WO2001096672A1

WO2001096672A1 - Latch bar construction for a quick change bracket

Info

Publication number: WO2001096672A1
Application number: PCT/US2001/018712
Authority: WO
Inventors: Wally L. Kaczmarski; Craig A. Berard
Original assignee: Clark Equipment Company
Priority date: 2000-06-12
Filing date: 2001-06-11
Publication date: 2001-12-20
Also published as: AU2001268292A1

Abstract

A quick attachment bracket (24) is made to receive a frame (48) that mounts onto an accessory tool, such as a loader bucket (20), or some powered attachment, and which frame is latchable onto the bracket (24). The bracket (24) carries a latch tongue (41) that is spring loaded toward the frame (48), and has a support saddle (40) for receiving an end of the frame (48). A latch bar (49) that has a continuous peripheral surface is supported on the frame (48) at one end thereof and is adapted to fit within the saddle (40), and has an inclined surface (49A) that is engaged by the latch tongue (41) so that the latch bar (49), and the frame (48) connected thereto, are held by the latch tongue (41) against the retainer or saddle (40) of the bracket (24).

Description

ATCH BAR CONSTRUCTION FOR A

QUICK CHANGE BRACKET

BACKGROUND OF THE INVENTION

The present invention relates to a latch bar construction used on a mounting frame for attachment of a tool, such as a clamshell, bucket, grapple, or power unit support to a bracket on an arm or boom, such as a backhoe or excavator arm.

With the advance of reliable, positive locking quick attachment brackets, it has become desirable to use a quick attachment arrangement for interchanging buckets, power earth augers, compactors, clam shells, grapples, breakers and other implements as well. In the prior art U.S.A. 5,974,706 and U.S.A. 6,163,989 show couplings that can quickly connect tools to an articulated arm of an excavator, backhoe or the like are shown. The basic coupling action is described in such patents. The latch bars used on the mounting frame in the prior art patents are made in multiple welded parts, which require assembly, time and fixturing.

SUMMARY OF THE INVENTION The present invention relates to a mounting frame having a latch bar that is preformed as an extrusion a roll formed bar or a formed (bent) and seam welded bar. The bar is made to have a continuous wall having the desired configuration. The dimensions of the formed latch bar can be closely controlled for insuring a good fit and adjustment for wear. The latch bar is welded into a plate assembly used in a frame with simple fixtures that accurately locate the latch bar. The plate assembly, including the formed latch bar, can be welded directly to the tool, or in cases where the tool normally is attached to an arm with pin connectors, the plate assembly can include an adapter plate that pins to the existing pin holes on the tool.

The latch bar of the present invention is shown as being used with an automatically engaging latch tongue that engages one of the exterior surface for positive location and latching. The latch bar is mounted onto a base mounting frame that couples to a bracket on a boom or arm of an excavator or backhoe. The latch tongue is carried on the bracket and as the frame and bracket are moved together for coupling, the latch bar slides into a receptacle or seat on the bracket. As the bracket seats in position on the framed the latch tongue snaps into place under a spring load to engage a surface of the latch bar and securely hold the base mounting frame on the bracket. The surface engaged by the latch can be hardened in selected regions to increase wear resistance. The load carrying wall of the latch bar can be made thicker to increase load carrying ability and minimize deflection. The frame and bracket also can be secured together by bolts or other fasteners without the automatically engaging latch tongue and the advantage of the precise latch bar construction is available.

