WO2018070920A1

WO2018070920A1 - An implement connectable to a working vehicle

Info

Publication number: WO2018070920A1
Application number: PCT/SE2017/050987
Authority: WO
Inventors: Roger WESTPIL
Original assignee: Ålö AB
Priority date: 2016-10-10
Filing date: 2017-10-09
Publication date: 2018-04-19
Also published as: SE1651326A1; SE541993C2

Abstract

The present disclosure relates to an implement connectable to a working vehicle. The implement (1) comprises an arm (2);an attaching arrangement (4) connected to the arm (2), said attaching arrangement (4) being attachable to a working tool (5);a locking arrangement (10) connected to the attaching arrangement (4) and configured to securely lock the working tool (5) to the attaching arrangement (4), said locking arrangement (10) comprising a hydraulic lock actuator (12); a first hydraulic circuit (40) configured to carry hydraulic fluid to a first hydraulic function (44) and to the locking arrangement; the locking arrangement (10) comprising a first safety valve (16)and a second safety valve (18) connected to the first hydraulic circuit (40), being configured to stop fluid acting on the hydraulic lock actuator (12) in the unlocking direction;the first safety valve (16) and the second safety valve (18) are connected in series.

Description

AN IMPLEMENT CONNECTABLE TO A WORKING VEHICLE TECHNICAL FIELD

The present disclosure relates to an implement connectable to a working vehicle and attachable to a working tool; and a first hydraulic circuit configured to carry hydraulic fluid from a first hydraulic connection to at least one hydraulic function. The present disclosure further comprises a working vehicle arrangement comprising a working vehicle comprising an arrangement connectable to the implement; and said implement. BACKGROUND

Working vehicles and agricultural vehicles, such as tractors may be provided with an implement such as different kind of loaders. Typically, the implement comprises an attaching arrangement configured such that a working tool can be attached to the implement. Movements of the implement are typically controlled from the working vehicle by means of a hydraulic source and a control valve connected to a hydraulic connection of the implement. The hydraulic circuit is, on the implement side, connected to at least one hydraulic function. If the hydraulic circuit is connected to a plurality of hydraulic functions, the hydraulic circuit may comprise at least one switch valve configured to switch the hydraulic circuit between the hydraulic functions. The hydraulic functions can for example be implemented to move or tilt the working tool in relation to the implement, to control a function of the working tool or to move the implement in relation to the working vehicle.

There are different ways to attach a working tool to the implement. One option is to use the fluid in the hydraulic circuit to control if the implement is kept attached to the working tool. This can be done by arranging a locking arrangement comprising a hydraulic lock actuator on the same hydraulic circuit where a hydraulic function is implemented. Depending on the direction of the flow of the fluid the hydraulic lock actuator is either pushed in a direction to lock the working tool to the implement or to release the working tool from the implement. Hence, by actuating the fluid flow in the direction which is locking the implement to the working tool, the working tool is kept locked to the implement. In order to release the working tool from the implement, the working vehicle actuates the hydraulic fluid such that the fluid flows in the direction to unlock the working tool from the implement. Consequently, the hydraulic lock actuator is pushed in the direction to release the working tool from the implement. However, a drawback with this implementation is that, during operation of the implement, external force can accidentally be applied on the hydraulic function, such that the hydraulic function is generating a pressure on the fluid in the hydraulic circuit to flow in the unlocking direction, which causes the locking arrangement to release the working tool from the implement. This might cause accidents and physical damages. Hence, there is a need to improve the hydraulically implemented locking arrangement in order to increase safety during operation of the implement and the working tool.

SUMMARY

One object of the present disclosure is to obtain an implement, connectable to a working vehicle, having an improved locking arrangement for locking the implement to a working tool.

This has in different embodiments been achieved by means of an implement connectable to a working vehicle. The implement comprises an arm having a first part and a second part. Further, the implement comprises a fastening arrangement connected to the first part of the arm, the fastening arrangement being connectable to the working vehicle. Yet further, the implement comprises an attaching arrangement connected to the second part of the arm, said attaching arrangement being attachable to a working tool. Further, the implement comprises a locking arrangement connected to the attaching arrangement and configured to securely lock the working tool to the attaching arrangement. The locking arrangement comprises a hydraulic lock actuator connected to a mechanical lock. The mechanical lock is configured to securely lock the working tool to the attaching arrangement. The hydraulic lock actuator is configured to control the mechanical lock by means of hydraulic fluid acting on the hydraulic lock actuator. Yet further, the implement comprises a first hydraulic circuit configured to carry hydraulic fluid from a first hydraulic connection to a first hydraulic function and to the locking arrangement. The locking arrangement is connected in parallel with the first hydraulic function. The locking arrangement further comprises a first safety valve connected to the first hydraulic circuit. The first safety valve is configured to stop the supply of hydraulic fluid acting on the hydraulic lock actuator in the unlocking direction. The unlocking direction is defined as the fluid flow direction by which the hydraulic fluid is acting on the hydraulic lock actuator to unlock the mechanical lock. The locking arrangement further comprises a second safety valve connected to the first hydraulic circuit. The second safety valve is configured to stop the supply of hydraulic fluid in the unlocking direction. The hydraulic lock actuator, the first safety valve and the second safety valve are connected in series.

An advantage, of that the locking arrangement further comprises a second safety valve connected to the first hydraulic circuit, said second safety valve being configured to stop the supply of hydraulic fluid in the unlocking direction, wherein the hydraulic lock actuator, the first safety valve and the second safety valve are connected in series, is that in case the first safety valve fails to stop the supply of hydraulic fluid acting on the hydraulic lock actuator in the unlocking direction, the second safety valve will stop the supply of hydraulic fluid in the unlocking direction. Hence, the implementation of the second safety valve improves the safety during operation of the implement and the working tool.

According to an aspect of the invention, the first safety valve and the second safety valve are arranged on different sides of the hydraulic lock actuator. An advantage, of positioning the first safety valve and the second safety valve on different sides of the hydraulic lock actuator, is that it is possible to stop fluid from reaching the mechanical lock from both sides of the hydraulic circuit.

According to an aspect of the invention, the second safety valve is configured to close and stop the supply of hydraulic fluid acting on the hydraulic lock actuator in the unlocking direction, as long as the pressure of the hydraulic fluid acting on the second safety valve in the unlocking direction is below a pre-set pressure. An advantage, of stopping the supply of hydraulic fluid acting on the hydraulic lock actuator in the unlocking direction as long as the pressure less is below a pre-set pressure, is that the pre-set pressure can be selected such that the pre-set pressure is higher than the pressure that accidentally can be generated by the first hydraulic function due to external force acting on the first hydraulic function, causing the fluid to flow in the unlocking direction, but lower than the pressure that normally can be introduced by the hydraulic source connected to the first hydraulic circuit. Hence, the hydraulic source can cause the locking arrangement to unlock the working tool from the implement. On the other hand, an accidentally introduced pressure generated by the first hydraulic function due to external force, which is below the pre-set pressure, cannot cause the locking arrangement to unlock the working tool from the implement.

