ADAPTER WITH CONCEALMENT PORTION AT BUCKET TIP END AND BUCKET MOUNTED ON WORKING MACHINE FOR EXCAVATION AND THE LIKE

Abstract

[Problem] The present invention provides an adapter with concealing portion at a bucket tip end having an existing adapter function in this type of adapters, that is, a function as an adapter tool when a tooth board or a point is attached to a bucket tip end portion, and if being used as an adapter when the tooth board is attached to the bucket tip end portion, by being configured to cover/conceal the bucket tip end portion (edge portion), abrasion at the bucket tip end portion is drastically reduced and a life of the bucket itself is drastically extended and thus, a replacement period/replacement work of a bucket can be drastically extended and as a result, cost reduction of this type of working machines can be realized. [Solution] An adapter 11 with concealing portion at a bucket tip end of the present invention is to be attached to an edge portion 2 of a bucket 1 for an operation performing excavation and the like and is configured to have an adapter main body 14 provided with an attachment portion 12 attached to the edge portion 2 of the bucket 1 and a projecting body 13 for attaching a point 31 or a tooth board 41, projected from this attachment portion 12; and a concealing portion 15 integrally formed in a state projecting sideward from the attachment portion 12 of the adapter main body 14, attached to this edge portion in a state covering the edge portion on the side of the attachment portion 12 and concealing the edge portion 2.

Description

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to an adapter with a concealment portion at a bucket tip end and a bucket mounted on a working machine for performing excavation and the like or more particularly to an adapter with a concealment portion at a bucket tip end having an existing adapter function in this type of adapters, that is, a function as an adapter tool when a tooth board or a point is attached to a bucket tip end portion, and if being used as an adapter when the tooth board is attached to the bucket tip end portion, by being configured to cover/conceal the bucket tip end portion (edge portion), abrasion at the bucket tip end portion is drastically eliminated and a life of the bucket itself is drastically extended and thus, a replacement period/replacement work of a bucket can be drastically extended and as a result, cost reduction of this type of working machines can be realized and a bucket attached to a working machine for performing excavation and the like configured to be attached with the adapter.

2. Background Art

In a prior-art bucket of a working machine for performing excavation and the like such as a power shovel, a shovel loader and the like, attachment portions of a plurality of adapter portions are fixed at intervals to an edge portion occupying a tip end position of the bucket by welding or the like, attachment portions of a point for excavation for performing excavation and the like or a tooth board for a spreading and grading work are fitted to each of the adapter portions, the adapter portion and the point or the tooth board are integrally connected and fixed by fixing means such as a lock pin, whereby excavation of earth and sand, spreading and loading of the excavated earth and sand, transfer to a transport vehicle and the like are performed.

In this case, concealment of the edge portion of the bucket is extremely important, and insufficient concealment of the edge portion incurs abrasion or damage of the edge portion and further causes a serious nonconformity state of reduction of a bucket life.

Patent Literature 1 proposes a tooth board to be attached to a bucket for a shovel machine as a technology relating to the present invention and the tooth board is detachably provided through an adapter member projected at a tip end of the bucket and the tooth board to be attached to a bucket for a shovel machine is configured such that, when the tooth board is attached to the tip end of the bucket, a concealing portion for concealing a gap generated between the bucket tip end and a base end of the tooth board is provided on this tooth board, and this concealing portion is provided at an outer position on the base end side of the tooth board and disposed in an overlapping state on an outer surface portion of the bucket tip end and the concealing portion is connected and fixed to the bucket by a fixing portion.

Moreover, Patent Literature 2 proposes an abrasion member for protecting an excavating edge of an excavating apparatus, comprising a front end portion, a cavity opened rearward and configured to receive a support structure of the excavating apparatus and having a front end portion defined by an upper surface, a lower surface, and a front-side contact surface extending between the upper surface and lower surface, in which the upper and lower surfaces are generally inclined in the same direction with respect to a center plane of the support body structure, and an opening for receiving a lock so as to hold the abrasion member on the support structure.

However, no technology is found at present that employs a configuration for an adapter itself directly attached/mounted on the edge portion of the bucket (tip end portion of the bucket) to cover/conceal the edge portion of the bucket so as to provide a function of covering/concealing the edge portion of the bucket.

