JP3680082B2 - Opening and closing device for bottom cover of rotating bucket - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a bottom cover opening and closing device for a rotating bucket that opens and closes a bottom cover of a rotating bucket that is attached to a kelly bar and excavates a pile hole.
[0002]
[Prior art]
Conventionally, as shown in FIG. 13 and FIG. 14, a rotating bucket 100 is known that is rotated by a kelly bar 105 and excavated and pulled up to the ground to discharge internal sediment. In the rotating bucket 100, a cylindrical portion 104 is formed on an upper portion of a cylindrical bucket main body 102, and the cylindrical portion 104 is fixed to a kelly bar 105. A bottom lid 108 provided with a digging bit 106 is provided below the bucket body 102 so as to be opened and closed by a hinge 110.
[0003]
The bucket body 102 is closed by the bottom lid 108 to form a storage chamber 112, and the bottom lid 108 has a window 114 for taking the earth and sand excavated by the excavation bit 106 into the storage chamber 112. A stopper 116 is supported on the rotating bucket 100 so as to be swingable around a vertical axis, and a substantially triangular engagement portion 118 is formed at the tip of the stopper 116. A rectangular through hole 120 corresponding to the engaging portion 118 is formed in the bottom lid 108, and the engaging portion 118 protrudes from the bottom lid 108 through the through hole 120 to swing the stopper 116 by a predetermined angle. Thus, the phases of the engaging portion 118 and the through hole 120 are shifted so that the bottom lid 108 can be held closed.
[0004]
[Problems to be solved by the invention]
However, in such a conventional apparatus, when the rotary bucket 100 is lifted to the ground and the earth and sand are discharged, the operation is performed jointly by an operator such as a crane and other workers. At that time, the operator operates the crane and lowers the rotating bucket 100 to the earth discharging place on the ground, and the operator opens the stopper 116 by hand or by using a hook-shaped bar. The stopper 116 is swung.
[0005]
Then, by slowly raising the rotating bucket 100 from that state, the bottom lid 108 is opened and discharged, but an operator other than the crane operator is required to operate the stopper 116. Arranging a dedicated worker for opening and closing the bottom lid 108 is inefficient and leads to an increase in construction cost. If the worker is shared with other work, depending on the timing of the shared work, the worker may not be conveniently present, leading to a reduction in efficiency.
[0006]
Also, since the discharged earth and sand often contain a stabilizing solution for preventing hole wall collapse, the discharge location is poor, especially when discharging to a dump truck bed and the work place is not good. However, there is a problem that it is difficult to operate the stopper 116.
An object of the present invention is to provide a bottom cover opening and closing device for a rotating bucket that can improve the operability and efficiently open the bottom cover of the rotating bucket.
[0007]
[Means for Solving the Problems]
In order to achieve this problem, the present invention has taken the following means for solving the problem. That is,
A bottom cover of a rotating bucket that is attached to a forward and reverse rotating kelly bar and that is supported in a closed state by a stopper that engages with the bottom cover. In switchgear,
The kelly bar and the rotation by a connection mechanism that allows a predetermined angle of rotation between the kelly bar and the rotating bucket and allows a predetermined amount of movement between the excavation position and the lifting position in the axial direction of the kelly bar. Providing a release mechanism for connecting the bucket and releasing the engagement of the stopper by reverse rotation of the kelly bar at a time other than the excavation position ;
The connection mechanism includes a leg member attached to the kelly bar side, and a transmission member attached to the rotary bucket side to transmit rotation by contacting the leg member, and the excavation position and the lifting position. A bottom cover opening and closing device for a rotating bucket , wherein the transmission member enters a notch formed in the leg member by reverse rotation of the kelly bar to allow rotation of the predetermined angle at an intermediate position between is there.