According to an aspect of the invention, the first safety valve is connected to a first electrical circuit and the first safety valve is configured to open and allow the supply of hydraulic fluid acting on the hydraulic lock actuator in the unlocking direction, in response to an electrical signal from the first electrical circuit. An advantage, of that the first safety valve is configured to open in response to an electrical signal from the first electrical circuit, is that by controlling the electrical signal from the first electrical circuit it is possible to control when the locking arrangement can release the working tool and when the locking arrangement stays locked to keep the working tool attached to the implement. According to an aspect of the invention, the second safety valve is connected to a second electrical circuit and the second safety valve is configured to open and allow the supply of hydraulic fluid acting on the hydraulic lock actuator in the unlocking direction, in response to an electrical signal from the second electrical circuit. An advantage, of that the second safety valve is configured to open in response to an electrical signal from the second electrical circuit, is that by controlling the electrical signal from the second electrical circuit it is possible to control when the locking arrangement can release the working tool and when the locking arrangement stays locked to keep the working tool attached to the implement.

According to an aspect of the invention, the hydraulic lock actuator is a hydraulic lock cylinder configured to unlock the mechanical lock when hydraulic fluid is acting on the hydraulic lock cylinder in the unlocking direction and to lock the mechanical lock when hydraulic fluid is acting on the hydraulic lock cylinder in the locking direction. An advantage, of that the hydraulic lock actuator is a hydraulic lock cylinder, is that translational movements of the hydraulic lock cylinder can be used to put the mechanical lock in a locked position or an unlocked position. According to an aspect of the invention, the hydraulic lock actuator is a hydraulic lock motor configured to unlock the mechanical lock when hydraulic fluid is acting on the hydraulic lock motor in the unlocking direction and to lock the mechanical lock when hydraulic fluid is acting on the hydraulic lock motor in the locking direction. An advantage, of that the hydraulic lock actuator is a hydraulic lock motor, is that electrical transmission instead of mechanical transmission is used between the hydraulic lock motor and the mechanical lock, which has the effect that the mechanical lock can be arranged more arbitrary in relation to the hydraulic lock motor. According to an aspect of the invention, the first hydraulic circuit is arranged along the arm, from the first hydraulic connection at the first part of the arm to the attaching arrangement.

According to an aspect of the invention, the first hydraulic circuit is further configured to carry hydraulic fluid to a second hydraulic function connected in parallel with the first hydraulic function. A first switch valve is arranged between the first hydraulic function and the second hydraulic function. The first switch valve is configured to switch the hydraulic fluid between the first hydraulic function and the second hydraulic function. The locking arrangement is arranged after the first switch valve and is connected in parallel with the second hydraulic function such that no hydraulic fluid is flowing to the locking arrangement when the hydraulic fluid is switched through the first hydraulic function. An advantage, of that no hydraulic fluid is flowing to the locking arrangement when the hydraulic fluid is switched through the first hydraulic function, is that fluid pressure introduced by the first hydraulic function will not reach the locking arrangement. According to an aspect of the invention, the first hydraulic function comprises a hydraulic cylinder attached to the arm and to the attaching arrangement. The hydraulic cylinder is configured to control the angle between the attaching arrangement and the arm. It should be understood that also the second hydraulic function or any further hydraulic function may comprise a hydraulic cylinder attached to the arm and to the attaching arrangement being configured to control the angle between the attaching arrangement and the arm. According to an aspect of the invention, the second hydraulic function comprises a hydraulic cylinder attached to the working tool, said hydraulic cylinder being configured to control a function of the working tool. It should be understood that also the first hydraulic function or any further hydraulic function may comprise a hydraulic cylinder attached to the working tool being configured to control a function of the working tool.

According to an aspect of the invention, the second hydraulic function comprises a hydraulic motor configured to operate a function of the working tool. It should be understood that also the first hydraulic function or any further hydraulic function may comprise a hydraulic motor configured to operate a function of the working tool.

According to an aspect of the invention, the implement further comprises a second hydraulic circuit configured to carry hydraulic fluid from a second hydraulic connection connectable to the working vehicle to a further hydraulic cylinder, said further hydraulic cylinder being attached to the first part of the arm and to the fastening arrangement and being configured to control the angle between the arm and the fastening arrangement.

According to an aspect of the invention, the first hydraulic connection and the second hydraulic connection are connected to a common connection device arranged between the first part of the arm and the working vehicle.

According to an aspect of the invention, the implement is a front loader, a wheel loader, an end loader, a skid loader, a track loader, a swing loader, a telescopic handler, a forklift, an excavator or a crane.

Another object of the present disclosure is to obtain an improved working vehicle arrangement comprising an implement connectable to a working vehicle, as described in this disclosure, and the working vehicle comprising an arrangement for connecting the implement to the working vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing will be apparent from the following more particular description of the example embodiments, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the example embodiments. Fig. 1 illustrates an example of a working vehicle arrangement comprising a working vehicle and an implement attached thereto.

Fig. 2 illustrates an example of an implement being connectable to a working vehicle and attachable to a working tool.

Fig. 3 illustrates a first hydraulic circuit diagram for controlling the implement according to a first example.

Fig. 4 illustrates a locking arrangement for locking a working tool to the implement according to prior art.

Fig. 5 illustrates a locking arrangement for locking a working tool to the implement according to a first example. Fig. 6 illustrates a locking arrangement for locking a working tool to the implement according to a second example.

Fig. 7 illustrates a first hydraulic circuit diagram for controlling an implement according to a second example.

Fig. 8 illustrates an example of an implement being connectable to a working vehicle and attachable to a working tool; and first and second hydraulic circuits for controlling the implement, the first hydraulic circuit comprising a locking arrangement for locking a working tool to the implement.

Fig. 9 illustrates a locking arrangement for locking a working tool to the implement according to a third example. DETAILED DESCRIPTION

Aspects of the present disclosure will be described more fully hereinafter with reference to the accompanying drawings. The apparatuses and methods disclosed herein can, however, be realized in many different forms and should not be construed as being limited to the aspects set forth herein. Like numbers in the drawings refer to like elements throughout.

The terminology used herein is for the purpose of describing particular aspects of the disclosure only, and is not intended to limit the disclosure. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

The unlocking direction is defined as the flow direction by which the hydraulic fluid is acting on the hydraulic lock actuator to unlock the mechanical lock from a working tool. The locking direction is defined as the flow direction by which the hydraulic fluid is acting on the hydraulic lock actuator to lock the mechanical lock to a working tool.

