JP2002070395A - Canopy lock device for container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the working efficiency in a canopy lock device for container for opening a canopy to either one lateral side of a container and locking the canopy in a closed state on the other side by providing such a structure as to be capable of confirming the locked state or unlocked state of the canopy from both lateral sides of the container. SOLUTION: A rod 42 is provided through both lateral sidewalls 7 of the container 1, the operation lever 39 of the canopy lock device 34 is provided on one end of the rod 42, and a pointer 43 is provided on the other end. Accordingly, the locked state or unlocked state of the canopy 20 can be grasped from both lateral sides of the container 1 by confirming the operation lever 39 or the pointer 43.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a container having a canopy which can be mounted on a vehicle or a railway.

[0002]

2. Description of the Related Art Conventionally, in a canopy opening / closing device in which a canopy provided above a container is opened to one of right and left sides of the container, when the canopy is closed, the other side is opened. Is provided with a canopy locking device that locks the canopy in a closed state to prevent the canopy from being opened due to vibration or the like during the transportation of the container.

[0003]

In the case where the canopy locking device is provided, if the canopy is opened while the canopy is locked, there is a risk that the canopy may be damaged. It is necessary to confirm whether or not. When transporting a container, it is necessary to check whether the canopy is locked. However, in the above structure, the work efficiency is poor because the locked or unlocked state of the canopy cannot be grasped unless the canopy lock device is provided around one side of the container. There was a problem. SUMMARY OF THE INVENTION The present invention provides a canopy locking device for a container in which the locked state or the unlocked state of the canopy can be confirmed from both the left and right sides of the container, thereby improving the working efficiency.

[0004]

According to claim 1 of the present invention,
Stands are erected at the four corners of the front, rear, left and right, and floors, side walls, front walls, and rear doors are provided between each of the posts, and an inlet is formed at the top,
A canopy that opens and closes the opening is rotatably supported on a rotation axis on one side of the inlet, and a canopy lock device that holds the canopy in a closed state is provided on the other side wall of the inlet. In the container provided, the canopy locking device includes a hook that can be engaged with a part of the canopy, an operation lever for operating the hook, and penetrating both side walls below the floor surface of the container, and operating at one end. It has a rod to which a lever is fixed, and a pointer fixed to the other end of the rod. Thus, by checking the operation lever or the pointer, the locked state or the unlocked state of the canopy can be grasped from both left and right sides of the container, and the work can be performed efficiently.

According to claim 2, the canopy lock device includes:
A hook that can be engaged with a part of the canopy is connected to a part of the operating lever by a connecting member, and the connecting member is provided with a spring that constantly biases the hook toward the disengagement side, and is provided near the operating lever. Is characterized in that a regulating member for regulating movement of the operation lever to the hook disengagement side is provided. Thus, it is possible to reliably prevent the hook from coming off due to vibration or the like during the transportation of the container and the canopy from being unlocked.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 3 is an overall view of a container provided with a canopy opening / closing device. The container 1 accommodates trash, earth and sand, and can be transported by a transport vehicle 2 or a railway wagon. FIG. 1 is an overall view in which a container 1 is mounted on a transport vehicle 2, and FIG. 2 is a work state diagram in which the container 1 is dumped and the contents are discharged.

In the transport vehicle 2, a dump frame 4 is mounted on a vehicle body 3 so as to be tiltable rearward at a rear hinge 5, and a container 1 is mounted on the dump frame 4. The container 1 is a locking device on the dump frame 4. (Not shown) so that it can be integrated with the dump frame 4. Further, the container 1 can be mounted on a railway wagon. 4a is a lifting device for tilting the dump frame 4.

Next, the container 1 will be described. In the container 1, first, a box-shaped support 6 is erected at four front, rear, left and right positions, and a side wall 7 is provided between the left and right front and rear support 6 and a front left and right support 6 is provided. A front plate 11 having a front wall 8 therebetween, a floor surface 9 below, and a rectangular input port 10 above is provided, and an openable rear door 12 is provided between the left and right columns 6 at the rear.
Via a hinge arm 13 extending therefrom. At a position below the floor surface 9 of the side wall 7, a pair of insertion ports 14 are provided in front, rear, left and right so that a fork of a forklift can be inserted to lift the container 1.