[Patent Literature 1] Japanese Patent Laid-Open No. 2004-124414

[Patent Literature 2] Japanese Patent Laid-Open No. 2009-506241

SUMMARY OF THE INVENTION

[Problem to Be Solved by Invention]

A problem to be solved by the present invention is a point that there is no such an adapter with concealing portion at a bucket tip end which employs a configuration in which the adapter itself in a bucket for a working machine for performing excavation and the like covers/conceals the edge portion of the bucket and has a function of covering/concealing the edge portion of the bucket and a bucket which can be attached to the working machine for performing excavation and the like.

[Solution to Solve the Problem]

The present invention is an adapter with concealing portion at a bucket tip end attached to the edge portion of the bucket for an operation performing excavation and the like and a bucket to be attached to a working machine for performing excavation and the like, and particularly the adapter with concealing portion at the bucket tip end is composed of an adapter main body provided with an attachment portion to be attached to the edge portion of the bucket and a projecting body for attaching a point or a tooth board, projected from this attachment portion and a concealing portion integrally formed in a state projecting sideward from the attachment portion of the adapter main body and attached to this edge portion in a state covering the edge portion of the bucket on the side of the attachment portion and covering/concealing the edge portion.

[Advantageous Effects of Invention]

According to each of the inventions described in claims 1 to 5, an existing adapter function in this type of adapters, that is, a function as an adapter tool when a tooth board or a point is attached to an edge portion (tip end portion) of a bucket 1 is provided, and when the adapter is configured to cover/conceal the edge portion of the bucket when being used as an adapter when the tooth board is attached to the bucket so that abrasion of the edge portion of the bucket can be drastically eliminated, and the life of the bucket itself can be drastically extended and thus, a replacement period/replacement work of the bucket can be drastically extended, and as a result, cost reduction of this type of working machines can be realized.

Moreover, according to each of the inventions described in claims 1 to 5, a projecting dimension of the concealing portion in the adapter with concealing portion is not made uniform but by fabricating a plurality of adapters with concealing portion with varied projecting dimensions of the concealing portions in accordance with a width of the edge portion of the bucket in advance or, assuming that a width of the adapter with concealing portion is W1, a width of the adapter without concealing portion is W2, and a width of the edge portion of the bucket is W0, for example, by fabricating the adapter so that it is (W1×4)+W2<W0 and (W1×4)+W2 is 95 to 98% of W0, for example, when a plurality of adapters with concealing portion are used, interval adjustment between each of the adapter main bodies can be realized, and pitch adjustment of right and left adapter main bodies can be made possible.

According to each of the inventions described in claims 6 to 9, a bucket to be attached to a working machine for performing excavation and the like that can exert the effect of each of the inventions described in claims 1 to 5 can be realized and provided by combining and lining-up an adapter with concealing portion and an adapter without concealing portion on an edge portion of the bucket.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an outline perspective view illustrating a bucket in which an adapter with concealing portion and an adapter without concealing portion are attached to an edge portion in an embodiment of the present invention.

FIG. 2 is an outline plan view of the adapter with concealing portion according to this embodiment.

FIG. 3 is an outline side view of the adapter with concealing portion according to this embodiment.

FIG. 4 is an outline rear view of the adapter with concealing portion according to this embodiment.

FIG. 5 is an outline plan view of the adapter without concealing portion according to this embodiment.

FIG. 6 is an outline side view of the adapter without concealing portion according to this embodiment.

FIG. 7 is an outline rear view of the adapter without concealing portion according to this embodiment.

FIG. 8 is an explanatory diagram illustrating a dimensional relationship in a width direction in the adapter with concealing portion, the adapter without concealing portion, and the edge portion of the bucket in this embodiment.

FIG. 9 is an outline perspective view illustrating a state in which the adapter with concealing portion and the adapter without concealing portion in this embodiment are attached to the edge portion of the bucket and moreover, a tooth board is attached to each of the adapters.

FIG. 10 is an outline perspective view illustrating a state in which the adapter with concealing portion and the adapter without concealing portion in this embodiment are attached to the edge portion of the bucket and moreover, a point is attached to each of the adapters.

FIG. 11 is a variation according to the embodiment and is an outline plan view of the adapter with a lateral pinhole type concealing portion.

