KR100885194B1 - Grab bucket equipped means for opening passivity - Google Patents

Abstract

A grab bucket equipped with a manually opening unit is provided to open a check valve using an operating member in order for operating oil to flow in an opposite direction, thereby continuing a work in case a battery is discharged. A grab bucket equipped with a manually opening unit comprises a base, a grab, cylinders(30A,30B), a hydraulic circuit unit, a linking module, a controller, and manually opening unit. The grab fixed on the base is opened or closed. The cylinders include a piston. The hydraulic circuit unit including a two-way control check valve(43) controls flow of the operating oil. The linking module delivers movement of the piston to the grab.

Description

Grab bucket with manual opening means {GRAB BUCKET EQUIPPED MEANS FOR OPENING PASSIVITY}

The present invention relates to a grab bucket in which the hydraulic oil is selectively filled in the upper or lower portion of the piston head of the cylinder according to the control of the direction of the hydraulic oil flow in the hydraulic circuit portion, the interlock module is operated and the grab is opened and closed.

In particular, when the flow direction control of the conventional hydraulic fluid is operated by the remote controller, in order to solve the problem that the work progress is impossible due to the discharge of the battery or the failure of the control panel.

By opening the two-way control check valve of the hydraulic circuit part by the operating member constituting the manual opening means so that it can be controlled manually using the operating rope at a long distance (more than 30m is possible), the flow of hydraulic oil is reversed,

Even in the above-mentioned emergency, it is possible to improve the work efficiency by enabling continuous work without interruption through manual operation by the worker, and at the same time, to reduce the economic loss due to the interruption of work,

Furthermore, since the configuration of the manual opening means is simple and simple, the present invention relates to a grab bucket equipped with a manual opening means which can be applied by only a simple design change of an existing grab bucket, thereby improving economic efficiency.

Generally, grab bucket is a device for hanging a crane and grabbing or scooping up a grain of coal, gravel, soil, etc.

Applicant has attempted to solve the problem of frequent failure and high energy consumption due to the excessive weight and complicated structure raised in the conventional grab that tighten and open the gripper using engine power and electric power.

Patent No. 10-0321895 (registered on Jan. 11, 2002) has applied for and registered a grab that enables operation by self-weight and hydraulic pressure in the 'hydraulic grab bucket'.

In addition, it is also registered by filing an 'Orange Peel Type Grab', which is made by a remote controller that controls a solenoid valve to determine the flow of hydraulic oil, thereby enabling remote control. I have received it.

However, the registered patents are advantageous in that each valve operates through a receiving unit receiving a signal by a remote controller for remote control, thereby ensuring convenience of work.

The battery is embedded in the controller including a remote controller for remote control and an associated electric device. In this case, the battery may be discharged due to long-term use and seasonal factors, or failure of the devices may occur. In case of stopping work, recharging the battery or replacing the battery or repairing the devices, the inevitable work must be stopped so that the work efficiency decreases,

In addition, when the work is interrupted as described above it has been found that there is a problem that must bear the economic losses caused by this.

The present invention has been made to solve the above problems,

In particular, it relates to a grab bucket that opens and closes the grab by moving the piston of the cylinder according to the hydraulic oil supplied from the hydraulic circuit part by a signal received by the remote controller at a long distance.

The battery is embedded in the back of the control unit including a remote controller for remote control and an associated electric device,

In this case, in order to solve the problem that the work should be stopped when the battery is discharged or a cause such as a failure occurs in the above devices,

By operating the hydraulic member of the hydraulic circuit part by the operating member constituting the manual opening means connected to the operating rope formed at a long distance (more than 30m), the flow of the hydraulic oil is reversed, thereby allowing manual operation by the operator in the above-mentioned emergency. Operation enables continuous work without interruption, increasing work efficiency and reducing economic loss due to interruption.

Furthermore, it is an object of the present invention to provide a grab bucket with a manual opening means which can be applied simply by changing the design of a conventional grab bucket and improving economic efficiency.

In addition, when opening and closing the grab, the piston, the cylinder by the flow of the hydraulic oil in the hydraulic circuit part, and the piston, the self-weight of the guide box and wheel box (including the wheel) assembly (first assembly) or the cylinder and base assembly (second assembly) Since it is possible to open and close the grab by operating the device, there is no need to install a separate power transmission device, thereby reducing the weight of the equipment, and thereby providing a grab bucket equipped with a manual opening means for lowering the energy consumption rate. It is another purpose.