A canopy opening / closing device 15 is provided above the top plate 11 so as to cover the slot 10. The canopy opening and closing device 15 is configured to prevent the contents from being scattered when the container 1 is transported by the transport vehicle 2 or the railway wagon. A rectangular parallelepiped block-shaped lower base 16 is fixed to the lower end of the column 6, and the lower base 16 has a hole 17 capable of engaging and disengaging with a dump frame 4 of the transport vehicle 2 and a twist lock (not shown) provided on a railway wagon. The lower end of the lower base 16 is located at a position slightly lower than the lower end of the side wall 7.

On the other hand, at the upper end of the column 6, an upper plate 18 having the same shape as the lower surface of the lower table 16 is fixed, so that the lower table 16 can be placed on the upper table 18. In addition, upper stand 18
A horizontal L-shaped stopper 19 is fixed to the outer periphery of the upper base 1.
The lower table 16 placed on the base 8 is prevented from shifting forward, backward, left and right. Furthermore, the position of the upper base 18 is set at a position slightly higher than the canopy opening / closing device 15, and when the containers 1 are stacked, the lower surface of the upper container 1 does not interfere with the canopy opening / closing device 15 of the lower container 1. It has become.

Next, the canopy opening / closing device 15 will be described. The canopy opening / closing device 15 comprises a canopy 20 capable of closing the slot 10 and a driving device 21 for opening and closing the canopy 20. As shown in FIGS. 10 to 13, the canopy 20 can be refracted by being divided right and left into two parts. First, the frame member 22 is divided into left and right parts (up and down in FIG. 11).
Each of three horizontal frames 22a and three vertical frames 2
2b are formed in a lattice shape, and only the horizontal frame 22a is formed so as to descend in an arc from the center to the side. Further, a rotating shaft 23 is fixed to a side end (upper end in FIG. 11) of the one frame member 22, and the rotating shaft 23 is supported by a bearing 24 erected on the top plate 11.

A plate-shaped canopy main body 25 is riveted to the upper portion of the frame member 22, and the entire canopy main body 25 has an arc shape along the horizontal frame 22a.
As described above, since the canopy main body 25 is formed in an arc shape, it is possible to reduce the occurrence of distortion between frames without providing a large number of horizontal frames 22a and to reduce the bending of the vertical frame 22b due to its own weight. To prevent bending of the vertical frame 22b.

A vertical cover 26 is fixed to the front and rear surfaces of the frame member 22, and the left cover 26 (the left side in FIG. 12) slightly enters the inside of the right cover 26 (the right side in FIG. 12). Of the canopy 2
When 0 is opened, the left and right canopies 20 are bent around this pivot point Y. Arms 27 are arranged at front and rear positions of the canopy body 25, respectively.
At 7, the right canopy 20 is supported when the canopy 20 is opened and closed, and the labor required for opening and closing the canopy 20 is reduced. That is, the base end of the arm 27 is pivotally supported on the top plate 11 and can be rotated left and right.
A pair of coil springs 29 provided between the regulating member 28 fixed to the top plate 11 and the top plate 11 are provided such that resilient forces act in directions opposite to the direction in which the canopy 20 attempts to rotate by its own weight. I have.

A long hole 30 is formed at the tip of the arm 27. The long hole 30 is engaged with a shaft 32 of a mounting member 31 fixed to the front and rear ends of the right canopy 20, so that the mounting member 31 and the arm A spring 33 is provided between the members 27 so as to be urged in a pulling direction. The hole of the arm 27 is elongated
What is set to 0 is a line XYZ (dash-dot line) connecting the center point X of the rotating shaft 23, the pivot point Y of the left and right canopies 20 and the center point Z of the shaft 32 of the mounting member 31, as shown in FIG. Is bent downward, and while the canopy 20 is being opened, the line XYZ becomes a straight line (FIG. 21b), and the distance between X and Z changes so as to become the maximum at that time. This change can be absorbed by the long hole 30.

