Cover component

Abstract

The present invention provides a novel cover member that can be easily attached to a component to be covered, even if the component to be covered is bent. [Solution] The cover member 10 is attached to cover the outer surface of the bent tube-shaped member 1, and comprises a cover body 11, a plurality of band pieces 23, 25 that can be wrapped around the cover body 11, and protrusions 24, 26 for wrapping and fixing the band pieces 23, 25. The cover body 22 comprises a main cover portion 20 and an extended cover portion 21, and the protrusion 24 corresponding to the main cover portion 20 and the protrusion 26 corresponding to the extended cover portion 21 have the same protruding direction.

Description

TECHNICAL FIELD

[0001] The present invention relates to a cover member that covers the outer surface of a member to be coated. BACKGROUND ART

[0002] Conventionally, various techniques have been proposed for covering the outer surface of a member to be coated such as a pipe with a cover member, for the purpose of sealing for waterproofing, corrosion protection, etc., or insulation. Patent Document 1 discloses a technique for coating a metal pipe using a cover member made of a corrosion-resistant polyethylene sheet.

[0003] As disclosed in Patent Document 1 and the like, it is customary for the conventional coating technique using this type of cover member to use a general-purpose sheet to wrap around and coat the member to be coated, and it can be applied to pipe coating of various dimensions. PRIOR ART DOCUMENTS PATENT DOCUMENTS

[0004] PATENT DOCUMENT 1 Japanese Unexamined Patent Publication No. 2018-112273 SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION

[0005] However, when the member to be coated is bent midway, even if a sheet with adjusted dimensions and shape is used, there is a risk that the work of wrapping the entire pipe will require a large number of man-hours.

[0006] The present invention has been proposed in view of such circumstances, and its purpose is to provide a novel cover member that can be easily assembled to the member to be coated even when the member to be covered is bent. Furthermore, another object is to form the cover member into a shape that allows easy removal from the mold (demolding) during manufacturing using a mold. MEANS FOR SOLVING THE PROBLEMS

[0007] To achieve the above objective, the cover member of the present invention is a cover member integrally formed of an elastic material that is attached to cover the outer surface of a bent tube-shaped member to be covered, and comprises at least a cover body made up of a plurality of halves connected together for covering the member to be covered, a plurality of band pieces that can be wrapped around the cover body, and projections for wrapping and fixing the band pieces, wherein the cover body comprises a main cover portion and an extended cover portion extending from one end of the main cover portion via a bent portion, depending on the shape of the member to be covered, and the band pieces are provided with recesses that engage with the projections corresponding to the main cover portion and the extended cover portion, respectively, and the projections corresponding to the main cover portion and the projections corresponding to the extended cover portion have the same projection direction. [Effects of the Invention]

[0008] Because the cover member of the present invention has the configuration described above, it can be easily assembled to the member to be covered, even if the member to be covered is bent. Furthermore, in the case of this cover member, it is easy to remove the product from the mold when demolding during the manufacturing of the cover member using a mold. [Brief explanation of the drawing]

[0009] [Figure 1] This is a perspective view showing the unfolded state of the cover member according to the first embodiment of the present invention. [Figure 2] This is a cross-sectional view corresponding to line AA in Figure 1. [Figure 3] (a) and (b) are cross-sectional views corresponding to line AA in Figure 1, showing the assembly procedure (1 / 2) of the cover member on the member to be covered in Figure 1. [Figure 4] (a) and (b) are cross-sectional views corresponding to line BB in Figure 1, showing the assembly procedure (2 / 3) of the cover member on the member to be covered in Figure 1. [Figure 5](a) and (b) are perspective views showing the assembly procedure (3 / 3) of the cover member in Figure 1 with respect to the member to be covered. [Figure 6] (a) and (b) are schematic longitudinal cross-sectional views showing the molding procedure (mold opening procedure) of the cover member in Figure 1, and (c) is a schematic longitudinal cross-sectional view showing the molding procedure (mold opening procedure) of a cover member used for comparison. [Figure 7] (a) is a perspective view of a cover member according to a second embodiment of the present invention, and (b) is a cross-sectional view corresponding to the CC line in (a). [Figure 8] This is a perspective view showing the unfolded state of the cover member according to the third embodiment of the present invention. [Modes for carrying out the invention]

[0010] Several embodiments of the present invention will be described below with reference to the accompanying drawings. First, the basic configuration of the cover member 10 according to the various embodiments described below will be explained.

