GB2474573A - Control apparatus for a hydraulic coupler - Google Patents
Control apparatus for a hydraulic coupler Download PDFInfo
- Publication number
- GB2474573A GB2474573A GB1017380A GB201017380A GB2474573A GB 2474573 A GB2474573 A GB 2474573A GB 1017380 A GB1017380 A GB 1017380A GB 201017380 A GB201017380 A GB 201017380A GB 2474573 A GB2474573 A GB 2474573A
- Authority
- GB
- United Kingdom
- Prior art keywords
- actuator
- valve
- hydraulic
- coupler
- locking mechanism
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- 230000007246 mechanism Effects 0.000 claims abstract description 72
- 239000012530 fluid Substances 0.000 claims abstract description 39
- 230000008878 coupling Effects 0.000 claims description 2
- 238000010168 coupling process Methods 0.000 claims description 2
- 238000005859 coupling reaction Methods 0.000 claims description 2
- 239000003921 oil Substances 0.000 description 48
- 241000764238 Isis Species 0.000 description 3
- 230000005484 gravity Effects 0.000 description 2
- 230000004913 activation Effects 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000010720 hydraulic oil Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
Classifications
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02F—DREDGING; SOIL-SHIFTING
- E02F3/00—Dredgers; Soil-shifting machines
- E02F3/04—Dredgers; Soil-shifting machines mechanically-driven
- E02F3/28—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets
- E02F3/36—Component parts
- E02F3/3604—Devices to connect tools to arms, booms or the like
- E02F3/3609—Devices to connect tools to arms, booms or the like of the quick acting type, e.g. controlled from the operator seat
- E02F3/3663—Devices to connect tools to arms, booms or the like of the quick acting type, e.g. controlled from the operator seat hydraulically-operated
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02F—DREDGING; SOIL-SHIFTING
- E02F3/00—Dredgers; Soil-shifting machines
- E02F3/04—Dredgers; Soil-shifting machines mechanically-driven
- E02F3/28—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets
- E02F3/36—Component parts
- E02F3/3604—Devices to connect tools to arms, booms or the like
- E02F3/3609—Devices to connect tools to arms, booms or the like of the quick acting type, e.g. controlled from the operator seat
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02F—DREDGING; SOIL-SHIFTING
- E02F3/00—Dredgers; Soil-shifting machines
- E02F3/04—Dredgers; Soil-shifting machines mechanically-driven
- E02F3/28—Dredgers; Soil-shifting machines mechanically-driven with digging tools mounted on a dipper- or bucket-arm, i.e. there is either one arm or a pair of arms, e.g. dippers, buckets
- E02F3/36—Component parts
- E02F3/3604—Devices to connect tools to arms, booms or the like
- E02F3/3609—Devices to connect tools to arms, booms or the like of the quick acting type, e.g. controlled from the operator seat
- E02F3/365—Devices to connect tools to arms, booms or the like of the quick acting type, e.g. controlled from the operator seat with redundant latching means, e.g. for safety purposes
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02F—DREDGING; SOIL-SHIFTING
- E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
- E02F9/20—Drives; Control devices
- E02F9/22—Hydraulic or pneumatic drives
- E02F9/226—Safety arrangements, e.g. hydraulic driven fans, preventing cavitation, leakage, overheating
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
- F15B2211/71—Multiple output members, e.g. multiple hydraulic motors or cylinders
- F15B2211/7114—Multiple output members, e.g. multiple hydraulic motors or cylinders with direct connection between the chambers of different actuators
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Mining & Mineral Resources (AREA)
- Civil Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Structural Engineering (AREA)
- Fluid-Pressure Circuits (AREA)
Abstract
Hydraulic coupler for an excavator arm and control apparatus. The coupler having a primary locking mechanism to secure an attachment to an arm of the excavator and a safety mechanism to prevent detachment of the attachment from the arm when the primary locking mechanism is released or fails. The control apparatus includes a hydraulic actuator for the primary lock 20 and a hydraulic actuator for the safety lock 40. The hydraulic actuators are operable so the safety lock can be locked independently of the primary locks position. The control apparatus includes a first valve 14 having a first state allowing fluid to the rod end of the two actuators causing them to extend and a second state where fluid is allowed to flow to retract the primary lock actuator. A second valve 44 controls the flow of fluid to retract the safety lock actuator.
Description
Control Apparatus for a Hydraulic Coupler
Field of the invention
The present invention relates to a control apparatus for a hydraulic coupler for excavators.
