WO2014165329A1

WO2014165329A1 - Locking system for quick coupler

Info

Publication number: WO2014165329A1
Application number: PCT/US2014/031341
Authority: WO
Inventors: Troy C. Robl; Trent R. Stefek
Original assignee: Caterpillar Inc.
Priority date: 2013-04-02
Filing date: 2014-03-20
Publication date: 2014-10-09
Also published as: GB201518579D0; CN105229240A; US20140294497A1; GB2527995B; GB2527995A

Abstract

A quick coupler (126) for holding an implement (104) is disclosed. The quick coupler (126) includes a frame (114) having a first plate (140) and a second plate (142). The quick coupler (126) includes a locking system (160) adapted to lock the implement (104) in the first plate (140) and the second plate (142). The locking system (160) includes a securing latch member and a hydraulic actuator (166) is operatively connected to the securing latch member. The securing latch member is configured to move along a guide provided in each of the first plate (140) and the second plate (142). The locking system (160) further includes a set of grooves (187) provided on at least one of the securing latch member and the guide. The set of grooves (187) are adapted to lock the securing latch member in a latched position.

Description

LOCKING SYSTEM FOR QUICK COUPLER

Technical Field

The present disclosure relates generally to a quick coupler and, more particularly to a locking system for the quick coupler.

Background

Quick couplers are generally well known and can be found in many systems and devices. Typically, a quick coupler is detachably connected to an arm of a machine for connecting and disconnecting the arm to and from implements. For example, a quick coupler can be attached to the arm of an excavator for connecting and disconnecting implements such as buckets, hammers, rippers, and grapples. Such quick couplers are advantageous because they allow a machine operator to change quickly from one implement to another. Thus, the use of a quick coupler makes the machine more efficient and versatile. The quick couplers may need to secure the implement tightly to the arm of the excavator so that undesirable release or loose movement of the implement with respect to the excavator arm is prevented, ensuring a safe operation.

U.S. Patent Number 7,654,019 discloses a quick coupling apparatus for coupling a tool to an arm of the machine. The quick coupling apparatus comprises a coupler member attached to the arm, and configured to engage a mounting bracket extending out from the tool. A wedge is mounted on the coupler member and is movable, when the coupler member and mounting bracket are engaged, from a closed position engaged in a groove on the mounting bracket to an open position where the wedge is removed from the groove. A wedge positioning mechanism selectively moves the wedge to the closed position and the open position. When the wedge moves into the groove and into the closed position, a remotely operated latch control moves a safety latch from an unlatched position to a latched position to prevent the wedge from moving toward the open position. However, there is still room for improvement in the art. Summary

In one aspect, a quick coupler for holding an implement is disclosed. The quick coupler includes a frame having a first plate and a second plate. The quick coupler includes a locking system adapted to lock the implement in the first plate and the second plate. The locking system includes a securing latch member and a hydraulic actuator is operatively connected to the securing latch member. The securing latch member moves along a guide provided in each of the first plate and the second plate. A set of grooves are provided on at least one of the securing latch member and the guide. Further, the set of grooves are adapted to lock the securing latch member in a latched position.

In another aspect, an implement system of a machine is disclosed. The implement system includes an implement and a quick coupler is detachably connected with the implement. The quick coupler includes a frame having a first plate and a second plate. The quick coupler includes a locking system adapted to lock the implement in the first plate and the second plate. The locking system includes a securing latch member and a hydraulic actuator is operatively connected to the securing latch member. The securing latch member moves along a guide provided in each of the first plate and the second plate. A set of grooves are provided on at least one of the securing latch member and the guide. Further, the set of grooves are adapted to lock the securing latch member in a latched position.

