orientation, a hydraulic failure will cause the pins and upper jaw to fall slightly under gravity, and nearly all of the vertical load from the tool and the tool load will be transferred to the spring-loaded latch. This transfer of force to the latch can cause damage or failure of the latch which is not robust enough to support the magnitude of the load, thereby risking the tool becoming uncoupled and dangerous.

[0005] A dangerous situation can also occur if an operator is unaware that he or she has not properly engaged the hitch with the implement pin. The process of engaging a hitch with an implement typically involves engaging the front fixed jaw of the hitch with a first pin of the implement (including engaging a front safety latch), then twisting the implement under the excavator arm to move the rear jaw of the hitch into engagement with the second pin. However, an operator is often unable to see the engagement of the rear jaw with the second pin, and may not realize that the rear jaw is not properly engaged with the second pin. Thus, there is a risk that an operator may attempt to move the excavator arm and attached hitch while the implement is only partially engaged.

[0006] If the excavator arm is moved in this condition, the implement may swing around and hang from the first pin as the hitch rises. The momentum of the swinging implement may force the first pin against the front latch, again resulting in the latch carrying most of the implement's load. Furthermore, as the implement pivots around the first pin, there have been incidents where the pivot pin in contact with the latch applies torque to the latch, causing it to pivot out of engagement. This can cause the first pin to be pulled away from the jaws, resulting in a dangerous fall of the implement. Summary of the Invention [Problem to be solved by the invention]

[0007] It is an aim of at least preferred embodiments of the present invention to address one or more of the above-mentioned shortcomings and / or to at least provide the public with a useful alternative.

[0008] Where patents, other external documents, or other sources of information are referenced herein, this is generally for the purpose of providing a context for discussing features of the present invention. Unless expressly stated, the reference to such external documents or sources should not be construed as an admission in any jurisdiction that such documents or sources are prior art or form part of the common general knowledge in the art. [Means for solving the problem]

[0009] In a first aspect, the invention broadly relates to a coupler for connecting a tool having first and second spaced parallel pins to an arm of a vehicle or machine. The coupler comprises a body for mounting on the arm of the vehicle or machine, a front first jaw fixed relative to the body, a pivotable locking member, a movable rear second jaw, and an actuator. The front first jaw defines an opening and a first seat for receiving the first tool pin and includes a distinct lip forward of the first seat, the lip projecting generally in a direction toward the body. The locking member is pivotable relative to the first jaw about a pivot axis located forward of the lip of the first jaw. The locking member pivots between a locked position in which a portion of the locking member projects into the opening of the first jaw and an unlocked position in which the locking member is substantially or completely withdrawn from the opening of the first jaw. The movable rear second jaw faces away from the first jaw and defines an opening and a second seat for receiving a second tool pin. The second jaw has an enlarged surface adjacent the jaw opening and rearward of the second seat. The actuator is operable to selectively move the second jaw toward and away from the first jaw along the axis of movement. The first jaw including the lip defines a direction of entry of the first pin into the seat of the first jaw that is not parallel to the axis of movement.

[0010] In one embodiment, the second jaw is movable between an extended position in which the second jaw is distal to the first jaw and a retracted position in which the second jaw is proximal to the first jaw.

[0011] In one embodiment, the movable second jaw is biased in a position away from the first jaw.

[0012] In one embodiment, the actuator is a hydraulic cylinder and a biasing member is arranged to bias the cylinder towards the extended position. The biasing member may comprise, for example, a die spring arranged within the rod of the cylinder. Alternatively, the biasing member may comprise an external compression spring.

[0013] In an alternative embodiment, the actuator may comprise a mechanical screw and screw mechanism.

[0014] The protruding lip of the first jaw may have a rear surface oriented at an angle of about 20 degrees to about 40 degrees, preferably about 25 degrees to about 35 degrees, and most preferably about 30 degrees, relative to the axis of movement.

[0015] In one embodiment, the lip of the first jaw is shaped such that in a vertical position of the coupler with the second jaw above the first jaw, weight forces from an implement secured to the coupler are at least partially supported by the lip.

[0016] In one embodiment, engagement of the first jaw with the tool pin requires a change in direction of the movement of the first jaw or the tool pin to avoid collision of the first jaw with the lip. During at least a portion of the movement, engagement of the first jaw with the tool pin may require the first jaw or the tool pin to move such that a movement vector includes a component that is perpendicular to the axis of movement of the movable member.

[0017] In one embodiment, the locking member is shaped such that in a vertical orientation of the coupler with the second jaw above the first jaw and the locking member in the locked position, a force due to weight from an implement carried by the coupler is at least partially supported by the locking member. In a vertical orientation of the coupler with the second jaw above the first jaw and the locking member in the locked position, a reaction force vector provided by the locking member to support the first implement may extend through the locking member pivot axis.

[0018] In one embodiment, in a vertical position of the coupler with the second jaw above the first jaw and the locking member in a locked position, at least a majority of the weight force from an implement held on the coupler is supported by the locking member and the lip of the first jaw. For example, the locking member and the lip together may support substantially all of the weight force of the implement load. In an alternative embodiment, the locking member and the lip together may support a majority of the weight force of the implement load, for example, greater than about 70% of the weight force of the implement load. The load supported by the locking member and the lip may be distributed evenly or unevenly between the locking member and the lip. For example, the lip may support about 50% and the locking member may support about 50%. Alternatively, the load ratio may be distributed between 30-70, 40-60, 60-40, 70-30, or any other such distribution.

[0019] In one embodiment, the locking member comprises a locking surface for contacting the first tool pin at a contact point, the contact point being substantially collinear with a centre of the pin and a pivot axis of the locking member.

[0020] The locking surface at the contact point is substantially perpendicular to an axis running between the centre of the pin and the pivot axis of the locking member.

