CN214614271U

CN214614271U - Excavator coupler

Info

Publication number: CN214614271U
Application number: CN202022427308.8U
Authority: CN
Inventors: Z·何; A·梅森
Original assignee: Earth Moving Industrial Engineering Pte Ltd
Current assignee: Earth Moving Industrial Engineering Pte Ltd
Priority date: 2020-01-28
Filing date: 2020-10-28
Publication date: 2021-11-05
Anticipated expiration: 2030-10-28
Also published as: AU2021214412A1; WO2021151146A1; DE212021000303U1; KR20220002803U; CN113250256A; JP3240613U

Abstract

The utility model relates to an excavator coupler, its arm that is used for coupling the excavator annex to the excavator. The coupling includes: a body having a first recess that engages a first pin of an accessory; a tongue member movable relative to the body having a second recess engaging a second pin of the accessory; a locking arm pivotally mounted to the body about a fixed pivot point; and an actuator assembly mounted between the locking arm and the tongue member. The actuator assembly has a hydraulic actuator and is configured to i) move the tongue member relative to the body to facilitate engagement and disengagement of the second recess with the second pin; and ii) pivoting the locking arm to selectively prevent withdrawal of the first pin from the first recess. A secondary failsafe mechanism in the form of a compression spring is provided so that a maximum pressure is set across the hydraulic actuator. Thus, if a hydraulic failure occurs, the compression spring continues to maintain the pressure of the tongue member on the second pin of the attachment, thereby ensuring that the attachment does not disconnect from the coupler.

Description

Excavator coupler

Technical Field

The present invention relates to an excavator coupler for coupling an excavator accessory, such as a bucket, to an arm of an excavator.

Background

Excavator couplers are used to connect an excavator with an excavator attachment, such as a bucket or other tool, such as a ripper, a swing arm breaker, a grapple machine, a saw, and the like. For convenience, the invention will be described herein primarily with reference to an excavator bucket attachment. The coupler is attached to the arm of the excavator and is hydraulically operated to enable the excavator operator to quickly and easily replace the attachment, in most cases without the operator having to move from the cab or operating location of the excavator. The accessory typically has a pair of parallel pins that engage a pair of recesses formed in the coupler to connect the accessory.

The coupling typically includes some form of mechanical lock to secure the accessory in the event of a hydraulic failure. In the past, couplers have relied on manual shear pins to install and remove each time an operator desires to change an accessory. This requires the operator to remove the shear pin from the excavator, then return to the machine to release the hydraulic coupling and remove the existing attachment, pick up the next selected attachment, then lower from the excavator to assemble the shear pin, and then return to the excavator for operation. Because of this constant movement, many operators are not confident in installing the shear pins. Thus, if there is a failure of the hydraulic system to the coupling, the accessories can fall off, possibly with catastrophic consequences.

It would be desirable to provide an excavator coupler of the general type described above having one or more improved features.

Any discussion of documents, devices, acts or knowledge in this specification is included to explain the context of the invention. It should not be taken as an admission that any of the material forms a part of the prior art base or the common general knowledge in the relevant art at or before the priority date of the claims herein.

SUMMERY OF THE UTILITY MODEL

According to the utility model discloses, an excavator coupler is provided, and it is used for coupling the excavator annex to the arm of excavator, and this coupler includes:

a body having a first recess for engaging a first pin of an accessory,

a tongue member movable relative to the body, the tongue member having a second recess for engaging a second pin of the accessory,

a locking arm pivotally mounted to the body, an

An actuator assembly mounted between the locking arm and the tongue member, the actuator assembly configured to:

i) moving the tongue member relative to the body to facilitate engagement and disengagement of the second recess with the second pin; and

ii) pivoting the locking arm to selectively prevent withdrawal of the first pin from the first recess.

When the first recess is engaged with the first pin and the actuator assembly moves the second recess into engagement with the second pin to couple the accessory to the arm, the force applied by the actuator assembly to maintain the coupling preferably pivots the locking arm to a locked position in which a portion of the locking arm moves into the first recess to prevent withdrawal of the first pin.

The portion of the locking arm is preferably an end region which projects into the first recess at an acute angle relative to the wall of the first recess when the locking arm is in the locked position. Furthermore, the end region of the locking arm preferably comprises a bottom wall surface which in said locking position abuts the first pin. The bottom wall surface may include a stepped or V-shaped portion that is wedged into the first pin in the locked position to prevent withdrawal of the first pin from the first recess.