The mounting frame is usable on a wide variety of tools that now are pinned to linkages on the boom or arm of a backhoe or excavator. BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a schematic representation of a backhoe or excavator arm having a quick attachment bracket for receiving and holding a mounting frame having a latch bar made according to the present invention installed on a bucket;

Figure 2 is an enlarged fragmentary view with parts in section and parts broken away showing details of a quick attachment bracket and a mounting frame using a latch bar made according to the present invention;

Figure 3 is a sectional view showing a mounting frame and quick attachment bracket having a latch bar made according to the present invention in a latched position;

Figure 4 is a side view of the latch bar installed on a backhoe or excavator bucket with a cross plate in position, and with bucket attachment plates removed; Figure 5 is a plan view taken on line 5—5 in Figure 4;

Figure 6 is a side perspective view illustrating a modified mounting frame using the latch bar of the present invention; and

Figure 7 is an end view taken generally along line 7—7 in Figure 6.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A powered implement boom or arm 16, such as on an excavator or backhoe, is used to mount a tool, as shown, a bucket 20. The arm 16 is pivotally mounted to a boom arm section that is in turn pivotally mounted to the excavator or backhoe represented at 10. The arm 16 is controlled and operated from a mounting platform, using hydraulic actuators operated from a source of hydraulic fluid under pressure, and operated by hydraulic valve controls 14. An outer end of the arm 16 as shown mounts a link assembly '18 that is used for controlling pivoting of a tool represented as a bucket 20 relative to the arm 16. The link assembly 18 is actuated with a double acting hydraulic actuator shown at 22 and operated through hydraulic valve controls 14. The actuator 22 extends and retracts an actuator rod 22A under power and controls pivotal movement of a quick attachment mounting bracket 24 that is pivotally mounted on a pin 26 to the outer end of the arm 16. The actuator 22, acting through link assembly 18 will control pivoting of the bracket 24 about the horizontal axis of the pin 26. The hydraulic actuator 22 can be attached directly to the bracket 24 to eliminate the link assembly 18, if desired. The link assembly 18 as shown, has a pair of links^s 19A and 19B that are pivotally mounted together with a pin 19C. The pin 19C also is the attachment pin for the actuator rod 22A. The links 19A and 19B are suitably bifurcated to permit attachment on the single pin 19C. The link 19A is pivotally mounted to the arm 16 with a pin 19D and the outer end of link 19B is pivotally mounted to quick attachment bracket 24 with a pin 28.

The quick attachment bracket 24 has a pair of spaced apart side plates 30, one of which is broken away in Figures 1, 2 and 3, that support a nose bar 32 that extends across the space between the side plates 30 at a nose or latching portion 33. The nose bar 32 is welded to the side plates 30 to form an assembly. The side plates 30 have lower support ears 36 that are recessed to support a "J" shaped saddle or retainer 40 that also extends across the space between the side plates 30 and is welded to secure the opposite ends of the side plates 30. A -plate 40C (Figure 3) from which the saddle is formed extends between the side plates 30. The saddle 40 is a retainer or latch seat that is open in direction toward nose or latching portion 33. The side plates 30 receive the main mounting pin 26 through provided bores, and the pin 26 extends across the space between the side plates 30. A latch pin 28 also extends through bores in side plates 30 and extends across the space between the side plates 30.

A pin 38 is supported on the outer ends of ears 36 of the side plates at an end of bracket 24 opposite nose portion 33 and is held in place partially under a lead-in lip 40A on one outer edge of the "J" shaped saddle 40. The pin 38 extends outwardly beyond the side plates 30 to provide support ends 38A, which are used to support a mounting frame 48, shown welded to the bucket in the first form of the invention, during mounting and releasing the frame 48 and attached tool from the quick attachment bracket 24.

The latch pivot pin 28 also mounts a frame latch tongue 41 (Figures 2 and 3) . The latch tongue 41 is a yoke shaped member that has a pair of latch arms 42 held together with a cross bar 43 at their outer ends. The arms 42 have hubs 44 that also have bores that pivotally mount over the pivot pin 28. The hubs 44 have control arms 45 extending therefrom, and the arms 45 are spring loaded with strong compression springs 46 that are retained in spring supports 47 that are fixed to the side plates 30 and bear against the arms 45. The end 43A of the latch tongue 41 is rounded with a large radius for smooth engagement when latching.

The latch tongue 41 is thus urged by the springs 46 to rotate in counterclockwise direction as shown in Figures 2 and 3, and the latch tongue 41 is retained from rotating beyond a desired position, by a block or cylinder 84 that has an extendable rod 85 that forms a stop.