Grab bucket is provided with a manual opening means according to the invention

Base;

A grab rotatably fixed to the base to open and close;

A cylinder with a piston;

Hydraulic circuit unit including a two-way control check valve for restricting the flow of the hydraulic fluid in either the upper or lower direction of the piston head;

An interlocking module for transferring the piston movement of the cylinder to the grab according to the movement of the hydraulic oil in the hydraulic circuit unit;

A control unit controlling the flow of the hydraulic oil; And

Manual opening means including an operation member for opening the bidirectional control check valve of the hydraulic circuit portion to reverse the flow of hydraulic oil, and an operation rope connected to the operation member;

It is made, including.

And the grab bucket according to the present invention further comprises an operating arm and a fixed plate, the manual opening means is connected to the two-way control check valve, the operation member is a link arm connected to the operation arm of the two-way control check valve, And a working rod mounted on a fixed plate and operated by the operating rope to move the link arm and elastically supported by a spring.

In addition, the actuating arm provided in the bidirectional control check valve is a cam type and is retracted by turning, and the link arm of the actuating member is connected to the actuating arm and is supported by a return spring connected to the fixed plate, and the actuating rod It is preferable to move the operating arm by making a linear motion in accordance with the pulling of the operating rope.

Furthermore, the hydraulic circuit portion of the grab bucket according to the present invention further includes a hydraulic oil storage tank, and a first conduit for guiding hydraulic oil is formed from the hydraulic oil storage tank to a first chamber which forms an upper portion of the piston head of the cylinder. A second conduit for directly connecting the first chamber of the upper portion of the piston head and the second chamber of the lower head is formed, and the bidirectional control check valve preferably opens and closes the second conduit.

In addition, in the grab bucket according to the present invention, the first conduit is provided with a speed control means for adjusting the flow rate of the working oil, and the cylinder is preferably two cylinders arranged side by side on the base and the interlocking module.

By a grab bucket provided with a manual opening means according to the invention

In particular, the present invention relates to a grab bucket that opens and closes a grab by moving a piston of a cylinder according to hydraulic oil supplied from a hydraulic circuit part by a signal received by a remote controller at a long distance. The bue is built in a battery, in this case, in order to solve the problem that the work should be stopped when the battery is discharged or the cause of the above-mentioned devices, such as failure,

By opening the check valve of the hydraulic circuit part by the operating member, which is a manual opening means connected to the operating rope formed at a long distance, to reverse the flow of the hydraulic oil, continuous operation without interruption of work is possible through manual operation by the operator even in the above-mentioned emergency. To improve work efficiency, and at the same time reduce the economic loss of downtime,

Furthermore, since the configuration of the manual opening means is simple and simple, it can be applied only by simple design change of the conventional grab bucket, thereby improving the economics.

In addition, when opening and closing the grab, the piston, the cylinder by the flow of the hydraulic oil in the hydraulic circuit part, and the piston, the self-weight of the guide box and wheel box (including the wheel) assembly (first assembly) or the cylinder and base assembly (second assembly) It can be opened and closed by operating the grab, there is no need to install a separate power transmission device to reduce the weight of the equipment by that, it can also lower the energy consumption rate.

Hereinafter, with reference to the accompanying drawings, the grab bucket having a manual opening means according to the present invention,

1 is a front view showing a grab bucket having a manual opening means according to the present invention,

Figure 2 is a side view showing a grab bucket equipped with a manual opening means according to the present invention,

3 is a schematic view showing a manual opening means according to the present invention;

4 is a hydraulic circuit diagram showing a hydraulic circuit unit according to the present invention;

5 is an operating state diagram showing the operation of the grab bucket according to the present invention,

1 to 4, the grab bucket provided with a manual opening means 70 according to the present invention is

Base 10; A grab 20 (grab) rotatably fixed to the base (10) to open and close; Cylinders 30A and 30B provided with pistons 32; Hydraulic circuit section 40 including a two-way control check valve 43 for restricting the flow of the hydraulic fluid in either the upper or lower direction of the piston head (32a); An interlocking module 50 which transmits the piston movement of the cylinder to the grab 20 according to the movement of the hydraulic oil in the hydraulic circuit unit; A control unit 60 for controlling the flow of the working oil; And an operating member 72 which opens the bidirectional control check valve 43 of the hydraulic circuit unit 40 so as to reverse the flow of the hydraulic oil, and an operating rope R connected to the operating member 72. Means (70).