Reference numeral 34 denotes a canopy lock device for holding the canopy 20 in a closed state. As shown in FIGS. 10 and 15 to 19, the canopy lock device 34 includes a pin 35, a hook 36, a connecting member 37, a spring 38, an operation lever 39,
It comprises a stopper 40 and a regulating member 41. The pin 35 protrudes at the center of one side surface of the canopy 20 (the side surface opposite to the rotation shaft 23). The hook 36 is pivotally supported by the side wall 7 of the container 1 close to the pin 35, and can be engaged with the pin 35 by rotating the hook 36 in the front-rear direction. The hook 36 is connected to one end of an operation lever 39 via an arm 36 a integral with the hook 36 and a connecting member 37. The operation lever 39 is
The middle is pivotally supported by a rod 42 below the side wall 7 (below the floor 9), and a handle 39a is formed at the other end.

A spring 38 is attached to the connecting member 37 so that the hook 36 can be disengaged in the direction of disengagement and the operating lever 39.
Is rotated counterclockwise, but the operation lever 39 can be held in the engaged state of the hook 36 by the regulating member 41. That is, the regulating member 41 is L
One end of the U-shape is rotatably supported on the side wall 7 side, and by rotating it downward, the other end restricts the counterclockwise rotation of the operation lever 39 so that the engagement state of the hook 36 can be maintained (FIG. 18). When rotated upward, the regulation of the operation lever 39 is released, and the operation lever 39 is rotated counterclockwise by the force of the spring 38 and the force of the operator (FIG. 19), and the engaged state of the hook 36 is released. Is done. When the hook 36 is engaged, the operating lever 39 is pushed against the stopper 40 against the force of the spring 38.
The hook 36 can be held in the engaged state by rotating clockwise until it comes into contact with the control member 41 and rotating the regulating member 41 downward (FIG. 18).

The rod 42 penetrates the container 1 as shown in FIG. 16, the other end protrudes from the other side wall 7, the other end fixes a pointer 43 as an indicator, and the hook 36 is engaged. It can be determined from the side of the side wall 7 opposite to the operation lever 39 from the position of the pointer 43 whether or not the engagement state is established. Next, the driving device 21 of the canopy opening / closing device 15 will be described. The driving device 21 includes a hydraulic pump 44, a hydraulic cylinder 45, and a pipe 46. The hydraulic pump 44 is fixed to a support 48 of a concave portion 47 formed in the center of the front wall 8, and a pipe 46 extends from the hydraulic pump 44. Further, a connecting section 49 having a rectangular cross section is provided from the hydraulic pump 44.
Is attached to the connecting portion 49, and the handle 50 having a hole adapted to the connecting portion 49 is attached to the connecting portion 49.
The hydraulic pump 44 is manually operated by the rotation of. A cover 51 is provided on the front wall 8 to hide the hydraulic pump 44.

The hydraulic cylinder 45 includes a hydraulic cylinder 4
A gear is formed on a part of the rotary shaft 23 so that the gear is rotated by the operation of the hydraulic cylinder 45 to rotate the rotary shaft 23. The hydraulic cylinder 45 has a hydraulic pump 4
A pipe 46 extending from the pipe 4 is connected, and pressure oil from a hydraulic pump 44 is supplied to a hydraulic cylinder 45.

At this time, the arm 27 supporting the canopy 20 is provided with a coil spring 29 so that the load on the hydraulic cylinder 45 is reduced when the canopy 20 is opened and closed. It can be done with little effort. 52 is rear fan door 12
A lower locking device (FIG. 6) for locking the lower part of
The lower locking device 52 includes a pair of left and right main locking devices 53 and a pair of left and right auxiliary locking devices 54.
2 is kept closed.

As shown in FIG. 25A, the auxiliary locking device 54 has a receiving member 56 having a concave portion 55 fixed to the outer surface of the girder 9a extending downward from the floor surface 9 and provided below the rear fan door 12. A part of the pin 57 enters the recess 55. Further, a hook 58 is pivotally supported below the floor surface 9 so as to be vertically rotatable. A part of the hook 58 partially protrudes from the opening 9 b of the spar 9 a, and a pin 57 inserted into the concave portion 55 of the receiving member 56 is attached. They are shackled.

The end of the hook 58 is connected to a rod 61 via a connecting member 59 and a bending link 60.
The connecting member 59 is provided with a spring 62 so as to constantly urge the hook 58 in a direction of releasing the securing.
Further, when the hook 58 reaches the securing position by the rotation of the rod 61, the bending link 60 is moved to a position beyond the dead point as shown in FIG. 25A, whereby the securing state of the hook 58 can be maintained. ing.