[0021] In one embodiment, the locking surface is substantially flat.

[0022] In one embodiment, the locking member is biased towards the locked position. A leaf spring may be provided and arranged to bias the locking member towards the locked position. For example, a first end of the leaf spring is fixed to the body and a second end of the leaf spring is fixed to the locking member, the leaf spring having a bent intermediate portion adjacent the locking member pin. Alternatively, a torsion spring or coil spring may be provided to bias the locking member towards the locked position.

[0023] In one embodiment, the locking member includes a cam surface and the movable jaw is disposed on a movable member configured to engage the cam surface and thereby retract the locking member from its locked position when the movable jaw moves toward the first jaw.

[0024] In one embodiment, the extension surface of the second jaw is configured to prevent rotation of an implement attached to the coupler by retaining the second pin within the second jaw when the second jaw moves slightly toward the first jaw as a result of a failure of the actuator.

[0025] In an embodiment, the extension surface of the second jaw is substantially flat and / or substantially parallel to the axis of movement.

[0026] The present invention may also be broadly said to consist of the parts, elements, and features referenced or indicated in the specification of this application, individually or collectively, and any or all combinations of any two or more of said parts, elements, or features. Where specific wholes (which have known equivalents in the art to which the invention pertains) are referred to herein, such known equivalents are deemed to be incorporated herein as if individually set forth.

[0027] The term "comprises" as used in the present specification and claims means "consisting at least in part of." When interpreting a description of the present specification and claims that includes the term "comprises," there may be other features present than the feature preceded by this term. Related terms such as "comprises" and "included" should be interpreted in the same manner.

[0028] Reference to a range of numerical values ​​disclosed herein (e.g., 1 to 10) is intended to incorporate reference to every rational number within that range, and to any rational number range within that range (e.g., 1 to 6, 1.5 to 5.5, and 3.1 to 10), and thus all subranges of every range explicitly disclosed herein are hereby expressly disclosed.

[0029] As used herein, nouns refer to the singular and / or the plural, unless the context specifies otherwise. The term "and / or" as used herein means "and" or "or," or both, where the context permits. [Brief description of the drawings]

[0030] The present invention will now be described, by way of example only, with reference to the accompanying drawings in which: [Figure 1] FIG. 2 is a front underside perspective view of a coupler according to a first exemplary embodiment; [Diagram 2] FIG. 2 is a perspective view of the rear underside of the connector of FIG. 1. [Diagram 3] FIG. 3 is a side view of the coupler of FIGS. 1 and 2 , the coupler being in a locked configuration and engaged with a pair of tool pins. [Figure 4] FIG. 4 is a side perspective view of the coupler of FIGS. 1-3 with the fixed jaw components hidden to reveal the moveable member, actuator, and front locking member. [Figure 5A] FIG. 5 is a side view corresponding to the view of FIG. 4 with the second jaw in position to engage the tool pin. [Figure 5B]FIG. 5 is a side view corresponding to the view of FIG. 4 with the second jaw in a position to release the first tool pin; [Figure 6] 5C is a side cross-sectional view of the coupler of FIGS. 1-5B taken through its midplane. FIG. [Figure 7] FIG. 7 is an exploded perspective view of the connector of FIGS. 1 to 6. [Figure 8] 8A-E are side views showing the steps of coupling a coupler attached to the end of an excavator arm to the parallel pins of an excavator bucket. FIG. 8A shows the coupler in an unlocked configuration, ready to be coupled to an implement. FIG. 8B shows the coupler receiving the first one of the pins. FIG. 8C shows the coupler pivoted and aligned about the second pin, ready to receive the second pin. FIG. 8D shows a front locking member developed to lock the first pin to the first jaw, with the second jaw moving towards the second pin. FIG. 8E shows the coupler in a locked configuration engaged with the second pin and with both pins locked to the coupler, with the excavator arm lifting the coupled bucket. [Figure 9A] FIG. 1 is a side cross-sectional view showing a front locking member positioned to lock a first pin to a first jaw, with the second jaw moved toward and prevented from engaging with the second pin in an out-of-position state. [Figure 9B] 9B shows a first stage of movement of the implement as the coupler moves from the position shown in FIG. 9A. [Figure 9C] 9C shows a second stage of movement of the implement as the coupler moves further from the position shown in FIG. 9B. [Figure 9D] 9C shows the next stage in the movement of the tool as the coupler moves further from the position shown in FIG. 9C. [Figure 10A] FIG. 13 is a side view of the connector connected to the implement in a vertical position illustrating the reaction forces. [Figure 10B] FIG. 13 is a side view of the coupling connected to the implement in a vertical position after a hydraulic failure, illustrating the reaction forces. [Figure 11A-E]Figures 11A-11E are detailed cross-sectional side views of the front jaws and locking member of an alternative embodiment coupler, with Figure 11A showing a pin seated in the first jaw and the path of travel for moving the pin inward and outward of that jaw. Figure 11B is similar to Figure 11A but showing the locking member. Figure 11C shows the first pin moving into contact with the locking member. Figure 11D shows the locking member moving to a retracted position. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] 1-10B illustrate an exemplary coupler 1 according to one embodiment of the present invention. The coupler 1 is suitable for connecting an implement having first and second spaced parallel pins 2a, 2b to the arm of a vehicle or machine. The transverse parallel pins 2a, 2b are typically provided as a standard feature on implements to aid in the attachment of the implement (e.g., digger buckets, ripping attachments, sieve buckets, clamps, wide buckets, hydraulic hammers, screw augers, etc.) to the arm / boom of a vehicle or other machine.

