Staple

Abstract

A staple according to the present disclosure is formed from a flexible wire material, and has a tip part engageable with an object to be drawn through deformation into a spiral shape so as to surround the object. A deformation promoting part is formed on: an inner peripheral part of the tip part to be opposed to the object in a post-deformation state; an outer peripheral part of the tip part on the opposite side of the inner peripheral part; or both of the inner peripheral part and the outer peripheral part.

Description

Staples

[0001] TECHNICAL FIELD The present disclosure relates to staples.

[0002] Staples are known for holding stems, vines, branches, etc. of plants, trees, etc. to guide elements such as wires, beams, strings, rods, pipes, tree branches, etc.

[0003] Patent Documents 1 to 3 disclose such staples and binding machines for binding using staples. The staple described in Patent Document 2 includes two legs and a main body (sometimes called a "crown") connecting the legs, and engages with a guide element (sometimes called an "object") by deforming the tip of one of the legs so that the tip advances spirally around the outer periphery of the object.

[0004] Japanese Patent Publication No. 2022-74007 Japanese Patent Publication No. 2023-13307 Japanese Patent Publication No. 2023-13317

[0005] However, when the staple is deformed, the tip portion may not deform into a spiral shape, or a load may be applied to other portions, causing the staple to buckle.

[0006] Therefore, an object of the present disclosure is to provide a staple that is easily deformed into a spiral shape.

[0007] The present application discloses a staple capable of holding plant stems, branches, etc. on a guide element, the staple being formed from a flexible wire and having a tip portion that can engage with an extending object by being deformed spirally to surround the object, the staple having a deformation-promoting portion formed on the inner periphery of the tip portion that faces the object after the deformation, on the outer periphery of the tip portion opposite the inner periphery, or on both the inner periphery and the outer periphery.

[0008] Here, a staple (sometimes called a "linear binding material") is formed from a flexible wire that can be plastically deformed, and includes a member (including those whose surfaces are plated or coated with resin, etc.) that engages with an object by deformation. Staples are also sometimes called wires, clips, wires, binding devices, etc.

[0009] The staple may have any shape including two legs and a connecting portion (sometimes called a crown portion) connecting the two legs. The two legs may be formed as parallel line segments, non-parallel line segments, curved lines, or a combination thereof. The crown portion may be formed linearly or curved. For example, the staple may have an asymmetric shape, as exemplified in this embodiment.

[0010] Binding also includes restraining relative movement between one object and another object using a staple. For example, binding of objects may be achieved by surrounding one object (which may be called a "second object," such as a plant) with a staple and engaging, for example, both ends (two tip ends) of the staple with the other object (which may be called a "first object," a "guide," or a "guide element," such as a wire, beam, string, rod, pipe, or tree branch).

[0011] The present disclosure provides a staple that is prone to helical deformation.

[0012] FIG. 1A is a plan view of a staple according to one embodiment in an undeformed state. FIG. 1B is an enlarged plan view of a staple tip according to one embodiment in an undeformed state. FIG. 1C is an enlarged side view (right side view) of a staple tip according to one embodiment in an undeformed state. FIG. 1D is an enlarged side view (left side view) of a staple tip according to one embodiment in an undeformed state. FIG. 1E is an enlarged view of the staple tip of FIG. 1B. FIG. 2A is a perspective view of a staple according to one embodiment in a deformed state. FIG. 2B is an enlarged plan view of a staple tip according to one embodiment in a deformed state. FIG. 2C is an enlarged side view (right side view) of a staple tip according to one embodiment in a deformed state. FIG. 2D is a perspective view of a staple tip according to one embodiment in a deformed state. FIG. 2E is a horizontal cross-sectional view (bottom view) of a staple tip according to one embodiment in a deformed state. FIG. 3 is a perspective view of a binding machine according to one embodiment. FIG. 4 is a horizontal cross-sectional view of a binding machine according to one embodiment. Fig. 5A is a perspective view of a staple according to a modified example, Fig. 5B is a perspective view of a staple according to a modified example, Fig. 5C is a perspective view of a staple according to a modified example, and Fig. 5D is a perspective view of a staple according to a modified example.

[0013] The following describes the configuration of a staple according to this embodiment and a binding machine for binding using this staple. However, as will be understood by those skilled in the art, this disclosure is not limited to the staple having the configuration shown in this embodiment. This disclosure is broadly applicable to staples that engage with an object by deforming in a spiral shape.

[0014] 1A, 1B, 1C, and 1D are respectively a plan view of the staple S in a state before binding (sometimes referred to as "before deformation"; the same applies hereinafter) according to this embodiment, a plan view (enlarged view) of the tip portion ST in the same top view, a right side view (enlarged view) of the tip portion ST, and a left side view (enlarged view) of the tip portion ST. Furthermore, Fig. 1E is an enlarged view of the tip portion ST in Fig. 1B (however, for the purpose of explanation, a groove portion GP, ​​which will be described later, is shown larger than in Fig. 1B).

[0015] 2A, 2B, and 2C are respectively a perspective view of staple S in a state after binding (sometimes referred to as "after deformation" or "when engaged," etc.; the same applies hereinafter) according to this embodiment, a plan view (enlarged view) of the tip portion as viewed from above, and a right side view (enlarged view) of the tip portion.

[0016] First, the structure of the staple S before binding will be described.

[0017] The staple S has a first leg S1, a second leg S2, and a main body S3 connecting the first leg S1 and the second leg S2. Before binding, the first leg S1 and the second leg S2 of the staple S are spaced apart, and an opening is provided between the first leg S1 and the second leg S2. In this embodiment, the direction from the main body S3, which is the closed portion, toward the opening (to the left in the plane of the paper in FIG. 1A ) may be referred to as an opening direction DR1 (of the staple S). Furthermore, a direction perpendicular to the extending direction of the staple S (for example, the opening direction DR1 in the case of the second leg S2 of the staple S in this embodiment) and perpendicular to the stacking direction, which will be described later, may be referred to as a side direction (of that portion of the staple S), and the surface of the staple S facing the side direction may be referred to as a side surface of the staple S. Furthermore, a direction perpendicular to the side direction and in which a plurality of staples S are connected is referred to as a stacking direction DR2 or a connecting direction DR2, and in particular, the upward direction on the paper surface in Fig. 1C (the forward direction perpendicular to the paper surface in Fig. 1A) may be referred to as an upward stacking direction DR21 (of staples S), and the downward direction (the depth direction perpendicular to the paper surface in Fig. 1A) may be referred to as a downward stacking direction DR22 (Fig. 1C). As will be described later, in this embodiment, the opening direction DR1 of the staples S coincides with the forward X1 (described later), which is the moving direction of the staples S set in the binding machine 10 (Fig. 3). In this embodiment, the stacking direction DR2 of the connected staples S supported by the magazine 14 of the binding machine 10 coincides with the vertical direction Z (described later), which is the extension direction of the magazine 14.