The end of the rod 61 is shown in FIGS.
As shown in FIG. 7, a connecting portion 64 protruding from the hole 63 of the side wall 7 and having the same shape as the connecting portion 49 of the hydraulic pump 44 is formed, so that the handle 50 used in the hydraulic pump 44 can also be used. . Reference numeral 65 denotes a bearing for supporting the rod 61. The main lock device 53 is for securely holding the rear door 12 in the closed state together with the auxiliary lock device 54, and makes the closed state firm. As shown in FIGS. 28 and 29, the main lock device 53 is firstly provided with a sealing member 6 on the spar 9a below the floor surface 9.
6 and an engaging member 67, and a sealing member 66 is provided to enhance a sealing effect when the rear door 12 is closed. The engaging member 67 has a flat plate-shaped concave portion 68 opened downward. Have.

On the other hand, a support bracket 69 having a U-shaped cross section is suspended from the lower end of the rear fan door 12, and the support bracket 6
9, a pair of left and right horizontal slots 70 is formed.
The horizontal axis 71 is made to penetrate through the long hole 70 so that the horizontal axis 71 penetrates through the long hole 70. The horizontal shaft 71 is provided with a pair of bases of an arm 72 and short pipes 73 disposed between the arms 72. An engagement pin 74 is fixed to a tip of the arm 72, and the engagement pin 74 is The bolt 75 is fixed to the short pipe 73 so as to be able to engage with the concave portion 68 of the member 67.

A nut 76 is screwed into the bolt 75. By tightening the nut 76, the horizontal shaft 71 is slid to the right and the engaging pin 74 is moved to the engaging member 67.
And the engagement state can be made strong. The outer shape of the nut 76 is rectangular in cross section, and has the same shape as the connecting portion 49 of the hydraulic pump 44 and the connecting portion 64 of the auxiliary lock device 54. The same handle as the handle 50 used for the hydraulic pump 44 may be used. I can do it.

In this embodiment, the stopper fixed to the upper base is formed in an L-shape. However, the same function and effect can be obtained by forming the stopper in a rectangular frame shape so as to surround the entire circumference of the upper base. It has. Further, although the drive device of the canopy opening / closing device is constituted by a hydraulic pump and a hydraulic cylinder, the drive device may be formed by a chain or a gear. Further, although the lower lock device is constituted by the main lock device and the auxiliary lock device, the lower lock device may be constituted by only one of the main lock device and the auxiliary lock device. Further, the shaft fixed to the arm side is connected to the long hole formed on the canopy side, but the same operation and effect can be obtained by connecting the shaft fixed to the canopy side to the long hole formed on the arm side. Have

The present invention is configured as described above, and its operation will be described below. First, when the container 1 is to be stored, if the site to be stored is large, store it on the site one by one as shown in FIG. 3, and if the site is narrow, store the container 1 in a stack as shown in FIG. I do. That is, when stacking the containers 1, the fork of the forklift is inserted into the insertion opening 14 of the container 1 to lift the container 1, and the lower base 16 of the lifted container 1 is placed on the upper base 18 of the separate container 1. Stack up.

At this time, since the canopy opening / closing device 15 is lower than the upper base 18, there is no danger that the bottom surface of the upper container 1 will interfere with the lower container 1, and the upper container 1 will be somewhat shaken. Since the lower base 16 is regulated by the stopper 19 even if it is displaced, the upper container 1
Misalignment can be reliably prevented. Next, container 1
When the container is used, the empty container 1 is mounted on the transport vehicle 2 or the railway wagon of FIG. 1 and transported to the work site. After the container 1 is lowered to the work site, the operation lever 39 of the canopy lock device 34 is operated to release the lock of the canopy 20. That is, when the regulating member 41 is rotated, the operation lever 39 is rotated in the direction of the arrow in FIG. 19 by the force of the spring 38 and the force of the operator, and the locked state by the hook 36 is released. At this time, since the unlocked state can be grasped also by the indicator pointer 43 located on the opposite side wall 7, the risk of damaging the canopy locking device 34 by opening the canopy 20 while the locked state is maintained is prevented. Can be.

When the unlocking of the canopy lock device 34 is completed, the handle 50 is attached to the connecting portion 49 of the hydraulic pump 44, and is manually rotated in the normal direction to operate the hydraulic pump 44. The pressure oil sent from the hydraulic pump 44 is supplied to a hydraulic cylinder 45 through a pipe 46, and the hydraulic cylinder 45 operates to rotate the canopy 20 in the opening direction. At this time, the coil spring 2 is attached to the arm 27 supporting the canopy 20.
Since the cover 9 is provided, the canopy 20 can be opened by operating the handle with a small force.

Immediately before the opening of the canopy 20, as shown in FIG. 20 b, since the line XYZ is bent downward, the linear distance of XZ is short, and the shaft 32 of the mounting member 31 is connected to the arm 27.
Is located on the left side of the long hole 30. Further canopy 20
Is rotated, and when the line XYZ becomes a straight line (FIG. 21B), X
The distance of Z becomes maximum and the shaft 32 moves to the right side of the long hole 30, so that the canopy 20 can be supported while absorbing the displacement of the shaft 32 with respect to the arm 27. When the container 1 is further rotated, it passes through FIG. 22B to reach FIG.
Is fully opened. At this time, since the pivot fulcrum Z is located above the right canopy 20, the canopy 20 can be brought closer to the side wall 7 of the container 1, and the amount of protrusion of the canopy 20 to the side of the container 1 is small, and the canopy 20 is narrow. The container 1 can be installed at a place.

In this state, a container such as garbage or earth and sand is charged. When the charging is completed, the connecting portion 4 of the hydraulic pump 44
9 is rotated in the reverse direction, the pressure oil is fed in the reverse direction, and the canopy 20 is rotated from the state of FIG.
a, The inlet 10 at the top of the container 1 is closed through FIG. 21a (FIG. 20a). At this time, since the canopy 20 is formed in an arc shape, earth and sand can be piled up along the canopy.

When the canopy 20 is closed, the operating lever 39 of the canopy locking device 34 is rotated clockwise against the spring 38 (FIG. 18).
9 is held in that position. As a result, the upper hook 36 is engaged with the pin 35 on the side of the canopy 20, and the opening of the canopy 20 is restricted. During transportation of the container 1, the hook 36 comes off due to vibration or the like, and the canopy 20 is locked. Release can be reliably prevented.

When the above operation is completed, the container 1 is mounted on the dump frame 4 of the transport vehicle 2 by a forklift and integrated therewith, and transported to the disposal place of the stored contents. Upon arriving at the disposal site, the transport vehicle 2 is stopped, the handle 50 is attached to the nut 76 of the main lock device 53 behind the container 1, and the engaging pin 74 is operated by operating the handle 50.
7 from the recess 68. After that, the handle 50 is moved to the side of the container 1 and the handle 50 removed from the nut 76 is attached to the connecting portion 64 of the auxiliary locking device 54, the handle 50 is turned, and the bending link 60 is rotated to release the dead point. Then, the hook 58 is released. At this time, if the container 1 is full of contents, the contents may push the rear fan 12 and leak out of the container 1 at the same time as the release of the lashing. Since the operation is performed, the worker can be prevented from being stained with the leaked contents.

Thereafter, when the dump frame 4 is tilted rearward around the rear hinge 5 by the lifting device 4a, the container 1 also tilts, and the lower portion of the rear fan door 12 is released from the securing. The rear door 12 rotates by its own weight, and discharges the contents of the container 1 to the rear of the container 1. At this time, if it is more efficient to open the canopy 20, the dump frame 4 may be tilted after opening the canopy 20. When the discharge of the container 1 is completed, the dump frame 4 is stored, the auxiliary lock device 54 is operated to secure the pin 57 of the rear fan 12, and the main lock device 53 is also secured with the same handle 50. I do. Then, the transport vehicle 2 transports the container 1 to the container storage location, and unloads the container 1 from the transport vehicle 2 at the storage location.

[0034]

As described above, according to the first aspect of the present invention, the canopy locking device is provided with a hook capable of engaging a part of the canopy, an operation lever for operating the hook, and a lower portion of the container below the floor surface. A rod penetrating both side walls and having an operation lever fixed to one end thereof and a pointer fixed to the other end of the rod are provided. Thus, the locked state or the unlocked state of the canopy can be grasped from, and the work can be performed efficiently.

According to a second aspect of the present invention, the hook is connected to a part of the operating lever by a connecting member, and the connecting member is provided with a spring which constantly urges the hook toward the disengagement side, and is provided near the operating lever. Has a regulating member that regulates the movement of the operation lever to the hook disengagement side, so that the canopy can be securely prevented from being unlocked due to vibration or the like during transportation of the container. be able to.

[Brief description of the drawings]

FIG. 1 is a side view of a transport vehicle equipped with a container with a canopy opening / closing device.

FIG. 2 is an operation state diagram when a container is dumped.

FIG. 3 is a right side view of the container.

FIG. 4 is a left side view of the container.

FIG. 5 is a front view of the container.

FIG. 6 is a rear view of the container.

FIG. 7 is an operation diagram showing a state in which containers are stacked.

FIG. 8 is an enlarged view of a main part of FIG. 7;

FIG. 9 is a perspective view showing upper and lower ends of a column.

FIG. 10 is a plan view of a container.

FIG. 11 is a plan view of a canopy.

FIG. 12 is a sectional view taken along line GG of FIG. 11;

FIG. 13 is a sectional view taken along the line EE of FIG. 11;

FIG. 14 is an FF diagram of FIG. 12;

FIG. 15 is an enlarged view of a main part of the canopy lock device.

FIG. 16 is a sectional view taken along line HH of FIG. 15;

FIG. 17 is a II diagram of FIG. 16;

18 is a JJ diagram of FIG.

FIG. 19 is an operation state diagram of the canopy locking device.

FIG. 20 is an operation state diagram showing a closed state of the canopy.

FIG. 21 is an operation state diagram showing a state immediately after the opening of the canopy is started.

FIG. 22 is an operation state diagram illustrating a state in which the canopy is being opened.

FIG. 23 is an operation state diagram showing an open state of the canopy.

FIG. 24 is a sectional view taken along the line AA of FIG. 5;

FIG. 25 is a sectional view taken along the line CC of FIG. 6 showing the auxiliary locking device.

FIG. 26 is a sectional view taken along line BB of FIG. 6;

FIG. 27 is a sectional view taken along line LL of FIG. 26;

FIG. 28 is a sectional view taken along the line DD of FIG. 6, showing the main lock device.

FIG. 29 is a KK diagram of FIG. 28;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Container 6 Prop 7 Side wall 8 Front wall 9 Floor surface 10 Input port 12 Rear door 20 Canopy 23 Rotating shaft 34 Canopy lock device 36 Hook 37 Connecting member 38 Spring 39 Operating lever 41 Restriction member 42 Rod 43 Guide

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yuji Okamoto 4-1-1 62 Fukami Nishi, Yamato City, Kanagawa Prefecture Inside the Kyokuto Kaihatsu Kogyo Co., Ltd. (72) Katsumi Toguchi 4-chome Fukami Nishi, Yamato City, Kanagawa Prefecture No. 62 Kyokuto Kaihatsu Kogyo Co., Ltd. F term (reference) 3E070 AA25 AB14 AB25 DA01 GA08 PA01 QA03 RA30 WH05

Claims (2)

[Claims] 1. A pillar is erected at four corners of front, rear, left and right, a floor surface, a side wall, a front wall, and a rear fan are provided between the pillars, and an inlet is formed at an upper part, and one side of the inlet is formed. A container that is provided with a canopy that opens and closes an opening so as to be rotatable around a rotation axis and that is provided with a canopy lock device that holds the canopy in a closed state on the other side wall side of the opening. A canopy locking device, a hook that can be engaged with a part of the canopy, an operation lever that operates the hook, a rod that penetrates both side walls below the floor of the container, and has an operation lever fixed to one end,
A canopy locking device for a container having a pointer fixed to the other end of the rod. 2. The canopy locking device according to claim 1, wherein a hook engageable with a part of the canopy is connected to a part of the operation lever by a connecting member, and the connecting member is always provided with a hook on a disengagement side. 2. The canopy lock device for a container according to claim 1, wherein a biasing spring is provided, and a regulating member for regulating movement of the operation lever toward the hook engagement release side is provided near the operation lever.