1 and 2 in the grab bucket according to the invention

Lower ends of the cylinders 30A and 30B are connected to the base 10, and when the piston 32 moves backward, the base 10 moves downward in association with the cylinders 30A and 30B. A fixing pin 14 is provided to support the gear 12 connected to the upper portion of the gear 12 so that the gears 12 can pivot.

In the grab bucket according to the invention, as shown in Figures 1 and 2, the grab 20 is

A bent portion 22 formed in a hook shape,

A first coupling portion 22a hinged to an end of the bent portion 22 of the gear 12;

In the middle portion of the bent portion 22 is formed a second coupling portion 22b which is hinged to the link member 54 formed in the interlocking module 50,

The blade 24 is formed at the end of the bent portion 22 to be detachable.

That is, the gears 12 are engaged with each other and rotated so that the respective grabs 20 can be operated in the same manner, thereby ensuring operational reliability.

The second coupling portion 22b is hinged to the link member 54 of the interlocking module 50 so that the pivoting movement of the grab 20 is moved by the link member 54 when the piston 32 is moved forward and backward. It becomes possible.

1 to 4, in the grab bucket according to the invention, the cylinders 30A, 30B are

The piston 32,

It is formed of a piston head 32a provided at the lower end of the piston 32,

The upper end of the piston 32 is connected to the guide of the interlocking module 50, and the lower ends of the cylinders 30A and 30B are connected to the base 10.

That is, the cylinders 30A and 30B and the piston 32 are connected to the guide portions of the base 10 and the interlocking module 50, respectively, so that the guide box 56 is lifted when the piston 32 moves up and down. By operating integrally with the guide unit and the base 10, the grab 20 can be opened and closed.

Lower ends of the first and second cylinders 30A and 30B are connected to the base 10, and a double cylinder is connected to the upper ends of the first and second pistons 32 inside the guide box 56 of the interlocking module. By taking the structure of 30A, 30B, it is possible to share the load added to the cylinders 30A, 30B to ensure long-term use of the equipment.

As shown in Figure 2 to 4 in the grab bucket according to the invention the hydraulic circuit portion 40 is

First and second conduits 46 and 47 for supplying the hydraulic oil to the first and second chambers 34 and 36 respectively formed above and below the piston head 32a of the cylinders 30A and 30B. Is formed,

Two-way control check valve 43 for opening the hydraulic fluid flows from the first chamber 34 of the cylinder to the second chamber by the manual opening means 70, which is the core of the present invention,

In addition, a normal check valve 44 is provided in the first pipe line 47.

In FIG. 4, the dotted line shows the forced opening relationship of the bidirectional control check valve 43 by the control unit 60 including the remote controller 64 and the operating rope R constituting the manual opening means 70.

The dashed-dotted line represents a first pipe line 46 connecting hydraulic oil from the hydraulic oil storage tank T to the upper first chamber 34 of the piston head 32a of the cylinders 30A and 30B.

The double-dotted line represents a second conduit 47 connecting hydraulic oil from the upper first chamber 34 of the piston head 32a of the cylinders 30A and 30B to the lower second chamber 35.

In FIG. 4, the conventional check valve 44 provided in the left first pipe 46 and the bidirectional control check valve 43 provided in the right first pipe 46 are connected to the cylinders 30A and 30B in the hydraulic oil storage tank T. Hydraulic fluid flows only to the first chamber 34 of the ().

In addition, the bidirectional control check valve 43 is opened by the operation rope 70 constituting the solenoid valve 42 or the manual opening means 70 according to the operation of the remote controller (64).

The second conduit 47 connecting the first chamber 34 and the second chamber 35 is forcibly opened to enable the operation of the grab 20, in particular the opening operation.

At this time, the two-way control check valve 43

Solenoid valve 42 and electronically controlled by the operation of the remote controller (64) and

The check valve 43 is mechanically opened by the [operation rod 74-link arm 76-operation arm 43a] according to the operation of the operation rope R constituting the manual opening means 70.

You can purchase and use a product that is capable of both electronic and mechanical control.

The solenoid valve 42 and the check valve 43 can be purchased separately and installed separately.

In the present specification, the 'bidirectional' control check valve 43 is used to prevent the back flow of the working oil from the first chamber 34 to the tank T at normal times (particularly when the grab is closed),

During grab operation (especially when opening), the second conduit 47 forcibly opened by the solenoid valve 42 or the manual opening means 70 to connect the first chamber 34 and the second chamber 36. ) To open the door.