[0018] The staple S comprises a main body S3 connecting the first leg S1 and the second leg S2 and surrounding a second object P such as a stem; a first leg S1 connected to one end of the main body S3 and including a first portion S11 that bends and extends outward, and a second portion S12 that bends further from the first portion S11 and extends in the opening direction DR1; and a second leg S2 connected to the other end of the main body S3 and including a third portion S23 that extends in the opening direction DR1 and a fourth portion S24 that bends outward from the tip of the third portion S23. As shown in the figure, the main body S3 is curved in a C-shape or a semicircular arc. The first portion S11 connecting the main body S3 and the second portion S12 is sometimes referred to as a crank portion, and the second portion S12 connected to the first portion S11 and extending linearly in the opening direction DR1 is sometimes referred to as a straight portion. Furthermore, a fourth portion S24, which corresponds to the other tip of the staple S and is bent at an acute angle relative to the third portion S23, is sometimes called a hook portion.

[0019] 2A and other figures showing the state after deformation, the hook portion S24 corresponding to the tip of the second leg S2 is engaged by bending the second leg S2 in a direction approaching the first object G by the binding machine 10 described below and hooking it onto the first object G. At this time, the opening that was provided between the two legs in the pre-deformation state is closed in top view, making it possible to surround the second object P using the staple S.

[0020] When the hook portion S24 engages with the first object G, the third portion S23 exerts an elastic force in a direction that widens the opening and returns to its original position. This allows the hook portion S24 to apply tension to the first object G in the direction that widens the opening, i.e., in the direction that moves the hook portion S24 away from the first leg portion S1 and returns to its original position. This makes it possible to prevent the first object G from bending and causing the staple S to fall off, etc.

[0021] 2A to 2C, the tip portion ST of the first leg portion S1 is a portion that engages with the first object G by being deformed into a spiral shape by the binding machine 10 so as to surround the outer periphery of the first object G. Therefore, the tip portion ST may be referred to as a spiral forming portion ST. Here, the tip portion ST of the first leg portion S1 being deformed into a spiral shape means that the tip portion ST of the first leg portion S1 is deformed so as to surround the outer periphery of the first object G at least once, as shown in FIGS. 2B and 2C, etc.

[0022] Here, the inventors of the present application have noticed that the staple S may not be deformed into the desired shape in the process of deforming the tip ST of the first leg S1 of the staple S into a spiral shape. That is, when a strong load is applied to deform the tip ST of the first leg S1 into a spiral shape, the straight portion S12 formed by extending linearly may buckle. Also, there are cases where the spiral pitch described by the tip ST of the first leg S1 is too wide and the staple S does not engage with the first object G with sufficient force, or conversely, where the spiral pitch is too narrow and the tip S1P of the first leg S1 (sometimes referred to as the "apex of the tip ST") collides with a part of the succeeding tip ST.

[0023] Therefore, the inventors of the present application came up with the idea of ​​forming a deformation promoting portion FT, as shown in FIGS. 1B to 1D, on the tip portion ST, which is the spiral-forming portion. By forming such a deformation promoting portion FT on the tip portion ST, it is possible to suppress the above-mentioned problem. Here, the deformation promoting portion FT refers to a configuration that is relatively more likely to deform into a spiral shape when the same force is applied, compared to when the deformation promoting portion FT is not provided. Therefore, the deformation promoting portion FT is not limited to the configuration shown in the figures, but may also be a configuration such as that shown in FIG. 5A (described below), or a combination of these, or may be realized using other configurations not shown in these figures. The configuration of the deformation promoting portion FT of this embodiment is described below.

[0024] In this embodiment, the deformation promoting portion FT is formed on an inner peripheral portion (sometimes referred to as an “inner peripheral portion STI” or “contact portion STI”) of the tip portion ST of the first leg S1 that faces and comes into contact with the first object G when engaged with the first object G (in a state after being deformed into a spiral shape), and on an outer peripheral portion (sometimes referred to as an “outer peripheral portion STO”) of the tip portion ST of the first leg S1 that is opposite the inner peripheral portion STI when engaged with the first object G (in a state after being deformed into a spiral shape). Hereinafter, the deformation promoting portion FT formed on the inner peripheral portion of the tip portion ST of the first leg S1 will be referred to as an inner peripheral deformation promoting portion FTI, and the deformation promoting portion FT formed on the outer peripheral portion will be referred to as an outer peripheral deformation promoting portion FTO. However, the deformation promoting portion FT does not have to include both the inner peripheral deformation promoting portion FTI and the outer peripheral deformation promoting portion FTO; it may include only one of them. The deformation promoting portion FT may be formed on at least a part of the tip portion ST of the first leg portion S1, or may be formed only on the tip portion ST of the first leg portion S1.

[0025] [Inner Circumferential Deformation Promoting Portion] As shown in Fig. 2B , which shows the state after deformation, the inner circumferential portion STI corresponds to the inner circumferential side portion of the tip portion ST that has been deformed into a spiral shape, and therefore corresponds to the compressed portion. For this reason, a large compressive stress is generated in the inner circumferential portion STI. Therefore, by forming the inner circumferential deformation promoting portion FTI so that the compressive stress is smaller than when the inner circumferential deformation promoting portion FTI is not deformed, it is possible to promote the spiral deformation of the tip portion ST.

[0026] In the present embodiment, the inner circumferential deformation promoting portion FTI is composed of a plurality of (for example, five or more) recesses formed at intervals, as shown in Fig. 1C which is a side view of the staple S. By forming such recesses, the internal stress acting to prevent compression is reduced compared to when there are no recesses, and it is therefore possible to promote the spiral deformation of the tip portion ST.

[0027] In this embodiment, the inner peripheral portion STI where the inner peripheral deformation promoting portion FTI is formed corresponds to the portion of the side surface of the straight portion S12 facing outward, rather than the inner surface facing inward opposite to the second leg portion S2, in the pre-deformation state ( FIG. 1A ). In other words, the tip portion ST of the first leg portion S1 deforms spirally outward away from the second leg portion S2, rather than in a direction approaching the second leg portion S2, thereby engaging with the first object G located outside the first leg portion S1.