Brief Description of the Drawings

FIG. 1 illustrates a side view of a machine with an implement and a quick coupler;

FIG. 2 illustrates a perspective exploded view of the implement and the quick coupler of FIG. 1 ;

FIG. 3 illustrates a perspective view of the quick coupler in an unlatched position;

FIG. 4 illustrates a perspective view of the quick coupler in a latched position; and

FIGS. 5 to 8 illustrate a perspective view of the quick coupler in the latched position, in an event of a hydraulic failure. Detailed Description

The present disclosure relates to a quick coupler having a locking system which is configure to secure the implement if the locking system fails. References will now be made in detail to specific embodiments or features of the present disclosure, examples of which are illustrated in the accompanying drawings. Generally, corresponding reference numbers will be used throughout the drawings to refer to the same or corresponding parts.

FIG. 1 illustrates a side view of a machine 100, such as a hydraulic excavator. The machine 100 includes an implement system 102 configured to move an implement 104, a drive system 106 for propelling the machine 100, a power source 108 that provides power to the implement system 102 and the drive system 106, and an operator station 1 10 to control the movement of the implement 104 and the machine 100. The implement system 102 includes a boom member 1 12 pivotally connected to a frame 1 14 of the machine 100 and configured to pivot in a vertical plane about a first horizontal axis (not shown) relative to a ground 1 16 by a pair of first hydraulic actuators 1 18 (only one side shown in FIG. 1). The implement system 102 further includes a stick member 120 pivotally connected to the boom member 1 12 and configured to pivot in the vertical plane about a second horizontal axis 122 by a second hydraulic actuator 124. Further, the implement 104, such as a bucket, is detachably coupled to a distal end of the stick member 120 via a quick coupler 126 and configured to pivot in the vertical plane about a third horizontal axis 128 by a third hydraulic actuator 130. Although the implement 104 is illustrated as the bucket in the present disclosure, in various embodiments, the implement 104 may be such as, but not limited to, a grapple, a hammer, a multi-processor, a rake, a ripper, a saw, a dozer blade, a pallet fork, a barrel handler, a tire manipulator, a jib boom, a pipe fork, or any other types of work tool attachments.

FIG. 2 illustrates a perspective exploded view of the implement 104 and the quick coupler 126 of FIG. 1. The implement 104 is provided with a pair of upstanding brackets 132. The brackets 132 are spaced apart by a predetermined distance, and a pair of coupling pins 134, 136 extends between the brackets 132. The quick coupler 126 includes a frame 138 having a pair of spaced apart side plates, a first plate 140 and a second plate 142. The first plate 140 and the second plate 142 may be interconnected by a cross plate 144. A top portion of the quick coupler 126 is configured to be pivotally connected to the distal end of the stick member 120 by a first pin 146 which is slidably received within a first pair of aligned openings 148 provided on the first and the second plates 140, 142. Likewise, the quick coupler 126 is configured to be pivotally connected to a power link 150 (as shown in FIG. 1) by a second pin 152 which is slidably received within a second pair of aligned openings 154. The power link 150 may be operative ly connected to the distal end of the stick member 120 and the third hydraulic actuator 130 for pivoting the quick coupler 126 about the first pin 146. A bottom portion of the quick coupler 126 is configured to be detachably connected to the implement 104. In the exemplary embodiment, each of the first and the second plates 140, 142 may include a notch 156, and a recess 158 shown in the form of an open jaw. The notches 156 and the recesses 158 are configured to receive the coupling pins 134, 136 of the implement 104, respectively.

According to an embodiment of the present disclosure, the quick coupler 126 includes a locking system 160. The locking system 160 may include one or more securing latch members such as a first securing latch member 162 and a second securing latch member 164 which are configured to secure the coupling pins 134, 136 of the implement 104 in the notches 156 and the recesses 158, respectively. The locking system 160 may further include a number of interconnected components for moving the first and the second securing latch members 162, 164 between an unlatched position and a latched position. In an exemplary embodiment, the locking system 160 may be a hydraulic locking system configured to move and retain the first and second securing latch members 162, 164 at the latched position under a hydraulic pressure. According to an aspect of the present disclosure, the first and second securing latch members 162, 164 are adapted to be maintained in a latched position to secure the coupling pins 134, 136 in the notches 156 and the recesses 158, in an event of a hydraulic failure in the locking system 160. The locking system 160, in accordance with an exemplary embodiment of the present disclosure, is explained in conjunction with FIGS. 3 - 5.

