AU746836B2

AU746836B2 - Coupling assembly for excavation equipment

Info

Publication number: AU746836B2
Application number: AU47640/99A
Authority: AU
Inventors: Norman John Smith
Original assignee: Ephemere Pty Ltd
Current assignee: ATLAS HEAVY ENGINEERING Pty Ltd
Priority date: 1998-07-15
Filing date: 1999-07-15
Publication date: 2002-05-02
Anticipated expiration: 2019-07-15
Also published as: AU4764099A

Description

WO 00/04242 PCT/AU99/00574 1

TITLE

COUPLING ASSEMBLY FOR EXCAVATION EQUIPMENT FIELD OF THE INVENTION This invention relates to coupling assemblies for the attachment of excavator buckets and other such implements to heavy duty excavating and like machinery.

BACKGROUND OF THE INVENTION Coupling assemblies facilitate the attachment of a range of implements used on heavy duty excavating and like machinery. In this specification, the terms "heavy duty excavating and like machinery" and "excavator" refer to all machinery, particularly backhoes, having an implement mounted at one end of an excavator arm.

Implements to be used with such machinery include excavator buckets, drills, ripping teeth and similar industrially available and used implements. A need to minimise the downtime and complexity associated with the changing of implements has motivated the development of a range of coupling assemblies which employ both manual and automatic means of installation. However, inherent in many of the designs of these coupling assemblies is the problem of premature wear in the slots, hook or jaw sections that engage and secure the coupling assembly to the pins of the implement. Even a small degree of wear in the slot, hook or jaw section that engages an implement can render the coupling assembly unsuitable.

Another design problem associated with automatic coupling systems is that implements can suddenly detach upon accidental damage to the hydraulic system.

OBJECT OF THE INVENTION It is therefore an object of this invention to devise a manually operated coupling assembly for excavator equipment and implements, that significantly SUBSTITUTE SHEET (Rule 26) (RO/AU) WO 00/04242 PCT/AU99/00574 2 extends the life of the parts which engage and secure the implement, thus extending the life of the coupling assembly.

SUMMARY OF THE INVENTION According to the present invention there is provided a coupling assembly for detachably connecting an implement to a hydraulic arm of an excavator, said coupling assembly comprising a pair of parallel load transmitting plates interconnected by a transverse plate; each said load transmitting plate having multiple apertures to enable attachment by hinge pins to a hydraulic arm, a recess to enable engagement with and retention by a first pin of the implement, and a rotating hooking element to enable engagement with and retention by a second pin of the implement; wherein each hooking element is rotatable in unison by a camming device mounted in an opening of the transverse plate to restrain or release the second pin with respect to the coupling.

Preferably the camming device comprises a manually operable clevis transversely pivoted in the opening of the transverse plate and coupled to a camming link which drives a transverse rod extending between the rotatable hooking elements. Preferably the clevis rotates from an over centre position where the hooking elements are retracted, through a centre position to an over centre position where the hooking elements restrain the second pin of the implement.

In a preferred embodiment, the camming link comprises a spring loaded arm which absorbs impact loading on the hooking elements without releasing the second pin of the implement. The clevis can be rotated by an operating handle which can be removably fitted to an extension of the axle pivoting the clevis in the opening of the transverse plate.

WO 00/04242 PCT/AU99/00574 3 Rotation of the handle in a counter-clockwise direction will result in the hooking elements rotating to a position which enables the second pin of the implement to be released, and rotation in a clockwise direction will result in the hooking elements rotating to restrain the second pin from movement.

As an additional failsafe mechanism, a linch pin can be inserted transversely between the load transmitting plates to prevent the hooking elements from rotating out of the locking position. The load transmitting plates can also have multiple aperture pairs providing alternative attachment points for the hydraulic arm of the excavator thereby altering the angle of attack of the bucket or implement.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a top perspective view of a coupler assembly according to the present invention, Figure 2 is a side view of the coupler assembly of Figure 1, Figure 3 is an internal elevation section of the coupler assembly of Figure 1, and Figure 4 is an elevation view of the coupler assembly of Figure 1 fitted to an excavator arm which is about to engage an excavator bucket.

DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION A preferred embodiment of the invention will now be described with reference to the drawings in which like reference numerals refer to like parts.

Referring to all the drawings simultaneously, the coupling assembly comprises two parallel load transmitting plates 2, 3 welded to opposite edges of a -r WO 00/04242 PCT/AU99/00574 4 transverse plate 4. The transverse plate 4 has a central opening 5. Two smaller plates 6, 7 extending parallel to the load transmitting plates 2, 3 are welded on opposite sides of the opening Clevis 8 is welded to shaft 9 which passes through plates 2, 3, 6, 7. One end of shaft 9 has a boss to receive an operating handle 50 which can rotate the cam element 8 either clockwise or counter-clockwise.

Aligned recesses 15, 16 are formed in the ends of the load transmitting plates 2, 3 to enable a first pin 17 of an associated excavator bucket 14 (see Figure 4) to be accommodated and retained therein. A second pin 13 of the excavator bucket can be accommodated by a pair of rotatable hooking elements 11, 12 and then retained by such elements about the second pin. This is effected manually by handle 50 which is rotated clockwise. This action also rotates an associated clevis 8 clockwise so that a cam-link 23 drives rod 50 between hooking elements 11, 12 rotating the latter about pivot 20 to lock the second pin 13 within recesses 19, 21. Cam-link 23 consists of two sections 30, 31 which trap a spring 32 and have limited relative axial movement on rod 35 during which movement spring 32 is compressed.

When clevis 8 rotates clockwise, hooking elements 11, 12 bear on second pin 13 and spring 32 is compressed as link 23 passes through the centre position of the cam. Clevis 8 then encounters stops and becomes locked in an over centre position and the spring 32 expands again. Accordingly, link 23 maintains hooking elements 11, 12 in locking engagement on second pin 13 but is able to absorb impact loading on the excavator bucket 14 by limited compression of spring 32, thus minimising wear and damage.

An additional failsafe locking mechanism is WO 00/04242 PCT/AU99/00574 provided by inserting linch pin 27 through load transmitting plates 2, 3 behind hooking elements 11, 12 preventing their disengagement from second pin 13. The coupling assembly is normally attached to arms 40, 41 of the excavator through bushings 36, 37, 38, 39 of the load transmitting plates 2, 3. However, arm 41 may also be attached through alternative bearings 42, 44 and 43, to achieve different angles of attack on the bucket 14.

These and other variations and modifications will be obvious to one skilled in the art without departing from the basic invention.

Claims

1. A coupling assembly for detachably connecting an implement to a hydraulic arm of an excavator, said coupling assembly comprising a pair of parallel load transmitting plates interconnected by a transverse plate; each said load transmitting plate having multiple apertures to enable attachment by hinge pins to a hydraulic arm, a recess to enable engagement with and retention by a first pin of the implement, and a rotating hooking element to enable engagement with and retention by a second pin of the implement; wherein each hooking element is rotatable in unison by a camming device mounted in an opening of the transverse plate to restrain or release the second pin with respect to the coupling, said camming device comprising a manually operable clevis transversely pivoted in the opening of the transverse plate and coupled to a camming link which drives a transverse rod extending between the rotatable hooking elements.

2. The coupling assembly of claim 1, wherein the clevis pivots from an over centre position where the hooking elements are retracted, through a centre position to an over centre position where the hooking elements restrain the second pin of the implement.

3. The coupling assembly of claim 2, wherein the camming link comprises a spring loaded arm which absorbs impact loading on the hooking elements without releasing the second pin of the implement.

4. The coupling assembly of claim 1, wherein the clevis is rotated by an operating handle which can be removably fitted to an extension of an axle pivoting the clevis in the opening of the transverse plate. 0 5. The coupling assembly of claim 1, wherein a linch pin is positioned transversely between the load

14.. .J z PCT/AU99/00574 Received 17 February 2000 7 transmitting plates to prevent the hooking elements from rotating out of the retrained position. 6. A coupling assembly substantially as herein described with reference to the accompanying drawings.