[0011] The cover member 10 is a member integrally formed from an elastic material that is attached to cover the outer surface of the bent tube-shaped member 1. The cover member 10 comprises at least a cover body 11 made up of multiple halves connected together for covering the member 1, multiple band pieces 23, 25 that can be wrapped around the cover body 11, and protrusions 24, 26 for wrapping and fixing the band pieces 23, 25.

[0012] The cover body 11 comprises a main cover portion 20 and an extended cover portion 21 extending from one end of the main cover portion 20 via a bent portion 22, depending on the shape of the member to be covered 1. The band pieces 23 and 25 are provided with recesses 23b and 25b that engage with projections 24 and 26, respectively, corresponding to the main cover portion 20 and the extended cover portion 21. The projection 24 corresponding to the main cover portion 20 and the projection 26 corresponding to the extended cover portion 21 have the same projection direction.

[0013] In the following description, the vertical direction is defined based on FIG. 1 and FIG. 2, where the main body cover portion 20 has a half-split chevron-shaped protruding form, with its convex side facing upward and the concave side on the inner side of the main body cover portion 20 facing downward for explanation.

[0014] All the cover members 10 according to the following multiple embodiments are configured to cover the member 1 to be coated, which is made of a metal tubular material (pipe). This member 1 to be coated is, for example, a component provided as an interior part of an electric vehicle or the like, and the cover member 10 is attached thereto for the purpose of insulation.

[0015] Examples of the elastic material that is the material of the cover member 10 include rubber materials, flexible synthetic resin materials, and the like. The member 1 to be coated may be made of resin, and the cover member 10 can also be used for the purpose of preventing deterioration of the resin pipe in a high-temperature environment.

[0016] Next, the detailed shape and structure of the cover member 10 according to the first embodiment will be described with reference to FIG. 1 and FIG. 2. FIG. 1 is a perspective view showing the deployed state of the cover member 10 before being assembled to the member 1 to be coated. FIG. 2 is a cross-sectional view taken along line A-A in FIG. 1.

[0017] The present cover member 10 includes a cover main body 11 that is a half-split exterior piece, and also includes a cover inner body 12 that is a half-split interior piece, which are connected to each other by two connecting pieces 28. Like the cover main body 11, the cover inner body 12 also has a bent shape, and includes a main body interior portion 30, an extended interior portion 31, and a bent portion 32.

[0018] In both the main body cover portion 20 and the extended cover portion 21, the cover main body 11 includes a peak portion 20a having a substantially triangular chevron shape in cross-sectional view, and leg portions 20c extending downward from both sides in the width direction of the peak portion 20a. The peak portion 20a has a bilaterally symmetrical shape and has a ridge-shaped top portion 20b. This top portion 20b faces upward. On the other hand, in both the main body interior portion 30 and the extended interior portion 31, the cover inner body 12 has a semicircular shape in cross-sectional view.

[0019] In the unfolded state before the cover member 10 is mounted on the member 1 to be covered, as shown in Figures 1 and 2, the main body cover portion 20 and the main body interior portion 30 are connected via two connecting pieces 28 so as to be parallel in plan view and aligned without vertical misalignment in side view. On the other hand, the extending cover portion 21 and the extending interior portion 31 are parallel in plan view, and extend away from each other along the direction away from the bent portions 22, 32 in side view.

[0020] In other words, both the top 20b of the peak portion 20a of the main body cover portion 20 and the top 30a of the main body interior portion 30 are formed along the same direction, and face upward. Note that such a shape is also the same for the cover member 10 according to other embodiments described later.

[0021] Further, the band pieces 23, 25 are attached to the side surfaces of the main body cover portion 20 and the extending cover portion 21 of the cover main body 11 on the side opposite to the connection side of the respective cover interior bodies 12. The band pieces 23, 25 are made of a strip plate material, and are fasteners for winding and fixing around the cover main body 11 and the cover interior body 12 that cover the member 1 to be covered.

[0022] The band piece 23 provided on the main body cover portion 20 has its longitudinal end connected to the lower end of the peak portion 20a of the main body cover portion 20 (the boundary portion between the peak portion 20a and the leg portion 20c) so as to extend in the width direction of the main body cover portion 20.