Backcjround to the Invention It is well known for a hydraulic coupler for attaching an attachment, such as a bucket, to an arm or dipper of an excavator or back hoe, to have a primary locking mechanism in the form of a hydraulically operated latching hook for engaging with the pins of an attachment, e.g. a bucket, for the arm of an excavator. Such couplers typically include a safety locking mechanism for preventing the attachment from becoming disengaged from the coupler in the event of hydraulic failure, for example to prevent release of the primary locking mechanism and/or to prevent complete detachment of the attachment from the coupler in the event of failure or unintentional release of the primary locking mechanism.
Many couplers are available on the market utilising a gravity operated safety mechanism, comprising a pivotal blocking member that prevents retraction of the primary locking mechanism when the coupler is in certain orientations. However, such simple mechanical gravity operated safety mechanisms are prone to failure in the adverse conditions in which the excavator frequently operates. The coupler as disclosed in European Patent Application No. 09011452.1, which is incorporated by reference, uses an additional hydraulic cylinder for operation of the safety mechanism. In the coupler previously disclosed the main hydraulic actuator of the primary locking mechanism and the additional hydraulic actuator of the safety mechanism work together from a common control apparatus.
It is an object of the present invention to provide an alternative control apparatus which allows independent operation of the safety mechanism through independent operation of the hydraulic actuator of the safety mechanism upon release of the safety mechanism.
Summary of the Invention
According to a first aspect of the invention there is provided a control apparatus for a hydraulic coupler of an excavator, the coupler having a primary locking mechanism selectively operable to secure an attachment to an arm of the excavator and a safety mechanism selectively operable to prevent detachment of the attachment from the arm when the primary locking mechanism is released or fails, said control apparatus comprising a first hydraulic actuator for operating the primary locking mechanism of the coupler, and a second hydraulic actuator for operating said safety locking mechanism of the coupler, wherein said first and second hydraulic actuators are operable such that said safety locking mechanism can be maintained in an operative position independently of an operative state of said primary locking mechanism.
By enabling the safety locking mechanism to be maintained in its operative position independently of the operative state of the primary locking mechanism, the safety locking mechanism can be maintained in its operative position as the primary locking mechanism is urged to move to its inoperative position, preventing uncontrolled release of the attachment from the coupler.
Preferably each of the first and second hydraulic actuators is provided with an extend line connected to an extend side of the respective actuator and a retract line connected to a retract side of the respective actuator.
Each of the first and second actuators preferably share a common hydraulic fluid feed line connected to a source of pressurised fluid, such as a pump, and selectively connectable to the respective extend and retract lines of the first and second actuators by suitable valve means.
Preferably at least the second actuator is provided with a pilot operated check valve for controlling the flow of fluid from the extend side of the second actuator into the extend line thereof to control retraction of the respective actuator. A similar pilot operated check valve may also be associated with the first actuator for controlling the flow of fluid from the extend side of the first actuator into the extend line thereof during retraction of the first actuator. Preferably the pilot operated check valve of the secondary actuator is controlled independently of the pilot operated check valve of the first actuator.
In a preferred embodiment, a first valve is provide for selectively controlling the flow of pressurised fluid from said feed line to the extend side of the first and second hydraulic actuators and to the retract side port of at least the first hydraulic actuator via the respective extend line, a second valve being provided for selectively controlling the flow of pressurised fluid to a pilot control line of said pilot operated check valve of the second hydraulic actuator, whereby retraction of the second hydraulic actuator is controlled by said second valve.
In one embodiment said first valve controls the flow of pressurised fluid to the retract side of both the first and second hydraulic actuators via the respective retract line thereof.
In an alternative embodiment the flow of pressurised fluid to the retract side the second hydraulic actuator is controlled by the second valve, the retract line of the second actuator being connected to pilot control line of the pilot operated check valve of the second hydraulic actuator, wherein said pilot operated check valve is opened when said feed line is connected to the retract line of the second hydraulic actuator via said second valve.
According to a further aspect of the present invention there is provided a hydraulic control apparatus for use with a hydraulic coupler for coupling an attachment or implement to a machine, said hydraulic control apparatus comprising a first hydraulic actuator for actuating a primary locking mechanism for securing an attachment on the coupler, a second hydraulic actuator for actuating a safety locking mechanism for preventing complete detachment of the attachment from the coupler; a first valve being provided having a first state, wherein pressurised fluid is supplied to a head end of both the first and second actuators and wherein a rod end of said first actuator is placed in fluid communication with a low pressure drain or reservoir to extend said first actuator, and a second state, wherein pressurised fluid is supplied to said rod end of said first actuator and wherein said head end of said first actuator is placed in fluid communication with said low pressure drain or reservoir to retract said first actuator; a second valve being provided having an operative state wherein pressurised fluid is supplied to a pilot control line of a pilot check-valve associated with an extend side port of said second hydraulic actuator for controlling retraction of said second hydraulic actuator.