[0032] An arrow marked "F" has been inserted in the figures where necessary to indicate the forward direction of the coupler 1. The front F of the coupler 1 in the illustrated embodiment is the side that corresponds to the front of the implement (the open side of the excavation bucket). The absolute orientation of the coupler 1 changes during use as the arm to which it is attached moves. Thus, the terms forward, rear, left and right (or similar) should be interpreted as referring to the forward direction F of the coupler, and not necessarily to the orientation shown in a given figure. The use of these terms is for ease of explanation and is not intended to be limiting.

[0033] The coupler 1 has a body 3, a first jaw 5 fixed relative to the body 3, a movable second jaw 7 movable relative to the body 3, and an actuator 9 operable to selectively move the second jaw 7 closer or further away. The body 3 is configured to be attached to an arm of a vehicle or machine, for example via a mounting mechanism. The coupler 1 is configured to hold the first pin 2a in the first jaw 5 and the second parallel pin 2b in the second jaw 7 in positions where the centres of the first and second pins are coincident with a virtual pin axis VPA (see Figures 3 and 6).

[0034] In the embodiment shown, the body 3 includes two spaced apart parallel plates 4 for receiving the ends of the arms or links from the arms between the plates 4. The plates 4 include mounting openings 6 for bolting the connector body 3 to the arms or arm links, although alternative mounting methods are possible. Lifting lugs 8 (FIG. 2) are preferably provided at the rear of the connector body 3 to facilitate lifting of various items at a work site, for example by use of chains placed through the openings in the lugs 8.

[0035] The first jaw 5 is hook-shaped and defines an opening 11 to the front F of the coupler 1. The inner surface of the first jaw 5 provides a seat 13 for receiving the first tool pin 2a. The first and second tool pins 2a, 2b are substantially cylindrical and therefore the surface of the first jaw 5 providing the seat 13 for the tool pin 2a is concave having a curvature that substantially corresponds to the curvature of the pin 2a.

[0036] In the illustrated embodiment, the first jaw 5 is provided by two parallel hooks formed from two spaced apart side plates 15 fixed relative to or integral with the body 3 of the connector 1. A web 16 bridges between the hooks of the two side plates 15 to provide rigidity. In some embodiments, the web 16 not only provides rigidity to the first jaw 5, but may also form at least a portion of a seat for the tool pin 2a.

[0037] With reference to FIG. 3, the first jaw 5 includes a distinct lip 17 raised forward of the pin seat 13. The lip 17 projects upward into the opening 11 of the first jaw 5, reducing the size of the opening adjacent the lip 17 and defining a recessed rear portion of the lip 17 that forms the seat 13. In the illustrated embodiment, the lip 17 is formed by a portion of the first jaw hook that curves around itself (with reference to FIG. 3) that portion of the hook forward of the vertical centerline VCa of the first pin 2a, with the rear surface of the lip 17 continuing with the seating surface and forming a smooth transition between the lip 17 and the seat 13. The rear surface of the lip 17 may be curved or substantially straight. For example, in some embodiments, the lip 17 may be a separate piece and / or a sharp protrusion. The lip 17 preferably extends across the width of the connector 1 between the two side plates 15, with a portion of the lip being formed by the web 16, although the lip may alternatively be provided solely by each jaw side plate 15.

[0038] The distinct lip has a height LH, measured from the lowest point of the seat 13 in a direction toward the pin axis VPA to the tip of the lip 17, that is at least 8% of the diameter of the pin 2a to which the coupler is attached and for which the coupler is configured for use (about 20% of the radius of curvature of the seat 13). More preferably, the lip 17 has a height of about 10% to about 25% of the diameter of the pin 2a (about 20% to about 50% of the radius of curvature of the seat 13). In the illustrated embodiment, the lip 17 has a height LH of about 12.5% ​​of the diameter of the pin 2a (about 25% of the radius of curvature of the seat 13).

[0039] In the illustrated embodiment, the tip of the lip 17 is located forward of the seat 13, at a point slightly rearward of the forward-most point of the first pin 2a when the pin is seated in the front jaw. For example, the tip of the lip 17 is a distance less than about 10% of a pin diameter rearward from the forward-most point of the first pin 2a. In alternative embodiments and as shown in Figures 11A, 11B, or 11C, the tip of the lip 17 may be slightly forward of the forward-most point of the first pin 2a. For example, the tip of the lip 17 may be a distance less than about 10% of a pin diameter forward of the forward-most point of the pin 2a.

[0040] It is clear that on its way through the opening 11 and into or out of a fully seated position on the seat 13, the lip 17 requires the tool pin 2a to traverse a non-linear path of movement relative to the coupler 1. The direction of movement of the tool pin 2a past the lip 17 (or of the lip 17 past the tool pin 2a) is not parallel to an imaginary pin axis, which is the direction of movement of the second jaw (axis of movement MA). That is, the direction of movement of the tool pin 2a has a component of movement perpendicular to the fore-aft direction of the coupler 1. Movement of the tool pin 2a into or out of engagement with the first jaw (or movement of the first jaw 5 into or out of engagement with the tool pin) is not possible by a purely "forward" or "backward" movement parallel to the axis of movement MA.

[0041] A locking member 19 is provided on the fixed first jaw 5. The locking member 19 is movable between a locked position shown in Figures 3, 5A and 6 (where a portion of the locking member 19 protrudes into the opening of the first jaw 5) and an unlocked position shown in Figure 5B (where the locking member 19 is substantially or completely withdrawn from the opening 11 of the first jaw 5). With the locking member 19 in the locked or unlocked position, the first jaw 5 can be moved to engage the tool pin 2a. In the locked position, the sloped surface at the front of the locking member means that sufficient force applied by the abutment pin 2a pushes the biased locking member 19 towards its retracted position so that the pin 2a can be inserted into the first jaw 5. However, in the locked position, the first locking member 19 prevents the tool pin from being removed from the first jaw 5.