[0023] Further, as shown in Figures 1 and 2, the band piece 23 has a band-shaped band main body 23a. The band piece 23 has a protrusion 24 protruding in the same direction as the protruding direction of the top 20b of the peak portion 20a, near the end of the band main body 23a on the main body cover portion 20 side, and has a recess 23b for fitting the protrusion 24 therein near the open end. Further, on the further open end side of the recess 23b, a grip portion 23c with anti-slip unevenness on both surfaces is formed.

[0024] In this illustrated example, the projection 24 is mushroom-shaped, comprising a head 24a and a body 24b with a smaller outer diameter than the head 24a. The head 24a is tapered towards the tip. The recess 23b is a through-hole with a diameter smaller than the maximum outer diameter of the head 24a and larger than the minimum outer diameter of the head 24a. In other words, the tapered surface can serve as a guide surface when engaging the projection 24 with the recess 23b.

[0025] The head portion 24a is fitted into the body portion 24b by pushing its tip into the through hole. Once the head portion 24a is fitted into the recess 23b, the inner edge of the recess 23b catches on the head portion 24a, and it cannot be easily removed unless the band body 23a is pulled. Thus, it is desirable that the projection 24 has a neck portion that the head portion 24a can catch on.

[0026] The band piece 25 provided on the extended cover portion 21 has its longitudinal end connected to either the boundary between the peak portion 21a and the leg portion 21c of the extended cover portion 21, or to one of them, so as to extend in the width direction of the extended cover portion 21.

[0027] Furthermore, the band body 25a, recess 25b, and gripping portion 25c of the band piece 25 of the extended cover portion 21 are generally the same shape and configuration as those of the main cover portion 20, and the shape and configuration of the projection 26, which consists of a head portion 26a and a body portion 26b, are also generally the same as those of the main cover portion 20.

[0028] For both the main body cover portion 20 and the extended cover portion 21, the orientation of the plate surfaces 23d and 25d of the band bodies 23a and 25a, the protruding direction of the protrusions 24 and 26, and the orientation of the recesses 23b and 25b are the same as shown in Figures 1 and 2, and furthermore, their orientations are substantially the same as the protruding direction of the top portion 20b of the main body cover portion 20.

[0029] In short, the two protrusions 24 and 26 face the same direction relative to each other, stand approximately perpendicular to the plate surfaces 23d and 25d of the band pieces 23 and 25, and also protrude upward in a direction approximately perpendicular to the top 20b of the main body cover portion 20.

[0030] Furthermore, in this cover member 10, the two band pieces 23 and 25 are formed parallel to each other in a plan view and also parallel to each other in a front view (AA cross-sectional view) (see Figures 1 and 2).

[0031] Furthermore, the two connecting pieces 28 are fixed between the main body cover portion 20 and the main body interior portion 30, and are arranged to be substantially parallel to each other in a plan view, with the longitudinal direction of the connecting piece 28 being substantially perpendicular to the direction in which the main body cover portion 20 extends. The two connecting pieces 28 are substantially the same width and thickness. Each connecting piece 28 has a fold portion 28a formed on it, which is thinner and thicker than the other parts to make it easier to fold.

[0032] The space between the connecting pieces 28 is a band-passing space 28b, and a band-passing portion 20d is formed at the position of the main body cover portion 20 corresponding to the band-passing space 28b by cutting out a part of the leg portion 20c.

[0033] Next, an example of the procedure for assembling the cover member 10 onto the member to be covered will be explained with reference to Figures 3 to 5.

[0034] Figure 3 is a cross-sectional view corresponding to line AA in Figure 1, illustrating the assembly of the cover body 11 and the cover interior 12, specifically the assembly of the main cover portion 20 and the main interior portion 30 to the member to be covered. In this figure, the extended cover portion 21 and the extended interior portion 31 are omitted from the illustration.

[0035] Figure 4 is a cross-sectional view corresponding to line BB in Figure 1, illustrating the assembly of the cover body 11 and the cover interior 12, specifically the assembly of the extended cover portion 21 and the extended interior portion 31 to the member to be covered 1. Figures 5(a) and 5(b) are perspective views of the entire cover member showing the assembly procedure to the member to be covered 1.

[0036] First, as shown in Figure 3(a), the main body interior part 30 is temporarily attached to the member to be covered 1, and while bending both connecting pieces 28 at the fold portion 28a, the main body cover part 20 and the main body interior part 30 are rotated relative to each other so that the member to be covered 1 is held by the main body cover part 20 and the main body interior part 30, as shown in Figure 3(b).