Said second valve may also be arranged to supply pressurised fluid to a retract side port of the second actuator when in its operative state. Alternatively said retract side port of the second actuator may be connected to said first valve such that pressurised fluid is supplied to said retract side port when said first valve is in its second state.
According to a further aspect of the present invention there is provided a coupler for an excavator, the coupler having a primary locking mechanism for securing an attachment to the coupler, said primary locking mechanism being moveable between a first operative state, wherein the attachment is secured to the coupler, and a second operative state, wherein the attachment is at least partially released from the coupler, said primary locking mechanism being moveable between its first and second operative states by means for a first hydraulic actuator, and a safety locking mechanism for preventing complete detachment of the attachment from the coupler, said safety locking mechanism being maintained in an operative configuration, either directly or indirectly, by means of a second hydraulic actuator, said first and second actuators being controlled by a hydraulic control circuit adapted such that said safety locking mechanism can be maintained in its operative configuration independently of the operative state of said primary locking mechanism.
In one embodiment the coupler comprises a body having a first and second spaced-apart recesses for receiving respective pins of an excavator attachment; the primary locking mechanism comprising a first latching member, said first latching member being moveable between a latching state, wherein it is capable of retaining the respective attachment pin in said first recess, when the primary locking mechanism is in its first operative state, and an open state, wherein the respective attachment pin can move into and out of said first recess, when the primary locking mechanism is in its second operative state; said first hydraulic actuator being adapted to move said first latching member between said latching and open states, said safety locking mechanism comprising a second latching member movable into and out of a latching state in which it is capable of retaining a respective attachment pin in said second recess; said second hydraulic actuator actuating said second latching member into and out of said latching state.
Brief Description of the DrawinQs
An embodiment of the invention is now described by way of example and with reference to the accompanying drawings in which: Figure 1 is a schematic view of a control apparatus for a hydraulic coupler according to a first embodiment of the present invention; and Figure 2 is a schematic view of a control apparatus for a hydraulic coupler according to a second embodiment of the present invention.
Detailed Description of the Drawings
In known hydraulic couplers, of the type disclosed in EP 09011452.1, the control apparatus consists of a 4/2 solenoid/spring valve fed with pressurised hydraulic oil from either the excavator main hydraulic line or the excavator servo (reduced pressure) hydraulic line. From the valve two high pressure hydraulic pipes either flexible or a mixture of flexible and rigid run from the engine compartment, up the excavator boom, unsupported across the excavator boom to dipper connection, down the dipper arm, unsupported across the excavator dipper to hitch, and terminate at the hydraulic cylinder within the hitch body.
An improved control apparatus for a hydraulic coupler in accordance with an embodiment of the present invention is illustrated in the drawings.
In the embodiment shown in Figure 1, the coupler contains two hydraulic actuators, each comprising a cylinder having a piston slidably mounted therein, the piston being mounted on the end of a piston rod extending from one end of the cylinder, the primary actuator providing the primary engagement force for the primary locking mechanism of the coupler, the second actuator operating the safety locking mechanism. The secondary actuator which actuates the safety locking mechanism may be extended by hydraulic pressure from the extend line of the main hydraulic cylinder via a teed connection into the existing extend line. The retraction of the secondary actuator which actuates the safety locking mechanism may be achieved via the addition of a third pipe to the coupler. This pipe is connected to its own independent 3/2 hydraulic valve or similar preferably mounted within the excavator engine compartment alongside the main coupler solenoid valve.
Figure 1 shows the hydraulic circuit for the coupler control in accordance with a first embodiment of the present invention. High pressure oil is supplied by a pump 1. High pressure oil flows though a feed line 10 a non return valve 12 and a flow restrictor 13 to an inlet port of a primary solenoid controlled spool valve 14. At the same time high pressure oil is supplied from the pump 1 to an inlet port of a secondary solenoid controlled spool valve 15.
When de-energised, the primary solenoid controlled valve 14 adopts a first position wherein said feed line 10 communicates with an extend line 6 of the primary actuator 20 on an extend side of the piston 28 of the actuator, extending the piston rod 26 of the primary actuator 20 and actuating a primary locking mechanism of a hydraulic coupler.