[0042] The locking member 19 is pivotable relative to the first jaw 5, for example by being pivotally mounted to the first jaw 5 or to the connector body 3. In the illustrated embodiment, the pivot axis for the locking member 19 is provided by a pin 21 extending between two side plates "slide rails" 15 of the first jaw 5, with the first locking member 19 seated between the side plates 15. However, other configurations of the locking member are envisioned.

[0043] The locking member pivot 21 is located forward of the first pin seat 13 and forward of the tip of the lip 17. In its locked position the locking member extends generally downward and rearward from the pivot 21 towards the seat 13. The locking member pivot 21 may be just above or forward of the mouth 11 of the first jaw 5. Preferably the position and shape of the locking member 19 is such that the locking member 19 does not normally contact the first pin 2a when the pin is seated in the first jaw 5. Rather, during normal use of the coupler there is a space between the locking face 27 of the locking member and the pin 2a, and contact only occurs when the locking member 19 is performing a safety function (e.g. in the event of actuator 9 failure).

[0044] Similarly, in some embodiments, the position and shape of the lip 17 of the first jaw is such that the lip 17 does not normally contact the first pin 2a when the pin is seated in the first jaw 5. Rather, a space exists between the tip of the lip 17 and the pin 2a during normal use of the coupler, and contact occurs only when the lip 17 is performing a safety function (e.g., in the event of a failure of the actuator 9).

[0045] The locking member 19 is biased towards its locked position, i.e. in the absence of any external force, the locking member is in its locked position. A biasing member is provided for biasing the locking member 19. In the illustrated embodiment, the biasing member comprises a leaf spring 22, the first end of which is fixed to the connector body and the second end of which is fixed to the body of the locking member 19 at the part of said locking member that extends into the jaw opening 11. The spring extends bent forward / underside of the locking member pivot 21 around the pivot 21 such that the pivot 21 acts as a fulcrum for the leaf spring. Although only a single spring is shown in the illustrated embodiment, there may alternatively be multiple springs biasing the locking member.

[0046] Leaf springs are less susceptible to clogging with sand and dirt than other types of springs, making them less likely to fail or become clogged when the coupling 1 is used in dusty or harsh environments. Leaf springs can also provide a significantly greater biasing force than a comparably sized torsion spring positioned about a pivot, making them less susceptible to failure.

[0047] The locking member includes a stop tab 25 for limiting rotation of the locking member 19. The stop tab 25 is located on the opposite side of the pivot 21 from the body 19a of the locking member 19. The stop tab 25 has a back surface that is arranged to abut against an opposing surface that is fixed relative to the locking member body when the locking member 19 is in the locked position. In the illustrated embodiment, the back surface 26 of the locking member 19 abuts against a flat vertical surface on the actuator 9 to define the locked position of the locking member 19. In the locked position, the back surface 26 of the stop tab 25 is in the locked position, although this may be different in alternative embodiments.

[0048] The locking member includes one or more cam surfaces 23 (FIGS. 5A, 5B, and 7) for moving the locking member 19. In the exemplary embodiment, two cam surfaces 23 are provided on opposite sides of the pivot axis 21 relative to the body of the locking member. However, in alternative embodiments, the locking member may include a single cam surface or more than two cam surfaces.

[0049] In the embodiment shown, two locking surfaces are provided adjacent and on either side of the stop tab 25. The or each cam surface 23 is preferably an inclined surface that faces generally rearwardly and upwardly when the locking member is in the locked position. The or each cam surface 23 is configured to interact with a moveable member 35 carrying the moveable jaw 7. A portion 38 of the moveable member slides along the respective cam surface 23 to move the locking member 19 into and out of the locked position, as will be described in more detail below.

[0050] The first locking member 19 has a locking surface 27 on a portion of the locking member that extends into the jaw opening 11 of the first jaw when the locking member 19 is in the locked position. The locking surface 27 faces the tool pin 2a when the locking member 19 is in the locked position. The locking surface 27 may not contact the first pin 2a when it is seated in the first jaw, but will contact the pin when the pin moves from its seat to prevent the pin 2a from exiting said jaw.

[0051] The locking member 19 has a locking surface 27 configured to face the pin 2a of the first jaw in the locked position. It is this locking surface 27 that the first pin contacts if the pin moves towards the mouth 11 of the first jaw when the locking member 19 is in the locked position. The locking surface 27 retains the first pin 2a within the jaw 5. In the embodiment of Figures 1-10, when the locking member is in the locked position and contacting the pin 2a, the locking surface 27 is substantially flat or otherwise shaped to have only a single point of contact with the tool pin 2a when locking. When contacting the tool pin 2a, the locking surface 27 abuts the cylindrical tool pin and therefore only contacts the pin at a single point CP (see Figure 10B).

[0052] In alternative embodiments, the locking surface 27 may be alternatively shaped in such a way that contact with the tool pin 2a is still achieved only at a single point, or in such a way that it contacts the pin along the length of the contact surface. For example, the locking surface 27 may be convex or concave, but with a radius of curvature significantly greater than that of the tool pin. Alternatively, the locking surface may be hook-shaped and closely match the curvature of the tool pin 2a. In the embodiment shown in Figures 11A-11E, the locking surface 127 is hooked on one side to help retain the first pin 102a within the first jaw 105.

[0053] 11A-11E show an alternative embodiment of the first jaw 105 and locking member 199. FIG.

[0054] 11A, in this embodiment the rear surface of the lip 117 is substantially straight and at an angle of about 30 degrees relative to the front-to-rear direction of the coupler or the front-to-rear sliding rail direction. In an alternative embodiment, the rear surface of the lip 117 may be curved, for example concave.

[0055] Line TP indicates the non-linear travel path that first pin 102a must follow relative to first jaw 105 in order to enter that jaw. The portion of the entry path TP forward of the defined lip 117 is straight; however, other paths are possible within the constraints created by the edges of the connector body and the angled lead-in at the front of jaw 105 / lip 117 (e.g., an upwardly angled path).