[0037] As shown in Figure 3(b), when the member to be covered 1 is held by the main body cover portion 20 and the main body interior portion 30, each of the connecting pieces 28 is folded and overlapping, and the connecting portion between the connecting piece 28 and the main body interior portion 30 is recessed into the inner space of the main body cover portion 20 together with the main body interior portion 30.

[0038] Furthermore, as shown in Figure 3(b), when the main body cover portion 20 and the main body interior portion 30 are holding the member to be covered, an overlapping portion 35 is formed where the main body cover portion 20 and the main body interior portion 30 overlap each other.

[0039] Before the band piece 23 is wrapped around the main body cover 20 and the main body interior 30, it is desirable that the dimensions of the overlapping portion 35 be such that there is a gap between the main body cover 20 and the main body interior 30. This is to prevent poor sliding between the rubber parts when attaching them.

[0040] Next, as shown in Figure 3(b), grasp the gripping portion 23c of the band piece 23 with your fingers, wrap the band body 23a from the main body interior portion 30 side through the band passing portion 20d of the leg portion 20c and through the band passing space 28b between the connecting pieces 28 to the main body cover portion 20 side, and fit the recess 23b into the protrusion 24 to complete the assembly of the main body cover portion 20 and the main body interior portion 30.

[0041] Next, with reference to Figure 4, the assembly of the extended cover portion 21 and the extended interior portion 31 to the member to be covered will be explained.

[0042] Figure 4(a) shows the state in which the member to be covered 1 is held by the extended cover portion 21 and the extended interior portion 31. The assembly procedure for the member to be covered 1 by the extended cover portion 21 and the extended interior portion 31 is generally the same as in Figure 3, so it has been omitted from the illustration.

[0043] Furthermore, the leg portion 21c of the extended cover portion 21 also has a band-passing portion 21d for passing the band piece 25 through. Also, the extended cover portion 21 and the extended interior portion 31 are not connected by a connecting piece 28, and therefore there is no band-passing space 28b like the one on the main body cover portion 20 side.

[0044] Since the orientation of the plate surface 25d of the band piece 25 is the same as the orientation of the plate surface 23d of the band piece 23 of the main body cover portion 20, as shown in Figure 4(a), in the cross-sectional view along line BB in Figure 1, the plate surface 25d of the band piece 25 is inclined with respect to the ridge direction of the top portion 21b of the extended cover portion 21 (the direction in which the top portion 21b extends).

[0045] As shown in Figure 4(b), twist the band piece 25 at its base 25e, align the plate surface 25d of the band piece 25 with the protruding direction of the top 21b of the extended cover portion 21, and then wrap it around the extended cover portion 21 and the extended interior portion 31 that are holding the member to be covered 1.

[0046] As the cover member 10 is made of a flexible elastic material, the band piece 25 can be easily twisted at its base 25e as shown in Figure 4(b), and can be wrapped in a manner similar to that of the main body cover portion 20 as shown in Figure 5(b).

[0047] The reason why both band pieces 23 and 25 are oriented in the same direction is due to the manufacturing reasons which will be explained next. These reasons will be explained with reference to Figure 6. Figures 6(a) and 6(b) are schematic longitudinal cross-sectional views showing the manufacturing method of the cover member 10 using the mold 40, in particular the die-cutting procedure for the band pieces 23 and 25. In Figures 6(a) and 6(b), 41 is the upper mold and 42 is the lower mold. Figure 6(b) shows the state with the upper mold 41 removed.

[0048] Figure 6(c) is a schematic longitudinal cross-sectional view showing the die-cutting procedure of another cover member 10A, which is used as a comparison for the cover member 10. In this cover member 10A, the plate surface 23d and projection 24 of the band piece 23 of the main cover portion 20 face the direction of protrusion of the top portion 20b of the main cover portion 20, and the plate surface 25d and projection 26 of the band piece 25 of the extension cover portion 21 face the direction of protrusion of the top portion 21b of the extension cover portion 21.

[0049] As shown in Figure 6(c), in the other cover member 10A, the plate surfaces 23d and 25d of the two band pieces 23 and 25 face in opposite directions, and consequently, the two protrusions 24 and 26 also face in opposite directions. Therefore, they must be individually die-cut in opposite directions (directions of the left and right arrows in the figure), which is time-consuming.