A first pilot operated check valve 24 is located between the extend line 6 and the extend side port of the primary actuator 20 communicating with an extend side Si of said primary actuator 20, and wherein a retract line 8 of the primary actuator communicates with a lower pressure drain or reservoir 2.
The extend line 6 of the primary actuator 20 also communicates with an extend line 6a of the secondary actuator 40, supplying pressurised fluid into the extend side S3 of the secondary actuator via a second pilot operated check valve 44 for extending a piston rod 46 of the secondary actuator to actuate a safety mechanism of the hydraulic coupler.
When in a second or energised state, the primary solenoid valve 14 adopts a second position wherein the extend lines 6,6a of both the primary and secondary actuators 20,40 communicate with said lower pressure drain or reservoir 2 while the feed line 10 communicates with a retract side S2 of the primary actuator 20. A pilot control line 15 of the first pilot operated check valve 24 communicates with the retract line 8 of the primary actuator 20 such that the pilot operated check valve 24 is opened when pressurised fluid is supplied to the retract line 8, allowing fluid to escape from the extend side Si of the primary actuator 20.
The secondary solenoid controlled spool valve 15 enables selective communication between feed line 10 and the second pilot operated check valve 44 associated with the secondary actuator 40 to control retraction of the piston rod 46 of the secondary actuator 40 independently of the retraction of the piston rod 26 of the primary actuator 20, as will be described below.
In the first embodiment, shown in Figure 1, when the secondary solenoid controlled spool valve 15 is de-energised, the valve adopts a first position wherein the retract line 7 of the secondary actuator communicates with said lower pressure drain of reservoir 2 to allow fluid to drain from the retract side S4 of the secondary actuator 40 as the secondary actuator extends. When the secondary solenoid valve 15 is energised said retract line 7 of the secondary actuator 40 communicates with the feed line 10, supplying pressurised fluid to the pilot control line 16 of the second pilot operated check valve 44 while also supplying pressurised fluid to the retract side S4 of the secondary actuator 40 causing the piston rod 46 of the secondary actuator 40 to retract.
The operation of the coupler control arrangement of Figure 1 will now be described.
Both primary valve 14 and secondary valve 15 de-energised (as shown in Figure 1).
As secondary valve 15 is de-energised oil flow from the pump 1 to the retract side S4 of the secondary actuator 40 and to the pilot control line 16 of the second pilot operated check valve 44 is effectively blocked by secondary valve 15.
As valve 14 is de-energised high pressure oil flows through primary valve 14 into extend line 6 of the primary actuator, through the first pilot operated check valve 24 via the extend side port P1 into the extend side Si of the primary actuator 20, causing the piston rod 26 of the primary actuator 20 to extend. Return oil flows from the retract side S2 of primary actuator via the retract side port P2 into retract line 8, through secondary valve 14 and back to the reservoir 2.
High pressure oil also flows through extend line 6a of the secondary actuator 40 through the second pilot operated check valve 44 into the extend side S3 of the secondary actuator 40 via extend side port P3, causing the piston rod 46 of the secondary actuator 40 to extend. Return oil flows from the retract side S4 of secondary actuator 40 via the retract side port P4 into retract line 7 of the secondary actuator 40, through secondary valve 15 and back to the reservoir 2.
Primary valve 14 energised and secondary valve 15 de-energised.
As the secondary solenoid valve 15 is de-energised oil flow from the pump 1 to the retract side S4 of the secondary actuator 40 and to the pilot control line 16 of the second pilot operated check valve 44 is effectively blocked by secondary valve 15.
As the primary valve 14 is energised, high pressure oil flows through the primary valve 14 into the retract line 8 of the primary actuator 20 and into the pilot control line 15 of the first pilot operated check valve 24, opening the pilot operated check valve 24, and flows into the retract side S2 of the primary actuator 20 via extend side port P2, causing the piston rod 26 of the primary actuator 20 to retract. Return oil flows from the extend side Si of primary actuator 20 via extend side port P1 into extend line 6, through primary valve 14 and back to the reservoir 2.
The oil pressure at the back of the second pilot operated check valve 44 drops to zero. However pressure is maintained within the extend side S3 of the secondary actuator 40 by the action of the second pilot operated check valve 44 which causes the piston rod 46 of the secondary actuator 40 to remain extended. The oil pressure in the retract line 7 of the secondary actuator 40 also remains at zero as the secondary valve 15 is de-energised.
Primary valve 14 energised and secondary valve 15 energised.