[0056] 11A-11E show the first pin 102a in a number of positions relative to the front jaw 105. These positions are designated (a), (b), (c) and (d). In position (a) shown in Figs. 11A and 11B, the front mounting pin is firmly seated in the front jaw seat 113 and will remain in this position during normal use of the device. As will be explained in more detail below, in the event of a failure or misuse of the coupler, the front mounting pin 102a may come into contact with the locking member 119, as shown in position (c) of Fig. 11C. In this position, the contact surface 127 of the locking member 119 is tangent to the pin 102a, and the point of contact is a line with the pin centre and the pivot 121 of the locking member. This means that any load is transferred through the pin centreline of the pivot pin 121, and therefore little or no bending moment is induced in the front locking member.

[0057] In the illustrated embodiment, the contact surface 127 of the locking member 119 is curved with a small lip 128. If the pin 102a acts in any way to begin to retract the locking member 119, the lip 128 of the locking member 119 acts to push the front pin 102 back towards the seated position, point (b) shown in Figure 11D.

[0058] Alternative shapes of contact surfaces of the locking member 119 are envisioned, for example a flat surface or a surface without a lip 128.

[0059] Figure 11E shows the movement of the pin 102a being withdrawn from the jaw 105 after the front locking member 119 has been retracted. The pin 102a can now advance to position (d) shown in Figure 11E, where the front locking member 119 is sufficiently retracted that withdrawal of the tool pin 102a from the front jaw 105 is no longer impeded.

[0060] Referring again to Figures 1-7, the movable second jaw 7 is a hook-shaped member and defines an opening 31 and a seat 33 for receiving the second tool pin 2b. The second jaw 7 opens to the rear of the coupler 1, i.e. the first and second jaws 5, 7 are back to back with respect to each other. The second jaw 7 comprises an extension 63 having an extension surface parallel to the imaginary pin axis VPA and the movement axis MA. The extension 63 is located rearward of the second jaw seat 33, the surface of the extension being preferably (but not necessarily) continuous with the surface of the seat 33. The surface of the extension has a rear end that is located rearward of the centerline of the vertical centerline VCb (Figure 3) of the second pin 2b when the second pin 2b is seated in the second jaw. The extension is of sufficient length that if the second jaw 7 becomes dislodged from the second pin 2b during use if there is a loss of pressure in the actuator, the vertical centre line VCb of said pin will be on a point on the extension 63 to resist rotation of the tool in the event of hydraulic failure. This function will be explained in more detail below.

[0061] In the illustrated embodiment, the rear end of the extension surface 63 is located rearward of the vertical centerline VCb of the second pin 2b when the second pin 2b is seated in the second jaw 7, but forward of the rearmost point of the pin 2b. However, in alternative embodiments, the extension portion 63 may be longer and extend rearward of the second pin 2b. The surface of the extension member 63 is preferably flat, but in alternative embodiments may have some concavity.

[0062] The movable second jaw 7 is movable between an extended engagement position with the second jaw at the distal end of the first jaw, where the first and second jaws 5, 7 are engaged with their respective tool pins, and a retracted position of the second jaw at the proximal end of the first jaw. The member may further be movable to a super-extended position, where the distance between the imaginary centres of the mouth of the fixed jaw 5 and the mouth of the movable jaw 7 is greater than the distance between the centres of the first and second tool pins 2a, 2b.

[0063] The movable jaw 7 is provided on the movable member 35, the movable jaw 7 being fixed to or integral with the movable member 35. The movable member 35 has two extensions 37 extending forward from the second jaw 7 in opposite directions of the jaw opening 31, and side ears 38 for connecting the movable member 35 to the actuator 9.

[0064] The movable member 35 is slidably mounted within the coupler 1 for linear movement relative to the coupler body 3 along an axis of movement MA towards and away from the fixed first jaw 5. When the coupler 1 is aligned to engage the tool pins 2a, 2b, the movement of the second jaw is perpendicular to the lateral tool pins 2a, 2b.

[0065] In the illustrated embodiment, the opposing inner surfaces of the first jaw side plate 15 each include a linear guide channel 43 (see FIG. 7). These guide channels 43 receive complementary guide features on the movable member (e.g., side edges 45 of the movable member 35). When the movable member is moved forward or rearward by the actuator 9, the sides 45 of the movable member 35 slide forward and rearward within the guide channels 43 to guide the movement of the movable second jaw 7. The guide channels 43 can include stops to define the limits of movement of the movable member 35, or the movement of the movable member may be determined by another constraint (e.g., the stroke of the actuator 9).

[0066] The movable member extensions 37 are positioned above the first and second jaw openings 11, 31, but below the actuator 9 when the coupler is in the generally horizontal orientation shown in Figures 1-7. The extensions 37 are positioned to interact with the cam surface 23 of the locking member 9. With reference to Figures 5A and 5B, from the extended, engaged position, as the movable jaw 7 moves towards the fixed jaw 5, the rounded tip 38 of the movable member extensions 37 moves into contact with the cam surface 23 of the locking member 19. Continued forward movement of the movable members 35 causes the flat lower surface of each movable member extension 37 to slide over the respective cam surface 23, pivoting the locking members 19 towards their retracted position. When the movable members 35 reach their forward-most / retracted jaw position, the locking members 19 are retracted and the cam surface 23 is substantially horizontal, parallel or nearly parallel to the lower surface of the extensions 37, as shown in Figure 5B.