[0028] With this configuration, it is possible to prevent the first leg S1 from coming into contact with and damaging the second object P inserted in the staple S, and therefore it is possible to insert a larger second object P into the staple S and bind it.

[0029] In this embodiment, each recess is composed of a groove portion GP that extends in a direction inclined rather than perpendicular to the extension direction DR3 of the tip portion ST of the first leg portion S1 in a side view ( FIG. 1C ) seen from a direction perpendicular to the extension direction DR3 of the tip portion ST of the first leg portion S1 (corresponding to the extension direction of the line connecting the centers of the cross section of the main portion of the tip portion ST, which in this embodiment is parallel to the opening direction DR1). Here, the inclined extending portion is sometimes referred to as an inclined portion IP. Therefore, as shown in FIG. 1C , in a side view seen from a direction opposite the tip portion ST, each inclined portion IP intersects the extension direction DR3 of the tip portion ST obliquely rather than perpendicularly.

[0030] More specifically, the inclined portion IP is formed to be inclined so as to approach the tip S1P of the first leg S1 of the staple S as it proceeds downward in the stacking direction DR22, which is a direction perpendicular to the stretching direction DR3 in Fig. 1C (in other words, so as to move away from the tip S1P of the first leg S1 of the staple S and approach the main body portion S3 as it proceeds upward in the stacking direction DR21). As will be described later, during deformation, the tip portion ST is deformed into a spiral shape by proceeding in a direction corresponding to the downward stacking direction DR22 as the axial direction of the spiral while proceeding in this direction so as to surround the outer periphery of the first object G extending in the up-and-down direction.

[0031] By providing such an inclined portion IP, the groove portion GP can effectively promote the deformation of the tip portion ST into a spiral shape, as described below. However, the groove portion GP may also include a portion other than the inclined portion IP, such as a groove portion connected to one or both ends of the inclined portion IP and extending in a direction parallel or perpendicular to the stacking direction DR21 upward in a side view. The region forming the deformation promoting portion FT and the angle θ1 of the inclined portion IP (FIG. 1C; sometimes referred to as the "inclination angle θ1") will be described later.

[0032] [Peripheral Deformation Promoting Portion] In the deformed state shown in Fig. 2B, the outer peripheral portion STO corresponds to the outer peripheral portion of the spirally deformed tip portion ST, and therefore corresponds to the portion that is stretched by tension. Therefore, a large tensile stress is generated in the outer peripheral portion STO. Therefore, by forming the outer peripheral deformation promoting portion FTO so that the tensile stress is smaller than when the outer peripheral deformation promoting portion FTO is not deformed, it is possible to promote the spiral deformation of the tip portion ST.

[0033] In this embodiment, the outer peripheral deformation promoting portion FTO is composed of a plurality of recesses formed at a distance from each other, as shown in Figures 1C and 1D. By forming such recesses, the internal stress that prevents pulling is reduced compared to when there are no recesses, making it possible to promote the spiral deformation of the tip portion ST. Note that in this embodiment, the outer peripheral portion STO corresponds to the inner surface side facing inward, facing the second leg portion S2, in the pre-deformation state (Figure 1A).

[0034] In this embodiment, the grooves and their inclined portions formed in the outer peripheral deformation promoting portion FTO are formed symmetrically with the grooves GP and their inclined portions IP formed in the inner peripheral deformation promoting portion FTI, and therefore the same reference numerals are used and a description thereof is omitted. However, the configuration of the deformation promoting portion formed in the inner peripheral deformation promoting portion FTI may be different from the configuration of the deformation promoting portion formed in the outer peripheral deformation promoting portion FTO. For example, the configurations of the recesses formed in the inner peripheral deformation promoting portion FTI and the outer peripheral deformation promoting portion FTO (e.g., the length of the grooves GP, the number of grooves GP, the width or depth of the grooves formed in the grooves GP, the inclination angle θ1 of the inclined portions IP, etc.) may be different from each other.

[0035] [Tilt Angle of Inclined Portion] The inventors of the present application have focused on the fact that, by forming the groove portions GP so that the extension direction of the groove portions GP formed in each of the outer peripheral deformation promoting portion FTO and the inner peripheral deformation promoting portion FTI is approximately parallel to the axial direction of the spiral formed by the tip portion ST in the deformed state as shown in Fig. 2C , it is possible to promote deformation into a desired spiral shape. If, in the deformed state, the extension direction of the groove portions GP and the axial direction of the spiral are not approximately parallel, for example, are nearly perpendicular, the balance of stress acting on the upper and lower parts of the cross section of the tip portion ST is significantly disrupted, and it may become impossible to form the desired spiral shape.

[0036] Therefore, it is preferable to set the inclination angle θ1 of the inclined portion IP so that the angle formed by the extension direction of the inclined portion IP and the axial direction of the spiral is approximately parallel in a side view after the inclined portion IP has been deformed into a spiral. Here, the axial direction of the spiral roughly coincides with the extension direction of the first object G. Therefore, it can be said that it is preferable to set the inclination angle θ1 of the inclined portion IP so that the extension direction of the inclined portion IP and the extension direction of the first object G are approximately parallel in a side view after the inclined portion IP has been deformed into a spiral.

[0037] As shown in Figures 2B and 2C, etc., if the diameter of a circle approximating the cross section of the first object G is D1 and the diameter of a circle approximating the cross section of the tip portion in the pre-deformation state is D2 (where D2 is between 75% and 125% of D1), it is preferable to set the inclination angle θ1 between the extension direction of the inclined portion IP and the extension direction DR3 of the tip portion ST in a side view in the pre-deformation state to between 55 degrees and 85 degrees, and it will be explained that this configuration makes the extension direction of the inclined portion IP and the axial direction of the spiral (i.e., the extension direction of the first object G) closer to being parallel.

[0038] Here, if the first object G is a guide string or the like made by twisting together thin, linear resin material such as polypropylene, its cross section may not necessarily be circular. In such cases, the diameter of a circle approximating the periphery of the first object G in the cross section is the diameter D1 of the circle approximating the cross section of the first object G. For example, it is possible to calculate the circle approximating the cross section of the first object G using the least squares method based on multiple points constituting the periphery of the cross section of the first object G. In this embodiment, the diameter D1 is, for example, 1.2 mm. Therefore, the staple S is a staple that can engage with the first object G having the diameter D1. For example, if a binding machine that performs binding using the staple S is designed to be able to engage both ends of the staple S with a guide string ("an example of the first object G") within a range that includes the diameter D1, the staple S is a staple that can engage with the first object G having the diameter D1. However, the staple S may also be able to engage with first objects G having diameters other than the diameter D1.