FIG. 12 is a variation according to the embodiment and is an outline side view of the adapter with a lateral pinhole type concealing portion.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[Description of Embodiment]

The present invention achieves an object of providing an adapter with an adapter with concealing portion at a bucket tip end having a function of covering/concealing an edge portion of a bucket (tip end portion of a bucket) continuing to a side of the edge portion to be covered/concealed by the adapter itself in the bucket of a working machine performing excavation and the like and the bucket to be attached to the working machine for performing excavation and the like by a configuration of the adapter with concealing portion at the bucket tip end attached/mounted on the edge portion of the bucket for an operation performing excavation and the like, provided with an adapter main body including an attachment portion in which an adapter main body recess portion is attached to the edge portion of the bucket and a vertical pinhole type or a lateral pinhole type projecting body projected from this attachment portion and attaching a point or a tooth board; and a concealing portion integrally formed in a state projecting sideward from the attachment portion of the adapter main body and provided with concealing portion recess portion having a shape similar to that of the adapter main body recess portion, in which the concealing-portion recess portion is attached to the edge portion of the bucket (tip end portion of the bucket) in a state covering the edge portion on the side of the attachment portion for covering/concealing the edge portion.

[Embodiment]

An adapter with concealing portion at a bucket tip end and a bucket to be attached to a working machine performing excavation and the like according to an embodiment of the present invention will be described below in detail by referring to the attached drawings.

FIG. 1 illustrates a bucket 1 in a state in which four, for example, adapters 11 with concealing portion at a bucket tip end in this embodiment (hereinafter referred to as “adapter with concealing portion”) are used, while one, for example, adapter 21 without concealing portion at a bucket tip end (hereinafter referred to as “adapter without concealing portion”) used in combination with this adapter 11 with concealing portion is used, and they are lined up on an edge portion 2 of the bucket and attached.

The adapter 11 with concealing portion will be described in detail by referring to FIGS. 2 to 4.

The adapter 11 with concealing portion is provided with an adapter main body 14 including an attachment portion 12 in which an adapter main body recess portion 12a is attached to the edge portion 2 of the bucket 1 so as to cover the edge portion 2 and a projecting body 13 projected forward from this attachment portion 12; and a concealing portion 15 integrally formed in a state projecting to the left side in FIG. 2 (direction orthogonal to the adapter main body 14) from the attachment portion 12 of the adapter main body 14 and provided with concealing portion recess portion 16 having a shape similar to that of the adapter main body recess portion 12a, in which the concealing-portion recess portion 16 is attached to the edge portion 2 in a state covering the edge portion 2 on the side of the attachment portion 12 for covering/concealing the edge portion 2.

That is, the adapter main body recess portion 12a of the adapter main body 14 and the concealing-portion recess portion 16 of the concealing portion 15 form a U-shaped space corresponding to the shape of the edge portion 2 of the bucket 1 on a side view as illustrated in FIG. 3, and the adapter main body recess portion 12a and the concealing-portion recess portion 16 are configured to cover/conceal the edge portion 2 of the bucket 1 with dimensions corresponding to a width W1 of the adapter 11 with concealing portion as illustrated in FIGS. 2 and 8.

In the projecting body 13, a vertical pinhole 13a for connecting/fixing a point 31 or a tooth board 41 which will be described later is provided.

The adapter 11 with concealing portion in the present invention may be configured as an adapter 11A with concealing portion in which a lateral pinhole 13b for connecting/fixing a lateral pinhole type point or a tooth board is provided instead of the vertical pinhole 13a as illustrated in FIGS. 11 and 12. In this case, the adapter 11A with concealing portion can be put into practice as an adapter provided with a projecting body for attaching the lateral pinhole type point or a tooth board. Since the adapter 11A with concealing portion illustrated in FIGS. 11 and 12 has each portion other than the lateral pinhole 13b similar to each portion illustrated in this embodiment, the same reference numerals to those of each portion in this embodiment are used.

Moreover, the projecting body 13 is formed having a tapered angle body shape with a dimension gradually decreasing as going toward a projecting end from the attachment portion 12 side.

Subsequently, the adapter 21 without concealing portion will be described by referring to FIGS. 5 to 7.

The adapter 21 without concealing portion has a configuration similar to that of a well-known adapter and is provided with an adapter main body 24 including an attachment portion 22 in which an adapter main body recess portion 22a is attached to the edge portion 2 of the bucket 1 so as to cover the edge portion 2 and fixed by welding or the like and a projecting body 23 projected forward from this attachment portion 22.