[0067] As the coupler moves from the retracted, unlocked configuration shown in Figure 5B to the extended, engaged position of Figure 5A, rearward movement of the movable members 35 causes the flat underside of each movable member extension 37 to slide back on the respective cam surface until the movable member extensions 37 are no longer in contact with the locking members, allowing the locking members 19 to pivot towards their retracted position under the biasing force of the springs 22. The slope of the cam surfaces 23 is preferably such that the locking members 19 are allowed to gradually extend into their locked position rather than suddenly releasing. The stop surface of the locking members 25 is preferably configured to contact an opposing surface of the coupler body just as the movable member extensions 37 move out of contact with the cam surfaces 23 to prevent such sudden release.

[0068] The actuator 9 is a linear actuator, preferably in the form of a double acting hydraulic ram. The actuator 9 is housed in the coupler body 3 between the first jaw side plates 15. One end of the actuator is fixed to the coupler body 3 and the other end is fixed to the moveable member. In the illustrated embodiment, the cylinder of the hydraulic ram 9 is fixed to the first jaw side plate 15 via a pin 10. An actuator connection pin 41 extends through the left and right side ears 39 to attach the ram of the hydraulic actuator to the moveable member 35 such that extension or contraction of the hydraulic actuator 9 moves the moveable member 35 relative to the body.

[0069] The ram of the hydraulic cylinder 9 is biased to the extended position by a biasing member, such as a spring 51 (seen in Figures 9A-9D). The spring 51 ensures that the actuator 9 remains extended even in the event of a loss of hydraulic pressure. In the illustrated embodiment, the spring 51 is a compression die spring provided inside the actuator. The die spring is disposed at least partially within the cylindrical hollow of the cylinder rod and is arranged to act between the rod and the barrel to bias the rod from the barrel to the extended position. A central spindle preferably extends axially along the center of the spring to prevent buckling of the spring. The spindle may extend from the barrel of the cylinder and has a length approximately the same as or slightly less than the compressed length of the spring 51.

[0070] An internal die spring is advantageously sealed from environmental conditions, reducing the likelihood that dirt and debris from the operating environment will affect the operation and life of the spring. In contrast, an external spring tends to collect debris (e.g., sticks, stones, dirt) and takes up valuable space within a small hitch body. However, in alternative embodiments, an external compression spring may be provided around the barrel and / or rod of the actuator and configured to bias the actuator into the extended position.

[0071] Coupler operation Operation of the exemplary coupler 1 shown in the drawings will now be described with reference to Figures 8A-8E, which show the coupler mounted on the end of an excavator arm 70. The arm 70 includes a linkage to which the coupler 1 is attached via mounting aperture 6. The linkage can be operated using a hydraulic ram to move the linkage and thus the coupler 1.

[0072] In the first step shown in Figures 8A and 8B, the coupler 1 is moved and rotated if necessary using a bucket linkage on the arm 71 to align the first jaw 5 with the first tool pin 2a but hold the second jaw 7 not fixed to the second tool pin 2b. The coupler 1 is then moved so that the first jaw 5 engages the first tool pin 2a, which rests on the seating surface 13 behind the jaw lip 17. A chamfered or angled lead-in surface 18 on the first jaw in front of the lip 17 helps to guide the first jaw 5 onto the pin 2a by making an entrance to the first jaw that is wider than the diameter of the pin and gradually narrows towards the jaw. An angled inner upper surface 20 behind the lip 17 guides the pin 2a in a different direction towards the seating surface 13.

[0073] The relative motion between the first tool pin 2a and the first jaw 5 is non-linear because the lip 17 requires a change in direction of motion when moving into or out of engagement. The relative motion between the first tool pin 2a and the first jaw 5 in front of the lip 17 may be linear and parallel to the axis of movement MA, or may be at a slight angle as accommodated by the chamfered surface 18 at the front of the first jaw 5. However, behind the lip 17 (between the lip 17 and the seating surface 13), the motion vector changes and becomes non-parallel to the axis of movement MA. In the illustrated embodiment, the rearward motion of the lip is at an angle of about 30 degrees to the MA, although this angle may be different in different embodiments. For example, the motion may be at an angle between about 30 degrees and about 40 degrees, and more preferably between about 25 degrees and about 35 degrees.

[0074] In this first step, the movable member 35 is in the retracted position (as shown) and the locking member 19 is also retracted. Alternatively, the movable member may be in the extended position with the locking member 19 in the locked position. When the movable member 35 is in the extended position and the locking member 19 is in the locked position, moving the jaw 5 onto the first pin 2a presses against the angled front face of the locking member, causing the biased locking member 19 to retract to the unlocked position.

[0075] Either before coupling with the first pin 2a or after engaging with the first pin but before engaging with the second pin, the second jaw 7 and movable member 35 can be moved towards the first jaw 5 to a retracted position (also shown in FIG. 5B). As the movable member 35 moves towards the retracted position, the end of the engagement portion 37 slides on the cam surface 23 and pushes the cam surface downwards causing the first locking member 19 to pivot about its pivot axis 21 and move the locking member 19 upwards to the unlocked position.

[0076] Once the first pin 2a is seated in the first jaw 5 and the movable member 35 is retracted (FIG. 8B), the coupler 1 is then rotated about the first pin 2a, with the second jaw still in the retracted position, until the underside of the side plate 15 of the first jaw abuts the second pin 2b, and the second jaw 7 is aligned with the second pin, as shown in FIG. 8C.

[0077] Referring to Figure 8D, in the next step, the actuator 9 is extended, thereby moving the second jaw 7 away from the first jaw 5 towards the second pin 2b. As the second jaw 7 moves away from the first jaw 5, the extension portion 37 of the movable member slides away from the cam surface 23 of the locking member 19, allowing the locking member 19 to pivot under the biasing force from the leaf spring 22 until the extension portion 37 is completely out of engagement with the locking member and the stop tab 25 abuts the stop surface 26 of the connector body 3 (Figure 5A). The biased locking member 19 is then in its engaged position.