FIG. 3 illustrates a perspective view of the quick coupler 126 with the second plate 142 of the quick coupler 126 is removed to illustrate the locking system 160. As illustrated, the first and second securing latch members 162, 164 are in the unlatched position. In an embodiment, the locking system 160 may include a hydraulic actuator, such as a double-acting hydraulic actuator 166, operatively connected to the first and second securing latch members 162, 164. The double-acting hydraulic actuator 166 may include a cylinder 168 and a piston rod 170 configured to be slidably received in the cylinder 168. Further, the double-acting hydraulic actuator 166 may be connected to a plurality of hydraulic lines 172 with a pressure switch 174 to control a movement of the double-acting hydraulic actuator 166. It will be apparent to a person having ordinary skill in the art that the hydraulic actuator may be any type of linear actuator, such as, a pneumatically or a motor-driven actuator.

Moreover, the quick coupler 126 may include one or more lubrication lines 176 associated with various components, such as, but not limited to, the first and the second securing latch members 162, 164. The lubrication lines 176 may further include fittings 178, such as, but not limited to, a grease fitting, or a grease nipple, attached to the lubrication lines 176. The fittings 178 allows a lubricant, usually grease, to feed under a pressure, into the various components associated within the quick coupler 126. The fittings 178 may include a threaded connection to couple with the internal lubrication lines 176. It may be apparent to a person having ordinary skill in the art that, the fittings 178 may further include a valve that opens under pressure to allow lubricant to pass through the fittings to the various components within the quick coupler 126.

In accordance with an exemplary embodiment of the present disclosure, interconnections and mechanical relationships among the various components of the exemplary locking system 160 will now be described in detail. The first securing latch member 162 may be operatively connected to the cylinder 168 via a rocker assembly 180. The cylinder 168 is pivotally connected to the rocker assembly 180 to move the first securing latch member 162 between the latched position and the unlatched position. Moreover, a biasing element 181 is provided and configured to constantly apply a bias force on the first securing latch member 162 to keep the first securing latch member 162 in the latched position. The biasing element 181 may be a spring-plunger assembly with a positive stop against the frame 138 and configured to resist opening of the first securing latch member 162 in the event of the hydraulic failure in the locking system 160.

Further, the second securing latch member 164 and the piston rod 170 of the hydraulic actuator 166 are pivotally interconnected by a pin 182. More particularly, the pin 182 passes through corresponding bores provided on the second securing latch member 164 and the piston rod 170. In the unlatched position of the quick coupler 126, pressurized fluid in the hydraulic actuator 166 retracts the piston rod 170 into the cylinder 168. The retraction of piston rod 170 allows the second securing latch member 164 into the unlatched position as shown in FIG. 3, and may release the coupling pin 136 of the implement 104 from the recess 158. Further, the cylinder 168 moves the first securing latch member 162 via the rocker assembly 180 into the unlatched position, and may release the coupling pin 134 of the implement 104 from the notch 156.

As illustrated in FIG. 3, the first plate 140 and the second plate 142 may include guides 184 and the second securing latch member 164 is configured to move along the guides 184. Further, a bottom surface 186 of the second securing latch member 164 abuts with the guides 184 during a linear movement of the second securing latch member 164. Further, a top surface 185 of the second securing latch member 164 is configured to hold the coupling pin 136 of the implement 104 in the recess 158. Each of the guides 184 may include a shoulder portion 188. Further, the bottom surface 186 of the second securing latch member 164 may include a set of grooves 190 provided at a pre-determined distance from its distal end 192.