That is, the adapter 21 without concealing portion is configured without the concealing portion 15 of the adapter 11 with concealing portion described above.

In the projecting body 23, a vertical pinhole 23a for connecting/fixing the point 31 or the tooth board 41 which will be described later is provided.

Moreover, the projecting body 23 is formed having a tapered angle body shape with a dimension gradually decreasing as going toward a projecting end from the attachment portion 22 side.

Subsequently, a dimensional relationship in a width direction (end edge direction of the edge portion 2) among the four adapters 11 with concealing portion, for example, and one adapter 21 without concealing portion, for example, and the edge portion 2 of the bucket 1 will be described by referring to FIG. 8.

As illustrated in FIG. 8, assuming that a width of the adapter 11 with concealing portion is W1, a width of the adapter 21 without concealing portion is W2, and a width of the edge portion 2 of the bucket 1 is WO, for example, by setting the dimensions as (W1×4)+W2<W0 and (W1×4)+W2 is 95 to 98% of W0, for example, substantially a whole region of the edge portion 2 of the bucket 1 can be concealed by the four adapters 11 with concealing portion, for example, and the one adapter 21 without concealing portion, for example.

Subsequently, a specific use mode of the bucket 1 in which the adapter 11 with concealing portion and the adapter 21 without concealing portion of this embodiment are attached to the edge portion 2 will be described by referring to FIGS. 9 and 10.

FIG. 10 illustrates a state in which the four adapters 11 with concealing portion, for example, and the one adapter 21 without concealing portion, for example, in this embodiment are attached to the edge portion 2 of the bucket 1, and moreover, five well-known points 31 in total for ground excavation, for example, to each of the adapters 11 with concealing portion and the adapter 21 without concealing portion are detachably attached to each on the basis of the vertical pin-connection type configuration.

The point 31 is provided with a base portion 32 to be attached to the projecting body 13 of the adapter 11 with concealing portion or the projecting body 23 of the adapter 21 without concealing portion and a projecting blade body 33 projected forward from this base portion 32 and is configured as a well-known vertical pin-connection type to be detachably attached to the point 31.

Moreover, FIG. 9 illustrates a state in which the four adapters 11 with concealing portion, for example, and the one adapter 21 without concealing portion, for example, in this embodiment are attached to the edge portion 2 of the bucket 1 and moreover, five (five sets) well-known tooth boards 41 for spreading and grading work in total are detachably attached to each of the adapter 11 with concealing portions and the adapter 21 without concealing portion on the basis of the vertical pin-connection type configuration.

The tooth board 41 is constituted by a well-known configuration in which a base portion 42 to be attached to the projecting body 13 of the adapter 11 with concealing portion and the projecting body 23 of the adapter 21 without concealing portion, a grading plate 43 having a blade portion 44 on the tip end side integrally formed with the base portion 42, and a sandwiching connection portions 45 integrally formed with the grading plate 43 and sandwiching the grading plate 43 of the adjacent tooth board 41 are provided and configured as the well-known vertical pin-connection type to be detachably attached to the point 31.

According to the adapter 11 with concealing portion and the bucket 1 according to this embodiment described above, the following working effects are exerted.

That is, according to the adapter 11 with concealing portion according to this embodiment, as described above, the concealing portion 15 is configured to be integrally formed in a state projecting sideward from the attachment portion 12 of the adapter main body 14 and thus, by combining a plurality of (four, for example) the adapters 11 with concealing portion according to this embodiment and the adapter 21 without concealing portion, as illustrated in FIG. 9, substantially the whole region of the edge portion 2 of the bucket 1 can be covered/concealed, whereby the existing adapter function in this type of adapters, that is, the function as an adapter tool when the tooth board 41 or the point 31 is attached to the edge portion 2 (tip end portion) of the bucket 1 is provided, and when it is used as an adapter when the tooth board 41 is attached to the bucket 1, the configuration of covering/concealing the edge portion 2 of the bucket 1 can drastically eliminate abrasion of the edge portion 2 of the bucket 1 and can drastically extend a life of the bucket 1 itself so that a replacement period/replacement work of the bucket 1 can be drastically extended and as a result, cost reduction of this type of working machines can be realized.