The opening of the second conduit 47 forms a speed control means to prevent the grab 20 from opening rapidly, and enables only one-way hydraulic oil flow from the tank T to the first chamber 34. The throttle valve 45 prevents backflow of hydraulic oil into the tank.

In FIG. 4, the first conduit 46 and the second conduit 47 are communicated with each other at the first and second connecting portions J1 and J2 (indicated by the dashed block), in particular, the second connecting portion J2 directly. The first chamber 34 and the second chamber 36 are involved in communication.

On the other hand, the self-weight of the grab bucket according to the present invention and the automatic operation state by the flow of the hydraulic fluid to the hydraulic circuit portion 40 will be described at the end of the present specification.

1 and 2, the grab bucket according to the present invention, the interlocking module 50 is

In accordance with the hydraulic oil movement of the hydraulic circuit unit 40 to transfer the movement of the piston 32 of the cylinder (30A, 30B) to the grab 20,

The specific working relationship is the registered patent 10-0321895 (January 11, 2002) 'hydraulic grab bucket' and Patent No. 10-0556220 (registered February 22, 2006) by the applicant of the present invention 'Orange peel type grab It can be confirmed in the ', therefore, in the present specification will be described briefly with respect to the interworking module 50.

The interlock module 50 is a wire fastening portion 59 for the wire (W) that is hooked to the crane,

A holder 52 formed below the wire fastening part 59 and provided with a guide roller 57 for the wire W;

A guide box 56 surrounding the cylinders 30A and 30B from the outside and having an upper end portion of the piston 32 connected to an inner upper portion thereof;

A wheel box 58 connected to one side of the guide box 56 and including a wheel 58a wound around the wire W through the guide roller 57; and

The cylinder 30A, 30B according to the flow of the hydraulic fluid is composed of a link member 54 hinged to the coupling portion formed in the second coupling portion 22b and the holder 52 of each of the grabs 20, respectively. The piston 32 is transferred to the grab 20 to operate in conjunction with each other to open and close the grab 20.

And when the piston 32 is moved forward in the interlocking module 50.

Self-weight of the piston 32, the guide box 56 and the wheel box 58 (including the wheel 58a) (hereinafter referred to as 'first coupling') and the hydraulic pressure of the hydraulic circuit portion 40 Thereby enabling the piston 32 to move forward,

When the piston 32 is reversed

That is, when the cylinders 30A and 30B operate in the downward direction, the self-weight of the cylinders 30A and 30B and the base 10 assembly (hereinafter referred to as the 'second assembly') and the hydraulic circuit unit 40 By the operating hydraulic pressure of the piston 32 to enable the reverse operation,

The relative advantage of the cylinders 30A and 30B and the piston 32 is to enable operation without the use of electricity or other power transmission devices, which is advantageous in terms of economics.

In the grab bucket according to the present invention as shown in Figure 4, the control unit 60 is

A receiver 62 electrically connected to the solenoid valve 42 of the hydraulic circuit unit 40, a remote controller 64 for transmitting signals to the receiver 62 at a long distance, and the analog operation button press time or It is preferable that the operation is performed by a digital operation including a numeric display of a display window for indicating the opening degree of the grab 20 (specific circuit configuration or electronic components such as a processor will not be described).

As shown in Figures 3 and 4,

(A) of FIG. 3 is an enlarged side view of part (A) of FIG. 2, and part "A" is rotated 90 degrees to the right of part (A) of FIG. 3 to show the manual opening means 70 in more detail. Is an enlarged drawing,

3 (b) is a plan view of the part (a), part "B" is also turned right 90 degrees in the enlarged view (b), part "c" is a front view,

"D" part is a view in which the cam 43b and 43c provided in the operation arm 43a connected to the check valve 43 are enlarged in "C".

The actuating arm 43a is pivoted in conjunction with the [actuating rope R-actuating rod 74-link arm 76] while the actuating arm 43a is pulled out through the cams 43b and 43c. In the drawing, the valve 43 is opened while linearly moving to the right).

In the grab bucket according to the invention, the manual opening means (70)

It includes an operating member 72 for opening the check valve 43 of the hydraulic circuit portion 40 to reverse the flow of the hydraulic oil, and an operating rope (R) connected to the operating member 72,

It includes an operating arm (43a) exposed to the check valve 43, the manual opening means 70 further comprises a fixed plate 73, the fixed plate 73 is the check valve 44 and the solenoid valve It is connected to the valve mounting plate 49 which integrally forms the 42.