Fig. 1 illustrates an example of a working vehicle arrangement 30 comprising a working vehicle 20 and an implement 1 attached thereto. The working vehicle 20 comprises an attachment 21 connectable to an implement 1. The implement 1 comprises a fastening arrangement 3 configured to connect to the attachment 21 of the working vehicle 20. The implement 1 may be detachably connected to the working vehicle 20. The implement 1 forms an elongated working tool carrier. The implement 1 comprises an attaching arrangement 4 which is connectable to a working tool 5.

The working vehicle 20 can be any type of working vehicle such as an agricultural working vehicle. In the illustrated example the working vehicle 20 is a tractor. In the illustrated example the implement 1 is a front loader. However the implement 1 may also be, for example, a wheel loader, an end loader, a skid loader, a track loader, a swing loader, a telescopic handler, a forklift, an excavator or a crane.

Fig. 2 illustrates an example of the implement 1 being connectable to the working vehicle 20 and attachable to the working tool 5. In the illustrated example, the implement 1 comprises an arm 2. A fastening arrangement 3 is arranged at a first part 2a of the arm 2. The fastening arrangement 3 is connectable to the working vehicle 20. The attaching arrangement 4 is connected to a second part 2b of the arm 2. The attaching arrangement 4 is attachable to the working tool 5. Further, a locking arrangement 10 is connected to the attaching arrangement 4. However, not all parts of the locking arrangement 10 have to be arranged at the attaching arrangement 4. The locking arrangement 10 is configured to securely lock the working tool 5 to the attaching arrangement 4. The locking arrangement 10 will be described in detail in relation to Figs. 4-6 and Fig. 9.

In the illustrated example, the arm 2 is an elongated arm. In the illustrated example the arm is rigid. In a further example, the arm 2 is straight. In another example, the arm 2 has an elbow. Further, the arm 2 may comprise two parallel arms connected to each other by transverse supports.

Different working tools 5 can be attached to the implement 1, such as a bucket, a bale handler etc. The implement 1 may be a loader. Further, the implement 1 may be a front loader.

Fig. 3 illustrates a first hydraulic circuit diagram for controlling the implement 1 according to a first example. In the illustrated example, the implement 1 comprises a first hydraulic circuit 40 comprising hydraulic pipes. The first hydraulic circuit 40 is, when actuated from a hydraulic source, arranged to cause the implement 1 to control a first hydraulic function 44. In the illustrated example, the first hydraulic circuit 40 is connected to a first hydraulic connection 42. The first hydraulic connection 42 is connectable to a hydraulic source. The direction and pressure of the hydraulic fluid actuates the first hydraulic function 44. Further, the locking arrangement 10 is connected in parallel with the first hydraulic function 44. Hence, the hydraulic fluid actuating on the first hydraulic function 44 also actuates the locking arrangement 10. The first hydraulic function 44 may be accidentally mechanically actuated so that the hydraulic fluid in the first hydraulic circuit 40 changes the direction. The hydraulic source may be connected to a hydraulic fluid reservoir.

In one example (not illustrated), the hydraulic source is arranged in the working vehicle 20. In this example, an operator of the working vehicle 20 is operating the first hydraulic circuit 40 of the implement 1 to control the first hydraulic function 44. In this example, the first hydraulic connection 42 is connected to a first hydraulic connection of the working vehicle 20, wherein the first hydraulic connection of the working vehicle 20 is connected to the hydraulic source. However, the hydraulic source could also be arranged on the implement 1. In another example, the hydraulic source is connected directly to the first hydraulic connection 42 of the implement 1. In yet another example, the hydraulic source is comprised in the first hydraulic connection 42 of the implement l.The hydraulic source may be a hydraulic pump. The hydraulic source is configured to control the pressure of the hydraulic fluid. A first direction valve may be implemented between the hydraulic source and the first hydraulic connection 42 configured to control the direction of the hydraulic fluid in the first hydraulic circuit 40. The first direction valve may be a directional control valve. The first direction valve may be a proportional valve. More specific, the first direction valve may be a bi-directional proportional control valve.

In one example, the first hydraulic function 44 comprises a hydraulic cylinder attached to the arm 2 and to the attaching arrangement 4. In this case, the hydraulic cylinder of the first hydraulic function 44 is configured to control the angle between the attaching arrangement 4 and the arm 1.

In another example, the first hydraulic function 44 comprises a hydraulic cylinder attached to the working tool 5. In this case, the hydraulic cylinder of the first hydraulic function 44 is configured to control a function of the working tool 5. In a further example, the first hydraulic function 44 comprises a hydraulic motor. The hydraulic motor may be configured to control a function of the working tool 5.

In yet another example, the first hydraulic function 44 comprises a hydraulic cylinder connected to the fastening arrangement 3 and to the arm 2. In this case, the hydraulic cylinder of the first hydraulic function 44 is configured to control the angle between the fastening arrangement 3 and the arm 2. In other words, the hydraulic cylinder of the first hydraulic function 44 is configured to control the lift of the arm 2. In one example, the first hydraulic function 44 comprises a pair of hydraulic cylinders. When the arm 2 comprises a plurality of elongated supporting arms connected to each other by transverse supports, one or a plurality of hydraulic cylinders can be mounted to each of the supporting arms 2.

Fig. 4 illustrates a locking arrangement 10 for locking a working tool 5 to the implement 1 according to prior art. The locking arrangement 10 comprises a hydraulic lock actuator 12. The hydraulic lock actuator 12 is connected to a mechanical lock 14. The mechanical lock 14 is connectable to the working tool 5 such that hydraulic fluid acting on the hydraulic lock actuator 12 is causing the mechanical lock 14 to lock or unlock mechanical lock 14 to the working tool 5 depending on the flow direction of the hydraulic fluid. As described in relation to Fig. 3, the first hydraulic function 44 may be accidentally mechanically actuated so that the hydraulic fluid in the first hydraulic circuit 40 changes the direction. The accidental change of the direction of the hydraulic fluid might cause the mechanical lock 14 to accidentally unlock the working tool 5 from the implement 1. According to this prior art example, a first safety valve 16 is arranged on one of the hydraulic pipes leading to the hydraulic lock actuator 12. The first safety valve 16 is configured such that the first safety valve 16 allows the fluid to flow in the direction to lock the working tool 5 to the implement 1, but blocks the fluid to flow in the direction to unlock the working tool 5 from the implement 1. Hence, if the first hydraulic function 44 is accidentally mechanically actuated so that the hydraulic fluid in the first hydraulic circuit 40 changes the direction, the first safety valve 16 blocks the fluid from flowing in the direction to unlock the working tool 5 from the implement 1. Hereinafter, the unlocking direction is defined as the flow direction by which the hydraulic fluid is acting on the hydraulic lock actuator 12 to unlock the mechanical lock 14 from the working tool 5. Further, the locking direction is defined as the flow direction by which the hydraulic fluid is acting on the hydraulic lock actuator 12 to lock the mechanical lock 14 to the working tool 5.