According to an embodiment of the present disclosure, the grooves 190 are adapted to lock with the shoulder portions 188 of the guides 184 for locking the implement 104 in an event of the hydraulic failure in the quick coupler 126. In the event of the hydraulic failure, there may be a pressure drop in the pressurized fluid in the hydraulic actuator 166, which may allow the second securing latch member 164 to move into the unlatched position and may release the coupling pin 136 of the implement 104 from the recess 158. Further, the pre-determined distance for the grooves 190 may be selected in such a way so that the second securing latch member 164 may not pivot completely to a position releasing the coupling pin 136. The grooves 190 are provided at the pre-determined distance so that grooves 190 are locked into the shoulder portion 188 in the event of the hydraulic failure, without releasing the coupling pin 136 from the recess 158, which is further explained in FIGS. 4 and 5.

Industrial Applicability

The industrial applicability of the locking system 160 for the quick coupler 126, described herein will be readily appreciated from the foregoing discussion. The quick coupler 126 of the present disclosure may be widely used on industrial, earthmoving, mining, construction, farming, transportation and material handling machines and vehicles, or the like. It may be contemplated that the quick coupler 126 may be used to detachably or interchangeably connect the implement 104 to the stick member 120 of the machine 100. As illustrated in FIG. 1, the implement 104 is secured by receiving the coupling pins 134, 136 in the notches 156 and the recesses 158, respectively of the quick coupler 126.

In the event of the hydraulic failure in the quick coupler 126, the first securing latch member 162 retains the coupling pin 134 into the notch 156 of the quick coupler 126 as the first securing latch member 162 is spring biased into the latched position by the biasing element 181 and may not open without a hydraulic force from the hydraulic actuator 166. Further, the second securing latch member 164 is coupled to the hydraulic actuator 166 may come to an open position, releasing the coupling pin 136 of the implement 104 from the recesses 158 of the quick coupler 126. This may lead to accidental release of the implement 104 from the second securing latch member 164 and may not be a safe method of operating the quick coupler 126. Therefore, there rises a need of securement of coupling pin 136 in the second securing latch member 164, ensuring a safe operation of the quick coupler 126 in the event of the hydraulic failure. A person ordinarily skilled in the art may understand that, hydraulic failures may be at least one of a failure in the hydraulic supply lines or hoses, hydraulic pumps, hydraulic actuators, and one or more valves.

FIG. 4 illustrates a perspective view of the quick coupler 126 in the latched position, with plurality of hydraulic lines 172 and lubrication lines 176 removed for simplicity. In the latched position, the coupling pins 134, 136 of the implement 104 are secured between the first securing latch member 162 and the second securing latch member 164 in the notches 156, 158, respectively, Further, the pressurized fluid in the hydraulic actuator 166 allows the second securing latch member 164 to securely hold the coupling pin 136 of the implement 104 in the recess 158. Further, a reaction force from the coupling pin 136 acts on the second securing latch member 164 is neutralized by the pressurized fluid in the hydraulic actuator 166. Thus, the coupling pin 136 of the implement 104 is tightly withheld in the recess 158 by the second securing latch member 164.

Further, in the event of the hydraulic failure in the quick coupler 126, there may be a drop in the pressurized fluid in the hydraulic actuator 166. Further, the reaction forces acting on the second securing latch member 164 by the coupling pin 136 of the implement 104 and gravity may pivot the second securing latch member 164 about the pin 182. Further, the pivotal movement of the second securing latch member 164 may allow the grooves 190 provided on the bottom surface 186 of the second securing latch member 164 to lock with the shoulder portions 188 of the guides 184, as shown in FIG. 5. The locking of grooves 190 on the shoulder portions 188 of the guides 184 may hold the coupling pin 136 in the recess 158 of the quick coupler 126, avoiding accidental release of the implement 104 from the second securing latch member 164. The holding of the coupling pin 136 in the recess 158 in the secured manner, in the event of the hydraulic failure, aids in safe operation of the quick coupler 126. Further, as explained above, the coupling pin 134 is secured with the first securing latch member 162 by the biasing element 181, in the event of the hydraulic failure.