As primary valve 14 is energised, high pressure oil flows through the primary valve 14 into the retract line 8 of the primary actuator 20 and into the pilot control line 15, opening the first pilot operated check valve 24, and flows via retract side port P2 into the retract side S2 of the primary actuator 20, causing the piston rod 26 of the primary actuator 20 to retract and release the primary locking mechanism of the coupler. Return oil flows from the extend side Si of the primary actuator, via extend side port P1 into the extend line 6, through primary valve 14 and back to the reservoir 2.
As the secondary valve 15 is energised, oil flow from the pump 1 is allowed through the secondary valve 15 into the retract line 7 of the secondary actuator and into the pilot control line 16 of the second pilot operated check valve, opening the second pilot operated check valve 44, the oil flowing via retract side port P4 into the retract side S4 of the secondary actuator 40, which causes the secondary actuator to retract and release the safety mechanism of the coupler. Return oil flows from the extend side S3 of secondary actuator via the extend side port P3, through the second pilot operated check valve 44 and into extend line 6a, through primary valve 14 and back to the reservoir tank.
Primary valve 14 de-enerQised and secondary valve 15 enerQised.
As the primary valve 14 is de-energised, high pressure oil flows through the primary valve 14 into the extend line 6 and through the first pilot operated check valve 24, via extend side port P1, into the extend side Si of the primary actuator 20, causing the piston rod 26 of the primary actuator 20 to extend. Return oil flows from the retract side S2 of primary actuator 20 via retract side port P2 into retract line 8, through primary valve 14 and back to the reservoir 2.
High pressure oil also flows through the extend line 6a of the secondary actuator 40 and through the second pilot operated check valve 44 into the extend side S3 of the secondary actuator, causing the piston rod 46 of the secondary actuator 40 to extend.
As the valve 15 is energised, oil flow from the pump 1 is allowed through the secondary valve 15 into the retract line 7 of the secondary actuator 40. This high pressure oil opens the second pilot operated check valve 44 and flows, via the retract side port P4, into the retract side S4 of the secondary actuator 40. However as high pressure oil is also being supplied to the other side of the piston 48 of the secondary actuator 40 and the extend side S3 of piston 48 has a greater surface area than the retract side S4 of piston 48 the net force will still tend to cause piston rod 46 of secondary actuator 40 to extend.
Figure 2 shows a hydraulic circuit for a hydraulic coupler control apparatus according to a second embodiment of the present invention.
The arrangement of the components of the control apparatus of the second embodiment is similar to that of the first embodiment, and like components are given identical reference numerals. However, unlike the first embodiment, in the second embodiment high pressure oil is not supplied to the retract side of the secondary actuator 40 via the secondary solenoid operated spool valve 15, rather the retract side port P4 of the secondary actuator is connected to the retract line 8 of the primary actuator 20. The secondary valve 15 is instead connected only to the pilot control line 16 of the second pilot operated check valve 44 such that the secondary valve 15 controls the supply of pressurised oil to the pilot control line 16 of the second pilot operated check valve 44 to control operation of said second pilot operated check valve 44, controlling communication between the extend side S3 of the secondary actuator 40 and the drain 2 when the primary valve 14 is energised.
The operation of the coupler control apparatus of Figure 2 is described below:-Primary valve 14 and secondary valve 15 both de-energised (as shown in Fig. 2).
As secondary valve iSis de-energised, oil flow from the pump ito the pilot control line 16 of the second pilot operated check valve 44 is effectively blocked by secondary valve 15.
As the primary valve 14 is de-energised, high pressure oil flows through valve 14 into extend line 6, through the first pilot operated check valve 24, via extend side port P1 into the extend side Si of the primary actuator 20, causing the piston rod 26 to extend. Return oil flows from the retract side S2 of primary actuator 20 into the retract line 8, through primary valve 14 and back to the reservoir 2.
High pressure oil also flows through the extend line 6a, through the second pilot operated check valve 44 and into the extend side S3 of the secondary actuator 40, causing the piston rod 46 to extend. Return oil flows from the retract side S4 of secondary actuator into the retract line 7 and into retract line 8, through primary valve 14 and back to the reservoir 2.
Primary valve 14 energised and secondary valve 15 de-energised.
As the secondary valve iSis de-energised, oil flow from the pump ito the pilot control line 16 of the second pilot operated check valve 44 is effectively blocked by secondary valve 15.
As primary valve 14 is energised high pressure oil flows through the primary valve 14 into the retract line 8 and through the pilot control line 15, opening the first pilot operated check valve 24. Oil thus flows into the retract side S2 of the primary actuator 20, causing the piston rod 26 to retract. Return oil flows from the extend side Si of the primary actuator 20 into the extend line 6, through the primary valve 14 and back to the reservoir 2.