However, if the first safety valve 16 for some reason does not function, an accidental change of the direction of the hydraulic fluid might cause the mechanical lock 14 to accidentally unlock and release the working tool 5 from the implement 1. In one example, the first safety valve 16 is connected to a first electrical circuit and the first safety valve 16 is configured to open and allow the supply of hydraulic fluid acting on the hydraulic lock actuator 12 in the unlocking direction, in response to an electrical signal from the first electrical circuit. A short circuit occurring in the first electrical circuit might cause the first electrical circuit to send an electrical signal to open the first safety valve 16 and allow the supply of hydraulic fluid acting on the hydraulic lock actuator 12 in the unlocking direction.

Fig. 5 illustrates a locking arrangement for locking a working tool 5 to the implement 1 according to a first example. The locking arrangement 10 comprises the hydraulic lock actuator 12. The hydraulic lock actuator 12 is connected to the mechanical lock 14 which is connectable to the working tool 5 such that hydraulic fluid acting on the hydraulic lock actuator 12 is causing the mechanical lock 14 to lock or unlock the mechanical lock 14 to or from the working tool 5 depending on the direction of the hydraulic fluid. As described in relation to Fig. 3, the first hydraulic function 44 may be accidentally mechanically actuated so that the hydraulic fluid in the first hydraulic circuit 40 changes the flow direction. The accidental change of the flow direction of the hydraulic fluid might cause the mechanical lock 14 to accidentally unlock and release the working tool 5 from the implement 1. According to this example, the first safety valve 16 and a second safety valve 18 is arranged in series with the hydraulic lock actuator 12. Also the second safety valve 18 is configured such that the second safety valve 18 allows the fluid to flow in the direction to lock the working tool 5 to the implement 1, but blocks the fluid to flow in the direction to unlock the working tool 5 from the implement 1. Hence, if the first hydraulic function 44 is accidentally mechanically actuated so that the hydraulic fluid in the first hydraulic circuit 40 changes the flow direction, the second safety valve 18 blocks the fluid from flowing in the direction to unlock the working tool 5 from the implement 1. Thus, if the first safety valve 16 fails to block the fluid to flow in the direction to unlock the working tool 5 from the implement 1, the second safety valve 18 blocks the fluid from flowing in the direction to unlock the working tool 5 from the implement 1. Hence, the second safety valve 18 connected in series with the first safety valve 16 and the hydraulic lock actuator 12 increases the safety of the locking arrangement 10 in that the risk of accidentally unlocking the working tool 5 from the implement 1 is decreased. In Fig. 5, the first safety valve 16 and the second safety valve 18 are arranged on different sides of the hydraulic lock actuator 12. An advantage, of positioning the first safety valve 16 and the second safety valve 18 on different sides of the hydraulic lock actuator 12, is that it is possible to stop fluid from reaching the mechanical lock 14 from both sides of the first hydraulic circuit 40. However, the first safety valve 16 and the second safety valve 18 may also be arranged next to each other on one of the sides of the hydraulic lock actuator 12.

In one example, the second safety valve 18 is connected to a second electrical circuit and the second safety valve 18 is configured to open and allow the supply of hydraulic fluid acting on the hydraulic lock actuator 12 in the unlocking direction, in response to an electrical signal from the second electrical circuit. The second electrical circuit is arranged such that the second electrical circuit is operated independently from the first electrical circuit. Hence, it is not likely that both the first and the second electrical circuits suffer from short circuit simultaneously.

In another example, the second safety valve 18 is configured to close and stop the supply of hydraulic fluid acting on the hydraulic lock actuator 12 in the unlocking direction, as long as the pressure of the hydraulic fluid acting on the second safety valve 18 in the unlocking direction is below a pre-set pressure. The pre-set pressure for opening the second safety valve 18 in the unlocking direction should be set to a pressure that is higher than the pressure that can be introduced by external force acting the first hydraulic function 44 in the unlocking direction, but lower than the system pressure that the hydraulic source is able to introduce into the first hydraulic circuit 40. In one example, the pre-set pressure is 60-90 % of the system pressure that the hydraulic source is able to introduce into the first hydraulic circuit 40. An advantage of stopping the supply of hydraulic fluid acting on the hydraulic lock actuator 12 in the unlocking direction as long as the pressure is below the pre-set pressure, is that the preset pressure normally is higher than the pressure that accidentally can be generated by the first hydraulic function 44 due to external force acting on the first hydraulic function, causing the fluid to flow in the unlocking direction. On the other hand, the pre-set pressure is less than the pressure that normally can be introduced to the first hydraulic circuit 40 from the working vehicle 20 to which the implement 1 is connected. Hence, the working vehicle 20 can cause the locking arrangement 10 to unlock the working tool 5 from the implement 1 while an accidentally introduced pressure generated by the first hydraulic function 44 due to external force, cannot cause the locking arrangement 10 to unlock the working tool 5 from the implement 1. In relation to Fig. 2, it was described that the locking arrangement 10 is connected to the attaching arrangement 4. However, not all parts of the locking arrangement 10 have to be arranged at the attaching arrangement 4. For example, the first safety valve 16 and the second safety valve 18 can be arbitrary placed along any of the hydraulic pipes connected to the hydraulic lock actuator 12. Further, also the hydraulic lock actuator 12 can be arbitrary arranged in relation to the attaching arrangement 4. However, the mechanical lock 14 which is connectable to the working tool 5 has to be arranged at the attaching arrangement 4, since the mechanical lock 14 is the physical part which is able to grip to the working tool 5.

Fig. 6 illustrates a locking arrangement for locking a working tool 5 to the implement 1 according to a second example. In this example, the hydraulic lock actuator 12 is a hydraulic lock cylinder 125 configured to unlock the mechanical lock 14 when hydraulic fluid is acting on the hydraulic lock cylinder 125 in the unlocking direction and to lock the mechanical lock 14 when hydraulic fluid is acting on the hydraulic lock cylinder 125 in the locking direction. In one example, a pin 130 is attached to the hydraulic lock cylinder 125 in the cylinder translational direction, such that the position of said pin 130 is determining whether the working tool 5 is securely locked to the attaching arrangement 4. The pin 130 is configured to attach to the working tool 5 in a securely locked manner when the hydraulic fluid is acting on the hydraulic lock actuator 12 in the locking direction.