[0050] In the case shown in Figure 6(c), in order to efficiently die-cut the band pieces 23 and 25, one could, for example, die-cut them in the direction of the die-cutting of the main body cover portion 20 (the arrow on the right in the figure). However, if one attempts to die-cut in that direction, the protrusion 26 of the band piece 25 of the extended cover portion 21 may be damaged. In particular, the head portion 26a may break off. Furthermore, if die-cut in such a way, the band body 25a may also become difficult to remove.

[0051] On the other hand, in the case of the cover member 10, as shown in Figures 6(a) and 6(b), the plate surfaces 23d and 25d of both band pieces 23 and 25, and the protrusions 24 and 26 provided on them, respectively, are facing in substantially the same direction. Therefore, if both band pieces 23 and 25 are die-cut in the same direction (in the direction of the arrow in the figure), efficient die-cutting can be performed. This will be explained in detail.

[0052] First, when the upper mold 41 is opened, the stress applied to the protrusions 24 and 26 becomes uniform in the circumferential direction, making them less susceptible to damage such as cracks (see Figures 6(a) and 6(b)). Then, when removing the product from the lower mold 42, if both band pieces 23 and 25 are pulled straight up (in the direction of the arrows in Figure 6(b)), the stress applied to the protrusions 24 and 26 becomes uniform in the circumferential direction, making them less susceptible to damage. In other words, there is almost no risk of uneven stress on the protrusions 24 and 26 from the time the mold is opened until the product is removed.

[0053] In this way, by aligning the protruding directions of both protrusions 24 and 26 with the protruding direction of the top portion 20b of the main body cover portion 20, the protrusions 24 and 26 are less susceptible to damage during die-cutting, and productivity is clearly improved compared to the one shown in Figure 6(c), which requires die-cutting the protrusions 24 and 26 individually in different directions (the directions of the left and right arrows in the figure) when removing them.

[0054] Even when die-cutting in the same direction, there is some catching of the heads 24a and 26a, but because the cover member 10 is made of an elastic material, it is pulled out while undergoing elastic deformation, thus suppressing damage.

[0055] Next, the cover member 10 according to the second embodiment will be described with reference to Figure 7. Figure 7(a) is a perspective view of the cover member 10 showing the cover body 11 and the cover interior 12 in a state of temporary assembly (before fixing the band pieces 23 and 25), and Figure 7(b) is a cross-sectional view of Figure 7(a) along line CC. Note that this cover member 10 is a modified example of the cover member 10 in Figure 1.

[0056] In this cover member 10, the two band pieces 23 and 25 are not parallel in a plan view, unlike those in Figure 1. However, in a cross-sectional view along the CC line, both band pieces 23 and 25 are arranged parallel to each other, similar to those in Figure 1. The plate surfaces 23d and 25d and the protrusions 24 and 26 of both band pieces 23 and 25 face upward, that is, in the same direction as the protrusion of the top 20b of the main cover portion 20 (see Figures 7(a) and 7(b)).

[0057] Since the band piece 25 of the extended cover portion 21 extends so as to approach the band piece 23 of the main body cover portion 20 in a plan view, it can be wrapped around the extended cover portion 21 without deforming the base portion 25e.

[0058] In this cover member 10 as well, the plate surfaces 23d, 25d and protrusions 24, 26 of both band pieces 23, 25 are oriented in the same direction as the protruding direction of the top portion 20b of the main body cover portion 20, so that damage to the band pieces 23, 25 can be suppressed when they are die-cut.

[0059] Next, the cover member 10 according to the third embodiment will be described with reference to Figure 8. Figure 8 is a perspective view showing the unfolded state of the cover member 10.

[0060] In this cover member 10, the projection 24 is not formed on the band piece 23 of the main cover portion 20, but is formed on the top 20b of the peak portion 20a of the main cover portion 20. The recess 23b of the band piece 23 is formed closer to the main cover portion 20 than in Figure 1 so as to match the projection 24 on the top 20b. The band piece 25 of the extended cover portion 21 has a shape that is generally the same as that of Figure 1.

[0061] Furthermore, the two band pieces 23 and 25 are parallel in plan view, similar to those in Figure 1, and are also arranged parallel in cross-sectional view (cross-sectional view not shown), similar to those in Figure 1. The plate surfaces 23d and 25d of both band pieces 23 and 25, and the protrusions 24 and 26 of both band pieces 23 and 25, face upward, that is, in the same direction as the protrusion of the top 20b of the main body cover portion 20 (see Figures 1 and 2).