Preferably, in normal operation, the force applied by the actuator assembly to maintain said engagement and pivot the locking arm to the locked position is provided by a hydraulic actuator of the actuator assembly.

The actuator assembly may further include an assist mechanism to maintain the linkage and pivot the locking arm to the locked position. More specifically, in the event of an operational failure of the hydraulic actuator, the assist mechanism preferably continues to maintain the linkage and pivot the lock arm to the locked position.

The hydraulic actuator preferably includes a cylinder and a piston for extending and retracting the tongue member relative to the body to thereby adjust the spacing between the first and second recesses. Preferably, a cylinder is connected to the locking arm and a piston is connected to the tongue member, the connection of the cylinder to the locking arm being below the pivotal mounting of the locking arm to the main body.

The assist mechanism is preferably a biasing member biasing the tongue member and the locking arm away from each other. The biasing member may be mounted between the cylinder body and the tongue member. More preferably, the biasing member is in the form of a compression spring mounted around the cylinder. The hydraulic actuator is capable of acting against the compression spring during normal operation to move the tongue member toward the locking arm.

In one embodiment, the actuator assembly may further comprise an auxiliary spring mounted between the main body and the cylinder. The secondary spring provides a force to bias the cylinder to maintain the locking arm in the locked position.

In another embodiment, the actuator assembly further comprises a secondary spring mounted between the main body and the locking arm. The secondary spring directly provides a force to the locking arm to bias the locking arm to maintain the locked position.

Drawings

Fig. 1 is a perspective view of an excavator coupler attached to an arm of an excavator in the process of coupling with an excavator accessory according to an embodiment of the present invention;

FIG. 2 is a side view of the excavator coupler of FIG. 1 showing the coupler securely engaged with the front and rear pins of the excavator accessory with the locking arm in a locked position;

FIG. 3 is a side view of the excavator coupler of FIG. 1, showing the coupler in a release position in which the tongue member has been fully retracted and disengaged from the rear pin and the locking arm in a retracted unlocked position separated from the front recess and the front pin;

FIG. 4 is a side view of the coupling shown in FIG. 1, showing the positions of the tongue member and locking arm in the event of an operational failure of the hydraulic actuator; and

fig. 5 is a side view of an excavator coupler according to another embodiment, wherein an auxiliary spring is installed in front of and directly acts on the locking arm.

Detailed Description

Referring to the drawings, there is shown an excavator coupler (1) for coupling an excavator attachment (3), such as an excavator bucket, to an arm (5) of an excavator. The attachment (3) comprises a first front pin (7) and a second rear pin (9). The excavator coupler (1) is mounted at the end of an excavator arm (5) and is used to replace various accessories (3), including the excavator bucket, without the need for the operator to leave the cab or operating position of the excavator.

The excavator coupler (1) comprises a body (11) having a first front recess (13) which may be in the form of a horizontally open fork in which a front pin (7) of the attachment (3) may engage. The coupling (1) further comprises a tongue member (15) which is movable relative to the body (11). In this sense, the tongue member (15) is preferably able to slide back and forth along a track built into the body (11). The tongue member (15) comprises a second rear recess (17) configured to engage with a second rear pin (9) of the accessory (3).

The excavator coupler (1) further comprises a locking arm (19), the locking arm (19) being pivotally mounted to the main body (11) about a fixed pivot point (12) above the front recess (13). The locking arm (19) is designed to lock the front pin (7) in the front recess (13) unless the coupling (1) is deliberately and hydraulically operated to release the front pin (7). More specifically, in the event of a hydraulic failure, the lock arm (19) acts to restrict the front pin (7) from falling out of the front recess (13) so that the accessory (3) cannot be accidentally detached from the coupling (1) and endanger the safety of nearby workers.

The excavator coupler (1) further includes an actuator assembly (21) mounted between the locking arm (19) and the tongue member (15). The actuator assembly (21) being configured to (i) slide the tongue member (15) along the track of the main body (11) to facilitate engagement and disengagement of the rear recess (17) with the rear pin (9) of the accessory (3); and (ii) pivoting the locking arm (19) to selectively prevent the front pin (7) from backing out of the front recess (13).