According to another example, the hydraulic lock actuator 12 is a hydraulic lock motor configured to unlock the mechanical lock when hydraulic fluid is acting on the hydraulic lock motor in the unlocking direction and to lock the mechanical lock 14 when hydraulic fluid is acting on the hydraulic lock motor in the locking direction.

Fig. 7 illustrates a first hydraulic circuit diagram for controlling an implement 1 according to a second example. In this example, the first hydraulic circuit 40 is further configured to carry hydraulic fluid to a second hydraulic function 46 connected in parallel with the first hydraulic function 44. A first switch valve 48 is arranged between the first hydraulic function 44 and the second hydraulic function 46. The first switch valve 48 is configured to switch the hydraulic fluid between the first hydraulic function 44 and the second hydraulic function 46. In this example, the locking arrangement 10 is arranged in parallel with the first switch valve 48. Consequently, the hydraulic fluid can act on the locking arrangement 10, independently of if the first switch valve 48 is actuated to direct the hydraulic fluid to the first hydraulic function 44 or the second hydraulic function 46. In one example, the first switch valve 48 is actuated from the working vehicle 20. It should be understood that first hydraulic circuit 40 may comprise further hydraulic functions and further switch valves.

In one example, the second hydraulic function 46 comprises a hydraulic cylinder attached to the arm 2 and to the attaching arrangement 4. In this case, the hydraulic cylinder of the second hydraulic function 46 is configured to control the angle between the attaching arrangement 4 and the arm 1.

In another example, the second hydraulic function 46 comprises a hydraulic cylinder attached to the working tool 5. In this case, the hydraulic cylinder of the second hydraulic function 46 is configured to control a function of the working tool 5.

In a further example, the second hydraulic function 46 comprises a hydraulic motor. The hydraulic motor may be configured to control a function of the working tool 5.

In yet another example, the second hydraulic function 46 comprises a hydraulic cylinder connected to the fastening arrangement 3 and to the arm 2. In this case, the hydraulic cylinder of the second hydraulic function 46 is configured to control the angle between the fastening arrangement 3 and the arm 2. In other words, the hydraulic cylinder of the second hydraulic function 46 is configured to control lifting/lowering of the arm 2 in relation to the working vehicle 20.

In one example (not illustrated), the second hydraulic function 46 comprises a pair of hydraulic cylinders. When the arm 2 comprises a plurality of elongated supporting arms connected to each other by transverse supports, one or a plurality of hydraulic cylinders can be mounted to each of the supporting arms 2.

Fig. 8 illustrates an example of an implement 1 being connectable to a working vehicle 20 and attachable to a working tool 5; and first and second hydraulic circuits 40, 50 for controlling the implement 1, the first hydraulic circuit 40 comprising a locking arrangement 10 for locking a working tool 5 to the implement 1. As already described in relation to Fig. 2, the implement 1 comprises an arm 2. A fastening arrangement 3 is arranged at a first part 2a of the arm 2. The fastening arrangement 3 is connectable to the working vehicle 20. The attaching arrangement 4 is connected to a second part 2b of the arm 2. The attaching arrangement 4 is attachable to the working tool 5. Further, a locking arrangement 10 is configured to securely lock the working tool 5 to the attaching arrangement 4.

In this example, the implement 1 further comprises a second hydraulic circuit 50 comprising hydraulic pipes connected to a hydraulic function 54'. The second hydraulic circuit 50 is, when actuated, arranged to cause the implement 1 to control the hydraulic function 54' of the second hydraulic circuit 50. In the illustrated example, the second hydraulic circuit 50 is connected to a second hydraulic connection 52. The second hydraulic connection 52 is connectable to a hydraulic source. In one example, the hydraulic source is arranged in the working vehicle 20. The hydraulic source may be a pump. The hydraulic source is configured to control the pressure of the hydraulic fluid. A direction valve implemented between the hydraulic source and the second hydraulic connection 52 is configured to actuate the direction of the hydraulic fluid in the second hydraulic circuit 50. In this example, an operator of the working vehicle 20 can operate the second hydraulic circuit 50 of the implement 1 to control the hydraulic function 54' of the second hydraulic circuit 50. The direction and pressure of the hydraulic fluid actuates the hydraulic function 54' of the second hydraulic circuit 50. In Fig. 8, the hydraulic function 54' of the second hydraulic circuit 50 is a hydraulic cylinder 54' connected to the fastening arrangement 3 and to the arm 2. Hence, the hydraulic function 54' of the second hydraulic circuit 50 is configured to control the angle between the fastening arrangement 3 and the arm 2. Since the fastening arrangement 3 normally is rigidly fastened to the working vehicle 20, this could be described as that the hydraulic function 54' of the second hydraulic circuit 50 is configured to control the angle between the working vehicle 20 and the arm 2. In other words, the hydraulic function 54' of the second hydraulic circuit 50 is configured to control lifting/lowering of the arm 2 in relation to the working vehicle 20. The hydraulic source is connectable also to the second hydraulic connection 52. Hence, when the hydraulic source is connected to the second hydraulic connection 52, the hydraulic source can control the hydraulic function 54'.

If the hydraulic source is arranged in the working vehicle 20, the second hydraulic connection 52 is connected to a second hydraulic connection of the working vehicle 20 and the second hydraulic connection of the working vehicle 20 is connected to the hydraulic source. A second direction valve may be implemented between the hydraulic source and the second hydraulic connection 52. The second direction valve is configured to control the direction of the hydraulic fluid in the second hydraulic circuit 50 (not illustrated). The second direction valve may be a directional control valve. The second direction valve may be a proportional valve. More specific, the second direction valve may be a bi-directional proportional control valve.

In another example, a second hydraulic source is connectable to the second hydraulic connection 52. In this case, when the second hydraulic source is connected to the second hydraulic connection 52, the hydraulic source can control the hydraulic function 54'.

The first hydraulic connection 42 and the second hydraulic connection 52 may be connected to a common connection device arranged between the first part of the arm 2 and the working vehicle 20. In this case, the working vehicle 20 has a matching connection device to which the common connection device can be connected. When, the matching connection device and the common connection device are connected, the hydraulic fluid can be actuated from the hydraulic source to any of the first hydraulic connection 42 and the second hydraulic connection 52 by means of the first and the second direction valves.

In the example illustrated in Fig. 8, the first hydraulic circuit 40 is configured to carry hydraulic fluid to a second hydraulic function 46 connected in parallel with the first hydraulic function 44. A first switch valve 48 is arranged between the first hydraulic function 44 and the second hydraulic function 46. The first switch valve 48 is configured to switch the hydraulic fluid between the first hydraulic function 44 and the second hydraulic function 46. It should be understood that first hydraulic circuit 40 may comprise further hydraulic functions and further switch valves. In this example, the locking arrangement 10 is arranged in parallel with the second hydraulic function 46 but after the first switch valve 48. Consequently, when the first switch valve 48 is actuated to direct to the first hydraulic function 44, the hydraulic fluid does not act on the locking arrangement 10. On the other hand, when the first switch valve 48 is actuated to direct the hydraulic fluid to the second hydraulic function 46, the hydraulic fluid is also directed to the locking arrangement 10.

In Fig. 8, the first hydraulic function 44 is a hydraulic cylinder 44' attached to the arm 2 and to the attaching arrangement 4. The hydraulic cylinder 44' of the first hydraulic function 44 is configured to move or tilt the attaching arrangement 4 in relation to the implement 1. Further, the second hydraulic function 46 is a hydraulic cylinder 46' attached to the working tool 5. The hydraulic cylinder 46' of the second hydraulic function 46 is configured to control a function of the working tool 5.

As mentioned above, the hydraulic cylinder 46' of the second hydraulic function 46 is configured to control a function of the working tool 5. In this example, the hydraulic cylinder 46' is configured such that, under normal use, there is a very limited risk that a pressure higher than the pre-set pressure is generated by the hydraulic cylinder 46' due to external force acting on the hydraulic cylinder 46'. The hydraulic source operating the first hydraulic circuit 40, normally arranged in the working vehicle, does normally have enough power to introduce a pressure in the first hydraulic circuit 40 which is higher than the pressure that can be introduced by external force acting on the hydraulic cylinder 46' in the unlocking direction. Hence, if the second safety valve 18 is pressure controlled in the unlocking direction, the pre- set pressure for opening the second safety valve 18 in the unlocking direction should be set to a pressure that is higher than the pressure that can be introduced by external force acting on the hydraulic cylinder 46' in the unlocking direction, but lower than the system pressure that the hydraulic source is able to introduce into the first hydraulic circuit 40. Hence, the second safety valve 18 is configured to close and stop the supply of hydraulic fluid acting on the hydraulic lock actuator 12 in the unlocking direction, as long as the pressure of the hydraulic fluid acting on the second safety valve 18 in the unlocking direction is below the pre-set pressure. In this case, the pre-set pressure is higher than the pressure that accidentally can be generated by the hydraulic cylinder 46' due to external force acting on the hydraulic cylinder 46', configured to control a function of the working tool. On the other hand, the pre-set pressure is lower than the pressure that can be introduced to the first hydraulic circuit 40 from the working vehicle 20 to which the implement 1 is connected. Hence, the working vehicle 20 can cause the locking arrangement 10 to unlock the working tool 5 from the implement 1, while an accidentally introduced pressure, generated by the hydraulic cylinder 46' due to external force, cannot cause the locking arrangement 10 to unlock the working tool 5 from the implement 1. Thus, there is an advantage with having the first switch valve 48 arranged between the first hydraulic function 44 and the locking arrangement 10, if the second safety valve 18 is configured to block hydraulic fluid from passing in the unlocking direction as long as the pressure is below the pre-set pressure, provided that the first hydraulic function 44 is the hydraulic cylinder 44' attached to the arm 2 and the attaching arrangement 4, and the second hydraulic function 46 is the hydraulic cylinder 46' attached to the working tool 5.

As described above, if the second safety valve 18 is pressure controlled in the unlocking direction, the pre-set pressure for opening the second safety valve 18 in the unlocking direction should be set to a pressure that is higher than the pressure that can be introduced by external force acting on the hydraulic cylinder 46' in the unlocking direction, but lower than the system pressure that the hydraulic source is able to introduce into the first hydraulic circuit 40. The pressure introduced by external force acting on the hydraulic cylinder 46' in the unlocking direction, is rarely larger than 50 % of the system pressure that the hydraulic source is able to introduce into the first hydraulic circuit 40. In one example, the pre-set pressure is 50-95 % of the system pressure that the hydraulic source is able to introduce into the first hydraulic circuit 40. In a preferred embodiment, the pre-set pressure is 65-85 % of the system pressure that the hydraulic source is able to introduce into the first hydraulic circuit 40. Hence, if the working vehicle 20 has a hydraulic source that is able to introduce 200 bar, the pre-set pressure should be chosen to between 100 bar and 190 bar, more preferred 130 bar to 170 bar. If instead the working vehicle 20 has a hydraulic source that is able to introduce 400 bar, the pre-set pressure should be chosen to between 200 bar and 380 bar, more preferred between 260 bar and 340 bar. However, in other applications maybe the pressure that can be introduced by external force acting on the first or second hydraulic actuators 44, 46 in the unlocking direction is only 5 % of the system pressure that the hydraulic source is able to introduce into the first hydraulic circuit 40. In such a case the pre-set pressure can be set to 5-10 % of the system pressure that the hydraulic source is able to introduce into the first hydraulic circuit 40.

As mentioned above, the hydraulic cylinder 44' of the first hydraulic function 44 is, in this example, configured to move or tilt the attaching arrangement 4 in relation to the implement 1. When the attaching arrangement 4 is attached to the working tool 5, the hydraulic cylinder 44' of the first hydraulic function 44 is configured to move or tilt the working tool 5 in relation to the implement 1, since the attaching arrangement 4, in this case, is firmly attached to the working tool 5. If the force introduced by external force is applied to the working tool 5 from an unexpected direction, a pressure to push the hydraulic fluid in the unlocking direction may be generated by the hydraulic cylinder 44'. The pressure generated by the hydraulic cylinder 44' in an unexpected direction due to external force might cause the hydraulic cylinder 44' to push the hydraulic fluid of the first hydraulic circuit 40 in the reverse direction. The force introduced by external force from an unexpected direction may be a pressure to push the working tool 5 against gravity. The pressure generated by the hydraulic cylinder 44' due to external force acting on the working tool 5 could in this case almost reach the system pressure that the hydraulic source is able to introduce into the first hydraulic circuit 40. In fact, the pressure generated by the hydraulic cylinder 44' due to external force acting on the working tool 5 could momentarily reach a pressure higher than the system pressure that the hydraulic source is able to introduce into the first hydraulic circuit 40. Thus, if the locking arrangement 10 instead would be arranged directly in parallel with the hydraulic cylinder 44' of the first hydraulic function 44, without the first switch valve 48 being arranged between the locking arrangement 10 and the hydraulic cylinder 44', there would be a risk to introduce a pressure higher than the system pressure that the hydraulic source is able to introduce in the unlocking direction of the the locking arrangement 10. Hence, if the second safety valve 18 is configured to close and stop the supply of hydraulic fluid acting on the hydraulic lock actuator 12 in the unlocking direction, as long as the pressure of the hydraulic fluid acting on the second safety valve 18 in the unlocking direction is below the pre-set pressure, it is better to position the first switch valve 48 between the hydraulic cylinder 44', configured to move or tilt the attaching arrangement 4 in relation to the implement 1, and the locking arrangement 10.

However, the description is not limited to the example described in relation to Fig. 8. In one example the first hydraulic function 44 is a hydraulic cylinder. In another example the second hydraulic function 46 is a hydraulic cylinder. The hydraulic cylinder 44' may be arranged to control the tilt of the attaching arrangement 4 in relation to the arm 2. In another example, the hydraulic cylinder 46' is arranged to control a function of the working tool 5. In yet another example, the hydraulic cylinder 54' is arranged to control lifting/lowering of the arm 2 in relation to the working vehicle 20.

In another example, the first hydraulic function 44 is a hydraulic motor. In yet another example, the second hydraulic function 46 is a hydraulic motor. The hydraulic motor may be arranged to control a function of the working tool 5.

In a further example which is not illustrated, the implement 1 further comprises a third hydraulic circuit arranged to control a further hydraulic function. In one example, none of the hydraulic functions share the hydraulic circuit with another hydraulic function. Thus, the hydraulic functions are not connected in parallel. In other words, there is a hydraulic connector for each of the three hydraulic functions. All three hydraulic connectors are connected to the hydraulic source. In this case, there may be in total three direction valves on the side of the hydraulic source, i.e. one direction valve between each of the hydraulic connectors and the hydraulic pump. An advantage is that no switch valve is needed in the hydraulic circuits since each hydraulic connector is connected to one hydraulic function only. In this case, the locking arrangement 10 can be arranged in parallel with any of the hydraulic functions. However, it is suitable to arrange the locking arrangement 10 in parallel with the hydraulic cylinder 46' attached to the working tool 5, if the second safety valve 18 is configured to close and stop the supply of hydraulic fluid acting on the hydraulic lock actuator 12 in the unlocking direction, as long as the pressure of the hydraulic fluid acting on the second safety valve 18 in the unlocking direction is below a pre-set pressure, since the force introduced by external force acting on the hydraulic cylinder 46' in the unlocking direction, is rarely larger than 50 % of the system pressure that the hydraulic source is able to introduce into the hydraulic circuit.

In yet a further example which is not illustrated, the implement 1 only comprises one hydraulic circuit arranged to control all hydraulic functions. In this example, the hydraulic circuit may comprise a plurality of switch valves. For illustrative purposes, an example with a hydraulic circuit comprising three hydraulic functions will be described. In this example, a first hydraulic switch is arranged between the first hydraulic function and the second/third hydraulic functions. Further, a second hydraulic switch is arranged between the second hydraulic function and the third hydraulic function. The locking arrangement 10 can be arranged in parallel with any of the hydraulic functions. However, it is suitable to arrange the locking arrangement 10 in parallel with the hydraulic cylinder 46' attached to the working tool 5, if the second safety valve 18 is configured to close and stop the supply of hydraulic fluid acting on the hydraulic lock actuator 12 in the unlocking direction, as long as the pressure of the hydraulic fluid acting on the second safety valve 18 in the unlocking direction is below a pre-set pressure, since the force introduced by external force acting on the hydraulic cylinder 46' in the unlocking direction, is rarely larger than 50 % of the system pressure that the hydraulic source is able to introduce into the hydraulic circuit.

Fig. 9 illustrates a locking arrangement 10 for locking a working tool 5 to the implement 1 according to a third example. Basically, the hydraulic circuit diagram of Fig. 9, is the same as of Fig. 5. In this example, the first safety valve 16 is connected to a first electrical circuit and the first safety valve 16 is configured to open and allow the supply of hydraulic fluid acting on the hydraulic lock actuator 12 in the unlocking direction, in response to an electrical signal from the first electrical circuit. The first safety valve 16 is configured to always allow fluid acting on the hydraulic lock actuator 12 in the locking direction to pass.

In this example, the second safety valve 18 is configured to close and stop the supply of hydraulic fluid acting on the hydraulic lock actuator 12 in the unlocking direction, as long as the pressure, of the hydraulic fluid acting on the second safety valve 18 in the unlocking direction, is below a pre-set pressure. The second safety valve 18 is configured to always allow fluid acting on the hydraulic lock actuator 12 in the locking direction to pass. There are different ways of implementing the second safety valve 18 such that the second safety valve 18 is blocking fluid having a pressure up to the pre-set pressure in the unlocking direction. In the example illustrated in Fig. 9, the second safety valve 18 comprises a mechanical resistance, such as a mechanical spring, configured to push the second safety valve 18 into a position to blocking fluid in the unlocking direction. The second safety valve 18 is configured such that, as long as the pressure of the hydraulic fluid acting on the second safety valve 18 in the unlocking direction is below the pre-set pressure, the mechanical resistance of the second safety valve 18 is higher than the pressure of the hydraulic fluid, causing the second safety valve 18 to block hydraulic fluid in the unlocking direction. When the pressure of the hydraulic fluid acting on the second safety valve 18 in the unlocking direction exceeds the pre-set pressure, the pressure of the hydraulic fluid exceeds the mechanical resistance of the second safety valve 18. Consequently, the second safety valve 18 enters a position where the second safety valve 18 is allowing hydraulic fluid to pass in the unlocking direction. An advantage, of that the second safety valve 18 is mechanically actuatable, is that a further electrical circuit is avoided. Hence, the locking arrangement 10 requires a lower electrical power if the second safety valve 18 is mechanically actuatable instead of electrically actuatable. Further, the need for additional cabling and electrical switches to a further electrical circuit is avoided. There are other ways of implementing that the second safety valve 18 fulfils the function of blocking fluid having a pressure in the unlocking direction of up to the pre-set pressure. The second safety valve 18 may comprise a pressure sensor. As long as the pressure sensor measures a pressure that is lower the pre-set pressure the second safety valve 18 is blocking hydraulic fluid acting on the second safety valve 18 in the unlocking direction. When the pressure sensor measures a pressure that is higher than the pre-set pressure, the pressure sensor sends an electrical signal to the second safety valve 18 to open an allow hydraulic fluid acting on the second safety valve 18 in the unlocking direction. An advantage, of that the second safety valve 18 comprises a pressure sensor is that the pre-set pressure easily can be adjusted, by adjusting the pre-set pressure by which the pressure sensor sends an electrical signal to the second safety valve 18 to open an allow hydraulic fluid acting on the second safety valve 18 in the unlocking direction. Hence, the pre-set pressure can be adjustable to the working tool 5 that is attached to the implement 1. Further, the pre-set pressure can be adjustable to the hydraulic source that is connected to the implement 1. Yet further, the preset pressure can be adjustable to the specific application where the implement 1 is used. In one example, the pre-set pressure can at any time be arbitrary updated to current circumstances and current needs.

Claims

1. An implement (1) connectable to a working vehicle (20), said implement (1) comprising:

an arm (2) having a first part (2a) and a second part (2b); a fastening arrangement (3) connected to the first part (2a) of the arm (2), said fastening arrangement (3) being connectable to the working vehicle (20); an attaching arrangement (4) connected to the second part (2b) of the arm (2), said attaching arrangement (4) being attachable to a working tool (5); a locking arrangement (10) connected to the attaching arrangement (4) and configured to securely lock the working tool (5) to the attaching arrangement (4), said locking arrangement (10) comprising a hydraulic lock actuator (12) connected to a mechanical lock (14), said mechanical lock (14) being configured to securely lock the working tool (5) to the attaching arrangement (4), said hydraulic lock actuator (12) being configured to control the mechanical lock (14) by means of hydraulic fluid acting on the hydraulic lock actuator (12); and a first hydraulic circuit (40) configured to carry hydraulic fluid from a first hydraulic connection (42) to a first hydraulic function (44) and to the locking arrangement, said locking arrangement (10) being connected in parallel with the first hydraulic function (44); the locking arrangement (10) further comprising a first safety valve (16) connected to the first hydraulic circuit (40), said first safety valve (16) being configured to stop the supply of hydraulic fluid acting on the hydraulic lock actuator (12) in the unlocking direction, wherein the unlocking direction is defined as the fluid flow direction by which the hydraulic fluid is acting on the hydraulic lock actuator (12) to unlock the mechanical lock (14);

characterized in that the locking arrangement (10) further comprises a second safety valve (18) connected to the first hydraulic circuit (40), said second safety valve (18) being configured to stop the supply of hydraulic fluid in the unlocking direction, wherein the hydraulic lock actuator (12), the first safety valve (16) and the second safety valve (18) are connected in series.

The implement (1) according to claim 1, wherein the first safety valve (16) and the second safety valve (18) are arranged on different sides of the hydraulic lock actuator (12).

The implement (1) according to claim 1 or claim 2, wherein the second safety valve (18) is configured to close and stop the supply of hydraulic fluid acting on the hydraulic lock actuator (12) in the unlocking direction, as long as the pressure of the hydraulic fluid acting on the second safety valve (18) in the unlocking direction is below a pre-set pressure.

The implement (1) according to any of the preceding claims, wherein the first safety valve (16) is connected to a first electrical circuit and the first safety valve (16) is configured to open and allow the supply of hydraulic fluid acting on the hydraulic lock actuator (12) in the unlocking direction, in response to an electrical signal from the first electrical circuit.

5. The implement (1) according to any of the preceding claims, wherein the second safety valve (18) is connected to a second electrical circuit and the second safety valve (18) is configured to open and allow the supply of hydraulic fluid acting on the hydraulic lock actuator (12) in the unlocking direction, in response to an electrical signal from the second electrical circuit.

6. The implement (1) according to any of the preceding claims, wherein the hydraulic lock actuator (12) is a hydraulic lock cylinder (125) configured to unlock the mechanical lock (14) when hydraulic fluid is acting on the hydraulic lock cylinder (125) in the unlocking direction and to lock the mechanical lock (14) when hydraulic fluid is acting on the hydraulic lock cylinder (125) in the locking direction.

7. The implement (1) according to any of the preceding claims, wherein a pin (130) is attached to the hydraulic lock cylinder (125) in the cylinder translational direction, such that the position of said pin (130) is determining whether the working tool (5) is securely locked to the attaching arrangement (4), said pin (130) being configured to attach to the working tool (5) in a securely locked manner when the hydraulic fluid is acting on the hydraulic lock actuator (12) in the locking direction, wherein the locking direction is defined as the fluid flow direction by which the hydraulic fluid is acting on the hydraulic lock actuator (12) to lock the mechanical lock (14).

8. The implement (1) according to any of the preceding claims, wherein the hydraulic lock actuator (12) is a hydraulic lock motor configured to unlock the mechanical lock (14) when hydraulic fluid is acting on the hydraulic lock motor in the unlocking direction and to lock the mechanical lock (14) when hydraulic fluid is acting on the hydraulic lock motor in the locking direction.

9. The implement (1) according to any of the preceding claims, wherein the first hydraulic circuit (40) is arranged along the arm (2), from the first hydraulic connection (42) at the first part of the arm (2) to the attaching arrangement (4).

10. The implement (1) according to any of the preceding claims, wherein the first hydraulic circuit (40) is further configured to carry hydraulic fluid to a second hydraulic function (46) connected in parallel with the first hydraulic function (44), wherein a first switch valve (48) is arranged between the first hydraulic function (44) and the second hydraulic function (46) and is configured to switch the hydraulic fluid between the first hydraulic function (44) and the second hydraulic function (46); and wherein the locking arrangement (10) is arranged after the first switch valve and is connected in parallel with the second hydraulic function (46) such that no hydraulic fluid is flowing to the locking arrangement (10) when the hydraulic fluid is switched through the first hydraulic function (44).

11. The implement (1) according to any of the preceding claims, wherein the first hydraulic function (44) comprises a hydraulic cylinder (44') attached to the arm (2) and to the attaching arrangement (4), said hydraulic cylinder (44') being configured to control the angle between the attaching arrangement (4) and the arm (2).

12. The implement (1) according to any of the preceding claims, wherein the second hydraulic function (46) comprises a hydraulic cylinder (46') attached to the working tool (5), said hydraulic cylinder (46') being configured to control a function of the working tool (5).

13. The implement (1) according to any claims 1-11, wherein the second hydraulic function (46) comprises a hydraulic motor configured to operate a function of the working tool (5).

14. The implement (1) according to any of the preceding claims, wherein the implement (1) further comprises a second hydraulic circuit (50) configured to carry hydraulic fluid from a second hydraulic connection (52) connectable to the working vehicle (20) to a further hydraulic cylinder (54'), said further hydraulic cylinder (54') being attached to the first part of the arm (2) and to the fastening arrangement (3) and being configured to control the angle between the arm (2) and the fastening arrangement (3).

15. The implement (1) according to any of the preceding claims, wherein the first hydraulic connection (42) and the second hydraulic connection (52) are connected to a common connection device arranged between the first part of the arm (2) and the working vehicle (20).

16. The implement (1) according to any of the preceding claims, wherein the implement (1) is a front loader, a wheel loader, an end loader, a skid loader, a track loader, a swing loader, a telescopic handler, a forklift, an excavator or a crane.

17. A working vehicle arrangement (30) comprising an implement (1) connectable to a working vehicle (20) according to any of claims 1-16 and the working vehicle (20) comprising an arrangement for connecting said implement (1) to the working vehicle (20).

18. The working vehicle arrangement (30) according to claim 17, wherein the working vehicle (20) is an agricultural vehicle.