In addition, the operation member 72 of the manual opening means 70 is attached to the link arm 76 connected to the operation arm 43a of the check valve 43, and to the fixing plate 73, and the link arm 76. It is operated by the operating rope (R) to move), the spring 74a provided between the fixing plate 73 and the connecting portion (74b) formed in the operating rod 74 surrounds the operating rod 74 It is formed so that the elastic support.

Therefore, when the operator pulls the operation rope R coupled to the connection portion 74b of the operation rod 74 at a long distance, the operation rod 74 enters and exits through the sleeve 73a formed on the fixed plate 73. In this case, the operation is smoothly supported by the elasticity of the spring 74a.

And the operation arm (43a) of the check valve 43 is advanced by turning the cam type,

The link arm 76 of the actuating member 72 is connected to the actuating arm 43a and is connected by a return spring 78 connected to the fixing plate 73.

The actuating rod 74 moves the actuating arm 43a by performing a linear motion according to the pulling of the actuating rope R.

That is, when the operation must be stopped due to the discharge of the battery or the failure of the equipment, etc. to the remote controller 64 or the receiver 62 receiving the signal of the remote controller 64,

When the operator pulls the operation rope R at a long distance, the end of the operation rod 74 pushes the link arm 76, and the link arm 76 thus pushed is the operation arm of the check valve 43. The check valve 43 and the solenoid valve 42 are opened by turning 43a.

In this case, assuming that the initial state of the stopped state in the emergency state that the hydraulic fluid is filled in the first chamber 34 and the grab 20 is closed,

When operating the operating rod 74 to open the check valve 43 and the solenoid valve 42 and at the same time to lift the crane, the self-weight of the second assembly and the hydraulic oil through the second conduit 47 The imaginary grab 20 is opened while being filled in the second chamber 36,

On the contrary, assuming that the grab 20 is opened with the hydraulic fluid filled in the sieve chamber 2,

When the operating rod 74 is operated to open the check valve 43 and the solenoid valve 42 and lower the crane at the same time, the self-weight of the first assembly and the hydraulic oil flow through the first conduit 46. The grab 20 is closed while being filled in the first chamber 34.

Therefore, even in the above-mentioned emergency, continuous operation can be performed through manual operation by the operator's hand without interrupting work, thereby improving work efficiency and reducing economic losses caused by work interruption. .

Meanwhile, as shown in FIG. 4, in the grab bucket according to the present invention, the first and second conduits 47 are connected to a working oil storage tank T, and the first and second conduits 47 and the working oil storage are stored. Between the tank (T) is further provided with a speed control means for adjusting the flow rate of the working oil,

By the speed control means 45 to control the occurrence of the vacuum portion due to the backlash problem of the piston 32 and the lack of the hydraulic oil in the first or second conduit 47, the work by the grab bucket more efficient Make it possible.

Furthermore, the speed control means 45 is preferably designed to consider the case of weighting of the load by using a throttle valve.

In addition, the first and the second conduit 47 connected to the hydraulic oil storage tank T is further provided with a filter 48 for filtering the hydraulic oil adjacent to the hydraulic oil storage tank T, the first and second chambers By filtering impurities 36 and the hydraulic oil flowing in and out of the first and second pipe lines 47, it is possible to ensure durability and reliability of the equipment.

Finally, with reference to Figure 5 will be briefly described with respect to the automatic operation state by the flow of the hydraulic fluid to the self-weight and the hydraulic circuit portion 40 of the grab bucket according to the present invention.

First, it is assumed that the initial state of Fig. 5 (a), in this case, the piston 32 is a state in which the hydraulic fluid is filled in the second chamber (36) is backward,

In the state of FIG. 5 (a), when the user uses the crane to lower the wire, the first assembly is lowered due to its own weight, and at the same time the check valve 44 is opened to operate the hydraulic oil in the second chamber 36. While entering the first chamber 34 through the first conduit 46, the piston 32 is in a state of FIG. 5 (b).

In the state of FIG. 5 (b), when the piston 32 is fully lowered and then raised by using a crane, the grab 20 is closed and checked at the same time by the weight of the first and second combinations. Shut off the flow of the working oil by blocking the valve 44 and the check valve 43 and the solenoid valve 42, the state of Figure 5 (c), in this case the hydraulic fluid is filled in the first chamber 34 It is a state.

In the state of FIG. 5C, the signal by the remote controller 64 is transmitted to the check valve 43 and the solenoid valve 42 through the receiver 62, and thus the check valve 44 and the solenoid valve 42 are closed. Even though the check valve 44 is opened and the hydraulic fluid flows into the second chamber 36 through the second conduit 47 while the check valve 44 is shut off, The grab 20 in a state is in an open state.