[0062] In this cover member 10 as well, similar to that in Figure 1, wrapping is possible by twisting the base 25e of the band piece 25 of the extended cover portion 21 to deform the band piece 25 as shown by the dashed line.

[0063] Thus, the protrusion 24 does not necessarily have to be formed on the plate surface 23d of the band piece 23. As long as it faces approximately the same direction as the protrusion direction of the top portion 20b of the main body cover portion 20, damage to the protrusions 24, 26 and the band pieces 23, 25 can be suppressed when the band piece 23 is die-cut.

[0064] The cover member 10 in the embodiments described above is merely an example, and other types are also acceptable.

[0065] As described above, by designing the cover member 10 so that the plate surfaces 23d, 25d and protrusions 24, 26 of the band pieces 23, 25 are oriented in the same direction, it becomes easier to design the mold 40 (mold splitting design).

[0066] Furthermore, only the two protrusions 24 and 26 may face the same direction; the plate surfaces 23d and 25d of the band pieces 23 and 25 may face different directions. In other words, the protrusions 24 and 26 do not have to protrude approximately perpendicularly to the plate surfaces 23d and 25d of the band pieces 23 and 25. This is because the protrusions 24 and 26 are more susceptible to damage during die-cutting than the band pieces 23 and 25.

[0067] Furthermore, although the protrusions 24 and 26 are shaped like mushrooms with heads 24a and 26a, the recesses 23b and 25b may be shaped in a way that allows them to be fitted and press-fitted into each other, such as a tapered shape with a diameter increasing towards the tip, or a cylindrical or prismatic shape.

[0068] Furthermore, although the cover member 10 according to the embodiment described above is attached so as to cover the entire circumference of the member to be covered 1 with the cover body 11 and the cover interior body 12, it is also possible to use only one half-shaped member and have that member serve as the cover body 11 to cover the member to be covered 1 in a state where a part of it is exposed.

[0069] Furthermore, it goes without saying that the overall shape of the cover member 10 can be modified as appropriate from a design perspective.

[0070] Furthermore, although cylindrical pipes were exemplified as the member to be covered 1 in the various embodiments described above, the material is not limited to this, and may be any other type of pipe shape, as long as it is a bent pipe.

[0071] Furthermore, the present invention is also applicable to a cover member 10 corresponding to a cover target member 1 that is bent in multiple stages. That is, the cover member 10 has three or more band pieces 23, 25, and the plate surfaces 23d, 25d and three or more protrusions 24, 26 of these band pieces 23, 25 are oriented in the same direction. [Explanation of Symbols]

[0072] 1. Member to be covered 10 Cover component 11 Cover body 20 Main body cover 20a Yamabe 20b Top 20c legs 20d band pass-through section 21 Extended cover portion 21a Yamabe 21b Top 21c Legs 21d Band threading section 22 Bending section 23 (Band piece on the main body cover) 23a Band body 23b Recess 23c Grip 23d plate surface 24 Protrusion 24a head 24b Torso 25 (Band piece on the main body cover) 25a Band body 25b Recess 25c grip part 25d plate surface 25e base 26. Protrusion 26a Head 26b Torso 28 Connecting piece 28a Folded section 28b Band passage space 40 molds 41 Upper mold 42 Lower mold

Claims

1. A cover member integrally formed from an elastic material, which is attached to cover the outer surface of a bent tube-shaped member to be covered, The device comprises at least a cover body made up of multiple halves connected together, a multiple band piece that can be wrapped around the cover body, and projections for wrapping and securing the band piece, The cover body comprises, depending on the shape of the member to be covered, a main cover portion and an extended cover portion extending from one end of the main cover portion via a bent portion. The band piece is provided with recesses that engage with the projections, corresponding to the main body cover portion and the extension cover portion, respectively. A cover member characterized in that the projection corresponding to the main body cover portion and the projection corresponding to the extension cover portion have the same projection direction.

2. In claim 1, The cover member is characterized in that the projection comprises a head portion and a body portion having a smaller outer diameter than the head portion.

3. In claim 1 or 2, The aforementioned band piece is made of strip material, The cover member is characterized in that the recess is a through hole, while the projection is arranged on the plate surface of the band piece.

4. In claim 1 The cover member is formed by a mold, A cover member characterized in that the direction of protrusion of the aforementioned projection is the direction of die-cutting.

5. In claim 1, The cover member is characterized in that the direction of the projection of the protrusion is the same as the direction in which the upper surface of either the main body cover portion or the extension cover portion faces.

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