The mounting or attachment frame 48 is used to couple to quick attachment bracket 24 shown in Figures 1-3. The frame 48 in one form of the invention has, as a base, a latch backing cross plate 52. The latch backing cross plate 52 is welded to an extruded tubular latch bar or rim 49, that, as shown in Figures 2 and 3, is formed to mate with and be retained by the latch end 43A of latch tongue 41 of quick^attachment bracket 24. Plate 52 includes planar side portions on 52A, (see also Figure 5) or side portions 152A, of a modified plate 152. In the mid portions of the plate 52 a center section 52B or 152B is bent out of the plane of the side portions 52A or 152A along a bend line 52C or 152C to form a recess or opening 52E or 152E between the side portions 52F or 152F.

The latch bar 49 is a rim at one end of the frame, and extends across the width of cross plate 52 or 152, at the end thereof opposite from the flat planar section 52D (or 152D in the form shown in Figures 4 and 5) . The latch bar 49, as shown is preferably a tubular extruded bar, and it can also be made from a unitary plate formed into the irregular cross-sectional shape shown in Figure 4. The latch bar can be made tubular with walls that have different thicknesses to accommodate loads. The latch bar 49 bears the same numerals- as shown in Figures 1 through

3 even though the cross plate assembly is somewhat different in Figures 1-3. The description that follows will be in relation to Figures 1-3. The latch bar 49 has a formed latch wall 49A that is made heavier or thicker than the rest of the walls, and is inclined relative to the plane of the plate 52. Wall 49A joins a wall 49B, that has an outer surface that is substantially co-planar with the upper surface of the plate side portions 52A. The plate side portions 52A extend along opposite sides of recess 52E and the ends of side portions 52A are welded to the latch bar 49 at the junction of the walls 49A and 49B. A thicker or reinforced rounded corner portion 49C joins the wall 49B with a base wall

49D of the latch bar 49. The base wall 49D extends across the width of the saddle 40, as shown in Figures 2 and 3. A rounded corner portion 49E joins the wall 49D and a wall 49F of the latch bar 49 that is substantially parallel to the wall 49B. The wall 49F extends outward from the base wall 49D farther than the wall 49B, so it extends out of the saddle 40. A corner portion 49G joins wall 49F to a return wall 49H, which is spaced from the base wall 49D and extends from wall 49F to join the outer end of wall 49A. The walls form an irregular multi-sided cross section tubular latch bar 49.

Walls 49B and 49F are substantially parallel, and they are joined to the walls 49A, 49D and 49H. The wall 49H supports the inclined wall 49A which is also supported by the shorter wall 49B. The inclined wall 49A is the wall that is positioned to be engaged by latch tongue 41 when latching the frame into position on the bracket 33. When the frame is slid onto the bracket 24 the latch tongue 41 pivots so that the end 43A rides against the outer surface of the wall 49A. Wall 49D forms the base wall of the latch bar, and the corner 49C engages the inside surface of wall 40D of saddle 40. The corner 49C will seat on the curved saddle surface to move wall 49F against wall 40D of the saddle. Thus, even if some wear occurs on the mating parts, the corner 49C will seat further in along the curved inner surface of saddle 40 urging the wall 49F tightly into position against wall 40D to hold the parts securely. The end portion 43A of latch tongue 41 that will ride farther down along the inclined wall 49A to secure the frame in place.

The plate portions 52A are welded at their ends 52C to the top of inclined wall portion 49A, adjacent to junction of walls 49A and 49B. The end 52D of the bent down plate portion 52B is welded to the lower end of the inclined latch wall 49A, as shown.

The form of the invention shown in Figures 4 and 5 has the plate 152 with the bent down plate center portion 152B and plate side portion 152A on opposite sides of recess 152E that are welded to latch bar 49 at ends 152C. The end 152D of plate center portion 152B is welded to the latch bar as well.