Therefore, when opening and closing the grab as described above, the flow of the hydraulic oil in the hydraulic circuit portion at the same time as the piston, the self-weight of the guide box and wheel box (including wheels) assembly (first assembly) or the cylinder and base assembly (second assembly) By operating the piston or the cylinder to open and close the grab, there is no need to install a separate power transmission device to reduce the weight of the equipment by that much, it is possible to lower the energy consumption rate.

In the above description of the grab bucket provided with the manual opening means according to the present invention with reference to the accompanying drawings, the present invention has been described with a particular shape and direction, the present invention can be variously modified and changed by those skilled in the art, such variations and modifications It should be construed as being included in the scope of the present invention.

1 is a front view showing a grab bucket having a manual opening means according to the present invention,

Figure 2 is a side view showing a grab bucket equipped with a manual opening means according to the present invention,

3 is a schematic view showing a manual opening means according to the present invention;

4 is a hydraulic circuit diagram showing a hydraulic circuit unit according to the present invention;

5 is an operational state diagram showing the operation of the grab bucket according to the present invention.

<Explanation of Signs of Major Parts of Drawings>

W: Wire R: Operating Rope

10: base 12: gear

14: fixed pin

20: grab 22: bend

22a: first coupling portion 22b: second coupling portion

24: blade

30A, 30B: Cylinder 32: Piston

32a: piston head 34: first chamber

36: second chamber

40: hydraulic circuit portion 42: solenoid valve

43: 2-way control check valve 43a: working arm

44: check valve 45: speed control means

46: first pipeline 47: second pipeline

48 filter 49 valve mounting plate

50: interlock module 52: holder

54: link member 56: guide box

57: guide roller 58: wheel box

58a: wheel 59: wire connection

60: controller 62: receiver

64: remote controller

70: manual opening means 72: operating member

73: fixing plate 73a: sleeve

74: working rod 74a: spring

74b: connecting portion 76: link arm

78: return spring

Claims (6)

Base 10; A grab 20 rotatably fixed to the base 10 to open and close; Cylinders 30A and 30B provided with pistons 32; Hydraulic circuit section 40 including a two-way control check valve 43 for restricting the flow of the hydraulic fluid in either the upper or lower direction of the piston head (32a); An interlocking module 50 for transferring the movement of the piston 32 of the cylinder to the grab 20 according to the movement of the hydraulic oil in the hydraulic circuit unit 40; A control unit 60 for controlling the flow of the working oil; And Manual opening including an operating member 72 for opening the bidirectional control check valve 43 of the hydraulic circuit unit 40 to reverse the flow of hydraulic oil, and an operating rope R connected to the operating member 72. Means 70; comprising, The manual opening means 70 Further comprising a working arm (43a) and a fixed plate 73 exposed to the two-way control check valve 43, The actuating member 72 is mounted to the link arm 76 connected to the actuating arm 43a of the bidirectional control check valve 43 and the fixing plate 73 to move the actuating rope to move the link arm 76. Grab bucket, characterized in that it comprises a working rod (74) operated by (R) and elastically supported by a spring (74a). delete The method of claim 1, The actuating arm 43a of the bidirectional control check valve 43 is a cam type and is retracted by turning, The link arm 76 of the actuating member 72 is connected to the actuating arm 43a and supported by the return spring 78 connected to the fixing plate 73. The actuating rod 74 is a grab bucket, characterized in that for moving the actuating arm (43a) by making a linear motion in accordance with the pulling of the actuating rope (R). The method according to claim 1 or 3, The hydraulic circuit unit 40 further includes a hydraulic oil storage tank (T), A first conduit 46 for guiding hydraulic oil is formed in the first chamber 34 which forms an upper portion of the piston head 32a of the cylinder from the hydraulic oil storage tank T. A second conduit 47 is formed to directly connect the first chamber 34 of the upper portion of the piston head 32a and the second chamber 36 of the lower part of the head. The bidirectional control check valve 43 is a grab bucket, characterized in that for opening and closing the second conduit (47). The method of claim 4, wherein The first bucket (46) is a grab bucket, characterized in that the speed control means 45 for adjusting the flow rate of the working oil. 4. The cylinder of claim 1 or 3, wherein the cylinder is Grab bucket, characterized in that the two cylinders (30A, 30B) arranged side by side in the base (10) and the interlocking module (50).

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