[0078] The actuator 9 extends further until the second jaw 7 engages the second pin 2b. The coupler 1 is in the final coupled configuration when the second pin 2b seats on the seating surface 33 of the moveable second jaw 7. With both pins 2a and 2b engaged with the coupler 1, the coupler 1 can be manipulated using an arm or boom 70 attached to the coupler 1 to rotate and lift the implement as shown in FIG. 8E.

[0079] To remove the tool from the coupler 1, the above process is carried out in reverse. As a first step, the second movable jaw needs to be disengaged from the second tool pin 2b. To do this, the force applied to the movable member 35 by retracting the actuator 9 must be sufficient to overcome the biasing force from the spring 51 on the actuator and, later in the stroke, to overcome the biasing force from the locking member 19 to retract it. It is assumed that full hydraulic force is available to the actuator 9 during the decoupling process. It is therefore not difficult for the actuator 9 to provide the force required to overcome the biasing force of the spring and retract the second jaw.

[0080] When the movable jaw 7 is disengaged from the second tool pin 2b, the coupler 1 can be rotated about the first pin 2a, the second jaw 7 moves away from the second tool pin 2b, and the coupler can be removed from the first pin 2a.

[0081] Behavior under incorrect binding During the coupling process, the operator may not be able to see the engagement of the second jaw 7 with the second pin 2b because it is often hidden by the implement, excavator arm, or bucket linkage. Therefore, the operator may not realize that the rear jaw 7 is not properly engaged with the second pin 2A. Figures 9A-9C illustrate this scenario for a coupler according to the present invention.

[0082] Figure 9A shows the front jaw of the coupler coupled and locked to the front pin 2A of the tool similar to that shown in Figure 8D. However, the rear jaw is not precisely aligned with the rear pin, so movement of the movable jaw 7 towards the pin is stopped when the tip of jaw 7 abuts pin 2b. At this point, if the operator mistakenly thinks that the second pin 2b is seated in the second jaw and lifts the coupler, the tool may swing around the second pin 2a as shown in Figures 9B-9D until the tool hangs from the first pin as shown in Figure 9D.

[0083] In this hanging position, the lip 17 on the first jaw serves to keep the first pin 2a seated on the first jaw and preferably out of contact with the front locking member 19. Thus, although the tool is hanging from the coupler, it remains attached to the coupler by the first pin and does not fall off the coupler. In contrast, in the same scenario in a prior art system, the first pin 2a contacts the locking member and the force from the momentum of the swinging tool is transferred to the locking member. As the tool swings about the pin 2a, the rotational force from the rotation of the tool is transferred to the locking member on such prior art couplers as a torque about the locking member pivot. The direction of this transferred torque is in a direction that acts to retract the locking member, so that if the force is large enough, the locking member 19 of the prior art coupler is retracted in such a scenario, allowing the first pin to slip out of the first jaw, thereby completely disconnecting the tool from the coupler.

[0084] All connectors are subject to operator error, but the features of the present invention work together to reduce the risk of adverse consequences from complete detachment of the implement due to such operator error.

[0085] Operation in the event of hydraulic failure Various features of the coupler work together to prevent the first and second tool pins 2a, 2b from disengaging from the coupler 1 in the event of a coupler failure, such as a loss of hydraulic pressure in the actuator 9.

[0086] One of the worst case failure scenarios occurs when the hitch is in an upright position with the tool pins 2a, 2b vertically aligned, as shown in Figure 10 A. In this scenario, even if there is a complete hydraulic loss to the actuator 9, both tool pins 2a, 2b will remain connected to the hitch.

[0087] Figure 10B shows the behaviour of the coupler 1 in case of loss of hydraulic pressure. In this vertical position, the second jaw 7 can no longer resist the vertical weight of the implement and substantially all vertical load is transferred through the first pin 2a, which falls out of its seated position but is prevented from falling out of the first jaw 5 by the locking member 19, which remains in its locked position. The constriction of the first jaw opening 11 formed by the first locking member 19 and the lip 17 prevents the first implement pin 2a from slipping out of the first jaw 5 and limits the relative movement of the implement and the coupler.

[0088] The weight of the moveable member 35 and second jaw 7 (and potentially the actuator rod and other connected components) acts to force the moveable member 35 downwards against the connector body 3, disengaging the second pin 2b from the second jaw. However, the actuator spring 51 prevents the moveable member from dropping to the point where the extension 37 may interact with the locking member 19.

[0089] With the second tool pin 2b unseated, the gravitational forces are not transferred through the movable jaw 7, and the gravitational forces from the tool 73 act rotationally around the first tool pin 2a. The extension 63 of the second jaw (which is parallel to the axis of movement MA) provides a reaction surface for the rotational forces. As the reaction forces RF1, RF2 are primarily perpendicular to the axis of movement MA (i.e. horizontal in the illustrated scenario), they do not cause a movement of the movable member 35 along the axis of movement MA, but are instead transferred to the connector body 3. In the illustrated embodiment, the reaction forces are transferred to the connector body via a guide 45 on the movable member 35.

[0090] The lip 17 and the locking member 19 cooperate to support at least most, if not substantially all, of the weight of the tool. Figure 10B shows reaction forces RF3, RF4 acting through the lip and the locking member 19. These reaction forces are radial to the first pin, extend through the center point of the pin and are perpendicular to the surfaces at their respective contact points. The reaction force provided by the locking member 19 preferably acts through the pivot point 21 of the locking member (or a point very close to the pivot point 21). This is to prevent the reaction forces from exerting large twisting forces on the locking member 19, and in particular to ensure that reaction force RF4 does not tend to pivot the locking member 19 towards its retracted position.

[0091] Thus, the actuator spring 51, second jaw extension 63 and front locking member 7 all act together to ensure that both pins 2a, 2b are retained within the coupling 1 for all potential positions of the tool in the event of a hydraulic failure.