This high pressure oil in retract line 8 flows into the retract line 7 of the secondary actuator 40 and passes into the retract side S4 of the secondary actuator 40. However as the second pilot operated check valve 44 is closed, escape of oil from the extend side S3 of the secondary actuator is prevented, thus preventing any retraction of the piston rod 46 of the secondary actuator 40.
Primary valve 14 energised and secondary valve 15 enerQised.
As the primary valve 14 is energised high pressure oil flows through primary valve 14 into retract line 8 and into pilot control line 15, opening the first pilot operated check valve 24, and flows via retract side port P2 into the retract side S2 of the primary actuator, causing the piston rod 26 to retract and release the primary locking mechanism of the coupler. Return oil flows from the extend side Si of the primary actuator 20, via the extend side port, into the extend line 6, through the primary valve 14 and back to the reservoir 2.
As the secondary valve iSis energised, oil flow from the pump 1 is allowed into the pilot control line 16 of the second pilot operated check valve 44, opening the second pilot operated check valve 44.
High pressure oil in retract line 7 flows, via the retract side port P4, into the retract side S4 of the secondary actuator 40, causing the piston rod 46 to retract, releasing the safety mechanism of the coupler. Return oil flows from the extend side S3 of the secondary actuator 40, via the extend side port P3, through the opened second pilot operated check valve 44 into extend line 6a, through primary valve 14 and back to the reservoir 2, allowing the piston rod 46 to retract.
Primary valve 14 de-enerQised and secondary valve 15 enerQised.
As primary valve 14 is de-energised, high pressure oil flows through primary valve 14 into the extend line 6, through the first pilot operated check valve 24 via extend side port P1 into the extend side Si of the primary actuator 20, causing the piston rod 26 to extend. Return oil flows from the retract side S2 of first actuator 20 via the retract side port P2 into retract line 8, through primary valve 14 and back to reservoir 2.
High pressure oil also flows through extend line 6a of the secondary actuator 40 through the second pilot operated check valve 44 into the extend side S3 of the secondary actuator 40, causing the piston rod 46 to extend. Return oil flows from the retract side S4 of second actuator via retract side port P4 into retract line 7 and retract line 8, through primary valve 14 and back to the reservoir 2.
As the secondary valve 15 is energised, oil flows from the pump 1 through the secondary valve 15 into the pilot control line 16, opening the second pilot operated check valve 44. This has no effect upon the state of secondary actuator 40 as the second pilot operated check valve 44 is already opened by high pressure oil being supplied to extend line 6a, so the secondary actuator 40 remains in the extended state.
By connecting the primary actuator 20 to the primary locking member of a coupler, and connecting of secondary actuator cylinder 40 to a secondary safety mechanism within a coupler, independent switching of primary valve 14 and secondary valve 15, e.g. by the use of two separate switches, means that the secondary safety mechanism may only be disengaged following the activation of a first switch operating primary valve 14 and then the subsequent separate switching of secondary valve 15.
The invention is not limited to the embodiment described herein which may be modified or varied without departing from the scope of the invention.
Claims (17)
- Claims 1. A control apparatus for a hydraulic coupler of an excavator, the coupler having a primary locking mechanism selectively operable to secure an attachment to an arm of the excavator and a safety mechanism selectively operable to prevent detachment of the attachment from the arm when the primary locking mechanism is released or fails, said control apparatus comprising a first hydraulic actuator for operating the primary locking mechanism of the coupler, and a second hydraulic actuator for operating said safety locking mechanism of the coupler, wherein said first and second hydraulic actuators are operable such that said safety locking mechanism can be maintained in an operative position independently of an operative state of said primary locking mechanism.
- 2. An apparatus as claimed in claim 1, wherein each of the first and second hydraulic actuators is provided with an extend line connected to an extend side of the respective actuator and a retract line connected to a retract side of the respective actuator.
- 3. An apparatus as claimed in claim 2, the first and second actuators share a common hydraulic fluid feed line connected to a source of pressurised fluid, such as a pump, and selectively connectable to the respective extend and retract lines of the first and second actuators by suitable valve means.
- 4. An apparatus as claimed in claim 3, wherein the second actuator is provided with a first pilot operated check valve for controlling the flow of fluid from the extend side of the second actuator into the extend line thereof to control retraction of the respective actuator.