[0008]
In addition, a rotating bucket that is attached to a forward and reverse rotating kelly bar and that supports the opening and closing of the rotating bucket that excavates the pile hole while rotating forward is held closed by a stopper that engages the bottom cover. In the bottom lid opening and closing device,
The kelly bar and the rotation by a connection mechanism that allows a predetermined angle of rotation between the kelly bar and the rotating bucket and allows a predetermined amount of movement between the excavation position and the lifting position in the axial direction of the kelly bar. Providing a release mechanism for connecting the bucket and releasing the engagement of the stopper by reverse rotation of the kelly bar at a time other than the excavation position;
In addition, the connection mechanism includes a sliding hole formed in the axial direction of the Kellyba and a connecting shaft that is slidably inserted into the sliding hole, and has a groove formed in the sliding hole. When the protrusion formed on the connecting shaft is inserted into the groove, and the intermediate position between the excavation position and the lifting position, the groove is formed in the notch formed in the protrusion by reverse rotation of the kelly bar. This is a bottom cover opening and closing device for a rotating bucket, characterized in that a protrusion formed on the inside enters and permits rotation at the predetermined angle.
[0009]
The connection mechanism includes a large-diameter hole having a predetermined length formed in the axial direction of the kelly bar, and a large-diameter shaft portion movable in the large-diameter hole, and the excavation position and the lifting position are A predetermined amount of movement between the two may be allowed.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The same members as those of the rotating bucket 100 shown in FIGS. 13 and 14 described above are denoted by the same reference numerals, and detailed description thereof is omitted.
[0011]
As shown in FIG. 12, the excavator wraps a wire rope 8 that is fed out or wound up by a winch 6 around a sheave 4 that is rotatably supported at the tip of a boom 2 provided in a self-propelled main body 1. The kelly bar 10 is hung from the tip of the wire rope 8 so as to be rotatable by the swivel joint 12 and the winch 6 is driven to raise and lower the kelly bar 10.
[0012]
A rotation drive mechanism 16 is disposed at the tip of the arm 14 supported by the main body 1, and the kelly bar 10 is inserted into the rotation drive mechanism 16, and the kelly bar 10 rotates forward and backward by driving the rotation drive mechanism 16. In addition, the kelly bar 10 is configured to slide up and down in the rotation drive mechanism 16. The rotational direction in which excavation is performed by the excavation bit 106 of the rotary bucket 100 is defined as normal rotation. The excavator is not limited to this case, and can be similarly implemented even if it has a configuration that rotates the kelly bar supported by the rotary drive mechanism attached to the leader of the so-called pile driver so that it can be moved up and down. is there.
[0013]
A rotating bucket 100 is attached to the tip of the kelly bar 10 via a connection mechanism 20. As shown in FIG. 2, in the connection mechanism 20, the kelly bar 10 is inserted into the mounting member 22 and is integrally connected by a pin 24. The attachment member 22 includes a flat plate-like flange portion 22a orthogonal to the axial direction of the Kelly bar 10, and the flange portion 26a of the connecting member 26 is attached to the flange portion 22a by a bolt or the like (not shown).
[0014]
The connecting member 26 is formed with a large-diameter hole 28 having a predetermined length formed in the axial direction of the Kelly bar 10 and a sliding hole 30 connected to the large-diameter hole 28 via a step portion 29 from the attachment member 22 side. A large-diameter shaft portion 34 of the connecting shaft 32 is movably inserted into the large-diameter hole 28. A guide shaft portion 36 of the connection shaft 32 is slidably inserted into the slide hole 30. A predetermined amount of movement is allowed between the excavation position where movement is restricted when the large-diameter shaft portion 34 abuts against the flange portion 22a and the lifting position where movement is restricted when the large-diameter shaft portion 34 abuts against the stepped portion 29. It is configured.
[0015]
A square shaft portion 38 at the tip end of the connection shaft 32 is inserted into an attachment member 40 attached to the bucket body 102 and is integrally connected by a pin 42. A large-angle shaft portion 44 is formed between the guide shaft portion 36 and the angular shaft portion 38, and a transmission member 46 is inserted into the large-angle shaft portion 44 and is integrally connected by a pin 47.