Moreover, according to the adapter 11 with concealing portion according to this embodiment, the projecting dimension of the concealing portion 15 in the adapter 11 with concealing portion is not made uniform but by fabricating the plurality of adapters 11 with concealing portion with varied projecting dimensions of the concealing portions 15 in accordance with the width of the edge portion 2 of the bucket 1 in advance or, assuming that the width of the adapter 11 with concealing portion is W1, the width of the adapter 21 without concealing portion is W2, and the width of the edge portion 2 of the bucket 1 is W0 as illustrated in FIG. 8, for example, by fabricating the adapter so that it is (W1×4)+W2<W0 and (W1×4)+W2 is 95 to 98% of WO, for example, when the plurality of adapters 11 with concealing portion are used, interval adjustment between each of the adapter main bodies 14 can be realized, and pitch adjustment of right and left adapter main bodies 14 can be made possible.

Regarding the adapter 11 with concealing portion, the example in which the concealing portion 15 is formed by projecting to the left side from the attachment portion 12 of the adapter main body 14 is explained as illustrated in FIGS. 1 and 2, but a configuration in which the concealing portion 15 is formed by projecting to the right side from the attachment portion 12 of the adapter main body 14 also exerts the effect similar to that described above.

Moreover, in the example illustrated in FIG. 1, the example in which the four adapters 11 with concealing portion and the one adapter 21 without concealing portion are used is illustrated, but the number of the adapters 11 with concealing portion and the adapters 21 without concealing portion in use are not particularly limited but can be changed in various ways in accordance with the width of the edge portion 2 of the bucket 1 to be used.

INDUSTRIAL APPLICABILITY

The present invention can be widely applied to various types of buckets used for working machines performing excavation and the like such as a power shovel, a shovel loader and the like.

REFERENCE SIGNS LIST

1 bucket

2 edge portion

11 adapter with concealing portion

11A adapter with concealing portion

12 attachment portion

12a adapter main body recess portion

13 projecting body

13a vertical pinhole

13b lateral pinhole

14 adapter main body

15 concealing portion

16 concealing-portion recess portion

21 adapter without concealing portion

22 attachment portion

22a adapter main body recess portion

23 projecting body

23a vertical pinhole

24 adapter main body

31 point

32 base portion

33 projecting blade body

41 tooth board

42 base portion

43 grading plate

44 blade portion

45 sandwiching connection portion

W0 width of edge portion

W1 width of adapter with concealing portion

W2 width of adapter without concealing portion

Claims

1. An adapter with concealing portion at a bucket tip end to be attached to an edge portion of a bucket for an operation performing excavation and the like, comprising:

an adapter main body provided with an attachment portion to be attached to the edge portion of said bucket and a projecting body for attaching a tooth board or a point, projected from this attachment portion; and

a concealing portion integrally formed in a state projecting sideward from the attachment portion of said adapter main body and configured to be attached to this edge portion in a state covering the edge portion of the bucket on the side of said attachment portion and concealing said edge portion.

2. An adapter with concealing portion at a bucket tip end to be attached to an edge portion of a bucket for an operation performing excavation and the like, comprising:

an adapter main body provided with an attachment portion in which an adapter main body recess portion is attached to the edge portion of said bucket and a vertical pinhole type or lateral pinhole type projecting body for attaching a tooth board or a point, projected from this attachment portion; and

a concealing portion integrally formed in a state projecting sideward from the attachment portion of said adapter main body, provided with a concealing-portion recess portion having a shape similar to that of said adapter main body recess portion, and configured such that the concealing-portion recess portion is attached to this edge portion in a state covering the edge portion of the bucket on the side of said attachment portion and conceals said edge portion.

3. The adapter with concealing portion at a bucket tip end according to claim 1, wherein

said concealing portion is integrally formed in a state projecting to a left side or a right side with respect to the adapter main body.

4. The adapter with concealing portion at a bucket tip end according to claim 1, wherein

a plurality of said adapters with concealing portion at a bucket tip end and one or two or more adapters without concealing portion at a bucket tip end not provided with a concealing portion and having a portion other than this with the same configuration as that of the adapter with concealing portion are configured to conceal the edge portion of said bucket.

5. The adapter with concealing portion at a bucket tip end according to claim 1, wherein

four units of said adapters with concealing portion at a bucket tip end and one unit of the adapter without concealing portion at a bucket tip end not provided with a concealing portion and having a portion other than this with the same configuration as that of the adapter with concealing portion are configured to conceal the edge portion of said bucket.