[0039] On the other hand, the cross section of the tip portion ST of the staple S may not be a circle. In such a case, the diameter of a circle that similarly approximates the outer periphery of the tip portion ST in the cross section using the least squares method is the diameter D2 of the circle that approximates the cross section of the tip portion ST. In this embodiment, the diameter D2 is, for example, not less than 0.9 mm (75% of the diameter D1) and not more than 1.5 mm (125% of the diameter D1).

[0040] 2C , in a side view in a deformed state, there is a first object G with a diameter D1 at the center, with tip portions ST with diameters D2 provided on both sides of the first object G, and considering that the height varies by approximately the diameter D2 when tip portions ST go around the first object G, the inclination angle of tip portions ST in a side view is about 8 degrees (when diameter D2 = 75% of diameter D1) to about 10 degrees (when diameter D2 = 125% of diameter D1) with a center of about 9 degrees. Therefore, by providing inclined portions IP so that the inclination angle θ1 with respect to the extension direction of tip portions ST is between about 80 degrees and 82 degrees inclusive in a side view in a state before deformation as shown in FIG. 1C , the extension direction of inclined portions IP and the axial direction of the spiral (i.e., the extension direction of first object G) become approximately parallel in a deformed state.

[0041] Through experiments, the inventors of the present application have found that a good spiral shape can be formed even when the inclination angle θ1 is approximately 80 degrees or less. One reason for this is the springback phenomenon that occurs after deformation into a spiral shape. The springback phenomenon releases at least a portion of the residual stress inside the tip portion ST, causing the spiral-forming portion ST to tighten (contract) upward in the stacking direction DR21 (upward Z1). Therefore, it was confirmed that a particularly good spiral shape can be formed when the inclination angle θ1 is approximately 70 degrees, which is approximately 10 degrees smaller than the theoretical value. Additionally, it was also confirmed that a certain degree of effectiveness can be achieved if the extension direction of the inclined portion IP and the axial direction of the spiral are roughly parallel, or approaching parallel, even if they are not perfectly parallel after deformation. On the other hand, through experiments, it was also confirmed that when the inclination angle θ1 is less than 55 degrees, the inclination angle θ1 is too small, and the spiral-forming portion ST may not engage with the first object G with sufficient force, regardless of the springback phenomenon. As described above, the inclination angle θ1 of the inclined portion IP relative to the extension direction DR3 of the tip portion ST in a side view (Figures 1C and 1D) before deformation may be 55 degrees or more and 85 degrees or less, with 70 degrees as the center, and preferably 60 degrees or more and 80 degrees or less.

[0042] 1C and 1D , the inner peripheral deformation promoting portion FTI and the outer peripheral deformation promoting portion FTO of this embodiment each comprise 13 recesses (e.g., grooves GP) spaced apart from one another. Here, L1 is the length along the extension direction DR3 between the tip S1P of the first leg S1 and the position where the first groove GP closest to the tip S1P is formed (the position closest to the tip S1P). L2 is the length along the extension direction DR3 between the position where the first groove GP is formed (the position closest to the tip S1P) and the position where the thirteenth groove GP farthest from the tip S1P is formed (the position farthest from the tip S1P). L2 corresponds to the length of the region where the thirteen grooves GP are formed.

[0043] Below, we will explain that if the diameter of a circle approximating the cross section of the first object G is D1 and the diameter of a circle approximating the cross section of the tip portion in the pre-deformation state is D2 (where D2 is between 75% and 125% of D1), then L3 (Figures 1C and 1D), which corresponds to the length along the extension direction DR3 of the area in which multiple recesses are formed, is preferably 7 x D1 or more (L3 ≧ 7 x D1).

[0044] 2B , which is a plan view of the tip portion ST in a deformed state, the inner circumferential portion STI of the tip portion ST contacts and faces the first object G, and therefore the inner circumferential length of the tip portion of the tip portion ST for one spiral revolution is approximated to D1×π, which is the circumference of a circle with a diameter D1 that approximates the cross section of the first object G. On the other hand, the outer circumferential length of the tip portion of the tip portion ST for one spiral revolution is approximated to (D1+2D2)×π, which is the circumference of a circle with a diameter (D1+2D2). Considering that the inner circumferential portion STI of the tip portion ST is compressed and the outer circumferential portion STO is stretched, by forming a plurality of recesses over an area with a length of at least (D1+D2)×π, which is the average length, it is possible to form a deformation promoting portion over the length of at least one spiral revolution.

[0045] Since D2 is 125% or less of D1, (D1 + D2) × π ≦ 7.06 × D1. Therefore, by forming a plurality of recesses (e.g., groove portions GP) in the stretching direction DR3 over an area of ​​L2 ≧ 7 × D1 in the state before deformation of the tip portion ST, it is possible to favorably promote deformation.

[0046] The distance between the groove portions GP can be changed as appropriate. For example, the groove depth and / or groove width of each groove portion GP can be increased to increase the distance between the groove portions GP (and therefore reduce the total number of groove portions GP), or conversely, the groove depth and / or groove width of each groove portion GP can be decreased to reduce the distance between the groove portions GP (and therefore increase the total number of groove portions GP).

[0047] Next, it will be explained that it is preferable that at least a portion of the recess (groove portion GP) closest to the tip S1P of the staple S is formed at a position 1.4×D1 or more and 3.5×D1 or less from the tip S1P in the extension direction DR3.

[0048] The inventors of the present application focused on the fact that the shape of the tip portion ST after deformation varies depending on the position of the recess (groove portion GP) closest to the tip S1P. If a recess is formed at a position far away from the tip S1P, the straight portion S12 may buckle, whereas if a recess is formed at a position very close to the tip S1P, deformation may occur at a premature timing.

[0049] As a result of trial and error, the inventors of the present application came up with the idea that when the tip S1P, which initially advances in the forward direction X1, abuts against the inner wall surface of the hole portion described below and advances while changing direction in an arc to deform into a spiral shape along this inner wall surface, a large bending stress acts on the part where the tip S1P begins to bend between the point at which it points in a direction approximately 90 degrees perpendicular to the direction of advancement and the point at which it points in the backward direction X2, which is the opposite direction of the forward direction X1 (i.e., an arc of diameter (D1 + D2) with a central angle of 90 degrees or more and 180 degrees or less), and therefore, by forming a first deformation-promoting part in this part and providing an opportunity for bending, it is possible to promote the deformation into a spiral shape.