In both forms of the invention shown the respective cross plates 52 and 152 have side plates 50 welded thereto which are spaced wider than the side plates 30 on the bracket 24, and under the bar 32 and the "J" shaped saddle 40 of bracket 24. The side plates 50 thus will fit over the outside of the quick attachment bracket 24 when the bracket 24 seats on the quick attachment frame 48. The lower ends of the side plates 50 have ear or hook ends 54 with receptacles 56 formed in them for engaging rod ends 38A for support. The latch tongue 41 is held in its "ready" position shown in Figure 1 when the quick attach bracket 24 is ready to be used, and while many holders for holding the latch in a released position can be used, as shown in Figures 2 and 3, a pivoting pawl 58 is mounted on a shaft 57, on at least one side of the frame latch 41. The pivoting pawl 58 aligns with a hub 44 of the frame latch 41 and as shown in Figure 3 the pawl 58 is positioned to engage a stop lug 59 integral with that hub 44. The stop lug has a stop surface 59A for holding the latch tongue 41 in a retracAed or release position. The pawl 58 is spring loaded with a torsion spring (not shown) to rotate in clockwise direction. The pawl 58 is optional when an actuator 84 is provided, in that the latch tongue 41 can be held in its ready position by the actuator 84. The end 43A of the latch tongue 41 protrudes into the area overlying the "J" shaped saddle 40 when the latch is in its ready position as shown in Figure 2.

The attachment frame 48 plate 52D forms an adapter plate providing a base for support of the frame on tools such as the bucket 20. The plate 52 defines a reference plane for fastening additional supports that are used as welding or support brackets.

For example, in Figures 1, 2, 3, 6, and 7, the plate 52 is supported by bracket straps 60 that are welded to the plate 52 and are welded so they support the latch bar 49 on walls 49H with end portions 62. The bracket straps have lengths 64 that support the plate 52 and are sufficiently high so the latch bar 49 on the plate 52 will not interfere with the back wall of a bucket on which the frame 48 is mounted. In Figure 1 the frame 48 is welded to a conventional bucket back wall 20A. Using the plate 52 and the brackets 60 makes it possible to convert buckets with pivot pin brackets to be mounted on a quick exchange system, by cutting off the existing brackets and welding on the frame 48 using the brackets 60 and the cross plate 52.

The attachment frame 48 and the added bracket straps 60 permit mounting the attachment frame through the adapter plate to any tool that has a flat wall on an end used for the normal attachment location for the tool.

The latch bar 49 forms a first latching rim or interlocking retainer engaging the quick attachment bracket 24. The interlocking of latch bar 49 with saddle 40 is done with a linear motion. The first end of the attachment bracket 24 has a receptacle, namely the "J" shaped saddle 40, that is open in direction toward the nose piece or latching portion 33 and forms a first interlocking latching portion for engagement with latch bar 49, while the nose piece 33 forms a second latching portion for the bracket 24.

The side plates 50 have spaced apart ears 70 that protrude from the plate 52 (see Figures 5 and 6) . These ears 70 have slots that receive a cross retainer bar 72, that is thus spaced from the end 52F of plate 52 to form a receiver slot 73 for the nose portion 33 and nose bar 32. The quick attachment bracket 24 will slide into latched position along plate 52 after the bracket has been pivoted clockwise in Figure 2 until the edges 32A of plate 32 (Figure 3) rest on plate portions 52F. The nose bar 32 and nose piece 33 will then pass between the bar 72 and the plate portion 52F as the latch bar 49 seats in the receptacle formed by "J" shaped channel 40 on the quick attachment bracket 24.