6. A bucket to be attached to a working machine performing excavation and the like, characterized in that

adapters with concealing portion having an adapter main body provided with an attachment portion to be attached to an edge portion of a bucket itself and a projecting body for attaching a tooth board or a point, projected from this attachment portion and a concealing portion integrally formed in a state projecting sideward from the attachment portion of said adapter main body and configured to be attached to this edge portion in a state covering the edge portion of the bucket on the side of said attachment portion and to conceal said edge portion are provided in the required number matching a width size of the bucket.

7. A bucket to be attached to a working machine performing excavation and the like, comprising:

a plurality of adapters with concealing portion at a bucket tip end each having an adapter main body provided with an attachment portion in which an adapter main body recess portion is attached to the edge portion of said bucket and a vertical pinhole type or lateral pinhole type projecting body for attaching a tooth board or a point, projected from this attachment portion;

and a concealing portion integrally formed in a state projecting sideward from the attachment portion of said adapter main body, provided with a concealing-portion recess portion having a shape similar to that of said adapter main body recess portion, and configured such that the concealing-portion recess portion is attached to this edge portion in a state covering the edge portion of the bucket on the side of said attachment portion and conceals said edge portion; and

one or two or more adapters without concealing portion at a bucket tip end not provided with said concealing portion and having a portion other than this with the same configuration as that of the adapter with concealing portion.

8. The bucket to be attached to a working machine performing excavation and the like according to claim 7, wherein

four units of said adapters with concealing portion at a bucket tip end and one unit of the adapter without concealing portion at a bucket tip end are lined up and fixed to an edge portion of said bucket and configured to conceal the edge portion of this bucket.

9. The bucket to be attached to a working machine performing excavation and the like according to claim 6, wherein

a concealing portion of said adapter with concealing portion at a bucket tip end is integrally formed in a state projecting to a left side or a right side with respect to an adapter main body.

10. The adapter with concealing portion at a bucket tip end according to claim 2, wherein

said concealing portion is integrally formed in a state projecting to a left side or a right side with respect to the adapter main body.

11. The adapter with concealing portion at a bucket tip end according to claim 2, wherein

a plurality of said adapters with concealing portion at a bucket tip end and one or two or more adapters without concealing portion at a bucket tip end not provided with a concealing portion and having a portion other than this with the same configuration as that of the adapter with concealing portion are configured to conceal the edge portion of said bucket.

12. The adapter with concealing portion at a bucket tip end according to claim 2, wherein

said concealing portion is integrally formed in a state projecting to a left side or a right side with respect to the adapter main body; and

a plurality of said adapters with concealing portion at a bucket tip end and one or two or more adapters without concealing portion at a bucket tip end not provided with a concealing portion and having a portion other than this with the same configuration as that of the adapter with concealing portion are configured to conceal the edge portion of said bucket.

13. The adapter with concealing portion at a bucket tip end according to claim 2, wherein

four units of said adapters with concealing portion at a bucket tip end and one unit of the adapter without concealing portion at a bucket tip end not provided with a concealing portion and having a portion other than this with the same configuration as that of the adapter with concealing portion are configured to conceal the edge portion of said bucket.

14. The adapter with concealing portion at a bucket tip end according to claim 2, wherein

said concealing portion is integrally formed in a state projecting to a left side or a right side with respect to the adapter main body; and

four units of said adapters with concealing portion at a bucket tip end and one unit of the adapter without concealing portion at a bucket tip end not provided with a concealing portion and having a portion other than this with the same configuration as that of the adapter with concealing portion are configured to conceal the edge portion of said bucket.

15. The bucket to be attached to a working machine performing excavation and the like according to claim 7, wherein

a concealing portion of said adapter with concealing portion at a bucket tip end is integrally formed in a state projecting to a left side or a right side with respect to an adapter main body.

16. The bucket to be attached to a working machine performing excavation and the like according to claim 7, wherein

four units of said adapters with concealing portion at a bucket tip end and one unit of the adapter without concealing portion at a bucket tip end are lined up and fixed to an edge portion of said bucket and configured to conceal the edge portion of this bucket; and

a concealing portion of said adapter with concealing portion at a bucket tip end is integrally formed in a state projecting to a left side or a right side with respect to an adapter main body.