[0092] Numerous changes in the construction of the present invention and widely differing embodiments and applications will be apparent to those skilled in the art to which the present invention pertains without departing from the scope of the present invention as defined in the appended claims. For example, while in the exemplary embodiment the first jaw 5 is described as a front jaw, it will be apparent that the first jaw 5 can be a rear jaw and the second jaw 7 can be in front of the first jaw. In an alternative embodiment to the illustrated embodiment, a second locking member can be provided on the movable second jaw for selectively clamping the opening 31 of the second jaw 7.

[0093] In some embodiments, it may be desirable to provide hydraulic power to the coupled implement. The supply of hydraulic power to the implement can be via a separate hose connection that is manually connected, but more preferably, there are a number of quick connect hydraulic couplers available in the industry that can be incorporated into coupler 1, which allow for a hydraulic connection to occur when the implements are mechanically coupled.

[0094] The components of the coupler 1 may comprise any suitable material as would be apparent to one of ordinary skill in the art. For example, the major components (e.g., housing body 3, jaw plate 15, movable member 35, locking member 19) preferably comprise steel. These components may be machined or cast, or a mixture of both. However, it is contemplated that some or all of the components may comprise alternative materials (e.g., alternative metals, or composite materials). Similarly, the hydraulic actuator device may comprise any suitable material and is adapted to mate with a pressure hose.

[0095] The invention may also be broadly said to consist of the parts, elements, and features referred to or indicated in the specification of this application, either individually or collectively, and any or all combinations of any two or more of said parts, elements, or features. Where specific wholes that have known equivalents in the art to which the invention pertains are referred to herein, such known equivalents are deemed to be incorporated herein as if individually set forth.

Claims

1. 1. A coupler for connecting an implement having first and second spaced parallel pins to an arm of a vehicle or machine, the coupler comprising: a body for attachment to the arm of said vehicle or machine; a front first jaw fixed relative to the body; wherein the front first jaw defines an opening and a first seat for receiving the first tool pin, and has a distinct lip forward of the first seat, the lip projecting generally in a direction toward the body; a locking member pivotable relative to the first jaw about a pivot axis located forward of the lip of the first jaw; wherein the locking member pivots between a locked position in which a portion of the locking member projects into the opening of the first jaw and an unlocked position in which the locking member is substantially or completely withdrawn from the opening of the first jaw; a movable rear second jaw facing opposite the first jaw; wherein the movable rear second jaw defines an opening and a second seat for receiving the second tool pin, the second jaw having an enlarged surface adjacent the jaw opening and a rear portion of the second seat; and an actuator selectively movable toward and away from the first jaw along an axis of movement; Equipped with the first jaw, including the lip, defines an entry direction of the first pin into the seat of the first jaw that is not parallel to the axis of movement; The coupler.

2. The coupler of claim 1 , wherein the movable second jaw is biased away from the first jaw.

3. 3. The coupling of claim 2, wherein the actuator is a hydraulic cylinder and a biasing member is positioned to bias the cylinder toward the extended position.

4. The coupler of claim 3 , wherein the biasing member comprises a die spring.

5. The coupler of claim 1 , wherein the lip of the first jaw comprises a rear surface oriented at an angle of about 25 degrees to about 35 degrees relative to the axis of movement.

6. 2. The coupler of claim 1, wherein the lip of the first jaw is shaped such that, in a vertical position of the coupler with the second jaw above the first jaw, weight forces from an implement secured to the coupler are at least partially supported by the lip.

7. 2. The coupler of claim 1, wherein engagement of the first jaw with the tool pin requires a change in direction of movement of the first jaw or the tool pin to avoid collision of the first jaw with the lip.

8. 2. The coupler of claim 1, wherein the locking member is shaped such that, in a vertical position of the coupler with the second jaw above the first jaw and the locking member in a locked position, a weight force from an implement held on the coupler is at least partially supported by the locking member.

9. 9. The coupler of claim 8, wherein in a vertical orientation of the coupler with the second jaw above the first jaw and the locking member in a locked position, a reaction force vector provided by the locking member to support the first tool extends through a pivot axis of the locking member.

10. 2. The coupler of claim 1, wherein in a vertical position of the coupler with the second jaw above the first jaw and the locking member in a locked position, at least a major weight force from an implement held on the coupler is supported by the locking member and the lip of the first jaw.

11. 2. The coupler of claim 1, wherein the locking member includes a locking surface for contacting the first tool pin at a contact point, the contact point being substantially collinear with a center of the pin and a pivot axis of the locking member.

12. 12. The coupling of claim 11, wherein the locking surface at the point of contact is substantially perpendicular to an axis running between the center of the pin and the pivot axis of the locking member.

13. The coupler of claim 12 , wherein the locking surface is substantially flat.

14. 2. The coupler of claim 1, wherein the locking member is biased toward the locked position.

15. 15. The coupler of claim 14, further comprising a leaf spring arranged to bias the locking member toward the locked position.

16. 16. The coupler of claim 15, wherein a first end of the leaf spring is secured to the body and a second end of the leaf spring is secured to the locking member, the leaf spring including a bent intermediate portion adjacent the locking member pin.

17. The locking member includes a cam surface, and the movable jaw is disposed on a movable member configured to engage the cam surface and thereby retract the locking member from its locked position when the movable jaw moves toward the first jaw. The coupler of claim 1 .

18. 2. The coupler of claim 1, wherein the extended surface of the second jaw is configured to prevent rotation of an implement attached to the coupler by retaining the second pin within the second jaw if the second jaw moves slightly toward the first jaw as a result of a failure of the actuator.

19. 19. The coupler of claim 18, wherein the extension surface of the second jaw is substantially flat and / or substantially parallel to the axis of movement.

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