The actuator assembly (21) preferably comprises a hydraulic actuator having a cylinder (23) and a piston/rod (25), the piston/rod (25) being used to extend and retract the tongue member (15) relative to the body (11) to thereby adjust the spacing between the front recess (13) and the rear recess (17). The cylinder (23) has a base end (27) connected to the locking arm (19) on the main body (11) by a pin (29) below the fixed pivot point (12) of the locking arm (19). At the opposite end of the hydraulic actuator, a piston (25) is connected to the tongue member (15) via a mounting pin (31) or the like.

The actuator assembly (21) further comprises a secondary failsafe mechanism biasing the tongue member (15) and the locking arm (19) away from each other, thereby enabling the locking arm (19) to restrain the front pin (7) within the front recess (13) in the event of a hydraulic failure. In this sense, the assist mechanism is a mechanical biasing member, preferably in the form of a compression spring (33) mounted around the cylinder (23) and piston/rod (25) of the hydraulic actuator.

The actuator assembly (21) may also include a secondary spring (35) having an end connected to the body (11) and an opposite end connected to the cylinder (23). The secondary spring (35) is designed to maintain pressure on the base of the cylinder (23), which in turn maintains pressure on the locking arm (19) to maintain the locked position shown in fig. 2. In another embodiment as shown in fig. 5, the auxiliary spring (35) achieves the same effect, but acts directly on the locking arm (19), with one end connected to the main body (11) and the opposite end connected directly to the locking arm (19). In this case, the auxiliary spring (35) directly maintains the counterclockwise pressure on the lock arm (19).

The excavator coupling (1) is preferably operated by an electrical switch located in the excavator cab. The switch preferably has a spring return as a failsafe that automatically releases the switch when the operator removes pressure on the switch. The switch is preferably located in a position in the cab in which it is not inadvertently operated and ideally has an audible alarm when operated. The switch acts to operate the hydraulic actuator to retract the piston (25) into the cylinder (23) to bring the excavator coupler (1) to a release position, as shown in figure 3, in which the tongue member (5) is disengaged from the rear pin and retracted into abutment with a stop (37) on the main body (11) and the locking arm (19) is pivoted clockwise to a retracted unlocked position spaced from the forward recess (13) and the forward pin (7). Since the tongue member (15) cannot retract further because of the stop (37), any further retraction of the piston (25) into the cylinder (23) causes the cylinder (23) to be pulled rearwardly, the secondary spring (35) to be compressed thereby, and the locking arm (19) to pivot further rearwardly in a clockwise direction towards the hydraulic actuator.

To couple the attachment (3) to the excavator, the tongue member (15) is first moved to the fully retracted position shown in figure 3. The excavator arm is then manoeuvred appropriately and the associated coupler (1) is tilted down in front so that the front pin (7) of the attachment (3) can be positioned into the front recess (13). Once the front pin (7) is located in the front recess (13), the coupling (1) is tilted downwards at the rear until the main body (11) rests on the rear pin (9) of the accessory (3). The switch inside the cab is then released to automatically extend the hydraulic actuator. The hydraulic actuator of the coupling (1) is then extended so that the tongue member (15) moves rearwardly away from the front pin (9) and engages the rear pin (9) of the attachment (3), as shown in figure 2. The hydraulic actuator preferably applies the full hydraulic pressure to the rear pin (9), which ensures that the two pins (7, 9) are held hydraulically and cannot be disengaged. In addition to the force provided by the positive pressure of the hydraulic actuator, which keeps the front pin (7) engaged in the front recess (13) and the rear pin (9) engaged in the rear recess (17), the force exerted by the hydraulic actuator pivots the locking arm (19) counterclockwise downward to a locking position, as shown in fig. 2, in which a portion of the locking arm (19) moves into the front recess (13) to prevent the front pin (7) from backing out of the front recess (13). In this connection, the part of the locking arm (19) which moves into the front recess (13) is preferably an end region which projects downward at an acute angle of about 10mm into the front recess (13) relative to the upper wall (39) of the front recess (13). The end region of the locking arm (19) comprises a bottom wall surface (41), which bottom wall surface (41) abuts the front pin (7) when the locking arm (19) is in the locking position, as shown in fig. 2. The bottom wall surface (41) may include a stepped or V-shaped portion (43), and in the locked position, the stepped or V-shaped portion (43) wedges the front pin (7) downward to prevent withdrawal of the front pin (7). During normal operation, the positive pressure of the hydraulic actuator is maintained with the applied force maintaining the engagement of the front pin (7) with the front recess (13) and the engagement of the rear pin (9) with the rear recess (17), while the locking arm (19) is also maintained in the locked position. To release the pins (7, 9) from the coupling (1), a switch within the excavator cab is activated to retract the piston (25) into the hydraulic cylinder (23) and thereby compress the compression spring (33). The locking arm (19) will not disengage from the front pin (7) until the tongue member (15) is fully retracted to abut the stop (37).