The attachment frame 48 can easily be installed on the quick attachment bracket 24 on the arm 16 using a procedure shown schematically in Figures 2 and 3. When the bucket 20 or other tool is to be attached to the arm 16, the receptacles 56 of side plates 50 are hooked onto the ends 38A of the rod 38, with the bucket or tool in an appropriate stored position. As shown, the bucket can be stored by resti g it on the ground. Elongated tools can be stored either to be in a substantially horizontal position, or supported in a vertical rack. - Moving the arm 16 to the desired location and extending the actuator 22 will roll the quick attachment bracket 24 so that the nose bar 32 and nose portion 33 fit between the side plates 50, 50 and edges 32A of plate 32 can be rested against the plate portion 52F which are part of plate 52, when the receptacles 56 are supported on rod ends 38A. The relative position of frame 48 is shown in dotted lines in Figure 3. The latch bar 49 slips into "J" shaped saddle or retainer receptacle 40 by moving the arm 16 about its mounting pivot to linearly slide the attachment bracket 24 so the frame 48 moves relatively in direction as indicated by arrow 75 in Figure 3. The bracket will engage and retain both ends of the attachment frame 48. The latch bar 49 is moved to be held in "J" shaped member 40 and the nose piece 33 slides under the bar 72 to be held in slot 73 (Figures 6 and 7) by bar 72, plate portion 52F and side plates 50.

The latch tongue 41, and in particular the ends of arms 42 and the cross member 43, will slide out of the way as the quick attachment bracket 24 moves into position on the frame 48 until the frame is retained by the saddle 40 and the nose portion 33 is held in slot 73 by the cross bar 72. The latch tongue 41 will slide on the outer surface of latch bar wall 49B and will then spring inwardly to cause the end 43A to rest against the inclined surface of latch bar wall 49A and hold the quick attachment frame 48 securely on the quick attachment bracket 24. The latch tongue 41 can be released for disconnecting frame 48 by actuating suitable actuators 84 that are mounted on brackets 86 on the side plates 30. The actuators 84 have rods 85 that act on the arms 45 and retract the latch tongue 41 so end 43A clears the latch bar 49 and permits the quick attachment frame 48 to be released from the quick attachment bracket 24. Pawl 58 will seat on the surface 59A to hold the latch tongue 41 in its released position after the quick attachment frame 48 has been removed. The pawl 58 is spring loaded with a torsion spring toward the surface 59A. A pry bar or lever can be used in recess 80 for unlatching the latch 44, for manual operation. For unlatching, the motion of the bracket 24 can be reversed so the frame 48 is in the relative dotted position of Figure 3. The receptacles 56 will receive the ends 38A of rod 38, so as the bracket 24 is lifted away from the frame 48 and the tool, the frame 48 and tool will hang on rod 38 for permitting movement to a stored location.

The bucket 20 or other tool thus can be quickly attached to or removed from a backhoe or excavator arm when using the adapter plate and frame of the present invention.

Figures 4 and 5 illustrate the latch bar 49 installed as a permanent attachment to a bucket 120, that is shown only schematically, but is essentially the same construction as shown in Figure 1. The bucket has a wall 120A that is a back wall, and this wall has a flat upper portion 120B. In this form of the invention, the plate 152, in addition to the portions that lie parallel to the portions 152C, has a bent over lip 152L that fits against the wall 120A and can be welded in place for additional support. The wall ^120B has an outer edge 122, which also can be welded to the latch bar 49 at the corner 49G. Suitable clearances for the bracket will be provided.

The plate 152 can support the side plates 50 in the same manner as before, and these are shown only schematically in Figure 5 and are omitted in Figure 4.

The corners 49C and 49E will seat against the "J" shaped saddle 40, as described in connection with

Figures 1 through 3 and 6 and 7, but the latch bar 49 will be mounted in a different manner, while using the plate 152 which has the bent portion 152B to provide for access for the latch tongue to the outer surface of the inclined wall 49A.

The standoff bracket straps 60 are not used in this form of the invention, in that the plate 152 and the latch bar 49 are welded directly to support walls of the bucket 120.