[0050] Here, the length of the arc with a central angle of 90 degrees is roughly approximated to (D1 + D2) × π / 4. Therefore, it is preferable to form at least a portion of the first recess (groove portion GP) at a position where 1.37 × D1 (when D2 is 75% of D1) ≦ L1 is satisfied from the tip S1P along the extension direction DR3 in the pre-deformation state. Therefore, when D1 is 1.2 mm, L1 is approximately 1.65 mm, so it is preferable to form at least a portion of the first recess (e.g., groove portion GP) at a position approximately 1.65 mm or more from the tip S1P. This configuration makes it possible to prevent the staple S from curling earlier than expected.

[0051] On the other hand, the length of the arc with a central angle of 180 degrees is roughly approximated to (D1 + D2) × π / 2. Therefore, it is preferable to form at least a part of the first recess (groove portion GP) at a position that satisfies 3.53 × D1 (when D2 is 125% of D1) ≥ L1 from the tip S1P along the extension direction DR3 in the pre-deformation state.

[0052] Therefore, when D1 is 1.2 mm, L1 is approximately 4.24 mm, so it is preferable to form at least a part of the first recess (for example, groove portion GP) at a position approximately 4.24 mm or less from the tip S1P. With such a configuration, it is possible to prevent the staple S from buckling without bending.

[0053] As described above, it is preferable that at least a part of the recess closest to the tip S1P of the staple S in the pre-deformation state is formed at a position not less than 1.4×D1 and not more than 3.5×D1 from the tip S1P.

[0054] However, as described below, it is also possible to adjust the position where the curling begins, etc., by using another structure formed in addition to the recess. In such a case, at least a portion of the recess closest to the tip S1P of the staple S in the pre-deformation state does not have to be formed at a position between 1.4 × D1 and 3.5 × D1 from the tip S1P. For example, in FIG. 1B , if the length in the extension direction DR3 of the inclined portion (an example of a "second portion") formed by inclining the tip S1P to the portion of the tip ST where the recess (groove portion GP) is formed (an example of a "first portion") is relatively long (i.e., if the angle of the tip S1P is relatively small), this inclined portion will exhibit the same effect as the thin-walled portion FT40 described below as a modified example, and it will be possible to promote the spiral deformation. In such a case, L1 may be greater than 3.5 × D1 from the tip S1P, and the first recess closest to the tip S1P (e.g., groove portion GP) may be formed adjacent to this inclined portion. Here, the first portion where the recess is formed may be expressed as a portion corresponding to the main part of the tip portion ST (for example, a portion where the diameter of a circle approximating the cross section in the pre-deformation state is approximately constant).

[0055] In the staple S described above, the inventors of the present application also focused on the optimal depth of the recess (groove portion GP). Specifically, they found that if the recess is formed too shallow (too small a depth), it becomes difficult to sufficiently reduce the compressive stress generated in the inner circumferential portion STI and the tensile stress generated in the outer circumferential portion STO, making it difficult to sufficiently promote spiral deformation of the distal end portion ST. On the other hand, if the recess is formed too deep (too large a depth), the tensile stress generated in the outer circumferential portion STO may cause breakage, resulting in insufficient engagement with the first object G. Therefore, the inventors of the present application found the optimal depth GPD of the recess (groove portion GP) through experiments and other means (Figure 1E). Specifically, when the diameter of a circle approximating the cross section of the distal end portion ST in an undeformed state is D2, the depth GPD is preferably 0.03 x D2 or greater to promote deformation. Furthermore, the depth GPD is preferably 0.22 x D2 or less to suppress breakage. It is more preferable that the depth GPD is 0.15×D2 or less, and within this range, stable deformation into a spiral shape can be achieved without breakage.

[0056] 1E , the inventors of the present application have further focused on providing an inclined portion such that the tip S1P is located at a position spaced apart from the outer circumferential portion STO and close to the inner circumferential portion STI. By providing the tip S1P at a position offset toward the inner circumferential portion STI from a line connecting the centers of the main portion of the tip ST in this manner, it becomes possible to induce the tip ST to be displaced in the spiral direction. Note that, in the case where the inner circumferential portion STI and the outer circumferential portion STO of the tip ST each have a substantially flat side surface, the position spaced apart from the outer circumferential portion STO and close to the inner circumferential portion STI means that the distance between the side surface of the outer circumferential portion STO and the tip S1P in the normal direction of the side surface (the left-right direction Y in this embodiment) is greater than the distance between the side surface of the inner circumferential portion STI and the tip S1P in the same direction.

[0057] As described above, according to the staple S of this embodiment, among the portions that deform into a spiral shape and engage with the first object G, the deformation promoting portion FT is provided on both the inner circumferential portion STI and the outer circumferential portion STO of the tip portion ST that faces the first object G. As shown in Fig. 2B, in the deformed state, the inner circumferential portion STI is compressed, and the groove of the groove portion GP formed as the inner circumferential deformation promoting portion FTI becomes so small that it cannot be seen. If the deformation promoting portion FT were not provided, this portion would have hindered compression, so it can be understood that the deformation promoting portion FT relatively promotes deformation (curling) into a spiral shape.

[0058] Similarly, after deformation, the outer peripheral portion STO is elongated, and the grooves of the groove portions GP formed as the outer peripheral deformation promoting portions FTO are significantly widened. If the deformation promoting portions FT were not provided, these portions would have prevented the elongation (pulling), so it can be understood that the deformation promoting portions FT relatively promoted the spiral deformation (curl). However, as described above, in the present disclosure, only one of the inner peripheral deformation promoting portions FTI and the outer peripheral deformation promoting portions FTO may be formed, or both may have deformation promoting portions with different configurations.

[0059] Furthermore, in the staple S of this embodiment, the deformation promoting portion FT is formed only in the tip portion ST of the first leg S1, and is not formed in the second leg S2 and the main body S3, which are not deformed into a spiral shape. Therefore, it is possible to maintain the strength of the straight portion S12 except for the tip portion ST, and it is also possible to suppress buckling of the straight portion S12. However, this does not prevent the formation of a groove or the like to promote deformation in a portion of these other portions that is to be bent (for example, a portion that serves as a fulcrum for bending the second leg S2).