Further, after the hydraulic failure is rectified, the coupling pin 136 of the implement 104 secured in the second securing latch member 164 may need to be unlocked from the quick coupler 126. While unlocking, the hydraulic actuator 166 may push the second securing latch member 164 in a forward direction releasing the locking of grooves 190 with the shoulder portions 188 of the guides 184. Further, the hydraulic actuator 166 may push the second securing latch member 164 in the backward direction in the linear movement so that the grooves 190 may not lock with the shoulder portions 188 of the guides 184. The second securing latch member 164 may return back to the unlatched position, as shown in FIG. 3, releasing the coupling pin 136 of the implement 104 from the second securing latch member 164. In an aspect of the present disclosure, the set of grooves 190 provided on the bottom surface 186 of the second securing latch member 164 may be elliptical grooves. The elliptical grooves 190 are adapted to engage with multiple pin center to center dimensions of the implement 104, as shown in FIG. 6. In an alternative embodiment, the set of grooves 190 provided on the bottom surface 186 of the second securing latch member 164 may be serrated or curvilinear grooves, as shown in FIG. 7. In an another alternative embodiment, distal end of the guides 184 may include a set of grooves 187, such as, but not limited to, curvilinear grooves, so that rear edge of the second securing latch member 164 is configured to lock with the set of grooves 187 provided in the guides 184, as shown in FIG. 8. Alternatively, the quick coupler 126 may include both the grooves 190 on the second securing latch member 164 and the set of grooves 187 on the distal end of the guides 184.

It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed quick coupler without departing from the scope of the disclosure. Other embodiments of the quick coupler will be apparent to those skilled in the art from consideration of the specification and practice of the system disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope of the disclosure being indicated by the following claims and their equivalents.

From the foregoing it will be appreciated that, although specific embodiments have been described herein for purposes of illustration, various modifications or variations may be made without deviating from the spirit or scope of inventive features claimed herein. Other embodiments will be apparent to those skilled in the art from consideration of the specification and figures and practice of the arrangements disclosed herein. It is intended that the specification and disclosed examples be considered as exemplary only, with a true inventive scope and spirit being indicated by the following claims and their equivalents.

Claims

1. A quick coupler (126) for holding an implement (104), the quick coupler (126) comprising:

a frame (1 14) having a first plate (140) and a second plate (142);

a guide provided on each of the first plate (140) and the second plate

(142); and

a locking system (160) adapted to lock the implement (104) in the first plate (140) and the second plate (142), the locking system (160) comprising:

a securing latch member configured to move along the guide; a hydraulic actuator (166) operatively connected to the securing latch member; and

a set of grooves (187) provided on at least one of the securing latch member and the guide, the set of grooves (187) are adapted to lock the securing latch member in a latched position.

2. The quick coupler (126) of claim 1, wherein the securing latch member is configured to hold coupling pins (134) of the implement (104) received in a notch (156) and a recess (158) provided in each of the first plate (140) and the second plate (142).

3. The quick coupler (126) of claim 2, wherein the securing latch member includes a top surface (185) configured to hold the coupling pin (134) of the implement (104).

4. The quick coupler (126) of claim 1, wherein the securing latch member includes a bottom surface (186), the set of grooves (187) are provided on the bottom surface (186) of the securing latch member.

5. The quick coupler (126) of claim 4, wherein the set of grooves (187) provided on the bottom surface (186) of the securing latch member are elliptical grooves (190).

6. The quick coupler (126) of claim 4, wherein the set of grooves (187) provided on the bottom surface (186) of the securing latch member are serrated or curvilinear grooves (187).

7. The quick coupler (126) of claim 1, wherein the securing latch member and the hydraulic actuator (166) are pivotally interconnected by a pin (182).