Otherwise, the action is exactly the same as described, with the side plates 50 being used for supporting the bucket on the quick attachment bracket. The frame assembly 48 is integrated with the tool on which it is mounted. The plate 52 or 152 can be termed an adapter plate that will permit attachments to tools directly, as shown in Figures 4 and 5, or with suitable brackets such as those shown at 60 for adapting the frame to mount on different types of tools. It should be noted that if desired, the latch bar 49, while providing an accessible latch surface, also provides a sturdy support for the end of the frame that seats into the "J" shaped saddle so the nose portion 33 and the cross bar 32 can be used in a bolt arrangement as shown in U.S.A. 6,163,989. The latch bar 49 can be extruded, or even have a solid cross-section, but is a unitary piece that does not require welding pieces together for forming. The latch bar can be made of a folded or bent plate, formed into the desired cross-section as well. The cross-section shown, which is an irregular polygon tube has a base wall and a pair of side walls extending outwardly from the base wall different amounts. A connecting wall joins one of the side walls to an outer end of an inclined latch wall, with the inner end of the inclined latch wall supported on the shorter sidewall. The inclined latch wall can be positioned at the desired angle relative to the base wall for engagement by the latch tongue 41. Also the inclined latch wall has to be of sufficient length so that it can provide take up for wear.

There are only a single thickness of wall around the entire periphery. By having essentially a continuous wall without- a plurality of components, the latch bar is less costly and can be held to closer tolerances and is very rigid.

Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.

Claims

WHAT IS CLAIMED IS:

1. A frame for releasable attachment to a bracket having a latch tongue mounted on a pivot axis and spring loaded in the first direction of pivoting, and the bracket having a saddle open in a first direction and spaced from the latch tongue, the frame including a cross plate for mating with the bracket and a latch tongue extending across the frame at one end of the cross plate, the latch bar having a continuous peripheral surface around a central axis and forming a cross section including a base wall having spaced corners that engage the saddle of the bracket, and an inclined wall on the opposite side of the latch bar from the base wall, the inclined wall being engaged by the latch tongue of a bracket to hold the frame in place on the bracket.

2. The frame of claim 1, wherein said latch tongue is spring loaded to protrude into a plane defined by the cross plate when seated on the bracket, the inclined surface being positioned on an opposite side of the plane of the cross plate from the pivot axis.

3. The frame of claim 1 wherein said cross plate defines a plane, a center portion of the cross plate being recessed away from the plane, said latch bar being mounted at an end of said cross plate where the center portion is recessed a maximum amount, and side portions of the cross plate being fixed to the latch bar at opposite ends of the latch bar, an end of the center portion of the cross plate also being fixed to the latch bar with the inclined latch surface exposed to the plane of the cross plate through the recess formed.

4. The frame of' claim 1, wherein said cross plate has a first end that is substantially planar, and a second end that is formed with two side portions spaced apart, and a center portion of the cross plate being bent out of a plane of the cross plate such that the second end of the center portion is recessed and spaced from the plane of the cross plate, the latch tongue fitting onto the second end of the cross plate, and welded to the second ends of the cross plate side portions and the center portion, the inclined surface of the latch bar being exposed in a recess space between the second end of the center portion and the plane of the cross plate.

5. A latch bar for a frame mountable on a bracket, the latch bar having an elongated central axis and a continuous peripheral surface generated by planar walls around the central axis and including a plurality of planar outer surface walls having surfaces including a base wall, a front wall generally parallel to the base wall and joined thereto with a connecting wall, the front wall being substantially shorter in extension from the connecting wall than the base wall, a top wall connected to an opposite end of the base wall from the connecting wall, and extending from the base wall parallel to the connecting wall but extending from the base wall a lesser distance than the connecting wall, and a latch wall extending from an edge of the front wall to the top wall to form a latching surface that is inclined relative to both the top and front walls.

6. The latch bar claim 5, wherein said walls surround a central space around the elongated central^' axis.

7. The latch bar claim 5, wherein said latch bar is an extruded cross section.

8. The latch bar claim 5, wherein said latch bar has a formed wall having rounded corners at opposite edges of the base wall, and being formed into a continuous wall spaced from and surrounding the central axis.

9. The latch bar of claim 8, wherein the latch bar walls has some sections with different thickness than other sections.