[0060] [Structure of Binding Machine] An example of the structure of the binding machine 10 for bending the staple S shown in Fig. 1A as shown in Fig. 2A to Fig. 2C etc. will be described below. However, other known structures may be adopted as means for deforming the tip of the staple into a spiral shape.

[0061] With the exception of some configurations being inverted left to right (i.e., the first displacement section and the second displacement section of the binding machine disclosed in Patent Document 3 being inverted left to right), the basic configuration of the binding machine disclosed in Patent Document 3 and the binding machine 10 of this embodiment are the same, so each configuration of the binding machine 10 will be described by appropriately omitting or simplifying it to the extent that a person skilled in the art can implement it based on the above patent document, the description of this specification, and the state of the art at the time of filing this application.

[0062] 4 may be referred to as the front X1, and the opposite, leftward direction on the paper as the rear X2, and both directions may be collectively referred to as the front-rear direction X. As described above, the front X1 corresponds to the direction in which the staples S at the top ends of the connected staples supported by the magazine 14 move after separating from the other staples S, and also coincides with the opening direction DR1.

[0063] In addition, the direction perpendicular to the paper surface in the drawing is referred to as the upward direction Z1, and the opposite direction perpendicular to the paper surface is referred to as the downward direction Z2, and both directions may be collectively referred to as the up-down direction Z. In this embodiment, the up-down direction Z corresponds to the extension direction of the magazine 14 and also coincides with the connecting direction DR2 (stacking direction) of the connected staples S supported by the magazine 14. Furthermore, the upward direction in the drawing is referred to as the leftward direction Y1, and the opposite downward direction in the drawing is referred to as the rightward direction Y2, and both directions may be collectively referred to as the left-right direction Y. Furthermore, a top view (bottom view) refers to the viewpoint when the binding machine 10, etc. is viewed from an upper Z1 (lower Z2) position toward a lower Z2 (upper Z1), a front view (rear view) refers to the viewpoint when the binding machine 10, etc. is viewed from a forward X1 (rear X2) position toward a rear X2 (forward X1), and a left side view (right side view) refers to the viewpoint when the binding machine 10, etc. is viewed from the left Y1 toward the right Y2 (from the right Y2 toward the left Y1).

[0064] Fig. 3 is a perspective view of the binding machine 10, and Fig. 4 is a top view of the binding machine 10 (however, for the purpose of explanation, the housing of the binding machine 10 may be removed in some cases). The binding machine 10 binds a first object G and a second object P together using a staple S having an opening formed therein.

[0065] The binding machine 10 includes a first displacement unit 20 that displaces the first leg S1 of the staple S so that it can engage with the first object G, and a second displacement unit 30 that displaces the second leg S2 of the staple S so that it can engage with the first object G. The first displacement unit 20 is provided in front of the first leg S1 and has a hole with an inner wall surface including a cylindrical surface. As will be described later, in the binding machine 10, with the first object G inserted on the central axis of this cylindrical surface, the tip S1P of the first leg S1 of the staple S advancing by the driver 42 abuts (collides) against the inner wall surface, deforming the tip ST into a spiral line so as to surround the first object G, thereby engaging the tip ST with the first object G. On the other hand, the second displacement unit 30 has a wall provided in front of the second leg S2. As will be described later, in the binding machine 10, with the first leg S1, the second leg S2, and the main body S3 of the staple S surrounding the second object P, the driver 42 causes the second leg S2 of the staple S to abut (collide) against a wall surface, bending the hook portion S24 of the second leg S2 so that it engages with the first object G, thereby engaging the hook portion S24 with the first object G. The binding machine 10 is configured to be able to bind the first object G and the second object P by engaging both ends of the staple S with the first object G with the staple S surrounding the second object P.

[0066] Specifically, the binding machine 10 includes a grip 12 that extends in the vertical direction so as to be held by a user and that is provided with a switch for driving the binding machine 10, a magazine 14 that is configured to support (hold) a plurality of staples S stacked in the vertical direction, a pusher (not shown) that urges the plurality of staples S stored in the magazine 14 upward Z1, a driver 42 that pushes the staple S located at the top end forward X1 that coincides with the opening direction DR1, thereby separating the staple S located at the top end from the other staples S and moving it forward X1, a moving mechanism for moving the driver 42, a first displacement unit 20 (sometimes referred to as a "clincher unit") for curving and deforming the first leg S1 of the staple S into a spiral, and a second displacement unit 30 for deforming the second leg S2 of the staple S by curving or bending it.

[0067] [Driver and Driver Movement Mechanism] As described in the above patent documents, the binding machine 10 is configured to move the nut component 52 and the driver 42 fixed thereto forward or backward by rotating the ball screw 50, which is installed extending in the front-to-rear direction approximately through the center of the binding machine 10, in a forward or reverse direction using a built-in motor 54. Because the nut component 52 and the driver 42 are configured to be movable forward X1 and backward X2, they are sometimes referred to as moving units. The binding machine 10 further includes a reducer connected to the output shaft of the motor 54 and a printed circuit board on which a CPU corresponding to a control device for the motor 54 is mounted.

[0068] The driver 42 is configured to be able to move forward X1 by separating the uppermost staple S of the plurality of staples S held in the magazine 14 and stacked in the vertical direction from the other staples S while maintaining a front-to-back relationship in which the opening of the staple S is in the front and the main body S3 is in the rear, and move forward X1. The driver 42 is configured to further move the separated staple S forward X1 and bring the first leg S1 into contact with a first displacement portion 20 (described later), thereby plastically deforming the first leg S1, and bring the second leg S2 into contact with a guide wall included in a second displacement portion 30 (described later), thereby plastically deforming the second leg S2.

[0069] [First Displacement Unit] The first displacement unit 20 (an example of a "displacement unit") has a function of displacing the first leg S1 of the staple S, which is moved in the forward direction X1 by the driver 42, by deforming it into a spiral shape so as to surround the first object G, so as to be able to engage with the first object G. However, the configuration for deforming the staple S, which is moved in the forward direction X1 by the driver 42, into a spiral shape may be realized by another known configuration.