- 5. An apparatus as claimed in claim 4, wherein the first actuator is provided with a second pilot operated check valve for controlling the flow of fluid from the extend side of the first actuator into the extend line thereof during retraction of the first actuator.
- 6. An apparatus as claimed in claim 5, wherein the first pilot operated check valve is controlled independently of the second pilot operated check valve.
- 7. An apparatus as claimed in any of claims 4 to 6, wherein a first valve is provide for selectively controlling the flow of pressurised fluid from said feed line to the extend side of the first and second hydraulic actuators and to the retract side port of at least the first hydraulic actuator via the respective extend line, a second valve being provided for selectively controlling the flow of pressurised fluid to a pilot control line of said first pilot operated check valve, whereby retraction of the second hydraulic actuator is controlled by said second valve.
- 8. An apparatus as claimed in claim 7, wherein said first valve controls the flow of pressurised fluid to the retract side of both the first and second hydraulic actuators via the respective retract line thereof.
- 9. An apparatus as claimed in claim 7, wherein the flow of pressurised fluid to the retract side the second hydraulic actuator is controlled by the second valve, the retract line of the second actuator being connected to pilot control line of the first pilot operated check valve, wherein said first pilot operated check valve is opened when said feed line is connected to the retract line of the second hydraulic actuator via said second valve.
- 10. A hydraulic control apparatus for use with a hydraulic coupler for coupling an attachment or implement to a machine, said hydraulic control apparatus comprising a first hydraulic actuator for actuating a primary locking mechanism for securing an attachment on the coupler, a second hydraulic actuator for actuating a safety locking mechanism for preventing complete detachment of the attachment from the coupler; a first valve being provided having a first state, wherein pressurised fluid is supplied to a head end of both the first and second actuators and wherein a rod end of said first actuator is placed in fluid communication with a low pressure drain or reservoir to extend said first actuator, and a second state, wherein pressurised fluid is supplied to said rod end of said first actuator and wherein said head end of said first actuator is placed in fluid communication with said low pressure drain or reservoir to retract said first actuator; a second valve being provided having an operative state wherein pressurised fluid is supplied to a pilot control line of a pilot check-valve associated with an extend side port of said second hydraulic actuator for controlling retraction of said second hydraulic actuator.
- 11. An apparatus as claimed in claim 10, wherein said second valve is arranged to supply pressurised fluid to a retract side port of the second actuator when in its operative state.
- 12. An apparatus as claimed in claim 10, wherein said retract side port of the second actuator may be connected to said first valve such that pressurised fluid is supplied to said retract side port when said first valve is in its second state.
- 13. A coupler for an excavator, the coupler having a primary locking mechanism for securing an attachment to the coupler, said primary locking mechanism being moveable between a first operative state, wherein the attachment is secured to the coupler, and a second operative state, wherein the attachment is at least partially released from the coupler, said primary locking mechanism being moveable between its first and second operative states by means for a first hydraulic actuator, and a safety locking mechanism for preventing complete detachment of the attachment from the coupler, said safety locking mechanism being maintained in an operative configuration, either directly or indirectly, by means of a second hydraulic actuator, said first and second actuators being controlled by a hydraulic control circuit adapted such that said safety locking mechanism can be maintained in its operative configuration independently of the operative state of said primary locking mechanism.
- 14. A coupler as claimed in claim 13, wherein the coupler comprises a body having a first and second spaced-apart recesses for receiving respective pins of an excavator attachment; the primary locking mechanism comprising a first latching member, said first latching member being moveable between a latching state, wherein it is capable of retaining the respective attachment pin in said first recess, when the primary locking mechanism is in its first operative state, and an open state, wherein the respective attachment pin can move into and out of said first recess, when the primary locking mechanism is in its second operative state; said first hydraulic actuator being adapted to move said first latching member between said latching and open states, said safety locking mechanism comprising a second latching member movable into and out of a latching state in which it is capable of retaining a respective attachment pin in said second recess; said second hydraulic actuator actuating said second latching member into and out of said latching state.
- 15. A control apparatus for a hydraulic coupler of an excavator substantially as herein described with reference to the accompanying drawings.
- 16. A hydraulic control apparatus for use with a hydraulic coupler substantially as herein described with reference to the accompanying drawings.