As mentioned previously, a secondary failsafe mechanism in the form of a compression spring (33) is provided around the cylinder (23). The compression spring (33) is designed such that it provides a maximum pressure when the hydraulic actuator is fully extended. Thus, if a hydraulic failure occurs due to a failure, the compression spring (33) continues to maintain the pressure of the tongue member (15) on the rear pin (9) of the attachment (3), thereby ensuring that the attachment (3) cannot be disconnected from the coupling (1).

As shown in fig. 4, the rear recess (17) may comprise a second tongue (belly) (45) into which the rear pin (9) may fall downwards in case of failure of the hydraulic actuator. In this sense, the compression spring (33) may allow the tongue member (15) to retract slightly in the event of a failure of the hydraulic actuator. This in turn enables the coupling (1) and the associated accessory (3) to rotate slightly about the front pin (7), thereby transferring weight from the rear pin (9) to the front pin (7). Due to the orientation of the coupling (1), further pressure is exerted on the locking arm (19) so that the arm (19) continues to prevent the front pin (7) from backing out of the front recess (13).

Claims

1. An excavator coupler for coupling an excavator accessory to an arm of an excavator, the coupler comprising:

a body having a first recess for engaging a first pin of the accessory,

a locking arm pivotally mounted to the body, an

2. The excavator coupler of claim 1, wherein when the first recess is engaged with the first pin and the actuator assembly moves the second recess into engagement with the second pin to couple the accessory to the arm, the force applied by the actuator assembly to maintain the coupling pivots the locking arm to a locked position in which a portion of the locking arm moves into the first recess to prevent withdrawal of the first pin.

3. The excavator coupler of claim 2, wherein the portion of the locking arm is an end region that projects into the first recess at an acute angle relative to a wall of the first recess when the locking arm is in a locked position.

4. The excavator coupler of claim 3, wherein the end region of the locking arm includes a bottom wall surface which abuts the first pin in the locked position.

5. The excavator coupler of claim 4, wherein the bottom wall surface includes a stepped or V-shaped portion which is wedged in the first pin in the locked position to prevent withdrawal of the first pin from the first recess.

6. The excavator coupler of any one of claims 2 to 5, wherein in normal operation, the force applied by the actuator assembly to maintain the engagement and pivot the locking arm to the locking position is provided by a hydraulic actuator of the actuator assembly.

7. The excavator coupler of claim 6, wherein the actuator assembly further comprises an assist mechanism to maintain the coupling and pivot the locking arm to the locked position.

8. The excavator coupler of claim 7, wherein in the event of an operational failure of the hydraulic actuator, the assist mechanism continues to maintain the coupling and pivot the lock arm to the locked position.

9. The excavator coupler of any one of claims 7 and 8, wherein the hydraulic actuator comprises a cylinder and a piston for extending and retracting the tongue member relative to the body to thereby adjust the spacing between the first and second recesses.

10. The excavator coupler of claim 9, wherein the cylinder is connected to the locking arm and the piston is connected to the tongue member, the connection of the cylinder to the locking arm being below the pivotal mounting of the locking arm to the main body.

11. The excavator coupler of claim 10, wherein the assist mechanism is a biasing member biasing the tongue member and the locking arm away from each other, the biasing member being mounted between the cylinder and the tongue member.

12. The excavator coupling of claim 11 wherein the biasing member is in the form of a compression spring mounted around the cylinder.

13. The excavator coupler of claim 12 wherein the hydraulic actuator is capable of acting against the compression spring during normal operation to move the tongue member toward the locking arm.

14. The excavator coupler of any one of claims 10, 12 and 13, wherein the actuator assembly further comprises an auxiliary spring mounted between the main body and the cylinder, the auxiliary spring providing a force to bias the cylinder to maintain the locking arm in the locked position.

15. The excavator coupler of any one of claims 10, 12 and 13, wherein the actuator assembly further includes an auxiliary spring mounted between the body and the locking arm, the auxiliary spring providing a force directly to the locking arm to bias the locking arm to maintain a locked position.