[0070] Although detailed description will be omitted because this can be easily implemented by a person skilled in the art based on the state of the art at the time of filing, including the above-mentioned patent documents, the first displacement section 20 according to this embodiment includes a hole having a cylindrical inner wall surface into which the tip S1P of the straight portion S12 of the first leg S1 of the staple S is inserted as the staple S is advanced by the driver 42, thereby causing the tip ST of the first leg S1 to advance downward Z2 (downward in the stacking direction DR22) while curving in an arc or spiral, and a groove for guiding the tip of the first leg S1 into the hole (e.g., this corresponds to the hole 210 and the groove 211 in the above-mentioned patent document 3). The hole is provided in the front X1 of the first leg S1 such that the axial direction of the cylindrical surface is parallel to the up-down direction Z. Therefore, as the staple S advances, the tip S1P of the straight portion S12 comes into contact with the inner wall surface of the hole, and the tip ST can be displaced so that it advances in a spiral shape in accordance with the shape of the inner wall surface. In addition, in order to encourage the tip ST to move downward Z2, the binding machine 10 may be provided with a lid that closes the top of the hole (the top surface of the cylinder), and the lid may be formed with a tapered surface that slopes downward Z2 along the circumferential direction to encourage the tip S1P to move downward Z2.

[0071] With this configuration, when the first object G, for example a guide string, is positioned so that it extends in the vertical direction along the central axis of the hole, and the tip S1P of the first leg S1 is inserted into the hole, the tip S1P will move in a spiral along the cylindrical inner wall surface of the hole, so that the tip ST can be deformed spirally around the first object G, allowing the tip ST to engage with the first object G.

[0072] Here, the tip portion ST has an inner peripheral deformation promoting portion FTI and an outer peripheral deformation promoting portion FTO formed from a position of length L1 from the tip S1P over an area of ​​length L2 along the extension direction DR3, making it possible to promote spiral deformation.

[0073] In order to strengthen the engagement between the first object G and the tip ST of the first leg S1, it is preferable that the inner diameter of the inner wall surface of the hole be less than the sum of twice the diameter D2 of a circle that approximates the cross section of the tip ST and the diameter D1 of a circle that approximates the cross section of the first object G. By setting the inner diameter in this manner, a portion of the first object G or the staple S is crushed, which makes it possible to strengthen the engagement between the staple S and the first object G.

[0074] Fig. 2D is a perspective view showing the post-deformation state in which the tip portion ST engages with the first object G (however, the second leg portion S2 and the second object P are not shown). Fig. 2E is a cross-sectional view (viewed from below) of the tip portion ST in the post-deformation state, taken along an imaginary plane parallel to the lateral direction.

[0075] 2E, the recesses (groove portions GP) formed as the inner circumferential deformation promoting portions FTI are compressed and deformed to close, so that at least a portion of the first object G enters the interior of the recesses (groove portions GP) and is clamped by the recesses (groove portions GP). Therefore, the inner circumferential deformation promoting portions FTI can further strengthen the engagement between the staple S and the first object G.

[0076] [Second Displacement Section] The second displacement section 30 (an example of a "displacement section") has a function of displacing the second leg S2 of the staple S moved forward X1 by the driver 42 so that the second leg S2 can engage with the first object G. Although detailed description will be omitted because it would be easily implemented by a person skilled in the art based on the state of the art at the time of filing, including the above-mentioned patent documents, the second displacement section 30 according to this embodiment is configured to displace the second leg S2 inward of the staple S as the driver 42 moves forward X1. Specifically, the second displacement section 30 has a first guide wall that is provided on the outside of the second leg S2 in the initial state before the staple S starts to be displaced, and that is adapted to bend the second leg S2 by contacting the second leg S2 of the staple S moving in the opening direction DR1 (forward X1). This first guide wall has a recess that is recessed outward of the staple S.

[0077] Furthermore, the second displacement portion 30 includes a second guide wall that is provided in front of the second leg S2 in the initial state before the staple S starts to be displaced, and that bends the second leg S2 when the second leg S2 of the staple S moving in the opening direction DR1 comes into contact with the second guide wall. This second guide wall has a wall surface facing the rear X2, and further has a convex portion that protrudes toward the rear X2. In the initial state, this convex portion is provided in front of the second leg S2 in the front-rear direction and inward of the second leg S2 in the left-right direction, and is provided at an inner end of the second guide wall so that the amount of protrusion toward the rear X2 increases as the convex portion advances inward.

[0078] With this configuration, the second leg S2 of the staple S, which is advanced by the driver 42, can be brought into contact (collide) with the inner wall surfaces of the first guide wall and the second guide wall, thereby bending the third part S23 of the second leg S2 so that it curves greatly, and therefore the hook part S24 can be displaced in a direction approaching the first object G and hooked onto the first object G.

[0079] As described above, of the staple S advanced by the driver 42, the first leg S1 is deformed spirally by the first displacement portion 20 and engages with the first object G, and the hook portion S24 of the second leg S2 is hooked onto and engaged with the first object G by the second displacement portion 30, making it possible to bind the first object G and the second object P together.

[0080] According to this embodiment, by providing the deformation promoting portion FT, it is possible to provide a staple S that is easily deformed into a spiral shape.

[0081] [First Modification] A modification of the staple S of this embodiment will be described below. However, the same components as those of the staple S will be assigned the same reference numerals, and detailed description will be simplified or omitted, with the focus on the differences being described (the same applies to the other modifications).

[0082] 5A is a perspective view of a staple S10 according to a first modified example of the staple S. As shown in the drawing, as an example of a recess that is a deformation-promoting portion, a tip portion ST10 of the staple S10 is provided with one or more dimple portions FT10 that are substantially circular (including circular, oval, elliptical, etc.) or rectangular (including rectangular, square, etc.) in side view and are recessed inward (toward the center of the cross section of the tip portion). The tip portion ST10 is provided with the dimple portions FT10 in either one or both of a region that becomes the inner periphery and a region that becomes the outer periphery when the tip portion is deformed into a spiral shape.

[0083] Even with such a configuration, it is possible to provide a staple in which the tip portion ST10 is easily curled and deformed into a spiral shape, and therefore it is possible to suppress buckling of other portions under load.

[0084] [Second Modification] Fig. 5B is a perspective view of a staple S20 according to a second modification of the staple S. As shown in Fig. 5B, the distal end portion ST20 of the staple S20 has side surfaces formed with alternating inclined surfaces facing forward and to the side and inclined surfaces facing backward and to the side, forming a triangular waveform in a top view. Therefore, the distal end portion ST20 of the staple S20 of this modification has one or more valley portions FT20 recessed inward by the connection of two inclined surfaces, as an example of a recess that is a deformation-promoting portion. The distal end portion ST20 has valley portions FT20 recessed inward (toward the center of the cross section of the distal end portion) in either or both of a region that becomes the inner periphery and a region that becomes the outer periphery when the staple S20 is deformed into a spiral shape. Instead of a triangular waveform, the side surfaces of the distal end portion ST20 may be formed to have a curved surface, a sawtooth shape, or the like.

[0085] Even with such a configuration, it is possible to provide a staple in which the tip portion ST20 is easily curled and deformed into a spiral shape, and therefore it is possible to suppress buckling of other portions under load.

[0086] 5C is a perspective view of a staple S30 according to a third modified example of the staple S. As shown in the drawing, as an example of a recess that is a deformation-promoting portion, the tip portion ST30 of the staple S30 has one or more necked portions FT30 formed around the tip portion ST30 and spaced apart from each other. Each necked portion FT30 is recessed toward the center of the cross section of the tip portion ST on an inner surface facing inward opposite the second leg portions S2, an upper surface facing upward in the stacking direction DR21 (FIG. 2C), an outer surface facing outward opposite the inner surface, and a lower surface facing downward in the stacking direction DR22 (FIG. 2C).

[0087] Even with such a configuration, it is possible to provide a staple in which the tip portion ST30 is easily curled and deformed into a spiral shape, and therefore it is possible to suppress buckling of other portions under load.

[0088] 5D is a perspective view of a staple S40 according to a fourth modified example of the staple S. As shown in the drawing, as an example of a recess that is a deformation promoting portion, a tip portion ST40 of the staple S40 is provided with a thin portion FT40 that is formed thin in the lateral direction over a predetermined distance from the tip so as to recess the outer surface inward.

[0089] This configuration also makes it possible to reduce the rigidity of the tip portion ST40, making it possible to provide a staple that is particularly prone to curling and spiral deformation in the area including the tip portion S1P where the bending begins, thereby suppressing buckling in other portions.

[0090] Furthermore, various modifications of the present disclosure are possible without departing from the spirit thereof. For example, some components of one embodiment can be added to other embodiments within the scope of ordinary creativity of a person skilled in the art. Also, some components of one embodiment can be replaced with corresponding components of other embodiments.

[0091] Although various embodiments have been described above with reference to the drawings, it goes without saying that the present disclosure is not limited to such examples. It is clear that a person skilled in the art can conceive of various modifications or alterations within the scope of the claims, and it is understood that these also naturally fall within the technical scope of the present disclosure. Furthermore, the components of the above-described embodiments may be combined in any manner without departing from the spirit of the invention.

[0092] This application is based on a Japanese patent application (Patent Application No. 2024-042474) filed on March 18, 2024, the contents of which are incorporated herein by reference.

[0093] The present disclosure provides a staple that is prone to helical deformation.

[0094] REFERENCE SIGNS LIST 10 Binding machine 12 Grip 14 Magazine 20 First displacement section 30 Second displacement section 42 Driver 52 Nut part 54 Motor D1 Diameter D2 Diameter DR1 Opening direction DR2 Stacking direction, connecting direction DR3 Extension direction DR21 Upward in stacking direction DR22 Downward in stacking direction FT Deformation promoting section FT10 Dimple section FT20 Valley section FT30 Neck section FT40 Thin-walled section FTI Inner peripheral deformation promoting section FTO Outer peripheral deformation promoting section G First object GP Groove section IP Inclined section P Second object S, S10, S20, S30, S40 Staple S1 First leg section S11 First section S12 Second section (straight section) S1P Tip ST Tip part (helical part) STI Inner circumference part (contact part) STO Outer circumference part S2 Second leg part S23 Third part S24 Fourth part (hook part) S3 Main body part

Claims

1. A staple formed from a flexible wire rod and having a tip portion that can engage with a stretching object by being deformed spirally to surround the object, wherein a deformation promoting portion is formed on the inner periphery of the tip portion that faces the object after deformation, on the outer periphery of the tip portion opposite the inner periphery, or on both the inner periphery and the outer periphery.

2. The staple according to claim 1, wherein said deformation promoting portion has a recess.

3. The staple according to claim 2, wherein the recess has a groove, and in the pre-deformed state, the groove has an inclined portion extending in a direction inclined with respect to the extending direction of the tip portion.

4. A staple according to claim 3, wherein, in the pre-deformed state, the inclined portion is formed at an angle so as to approach the tip of the staple as it progresses in a direction perpendicular to the extension direction of the tip portion, and the tip portion is deformed spirally to surround the extending object as it progresses in the perpendicular direction.

5. The staple according to claim 3, wherein the angle formed between the extending direction of said inclined portion and the extending direction of said tip portion is between 55 degrees and 85 degrees in side view before said deformation.

6. A staple according to claim 5, wherein D1 is the diameter of a circle approximating the cross section of the object, and D2 is the diameter of a circle approximating the cross section of the tip portion in the pre-deformed state, and D2 is 75% or more and 125% or less of D1.

7. The staple according to claim 2, wherein a plurality of said recesses are formed at intervals along the extending direction of said tip portion.

8. A staple according to claim 7, wherein, when the diameter of a circle approximating the cross section of the object is D1 and the diameter of a circle approximating the cross section of the tip portion in the pre-deformed state is D2, D2 is 75% or more and 125% or less of D1, and a plurality of the recesses are formed over an area having a length of 7 x D1 or more along the extension direction of the tip portion in the pre-deformed state.

9. A staple as described in claim 2, wherein, when the diameter of a circle approximating the cross section of the object is D1, at least a portion of the recess closest to the tip of the staple in the pre-deformed state is formed at a position not less than 1.4 x D1 and not more than 3.5 x D1 from the tip of the staple.

10. A staple according to claim 2, wherein the tip portion has a first portion in which the recess is formed and a second portion that is continuous with the first portion and slopes toward the tip, and the recess is formed at a position adjacent to the second portion.

11. The staple according to claim 2, wherein in the deformed state, at least a portion of the object is clamped by at least one of the recesses.

12. The staple according to claim 2, wherein the tip of the tip portion is offset toward the inner peripheral portion from the axial center of the tip portion.

13. A staple according to claim 2, wherein the depth of said recess is not less than 0.03 x D2 and not more than 0.22 x D2, where D2 is the diameter of a circle approximating the cross section of said tip portion before said deformation.

14. The staple according to claim 1, further comprising: a first leg; a second leg; and a main body connecting the first leg and the second leg, wherein the first leg has the tip portion capable of engaging with the object.

15. The staple according to claim 1, wherein the deformation promoting portion is formed only on the tip portion.

16. The staple according to claim 1, wherein said tip portion is capable of engaging with said object by deforming so as to surround at least one circumference of the outer periphery of said object.

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