- 17. A coupler for an excavator substantially as herein described with reference to the accompanying drawings.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GBGB0918144.7A GB0918144D0 (en) | 2009-10-16 | 2009-10-16 | Control apparatus for a hydraulic coupler |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB201017380D0 GB201017380D0 (en) | 2010-11-24 |
| GB2474573A true GB2474573A (en) | 2011-04-20 |
Family
ID=41462445
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GBGB0918144.7A Ceased GB0918144D0 (en) | 2009-10-16 | 2009-10-16 | Control apparatus for a hydraulic coupler |
| GB1017380A Withdrawn GB2474573A (en) | 2009-10-16 | 2010-10-14 | Control apparatus for a hydraulic coupler |
Family Applications Before (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GBGB0918144.7A Ceased GB0918144D0 (en) | 2009-10-16 | 2009-10-16 | Control apparatus for a hydraulic coupler |
Country Status (1)
| Country | Link |
|---|---|
| GB (2) | GB0918144D0 (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE202012009838U1 (en) * | 2012-07-24 | 2013-10-25 | Kinshofer Gmbh | Quick coupler |
| WO2014072709A1 (en) | 2012-11-08 | 2014-05-15 | Miller International Ltd. | Excavator coupler with a front latch, and a boom sensor arrangement |
| WO2014098618A1 (en) * | 2012-12-18 | 2014-06-26 | Wedgelock Equipment Limited | A control system |
| DE202013005679U1 (en) * | 2013-06-24 | 2014-09-25 | Kinshofer Gmbh | Quick coupler |
| CN104088324A (en) * | 2013-12-02 | 2014-10-08 | 湖南万容科技股份有限公司 | Excavator hydraulic system and excavator |
| DE202014001328U1 (en) * | 2014-02-13 | 2015-05-15 | Kinshofer Gmbh | Quick coupler |
| US11053660B2 (en) | 2019-06-17 | 2021-07-06 | Caterpillar Inc. | Coupling assembly and method of hydraulically coupling to a tool |
| BE1028952B1 (en) * | 2021-04-01 | 2022-07-19 | Warzee Michel | Attachment coupling system for agricultural vehicles |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2008031590A2 (en) * | 2006-09-13 | 2008-03-20 | Ian Hill | Coupler for excavators |
| EP2087178A2 (en) * | 2006-09-04 | 2009-08-12 | Miller UK Limited | Coupler |
| EP2161378A1 (en) * | 2008-09-08 | 2010-03-10 | HILL, Ian | Coupler with gravity operated safety device |
-
2009
- 2009-10-16 GB GBGB0918144.7A patent/GB0918144D0/en not_active Ceased
-
2010
- 2010-10-14 GB GB1017380A patent/GB2474573A/en not_active Withdrawn
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2087178A2 (en) * | 2006-09-04 | 2009-08-12 | Miller UK Limited | Coupler |
| WO2008031590A2 (en) * | 2006-09-13 | 2008-03-20 | Ian Hill | Coupler for excavators |
| EP2161378A1 (en) * | 2008-09-08 | 2010-03-10 | HILL, Ian | Coupler with gravity operated safety device |
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE202012009838U1 (en) * | 2012-07-24 | 2013-10-25 | Kinshofer Gmbh | Quick coupler |
| EP2690223A3 (en) * | 2012-07-24 | 2017-06-21 | Kinshofer GmbH | Rapid action coupling for a works machine |
| WO2014072709A1 (en) | 2012-11-08 | 2014-05-15 | Miller International Ltd. | Excavator coupler with a front latch, and a boom sensor arrangement |
| WO2014098618A1 (en) * | 2012-12-18 | 2014-06-26 | Wedgelock Equipment Limited | A control system |
| DE202013005679U1 (en) * | 2013-06-24 | 2014-09-25 | Kinshofer Gmbh | Quick coupler |
| US9388549B2 (en) | 2013-06-24 | 2016-07-12 | Kinshofer Gmbh | Quick-coupler |
| CN104088324A (en) * | 2013-12-02 | 2014-10-08 | 湖南万容科技股份有限公司 | Excavator hydraulic system and excavator |
| DE202014001328U1 (en) * | 2014-02-13 | 2015-05-15 | Kinshofer Gmbh | Quick coupler |
| US9689139B2 (en) | 2014-02-13 | 2017-06-27 | Kinshofer Gmbh | Quick coupler |
| US11053660B2 (en) | 2019-06-17 | 2021-07-06 | Caterpillar Inc. | Coupling assembly and method of hydraulically coupling to a tool |
| BE1028952B1 (en) * | 2021-04-01 | 2022-07-19 | Warzee Michel | Attachment coupling system for agricultural vehicles |
Also Published As
| Publication number | Publication date |
|---|---|
| GB0918144D0 (en) | 2009-12-02 |
| GB201017380D0 (en) | 2010-11-24 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |