SE1651326A1

SE1651326A1 - An implement connectable to a working vehicle

Info

Publication number: SE1651326A1
Application number: SE1651326A
Authority: SE
Inventors: Westpil Roger
Original assignee: Loe Ab
Priority date: 2016-10-10
Filing date: 2016-10-10
Publication date: 2018-04-11
Also published as: WO2018070920A1; 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

1AN ll\/lPLEl\/IENT CONNECTABLE TO A WORKING VEHICLE TECHNICAL FIELD The present disclosure relates to an implement connectable to a working vehicle andattachable to a working tool; and a first hydraulic circuit configured to carry hydraulic fluidfrom a first hydraulic connection to at least one hydraulic function. The present disclosurefurther 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 animplement such as different kind of loaders. Typically, the implement comprises an attachingarrangement 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 ahydraulic 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. lfthe hydraulic circuit is connected to a plurality of hydraulic functions, the hydraulic circuit maycomprise at least one switch valve configured to switch the hydraulic circuit between thehydraulic functions. The hydraulic functions can for example be implemented to move or tiltthe 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 thefluid 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 onthe same hydraulic circuit where a hydraulic function is implemented. Depending on thedirection of the flow of the fluid the hydraulic lock actuator is either pushed in a direction tolock 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 theworking tool, the working tool is kept locked to the implement. ln order to release the working tool from the implement, the working vehicle actuates the hydraulic fluid such that the fluid 2flows in the direction to unlock the working tool from the implement. Consequently, thehydraulic 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 hydraulicfunction is generating a pressure on the fluid in the hydraulic circuit to flow in the unlockingdirection, which causes the locking arrangement to release the working tool from theimplement. This might cause accidents and physical damages. Hence, there is a need toimprove the hydraulically implemented locking arrangement in order to increase safety during operation ofthe implement and the working tool.

SUMMARYOne 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 aworking 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 thearm, the fastening arrangement being connectable to the working vehicle. Yet further, theimplement comprises an attaching arrangement connected to the second part ofthe arm, saidattaching arrangement being attachable to a working tool. Further, the implement comprisesa locking arrangement connected to the attaching arrangement and configured to securelylock the working tool to the attaching arrangement. The locking arrangement comprises ahydraulic lock actuator connected to a mechanical lock. The mechanical lock is configured tosecurely lock the working tool to the attaching arrangement. The hydraulic lock actuator isconfigured to control the mechanical lock by means of hydraulic fluid acting on the hydrauliclock actuator. Yet further, the implement comprises a first hydraulic circuit configured to carryhydraulic fluid from a first hydraulic connection to a first hydraulic function and to the lockingarrangement. The locking arrangement is connected in parallel with the first hydraulicfunction. The locking arra ngement 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 3on the hydraulic lock actuator in the unlocking direction. The unlocking direction is defined asthe fluid flow direction by which the hydraulic fluid is acting on the hydraulic lock actuator tounlock the mechanical lock. The locking arrangement further comprises a second safety valveconnected to the first hydraulic circuit. The second safety valve is configured to stop thesupply 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 valveconnected to the first hydraulic circuit, said second safety valve being configured to stop thesupply of hydraulic fluid in the unlocking direction, wherein the hydraulic lock actuator, thefirst safety valve and the second safety valve are connected in series, is that in case the firstsafety valve fails to stop the supply of hydraulic fluid acting on the hydraulic lock actuator inthe unlocking direction, the second safety valve will stop the supply of hydraulic fluid in theunlocking direction. Hence, the implementation ofthe second safety valve improves the safety during operation ofthe implement and the working tool.

According to an aspect of the invention, the first safety valve and the second safety valve arearranged on different sides of the hydraulic lock actuator. An advantage, of positioning thefirst 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 andstop the supply of hydraulic fluid acting on the hydraulic lock actuator in the unlockingdirection, as long as the pressure of the hydraulic fluid acting on the second safety valve in theunlocking direction is below a pre-set pressure. An advantage, of stopping the supply ofhydraulic fluid acting on the hydraulic lock actuator in the unlocking direction as long as thepressure less is below a pre-set pressure, is that the pre-set pressure can be selected such thatthe pre-set pressure is higher than the pressure that accidentally can be generated by the firsthydraulic function due to external force acting on the first hydraulic function, causing the fluidto 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 4hydraulic source can cause the locking arrangement to unlock the working tool from theimplement. On the other hand, an accidentally introduced pressure generated by the firsthydraulic 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 electricalcircuit and the first safety valve is configured to open and allow the supply of hydraulic fluidacting on the hydraulic lock actuator in the unlocking direction, in response to an electricalsignal from the first electrical circuit. An advantage, of that the first safety valve is configuredto open in response to an electrical signal from the first electrical circuit, is that by controllingthe electrical signal from the first electrical circuit it is possible to control when the lockingarrangement 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 secondelectrical circuit and the second safety valve is configured to open and allow the supply ofhydraulic fluid acting on the hydraulic lock actuator in the unlocking direction, in response toan electrical signal from the second electrical circuit. An advantage, of that the second safetyvalve 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 tocontrol 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 cylinderconfigured to unlock the mechanical lock when hydraulic fluid is acting on the hydraulic lockcylinder in the unlocking direction and to lock the mechanical lock when hydraulic fluid isacting on the hydraulic lock cylinder in the locking direction. An advantage, of that thehydraulic lock actuator is a hydraulic lock cylinder, is that translational movements of thehydraulic lock cylinder can be used to put the mechanical lock in a locked position or an unlocked position. 5According to an aspect of the invention, the hydraulic lock actuator is a hydraulic lock motorconfigured to unlock the mechanical lock when hydraulic fluid is acting on the hydraulic lockmotor in the unlocking direction and to lock the mechanical lock when hydraulic fluid is actingon the hydraulic lock motor in the locking direction. An advantage, of that the hydraulic lockactuator is a hydraulic lock motor, is that electrical transmission instead of mechanicaltransmission is used between the hydraulic lock motor and the mechanical lock, which has theeffect that the mechanical lock can be arranged more arbitrary in relation to the hydraulic lock mOtOF.

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 carryhydraulic fluid to a second hydraulic function connected in parallel with the first hydraulicfunction. A first switch valve is arranged between the first hydraulic function and the secondhydraulic function. The first switch valve is configured to switch the hydraulic fluid betweenthe first hydraulic function and the second hydraulic function. The locking arrangement isarranged after the first switch valve and is connected in parallel with the second hydraulicfunction such that no hydraulic fluid is flowing to the locking arrangement when the hydraulicfluid is switched through the first hydraulic function. An advantage, of that no hydraulic fluid isflowing to the locking arrangement when the hydraulic fluid is switched through the firsthydraulic 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 hydrauliccylinder attached to the arm and to the attaching arrangement. The hydraulic cylinder isconfigured to control the angle between the attaching arrangement and the arm. lt should beunderstood that also the second hydraulic function or any further hydraulic function maycomprise 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. 6According to an aspect of the invention, the second hydraulic function comprises a hydrauliccylinder attached to the working tool, said hydraulic cylinder being configured to control afunction of the working tool. lt should be understood that also the first hydraulic function orany 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 hydraulicmotor configured to operate a function of the working tool. lt should be understood that alsothe 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 hydrauliccircuit configured to carry hydraulic fluid from a second hydraulic connection connectable tothe working vehicle to a further hydraulic cylinder, said further hydraulic cylinder beingattached 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 secondhydraulic connection are connected to a common connection device arranged between the first part ofthe arm and the working vehicle.

According to an aspect of the invention, the implement is a front loader, a wheel loader, anend loader, a skid loader, a track loader, a swing loader, a telescopic handler, a forklift, an eXCaVatOl' OI' a Cfaﬂe.

Another object of the present disclosure is to obtain an improved working vehiclearrangement comprising an implement connectable to a working vehicle, as described in thisdisclosure, 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 7embodiments, as illustrated in the accompanying drawings in which like reference charactersrefer 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 andattachable to a working tool; and first and second hydraulic circuits for controlling theimplement, 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 tothe accompanying drawings. The apparatuses and methods disclosed herein can, however, berealized 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 thedisclosure 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 onthe hydraulic lock actuator to unlock the mechanical lock from a working tool. The lockingdirection 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.1illustrates an example of a working vehicle arrangement 30 comprising a working vehicle20 and an implement 1 attached thereto. The working vehicle 20 comprises an attachment 21connectable to an implement 1. The implement 1 comprises a fastening arrangement 3configured to connect to the attachment 21 of the working vehicle 20. The implement 1 maybe detachably connected to the working vehicle 20. The implement 1 forms an elongatedworking 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 workingvehicle. ln the illustrated example the working vehicle 20 is a tractor. ln the illustratedexample the implement 1 is a front loader. However the implement 1 may also be, forexample, 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 9and attachable to the working tool 5. ln the illustrated example, the implement 1 comprises anarm 2. A fastening arrangement 3 is arranged at a first part 2a of the arm 2. The fasteningarrangement 3 is connectable to the working vehicle 20. The attaching arrangement 4 isconnected to a second part 2b of the arm 2. The attaching arrangement 4 is attachable to theworking tool 5. Further, a locking arrangement 10 is connected to the attaching arrangement4. However, not all parts of the locking arrangement 10 have to be arranged at the attachingarrangement 4. The locking arrangement 10 is configured to securely lock the working tool 5to the attaching arrangement 4. The locking arrangement 10 will be described in detail in relation to Figs. 4-6 and Fig. 9. ln the illustrated example, the arm 2 is an elongated arm. ln the illustrated example the arm isrigid. ln a further example, the arm 2 is straight. ln 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 afirst example. ln the illustrated example, the implement 1 comprises a first hydraulic circuit 40comprising hydraulic pipes. The first hydraulic circuit 40 is, when actuated from a hydraulicsource, arranged to cause the implement 1 to control a first hydraulic function 44. ln theillustrated example, the first hydraulic circuit 40 is connected to a first hydraulic connection42. The first hydraulic connection 42 is connectable to a hydraulic source. The direction andpressure of the hydraulic fluid actuates the first hydraulic function 44. Further, the lockingarrangement 10 is connected in parallel with the first hydraulic function 44. Hence, thehydraulic fluid actuating on the first hydraulic function 44 also actuates the lockingarrangement 10. The first hydraulic function 44 may be accidentally mechanically actuated sothat the hydraulic fluid in the first hydraulic circuit 40 changes the direction. The hydraulic source may be connected to a hydraulic fluid reservoir. ln one example (not illustrated), the hydraulic source is arranged in the working vehicle 20. ln this example, an operator of the working vehicle 20 is operating the first hydraulic circuit 40 ofthe implement 1 to control the first hydraulic function 44. ln this example, the first hydraulicconnection 42 is connected to a first hydraulic connection of the working vehicle 20, whereinthe 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. ln anotherexample, the hydraulic source is connected directly to the first hydraulic connection 42 of theimplement 1. ln yet another example, the hydraulic source is comprised in the first hydraulicconnection 42 of the implement 1.The hydraulic source may be a hydraulic pump. Thehydraulic source is configured to control the pressure of the hydraulic fluid. A first directionvalve may be implemented between the hydraulic source and the first hydraulic connection 42configured to control the direction of the hydraulic fluid in the first hydraulic circuit 40. Thefirst direction valve may be a directional control valve. The first direction valve may be aproportional valve. More specific, the first direction valve may be a bi-directional proportional control valve. ln one example, the first hydraulic function 44 comprises a hydraulic cylinder attached to thearm 2 and to the attaching arrangement 4. ln this case, the hydraulic cylinder of the firsthydraulic function 44 is configured to control the angle between the attaching arrangement 4 and the arm 1. ln another example, the first hydraulic function 44 comprises a hydraulic cylinder attached tothe working tool 5. ln this case, the hydraulic cylinder of the first hydraulic function 44 is configured to control a function ofthe working tool 5. ln a further example, the first hydraulic function 44 comprises a hydraulic motor. The hydraulic motor may be configured to control a function ofthe working tool 5. ln yet another example, the first hydraulic function 44 comprises a hydraulic cylinderconnected to the fastening arrangement 3 and to the arm 2. ln this case, the hydraulic cylinderof the first hydraulic function 44 is configured to control the angle between the fasteningarrangement 3 and the arm 2. ln other words, the hydraulic cylinder of the first hydraulic function 44 is configured to control the lift of the arm 2. 11 ln one example, the first hydraulic function 44 comprises a pair of hydraulic cylinders. Whenthe arm 2 comprises a plurality of elongated supporting arms connected to each other bytransverse supports, one or a plurality of hydraulic cylinders can be mounted to each of the supporting arms 2.

Fig. 4 i||ustrates a locking arrangement 10 for locking a working tool 5 to the implement 1according to prior art. The locking arrangement 10 comprises a hydraulic lock actuator 12. Thehydraulic lock actuator 12 is connected to a mechanical lock 14. The mechanical lock 14 isconnectable to the working tool 5 such that hydraulic fluid acting on the hydraulic lockactuator 12 is causing the mechanical lock 14 to lock or unlock mechanical lock 14 to theworking tool 5 depending on the flow direction of the hydraulic fluid. As described in relationto Fig. 3, the first hydraulic function 44 may be accidentally mechanically actuated so that thehydraulic fluid in the first hydraulic circuit 40 changes the direction. The accidental change ofthe direction of the hydraulic fluid might cause the mechanical lock 14 to accidentally unlockthe working tool 5 from the implement 1. According to this prior art example, a first safetyvalve 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 flowin the direction to lock the working tool 5 to the implement 1, but blocks the fluid to flow inthe direction to unlock the working tool 5 from the implement 1. Hence, if the first hydraulicfunction 44 is accidentally mechanically actuated so that the hydraulic fluid in the firsthydraulic 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 hydraulicfluid is acting on the hydraulic lock actuator 12 to unlock the mechanical lock 14 from theworking tool 5. Further, the locking direction is defined as the flow direction by which thehydraulic 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 12unlock and release the working tool 5 from the implement 1. ln one example, the first safetyvalve 16 is connected to a first electrical circuit and the first safety valve 16 is configured toopen and allow the supply of hydraulic fluid acting on the hydraulic lock actuator 12 in theunlocking direction, in response to an electrical signal from the first electrical circuit. A shortcircuit occurring in the first electrical circuit might cause the first electrical circuit to send anelectrical 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 1according to a first example. The locking arrangement 10 comprises the hydraulic lockactuator 12. The hydraulic lock actuator 12 is connected to the mechanical lock 14 which isconnectable to the working tool 5 such that hydraulic fluid acting on the hydraulic lockactuator 12 is causing the mechanical lock 14 to lock or unlock the mechanical lock 14 to orfrom the working tool 5 depending on the direction of the hydraulic fluid. As described inrelation to Fig. 3, the first hydraulic function 44 may be accidentally mechanically actuated sothat the hydraulic fluid in the first hydraulic circuit 40 changes the flow direction. Theaccidental change of the flow direction of the hydraulic fluid might cause the mechanical lock14 to accidentally unlock and release the working tool 5 from the implement 1. According tothis example, the first safety valve 16 and a second safety valve 18 is arranged in series withthe hydraulic lock actuator 12. Also the second safety valve 18 is configured such that thesecond safety valve 18 allows the fluid to flow in the direction to lock the working tool 5 to theimplement 1, but blocks the fluid to flow in the direction to unlock the working tool 5 from theimplement 1. Hence, if the first hydraulic function 44 is accidentally mechanically actuated sothat the hydraulic fluid in the first hydraulic circuit 40 changes the flow direction, the secondsafety valve 18 blocks the fluid from flowing in the direction to unlock the working tool 5 fromthe implement 1. Thus, if the first safety valve 16 fails to block the fluid to flow in the directionto unlock the working tool 5 from the implement 1, the second safety valve 18 blocks the fluidfrom flowing in the direction to unlock the working tool 5 from the implement 1. Hence, thesecond safety valve 18 connected in series with the first safety valve 16 and the hydraulic lockactuator 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. 13ln Fig. 5, the first safety valve 16 and the second safety valve 18 are arranged on differentsides of the hydraulic lock actuator 12. An advantage, of positioning the first safety valve 16and the second safety valve 18 on different sides of the hydraulic lock actuator 12, is that it ispossible to stop fluid from reaching the mechanical lock 14 from both sides of the firsthydraulic circuit 40. However, the first safety valve 16 and the second safety valve 18 may also be arranged next to each other on one ofthe sides ofthe hydraulic lock actuator 12. ln one example, the second safety valve 18 is connected to a second electrical circuit and thesecond safety valve 18 is configured to open and allow the supply of hydraulic fluid acting onthe hydraulic lock actuator 12 in the unlocking direction, in response to an electrical signalfrom the second electrical circuit. The second electrical circuit is arranged such that thesecond electrical circuit is operated independently from the first electrical circuit. Hence, it isnot likely that both the first and the second electrical circuits suffer from short circuit simultaneously. ln another example, the second safety valve 18 is configured to close and stop the supply ofhydraulic fluid acting on the hydraulic lock actuator 12 in the unlocking direction, as long asthe pressure of the hydraulic fluid acting on the second safety valve 18 in the unlockingdirection is below a pre-set pressure. The pre-set pressure for opening the second safety valve18 in the unlocking direction should be set to a pressure that is higher than the pressure thatcan be introduced by external force acting the first hydraulic function 44 in the unlockingdirection, but lower than the system pressure that the hydraulic source is able to introduceinto the first hydraulic circuit 40. ln one example, the pre-set pressure is 60-90 % of the systempressure that the hydraulic source is able to introduce into the first hydraulic circuit 40. Anadvantage of stopping the supply of hydraulic fluid acting on the hydraulic lock actuator 12 inthe unlocking direction as long as the pressure is below the pre-set pressure, is that the pre-set pressure normally is higher than the pressure that accidentally can be generated by thefirst hydraulic function 44 due to external force acting on the first hydraulic function, causingthe fluid to flow in the unlocking direction. On the other hand, the pre-set pressure is less thanthe pressure that normally can be introduced to the first hydraulic circuit 40 from the workingvehicle 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 14accidentally introduced pressure generated by the first hydraulic function 44 due to externalforce, cannot cause the locking arrangement 10 to unlock the working tool 5 from the implement 1. ln relation to Fig. 2, it was described that the locking arrangement 10 is connected to theattaching arrangement 4. However, not all parts of the locking arrangement 10 have to bearranged at the attaching arrangement 4. For example, the first safety valve 16 and the secondsafety valve 18 can be arbitrary placed along any of the hydraulic pipes connected to thehydraulic lock actuator 12. Further, also the hydraulic lock actuator 12 can be arbitraryarranged in relation to the attaching arrangement 4. However, the mechanical lock 14 which isconnectable 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 1according to a second example. ln this example, the hydraulic lock actuator 12 is a hydrauliclock cylinder 125 configured to unlock the mechanical lock 14 when hydraulic fluid is acting onthe 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. ln one example, a pin 130 is attached to the hydraulic lock cylinder 125 in the cylindertranslational direction, such that the position of said pin 130 is determining whether theworking tool 5 is securely locked to the attaching arrangement 4. The pin 130 is configured toattach 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 motorconfigured to unlock the mechanical lock when hydraulic fluid is acting on the hydraulic lockmotor 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. ln 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 hydraulicfunction 44. A first switch valve 48 is arranged between the first hydraulic function 44 and thesecond hydraulic function 46. The first switch valve 48 is configured to switch the hydraulicfluid between the first hydraulic function 44 and the second hydraulic function 46. ln thisexample, 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 ifthe first switch valve 48 is actuated to direct the hydraulic fluid to the first hydraulic function44 or the second hydraulic function 46. ln one example, the first switch valve 48 is actuatedfrom the working vehicle 20. lt should be understood that first hydraulic circuit 40 may comprise further hydraulic functions and further switch valves. ln one example, the second hydraulic function 46 comprises a hydraulic cylinder attached tothe arm 2 and to the attaching arrangement 4. ln this case, the hydraulic cylinder of thesecond hydraulic function 46 is configured to control the angle between the attaching arrangement 4 and the arm 1. ln another example, the second hydraulic function 46 comprises a hydraulic cylinder attachedto the working tool 5. ln this case, the hydraulic cylinder of the second hydraulic function 46 is configured to control a function of the working tool 5. ln a further example, the second hydraulic function 46 comprises a hydraulic motor. The hydraulic motor may be configured to control a function ofthe working tool 5. ln yet another example, the second hydraulic function 46 comprises a hydraulic cylinderconnected to the fastening arrangement 3 and to the arm 2. ln this case, the hydraulic cylinderof the second hydraulic function 46 is configured to control the angle between the fasteningarrangement 3 and the arm 2. ln other words, the hydraulic cylinder of the second hydraulicfunction 46 is configured to control lifting/lowering of the arm 2 in relation to the working vehicle 20. ln 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 16each other by transverse supports, one or a plurality of hydraulic cylinders can be mounted to each ofthe supporting arms 2.

Fig. 8 illustrates an example of an implement 1 being connectable to a working vehicle 20 andattachable to a working tool 5; and first and second hydraulic circuits 40, 50 for controlling theimplement 1, the first hydraulic circuit 40 comprising a locking arrangement 10 for locking aworking tool 5 to the implement 1. As already described in relation to Fig. 2, the implement 1comprises an arm 2. A fastening arrangement 3 is arranged at a first part 2a of the arm 2. Thefastening arrangement 3 is connectable to the working vehicle 20. The attaching arrangement4 is connected to a second part 2b of the arm 2. The attaching arrangement 4 is attachable tothe working tool 5. Further, a locking arrangement 10 is configured to securely lock the working tool 5 to the attaching arrangement 4. ln this example, the implement 1 further comprises a second hydraulic circuit 50 comprisinghydraulic pipes connected to a hydraulic function 54'. The second hydraulic circuit 50 is, whenactuated, arranged to cause the implement 1 to control the hydraulic function 54' of thesecond hydraulic circuit 50. ln the illustrated example, the second hydraulic circuit 50 isconnected to a second hydraulic connection 52. The second hydraulic connection 52 isconnectable to a hydraulic source. ln one example, the hydraulic source is arranged in theworking vehicle 20. The hydraulic source may be a pump. The hydraulic source is configured tocontrol the pressure of the hydraulic fluid. A direction valve implemented between thehydraulic source and the second hydraulic connection 52 is configured to actuate the directionof the hydraulic fluid in the second hydraulic circuit 50. ln this example, an operator of theworking vehicle 20 can operate the second hydraulic circuit 50 of the implement 1 to controlthe hydraulic function 54' of the second hydraulic circuit 50. The direction and pressure of thehydraulic fluid actuates the hydraulic function 54' of the second hydraulic circuit 50. ln 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 fasteningarrangement 3 and the arm 2. Since the fastening arrangement 3 normally is rigidly fastenedto 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 17and the arm 2. ln other words, the hydraulic function 54' of the second hydraulic circuit 50 isconfigured to control lifting/lowering of the arm 2 in relation to the working vehicle 20. Thehydraulic source is connectable also to the second hydraulic connection 52. Hence, when thehydraulic source is connected to the second hydraulic connection 52, the hydraulic source can control the hydraulic function 54'. lf the hydraulic source is arranged in the working vehicle 20, the second hydraulic connection52 is connected to a second hydraulic connection of the working vehicle 20 and the secondhydraulic connection of the working vehicle 20 is connected to the hydraulic source. A seconddirection valve may be implemented between the hydraulic source and the second hydraulicconnection 52. The second direction valve is configured to control the direction of thehydraulic fluid in the second hydraulic circuit 50 (not illustrated). The second direction valvemay be a directional control valve. The second direction valve may be a proportional valve.

I\/|ore specific, the second direction valve may be a bi-directional proportional control valve. ln another example, a second hydraulic source is connectable to the second hydraulicconnection 52. ln 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 connectedto a common connection device arranged between the first part of the arm 2 and the workingvehicle 20. ln this case, the working vehicle 20 has a matching connection device to which thecommon connection device can be connected. When, the matching connection device and thecommon connection device are connected, the hydraulic fluid can be actuated from thehydraulic 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. ln the example illustrated in Fig. 8, the first hydraulic circuit 40 is configured to carry hydraulicfluid to a second hydraulic function 46 connected in parallel with the first hydraulic function44. A first switch valve 48 is arranged between the first hydraulic function 44 and the secondhydraulic 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. lt should be 18understood that first hydraulic circuit 40 may comprise further hydraulic functions and furtherswitch valves. ln this example, the locking arrangement 10 is arranged in parallel with thesecond hydraulic function 46 but after the first switch valve 48. Consequently, when the firstswitch valve 48 is actuated to direct to the first hydraulic function 44, the hydraulic f|uid doesnot act on the locking arrangement 10. On the other hand, when the first switch valve 48 isactuated to direct the hydraulic f|uid to the second hydraulic function 46, the hydraulic f|uid is also directed to the locking arrangement 10. ln Fig. 8, the first hydraulic function 44 is a hydraulic cylinder 44' attached to the arm 2 and tothe attaching arrangement 4. The hydraulic cylinder 44' of the first hydraulic function 44 isconfigured 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 workingtool 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 isconfigured to control a function of the working tool 5. ln this example, the hydraulic cylinder46' is configured such that, under normal use, there is a very limited risk that a pressure higherthan the pre-set pressure is generated by the hydraulic cylinder 46' due to external forceacting on the hydraulic cylinder 46'. The hydraulic source operating the first hydraulic circuit40, normally arranged in the working vehicle, does normally have enough power to introducea pressure in the first hydraulic circuit 40 which is higher than the pressure that can beintroduced 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 toa pressure that is higher than the pressure that can be introduced by external force acting onthe hydraulic cylinder 46' in the unlocking direction, but lower than the system pressure thatthe hydraulic source is able to introduce into the first hydraulic circuit 40. Hence, the secondsafety valve 18 is configured to close and stop the supply of hydraulic f|uid acting on thehydraulic lock actuator 12 in the unlocking direction, as long as the pressure of the hydraulicf|uid acting on the second safety valve 18 in the unlocking direction is below the pre-set pressure. ln this case, the pre-set pressure is higher than the pressure that accidentally can be 19generated by the hydraulic cylinder 46' due to external force acting on the hydraulic cylinder46', configured to control a function of the working tool. On the other hand, the pre-setpressure is lower than the pressure that can be introduced to the first hydraulic circuit 40 fromthe working vehicle 20 to which the implement 1 is connected. Hence, the working vehicle 20can 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 toexternal 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 firsthydraulic function 44 and the locking arrangement 10, if the second safety valve 18 isconfigured to block hydraulic fluid from passing in the unlocking direction as long as thepressure is below the pre-set pressure, provided that the first hydraulic function 44 is thehydraulic 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 unlockingdirection, the pre-set pressure for opening the second safety valve 18 in the unlockingdirection should be set to a pressure that is higher than the pressure that can be introducedby external force acting on the hydraulic cylinder 46' in the unlocking direction, but lower thanthe system pressure that the hydraulic source is able to introduce into the first hydrauliccircuit 40. The pressure introduced by external force acting on the hydraulic cylinder 46' in theunlocking direction, is rarely larger than 50 % of the system pressure that the hydraulic sourceis able to introduce into the first hydraulic circuit 40. ln one example, the pre-set pressure is50-95 % of the system pressure that the hydraulic source is able to introduce into the firsthydraulic circuit 40. ln a preferred embodiment, the pre-set pressure is 65-85 % of the systempressure 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-setpressure should be chosen to between 100 bar and 190 bar, more preferred 130 bar to 170bar. lf 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 forceacting on the first or second hydraulic actuators 44, 46 in the unlocking direction is only 5 % ofthe system pressure that the hydraulic source is able to introduce into the first hydrauliccircuit 40. ln 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 thisexample, configured to move or tilt the attaching arrangement 4 in relation to the implement1. When the attaching arrangement 4 is attached to the working tool 5, the hydraulic cylinder44' of the first hydraulic function 44 is configured to move or tilt the working tool 5 in relationto the implement 1, since the attaching arrangement 4, in this case, is firmly attached to theworking tool 5. lf the force introduced by external force is applied to the working tool 5 froman unexpected direction, a pressure to push the hydraulic fluid in the unlocking direction maybe generated by the hydraulic cylinder 44'. The pressure generated by the hydraulic cylinder44' in an unexpected direction due to external force might cause the hydraulic cylinder 44' topush the hydraulic fluid of the first hydraulic circuit 40 in the reverse direction. The forceintroduced by external force from an unexpected direction may be a pressure to push theworking tool 5 against gravity. The pressure generated by the hydraulic cylinder 44' due toexternal force acting on the working tool 5 could in this case almost reach the system pressurethat the hydraulic source is able to introduce into the first hydraulic circuit 40. ln fact, thepressure generated by the hydraulic cylinder 44' due to external force acting on the workingtool 5 could momentarily reach a pressure higher than the system pressure that the hydraulicsource is able to introduce into the first hydraulic circuit 40. Thus, if the locking arrangement10 instead would be arranged directly in parallel with the hydraulic cylinder 44' of the firsthydraulic function 44, without the first switch valve 48 being arranged between the lockingarrangement 10 and the hydraulic cylinder 44', there would be a risk to introduce a pressurehigher than the system pressure that the hydraulic source is able to introduce in the unlockingdirection of the the locking arrangement 10. Hence, if the second safety valve 18 is configuredto close and stop the supply of hydraulic fluid acting on the hydraulic lock actuator 12 in theunlocking 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 21first 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. ln oneexample the first hydraulic function 44 is a hydraulic cylinder. ln another example the secondhydraulic function 46 is a hydraulic cylinder. The hydraulic cylinder 44' may be arranged tocontrol the tilt of the attaching arrangement 4 in relation to the arm 2. ln another example,the hydraulic cylinder 46' is arranged to control a function of the working tool 5. ln yetanother example, the hydraulic cylinder 54' is arranged to control lifting/lowering ofthe arm 2 in relation to the working vehicle 20. ln another example, the first hydraulic function 44 is a hydraulic motor. ln yet anotherexample, the second hydraulic function 46 is a hydraulic motor. The hydraulic motor may be arranged to control a function of the working tool 5. ln a further example which is not illustrated, the implement 1 further comprises a thirdhydraulic circuit arranged to control a further hydraulic function. ln one example, none of thehydraulic functions share the hydraulic circuit with another hydraulic function. Thus, thehydraulic functions are not connected in parallel. ln other words, there is a hydraulicconnector for each of the three hydraulic functions. All three hydraulic connectors areconnected to the hydraulic source. ln this case, there may be in total three direction valves onthe side of the hydraulic source, i.e. one direction valve between each of the hydraulicconnectors and the hydraulic pump. An advantage is that no switch valve is needed in thehydraulic circuits since each hydraulic connector is connected to one hydraulic function only.ln this case, the locking arrangement 10 can be arranged in parallel with any of the hydraulicfunctions. However, it is suitable to arrange the locking arrangement 10 in parallel with thehydraulic cylinder 46' attached to the working tool 5, if the second safety valve 18 isconfigured to close and stop the supply of hydraulic fluid acting on the hydraulic lock actuator12 in the unlocking direction, as long as the pressure of the hydraulic fluid acting on thesecond safety valve 18 in the unlocking direction is below a pre-set pressure, since the forceintroduced 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 22 into the hydraulic circuit. ln yet a further example which is not illustrated, the implement 1 only comprises onehydraulic circuit arranged to control all hydraulic functions. ln this example, the hydrauliccircuit may comprise a plurality of switch valves. For illustrative purposes, an example with ahydraulic circuit comprising three hydraulic functions will be described. ln this example, a firsthydraulic switch is arranged between the first hydraulic function and the second/thirdhydraulic functions. Further, a second hydraulic switch is arranged between the secondhydraulic function and the third hydraulic function. The locking arrangement 10 can bearranged in parallel with any of the hydraulic functions. However, it is suitable to arrange thelocking arrangement 10 in parallel with the hydraulic cylinder 46' attached to the working tool5, if the second safety valve 18 is configured to close and stop the supply of hydraulic fluidacting on the hydraulic lock actuator 12 in the unlocking direction, as long as the pressure ofthe hydraulic fluid acting on the second safety valve 18 in the unlocking direction is below apre-set pressure, since the force introduced by external force acting on the hydraulic cylinder46' 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 1according to a third example. Basically, the hydraulic circuit diagram of Fig. 9, is the same as ofFig. 5. ln this example, the first safety valve 16 is connected to a first electrical circuit and thefirst safety valve 16 is configured to open and allow the supply of hydraulic fluid acting on thehydraulic lock actuator 12 in the unlocking direction, in response to an electrical signal fromthe 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. ln this example, the second safety valve 18 is configured to close and stop the supply ofhydraulic fluid acting on the hydraulic lock actuator 12 in the unlocking direction, as long asthe pressure, of the hydraulic fluid acting on the second safety valve 18 in the unlockingdirection, 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. 23There are different ways of implementing the second safety valve 18 such that the secondsafety valve 18 is blocking fluid having a pressure up to the pre-set pressure in the unlockingdirection. ln the example illustrated in Fig. 9, the second safety valve 18 comprises amechanical resistance, such as a mechanical spring, configured to push the second safety valve18 into a position to blocking fluid in the unlocking direction. The second safety valve 18 isconfigured such that, as long as the pressure of the hydraulic fluid acting on the second safetyvalve 18 in the unlocking direction is below the pre-set pressure, the mechanical resistance ofthe second safety valve 18 is higher than the pressure of the hydraulic fluid, causing thesecond safety valve 18 to block hydraulic fluid in the unlocking direction. When the pressureof the hydraulic fluid acting on the second safety valve 18 in the unlocking direction exceedsthe pre-set pressure, the pressure of the hydraulic fluid exceeds the mechanical resistance ofthe second safety valve 18. Consequently, the second safety valve 18 enters a position wherethe second safety valve 18 is allowing hydraulic fluid to pass in the unlocking direction. Anadvantage, of that the second safety valve 18 is mechanically actuatable, is that a furtherelectrical circuit is avoided. Hence, the locking arrangement 10 requires a lower electricalpower if the second safety valve 18 is mechanically actuatable instead of electricallyactuatable. 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 ofblocking fluid having a pressure in the unlocking direction of up to the pre-set pressure. Thesecond safety valve 18 may comprise a pressure sensor. As long as the pressure sensormeasures a pressure that is lower the pre-set pressure the second safety valve 18 is blockinghydraulic fluid acting on the second safety valve 18 in the unlocking direction. When thepressure sensor measures a pressure that is higher than the pre-set pressure, the pressuresensor sends an electrical signal to the second safety valve 18 to open an allow hydraulic fluidacting on the second safety valve 18 in the unlocking direction. An advantage, of that thesecond safety valve 18 comprises a pressure sensor is that the pre-set pressure easily can beadjusted, by adjusting the pre-set pressure by which the pressure sensor sends an electricalsignal to the second safety valve 18 to open an allow hydraulic fluid acting on the secondsafety 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 24adjustable to the hydraulic source that is connected to the implement 1. Yet further, the pre-set pressure can be adjustable to the specific application where the implement 1 is used. lnone example, the pre-set pressure can at any time be arbitrary updated to current circumstances and current needs.

Claims

CLAll\/IS

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) andconfigured 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 configuredto securely lock the working tool (5) to the attaching arrangement (4), saidhydraulic 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 firsthydraulic connection (42) to a first hydraulic function (44) and to the lockingarrangement, 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) beingconfigured to stop the supply of hydraulic fluid acting on the hydraulic lockactuator (12) in the unlocking direction, wherein the unlocking direction isdefined as the fluid flow direction by which the hydraulic fluid is acting on thehydraulic lock actuator (12) to unlock the mechanical lock (14); characterized in that 26the locking arrangement (10) further comprises a second safety valve (18)connected to the first hydraulic circuit (40), said second safety valve (18) beingconfigured 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.

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

3. 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 lockactuator (12) in the unlocking direction, as long as the pressure of the hydraulic fluidacting on the second safety valve (18) in the unlocking direction is below a pre-set pFeSSUFe.

4. The implement (1) according to any of the preceding claims, wherein the first safetyvalve (16) is connected to a first electrical circuit and the first safety valve (16) isconfigured to open and allow the supply of hydraulic fluid acting on the hydraulic lockactuator (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 safetyvalve (18) is connected to a second electrical circuit and the second safety valve (18) isconfigured to open and allow the supply of hydraulic fluid acting on the hydraulic lockactuator (12) in the unlocking direction, in response to an electrical signal from the second electrical circuit. 27

6. The implement (1) according to any ofthe 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 unlockingdirection 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, suchthat the position of said pin (130) is determining whether the working tool (5) issecurely locked to the attaching arrangement (4), said pin (130) being configured toattach to the working tool (5) in a securely locked manner when the hydraulic fluid isacting on the hydraulic lock actuator (12) in the locking direction, wherein the lockingdirection 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 directionand 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 ofthe 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 switchvalve (48) is arranged between the first hydraulic function (44) and the secondhydraulic function (46) and is configured to switch the hydraulic fluid between the firsthydraulic 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

11.

12.

13.

14.

15.

16. 28with the second hydraulic function (46) such that no hydraulic fluid is flowing to thelocking arrangement (10) when the hydraulic fluid is switched through the first hydraulic function (44). The implement (1) according to any of the preceding claims, wherein the first hydraulicfunction (44) comprises a hydraulic cylinder (44') attached to the arm (2) and to theattaching arrangement (4), said hydraulic cylinder (44') being configured to control the angle between the attaching arrangement (4) and the arm (2). The implement (1) according to any of the preceding claims, wherein the secondhydraulic function (46) comprises a hydraulic cylinder (46') attached to the workingtool (5), said hydraulic cylinder (46') being configured to control a function of the working tool (5). 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)- 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 fluidfrom a second hydraulic connection (52) connectable to the working vehicle (20) to afurther hydraulic cylinder (54'), said further hydraulic cylinder (54') being attached tothe 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). The implement (1) according to any of the preceding claims, wherein the first hydraulicconnection (42) and the second hydraulic connection (52) are connected to a commonconnection device arranged between the first part of the arm (2) and the working vehicle (20). 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. 29

17. A working vehicle arrangement (30) comprising an implement (1) connectable to aworking 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.