[0016]
The transmission member 46 is formed with two sets of protrusions 48a, 48b, 49a, 49b protruding in the radial direction, and the connection member 26 is interposed between the two sets of protrusions 48a, 48b, 49a, 49b. A pair of leg members 50 and 51 attached and extending in the axial direction of the connecting shaft 32 are inserted. The distance between the two pairs of protrusions 48a, 48b, 49a, 49b and the width of the leg members 50, 51 are substantially equal, and the rotation of the connecting member 26 can be transmitted to the connecting shaft 32 via the leg members 50, 51 and the transmission member 46. Thus, the leg members 50 and 51 are configured to be able to slide between the protrusions 48a, 48b, 49a and 49b.
[0017]
Further, the leg members 50 and 51 are respectively formed with rectangular cutouts 52 and 53 in the circumferential direction, and the thickness of one projecting portion 48a and 49a of the transmission member 46 is the width of the cutouts 52 and 53. It is formed narrower. When the large-diameter shaft portion 34 of the connection shaft 32 is at an intermediate position between the excavation position and the lifting position, the protrusions 48a and 49a enter the notches 52 and 53 by the reverse rotation of the connection member 26, and are transmitted to the connection member 26. A predetermined angle of rotation with the member 46 is allowed.
[0018]
On the other hand, a fulcrum shaft 57 projecting radially toward the stopper 116 is fixed to the transmission member 46, and a release lever 58 is swingably mounted on the fulcrum shaft 57. A bifurcated portion 60 is formed at one end of the release lever 58, and the distal end of the stopper 116 is inserted therebetween, and the stopper 116 can be swung by swinging of the release lever 58. ing. As shown in FIG. 3, the stopper 116 swings in a direction in which the phases of the engaging portion 118 and the through-hole 120 are shifted by a spring 64 hung on a locking member 62 erected on the bucket body 102. It is energized to do.
[0019]
As shown in FIGS. 3 to 5, the connecting shaft 66 is slidably inserted in the direction orthogonal to the fulcrum shaft 57 on the other end side of the release lever 58, and the connecting shaft 66 swings on the fulcrum shaft 57. It is connected by a pin 70 to a drive lever 68 that is movably supported. A spring 71 is inserted into the connecting shaft 66, and a pair of nuts 72 and 73 are screwed. When the drive lever 68 is swung in the direction indicated by the arrow in FIG. 3, the release lever 58 is also swung in the same direction via the connecting shaft 66, nuts 72 and 73, and the spring 71.
[0020]
A fixed shaft 74 that protrudes toward the connecting member 26 side is attached to the drive lever 68 in parallel with the fulcrum shaft 57, and the connecting member 26 is pushed on the outer periphery thereof in correspondence with the fixed shaft 74. A plate 75 is attached. When the large-diameter shaft portion 34 is in the intermediate position and the rotation of the relative predetermined angle between the connecting member 26 and the transmission member 46 occurs, the push plate 75 hits the fixed shaft 74 and the drive lever 68 Is configured to swing in the direction of the arrow in FIG.
[0021]
A holding plate 76 is attached to hold the drive lever 68 at the solid line position so that the release lever 58 does not swing to the release side when in the excavation position of FIG. In this embodiment, the fulcrum shaft 57, the release lever 58, the connection shaft 66, the drive lever 68, the nuts 72 and 73, the spring 71, the fixed shaft 74, and the push plate 75 constitute a release mechanism 78.
[0022]
Next, the operation of the above-described rotating bucket bottom lid opening / closing device of this embodiment will be described.
First, when the kelly bar 10 is lifted, the connecting member 26 is pulled up via the pin 24 and the mounting member 22. As a result, the large-diameter shaft portion 34 slides in the large-diameter hole 28 to a lifting position where it hits the step portion 29, and the rotary bucket 100 is lifted via the connection shaft 32, the pin 42, and the attachment member 40.
[0023]
Then, when the rotating bucket 100 is lowered into the pile hole h and the bottom cover 108 hits the bottom of the pile hole h as shown in FIG. 7 (a), the large diameter shaft portion 34 slides in the large diameter hole 28. Thus, the excavation position hits the flange portion 22 a of the mounting member 22, and the own weight of the kelly bar 10 is applied to the rotating bucket 100.
[0024]
In this state, when the Kelly bar 10 is rotated forward by the rotation drive mechanism 16, the attachment member 22, the connecting member 26, and the leg members 50 and 51 are rotated. Then, the end surfaces of the leg members 50 and 51 and the protrusions 48 a and 49 b come into contact with each other to transmit the rotation to the transmission member 46, and the rotating bucket 100 is rotated forward via the connection shaft 32 and the attachment member 40.
[0025]
Therefore, the earth and sand excavated by the excavation bit 106 is taken into the bucket body 102 from the window 114 of the bottom lid 108. When excavation progresses and the bucket body 102 is filled with the earth and sand taken in, the rotation drive by the rotation drive mechanism 16 is stopped.
[0026]
In addition, during the excavation by rotating the kelly bar 10 forward, when it is necessary to temporarily reverse the rotation for rolling stones or the like, the rotation driving mechanism 16 is reversely rotated. Also in this reverse rotation, when the large-diameter shaft portion 34 is in the excavation position where it abuts against the flange portion 22a, the vertical phases of the notches 52, 53 and the protrusions 48a, 49a do not coincide with each other. No relative rotation of a predetermined angle occurs between the member 46 and the member 46. Therefore, the reverse rotation is transmitted as it is to the transmission member 46 via the leg members 50 and 51.
[0027]
The rotation of the kelly bar 10 is stopped and the kelly bar 10 is lifted. As a result, as shown in FIGS. 2 and 7 (b), the connecting member 26 is pulled up via the mounting member 22, and the large-diameter shaft portion 34 is brought into the lifting position where it hits the step portion 29. 42, the rotating bucket 100 is lifted through the attachment member 40.
[0028]
Then, the rotary bucket 100 is lifted out of the pile hole h, and the bottom cover 108 is lowered so as to contact the ground GL as shown in FIG. When the bottom cover 108 contacts the ground GL, the large-diameter shaft portion 34 slides in the large-diameter hole 28, and the leg members 50 and 51 slide between the protrusions 48a, 48b, 49a, and 49b. When the large-diameter shaft portion 34 slides to an intermediate position and the vertical phases of the notches 52 and 53 of the leg members 50 and 51 and the protrusions 48a and 49a coincide with each other, the lowering of the kelly bar 10 is stopped.
[0029]
Next, the Kelly bar 10 is reversely rotated by the rotation driving mechanism 16, and the leg members 50 and 51 are reversely rotated via the attachment member 22 and the connecting member 26. As a result, the protrusions 48 a and 49 a enter the notches 52 and 53, and a relative rotation of a predetermined angle occurs between the leg members 50 and 51 and the transmission member 46.
[0030]
Alternatively, when the kelly bar 10 is lowered while rotating in the reverse direction and the bottom lid 108 is brought into contact with the ground GL as shown in FIG. 7C, the excavation bit 106 attached to the bottom lid 108 and the ground GL are interposed. Resistance occurs. If the kelly bar 10 is lowered while rotating in the reverse direction, when the upper and lower phases of the notches 52 and 53 of the leg members 50 and 51 and the protrusions 48a and 49a coincide, Relative rotation of a predetermined angle occurs.
[0031]
By this reverse rotation, the push plate 75 pushes the fixed shaft 74 and swings the drive lever 68 around the fulcrum shaft 57. At that time, the release lever 58 is swung through the connecting shaft 66, the nuts 72 and 73, and the spring 71 to swing the stopper 116. Thereby, the phase of the engaging part 118 and the through-hole 120 corresponds, the engagement of the bottom cover 108 is released, and the bottom cover 108 can be opened. When the stopper 116 cannot be swung for any reason, the spring 71 is compressed and only the drive lever 68 is swung, and the stopper 116, the release lever 58, the drive The damage of the lever 68 etc. is prevented.
[0032]
In this state, when the kelly bar 10 is lifted again, as shown in FIG. 8 (d), the protrusions 48a and 49a are inserted into the notches 52 and 53 of the leg members 50 and 51 through the protrusions 48a and 49a. Thus, the rotating bucket 100 is lifted. Therefore, the bottom cover 108 swings around the hinge 110, the bottom cover 108 is opened, and the earth and sand in the bucket body 102 is discharged.
[0033]
When earth and sand are stuck on the inner wall of the bucket body 102 and it is difficult to discharge, when the rotary drive mechanism 16 is rotated forward and backward, the rotary bucket 100 rotates due to inertia and the protrusions 48a and 49a are detached from the notches 52 and 53. The leg members 50 and 51 slide between the protrusions 48a, 48b, 49a and 49b, and the large-diameter shaft portion 34 slides in the large-diameter hole 28 and comes into contact with the step portion 29. Therefore, the rotating bucket 100 is suddenly dropped to the lifting position, and the earth and sand stuck to the inner wall of the bucket body 102 due to the impact is discharged as shown in FIG. At this time, the push plate 75 is separated from the fixed shaft 74, and the stopper 116 is swung by the urging force of the spring 64 to return the release lever 58 and the drive lever 68 to the original positions shown by solid lines in FIG.
[0034]
After discharging the earth and sand, as shown in FIG. 8 (f), the kelly bar 10 is lowered to bring the bottom lid 108 into contact with the ground GL, and the bottom lid 108 is closed around the hinge 110 by using it. Rocks. When the engaging portion 118 passes through the through hole 120, it is swung against the urging force of the spring 64, and when the large-diameter shaft portion 34 comes into contact with the flange portion 22a and reaches the excavation position, the engaging portion 118 is engaged. The phase between the portion 118 and the through-hole 120 is shifted, and the stopper 116 holds the bottom lid 108 closed. Then, the kelly bar 10 is lifted again, and the rotary bucket 100 is inserted into the pile hole h to continue excavation.
[0035]
Thus, according to the bottom cover opening and closing device of the rotating bucket of the present embodiment, the operator of the excavator repeats the vertical movement of the kelly bar 10 and rotates the kelly bar 10 forward and backward by the rotation drive mechanism 16, The bottom lid 108 can be opened and closed without the help of the operator. Therefore, it is possible to continuously excavate with the rotating bucket 100 only by an operator's operation without being affected by the progress of work of other workers, and work efficiency is improved.
[0036]
Further, when notches 52 and 53 are formed in the leg members 50 and 51 and the kelly bar 10 is rotated in the reverse direction when the leg members 50 and 51 are in the intermediate positions, a rotation of a relative predetermined angle occurs between the connecting member 26 and the transmission member 46. Then, the release lever 58 is swung. Therefore, the bottom cover 108 does not open even if the kelly bar 10 is rotated in the reverse direction when it is in the excavation position or the lifting position. In the present embodiment, a drilling bucket is taken as an example of the rotating bucket 100, but a bottom expansion bucket used when expanding the bottom portion of the pile hole h can be similarly implemented.
[0037]
Next, a second embodiment different from the above-described embodiment will be described with reference to FIGS. Note that the same members as those in the above-described embodiment are denoted by the same reference numerals and detailed description thereof is omitted.
The connecting member 80 attached to the attachment member 22 is formed with a large-diameter hole 28 and a sliding hole 81 connected to the large-diameter hole 28 via a step portion 29. In the sliding hole 81, FIG. As shown, a pair of grooves 82 and 83 are formed along the axial direction. A large-diameter shaft portion 34 of the connecting shaft 84 is movably inserted into the large-diameter hole 28, and a guide shaft portion 85 is slidably inserted into the sliding hole 81.
[0038]
A pair of protrusions 86 and 87 inserted into the grooves 82 and 83 are formed along the axial direction on the outer periphery of the guide shaft portion 85, and are relatively between the connecting member 80 and the connection shaft 84. The widths of the ridges 86 and 87 are narrower than the widths of the grooves 82 and 83 so that the rotation at a predetermined angle is possible.
[0039]
9 and 11, a rectangular notch 86a (only the protrusion 86 is shown) is formed in the middle of the protrusions 86 and 87, while protruding into the grooves 82 and 83. A rectangular protrusion 82a (only the groove 82 is shown) is formed. The protrusion 82a is formed in a size that can be inserted into the notch 86a, the protrusion 86 can slide between the protrusion 82a and the side wall of the groove 82, and the connecting member 80 and the connecting shaft 84 It is formed so that relative rotation does not occur between the two.
[0040]
Further, when the large-diameter shaft portion 34 of the connection shaft 84 is at an intermediate position between the excavation position and the lifting position, the protrusion 82a enters the notch 86a by the reverse rotation of the connection member 80, and the connection member 80 and the transmission member 46 And a predetermined angle of rotation is allowed. The same applies to a protrusion (not shown) of the other groove 83. In the second embodiment, the connecting member 80 and the connecting shaft 84 constitute a connecting mechanism 94.
[0041]
In the second embodiment, when the connecting member 80 is pulled up by the kelly bar 10 via the mounting member 22, the large-diameter shaft portion 34 is in the lifting position where it hits the stepped portion 29, and the connecting shaft 84, the mounting member 40, the pin The rotating bucket 100 is lifted via 42. When the rotating bucket 100 is inserted into the pile hole h and the bottom cover 108 comes into contact with the bottom, the large-diameter shaft portion 34 slides within the large-diameter hole 28 and becomes an excavation position where it hits the flange portion 22a. .
[0042]
When the rotation drive mechanism 16 is rotated forward, the rotary bucket 100 is rotated via the attachment member 22, the connecting member 80, the connection shaft 84, and the attachment member 40, and excavation is performed. At this time, even if the rotation is reversed, the upper and lower phases of the protrusion 82 a and the notch 86 a do not coincide with each other, so that no relative rotation occurs between the connecting member 80 and the connecting shaft 84.
[0043]
Further, when the inside of the rotary bucket 100 is filled with earth and sand, the kelly bar 10 is lifted. As a result, the rotary bucket 100 is lifted by the lifting position where the large-diameter shaft portion 34 hits the stepped portion 29. The rotary bucket 100 is hung outside the pile hole h, lowered to a state where the bottom lid 108 is in contact with the ground GL, the vertical phase of the protrusion 82a and the notch 86a are matched, and the rotary drive mechanism 16 is reversely rotated. . Alternatively, the bottom lid 108 may be brought into contact with the ground surface GL by being lowered while being reversely rotated.
[0044]
As a result, the vertical phase of the projection 82a and the notch 86a coincide with each other, and a relative predetermined angle of rotation occurs between the connecting member 80 and the connecting shaft 84. The release lever 58 is swung. Thereby, the stopper 116 is swung and the engagement of the bottom cover 108 is released.
[0045]
Then, by lifting the kelly bar 10, the bottom cover 108 is opened in the same manner as described above, and the earth and sand inside is discharged. After the discharge, the rotary bucket 100 is lowered again to close the bottom lid 108 and then inserted into the pile hole h and the excavation is continued in the same manner as in the above-described embodiment.
[0046]
Thus, even in the case of the second embodiment, the operator of the excavator can open and close the bottom lid 108 without the assistance of other workers, and work efficiency can be improved. Claims 1 and 3 correspond to the first embodiment, and claims 2 and 3 correspond to the second embodiment.
[0047]
The present invention is not limited to such embodiments as described above, and can be implemented in various modes without departing from the gist of the present invention.
[0048]
【The invention's effect】
As described above in detail, the bottom cover opening and closing device of the rotating bucket according to the present invention can open and close the bottom cover of the rotating bucket without the help of the other operator from the operator of the excavator, thereby improving the work efficiency. There is an effect that it can be improved. Further, since rotation at a predetermined angle is allowed at the intermediate position, the bottom lid will not open even if the kelly bar is rotated in reverse at the excavation position and the lifting position.
[Brief description of the drawings]
FIG. 1 is a front view of an essential part of a bottom cover opening and closing device for a rotating bucket according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view of the main part of the bottom cover opening / closing device of the rotating bucket according to the present embodiment.
FIG. 3 is a side view of the main part of the bottom cover opening / closing device of the rotating bucket according to the present embodiment.
4 is a cross-sectional view taken along the line AA in FIG.
5 is an enlarged cross-sectional view taken along the line BB in FIG. 3;
FIG. 6 is an exploded perspective view of a main part of the bottom cover opening / closing device of the rotating bucket according to the embodiment.
FIG. 7 is an explanatory view showing the order of taking out from the excavation by the rotating bucket of this embodiment to the outside of the pile hole.
FIG. 8 is an explanatory diagram showing the opening / closing order of the bottom lid by the rotating bucket of the present embodiment.
FIG. 9 is a cross-sectional view of a main part of a bottom cover opening / closing device for a rotating bucket according to a second embodiment;
FIG. 10 is a cross-sectional view taken along CC in FIG.
FIG. 11 is a development view of protrusions and grooves of the second embodiment.
FIG. 12 is an overall front view of the excavator of the present embodiment.
FIG. 13 is a cross-sectional view of a rotating bucket.
FIG. 14 is a bottom view of the rotating bucket.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Kelly bar 16 ... Rotation drive mechanism 20, 94 ... Connection mechanism 26, 80 ... Connection member 29 ... Step part 32, 84 ... Connection shaft 46 ... Transmission member 48a, 48b, 49a, 49b ... Projection part 50, 51 ... Leg member 52, 53 ... Notches 58, 89 ... Release lever 68 ... Drive lever 75 ... Push plate 78 ... Release mechanism 86 ... Projection 100 ... Rotating bucket 108 ... Bottom lid 116 ... Stopper

Claims (3)

A bottom cover of a rotating bucket that is attached to a forward and reverse rotating kelly bar and that is supported in a closed state by a stopper that engages with the bottom cover. In switchgear,
The kelly bar and the rotation by a connection mechanism that allows a predetermined angle of rotation between the kelly bar and the rotating bucket and allows a predetermined amount of movement between the excavation position and the lifting position in the axial direction of the kelly bar. Providing a release mechanism for connecting the bucket and releasing the engagement of the stopper by reverse rotation of the kelly bar at a time other than the excavation position ;
The connection mechanism includes a leg member attached to the kelly bar side, and a transmission member attached to the rotary bucket side to transmit rotation by contacting the leg member, and the excavation position and the lifting position. A bottom cover opening and closing device for a rotating bucket , wherein the transmission member enters a notch formed in the leg member by reverse rotation of the Keriba at an intermediate position between the two and allows rotation of the predetermined angle . A bottom cover of a rotating bucket that is attached to a forward and reverse rotating kelly bar and that is supported in a closed state by a stopper that engages with the bottom cover. In switchgear,
The kelly bar and the rotation by a connection mechanism that allows a predetermined angle of rotation between the kelly bar and the rotating bucket and allows a predetermined amount of movement between the excavation position and the lifting position in the axial direction of the kelly bar. Providing a release mechanism for connecting the bucket and releasing the engagement of the stopper by reverse rotation of the kelly bar at a time other than the excavation position ;
In addition, the connection mechanism includes a sliding hole formed in the axial direction of the Kellyba and a connecting shaft that is slidably inserted into the sliding hole, and has a groove formed in the sliding hole. When the protrusion formed on the connecting shaft is inserted into the groove, and the intermediate position between the excavation position and the lifting position, the groove is formed in the notch formed in the protrusion by reverse rotation of the kelly bar. A projecting part formed on the rotating bucket allows the rotation of the predetermined angle to allow rotation of the bottom cover of the rotating bucket. The connection mechanism includes a large-diameter hole having a predetermined length formed in the axial direction of the kelly bar, and a large-diameter shaft portion movable in the large-diameter hole, and is provided between the excavation position and the lifting position. The bottom cover opening and closing device for a rotating bucket according to claim 1 or 2 , wherein a predetermined amount of movement is allowed.

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