Patent Publication Number: US-11376723-B2

Title: Stapler

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based upon and claims the benefit of priority from prior Japanese patent application No. 2018-207723, filed on Nov. 2, 2018, the entire contents of which are incorporated herein by reference. 
     TECHNICAL FIELD 
     Aspects of the present invention relate to a stapler configured to bind a sheet bundle of a plurality of sheets by a staple. 
     BACKGROUND ART 
     A stapler is configured to cause a pair of staple legs of a staple to penetrate a sheet bundle and to bind the sheet bundle by bending the pair of staple legs having penetrated the sheet bundle with a clincher part (for example, refer to JP-A-2018-69636). The clincher part includes a pair of clinchers configured to move along a surface direction of the sheet bundle so as to approach each other. When the clinchers are moved from an outer side of the staple legs, as described above, the staple legs are bent inwardly along a surface (also referred to as “sheet surface”) of the sheet bundle. 
     Since the staple legs bent by the pair of clinchers are linearly bent along the sheet surface, when the clinching (the bending of the staple legs) is not sufficiently performed upon the binding of the sheet bundle, the staple legs, particularly, the staple leg tips are likely to separate and float from the sheet surface. 
     SUMMARY 
     Accordingly, an aspect of the present invention provides a stapler capable of making it difficult for a tip of a staple leg having bound a sheet bundle to separate and float from a sheet surface. 
     According to an exemplary embodiment of the present invention, there is provided a stapler including: a striking part configured to cause a pair of staple legs to penetrate a sheet bundle; a bending part configured to bend the staple legs at a first position such that tips of the staple legs having penetrated the sheet bundle by the striking part are directed inwardly; and a clincher part configured to bend the staple legs at a second position located closer to the sheet bundle than the first position such that the staple legs of which the tips are bent inwardly at the first position by the bending part are entirely directed inwardly, wherein the bending part includes: a first part disposed on an inner side of the pair of staple legs and having a first tip portion facing the staple legs and located at the first position; a second part disposed on an outer side of the pair of staple legs and having a second tip portion facing the staple legs and located on a non-sheet bundle side spaced from the sheet bundle further than the first position; and a moving part configured to move at least one of the first part and the second part toward the staple legs. 
     The first part is disposed on the inner side of the pair of staple legs, and the first tip portion facing the staple legs is located at the first position of the staple legs. Also, the second part is disposed on the outer side of the pair of staple legs, and the second tip portion facing the staple legs is located on the non-sheet bundle side further than the first position. Therefore, when at least one of the first part and the second part is moved toward the staple legs by the moving part, the staple leg tips are bent inwardly about the first position as a support point by the first part and the second part. Then, when the entire staple legs of which the tips are bent inwardly about the first position as a support point are bent with the clincher part, the tips are directed toward the sheet bundle from the first position of the staple legs having bound the sheet bundle. For this reason, even when the staple legs are floated from the sheet surface, the staple leg tips are directed toward the sheet bundle. 
     According to the above stapler, the tip of the staple leg having bound the sheet bundle is difficult to separate and float from the sheet surface. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a configuration view illustrating an outline of an image forming system of an exemplary embodiment. 
         FIG. 2A  is a side view illustrating a stapler of the exemplary embodiment. 
         FIG. 2B  is a perspective view illustrating the stapler of the exemplary embodiment. 
         FIG. 2C  is a perspective view illustrating the stapler of the exemplary embodiment. 
         FIG. 3A  illustrates an example of an operation of binding sheets with a staple. 
         FIG. 3B  illustrates an example of the operation of binding sheets with the staple. 
         FIG. 3C  illustrates an example of the operation of binding sheets with the staple. 
         FIG. 3D  illustrates an example of the operation of binding sheets with the staple. 
         FIG. 3E  illustrates an example of the operation of binding sheets with the staple. 
         FIG. 4  is a perspective view illustrating a configuration of parts of the stapler of the exemplary embodiment. 
         FIG. 5  is a front view illustrating the configuration of parts of the stapler of the exemplary embodiment. 
         FIG. 6  is an enlarged view of an A part in  FIG. 5 . 
         FIG. 7  illustrates a preferred manner of bending staple legs. 
         FIG. 8A  is a perspective view illustrating an operation example of the stapler of the exemplary embodiment. 
         FIG. 8B  is a perspective view illustrating an operation example of the stapler of the exemplary embodiment. 
         FIG. 8C  is a perspective view illustrating an operation example of the stapler of the exemplary embodiment. 
         FIG. 8D  is a perspective view illustrating an operation example of the stapler of the exemplary embodiment. 
         FIG. 9A  is a front view illustrating an operation example of the stapler of the exemplary embodiment. 
         FIG. 9B  is a front view illustrating an operation example of the stapler of the exemplary embodiment. 
         FIG. 9C  is a front view illustrating an operation example of the stapler of the exemplary embodiment. 
         FIG. 9D  is a front view illustrating an operation example of the stapler of the exemplary embodiment. 
         FIG. 10A  is an enlarged view of an A part in  FIG. 9A . 
         FIG. 10B  is an enlarged view of an A part in  FIG. 9B . 
         FIG. 10C  is an enlarged view of an A part in  FIG. 9C . 
         FIG. 10D  is an enlarged view of an A part in  FIG. 9D . 
         FIG. 11A  is a configuration view illustrating a modified example of the stapler of the exemplary embodiment. 
         FIG. 11B  is a configuration view illustrating the modified example of the stapler of the exemplary embodiment. 
         FIG. 12A  is a configuration view illustrating a modified example of the stapler of the exemplary embodiment. 
         FIG. 12B  is a configuration view illustrating the modified example of the stapler of the exemplary embodiment. 
         FIG. 13A  is a configuration view illustrating a modified example of the stapler of the exemplary embodiment. 
         FIG. 13B  is a configuration view illustrating the modified example of the stapler of the exemplary embodiment. 
         FIG. 14A  is a configuration view illustrating a modified example of the stapler of the exemplary embodiment. 
         FIG. 14B  is a configuration view illustrating the modified example of the stapler of the exemplary embodiment. 
         FIG. 15A  is a configuration view illustrating a modified example of the stapler of the exemplary embodiment. 
         FIG. 15B  is a configuration view illustrating the modified example of the stapler of the exemplary embodiment. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereinbelow, exemplary embodiments of the present disclosure will be described with reference to the drawings. 
     &lt;Configuration Example of Image Forming System and Post Processing Apparatus&gt; 
       FIG. 1  is a configuration view illustrating an outline of an image forming system of an exemplary embodiment. 
     An image forming system  500 A of the exemplary embodiment includes an image forming apparatus  501 A and a post processing apparatus  502 A capable of performing at least one type of processing. The image forming apparatus  501 A is configured to form an image on a sheet fed from a feeder part (not shown) inside or outside the apparatus and to output the sheet. In the present example, the image forming apparatus  501 A is configured to form an image on a sheet by formation of an electrostatic latent image by scanning and exposure, developing of the electrostatic latent image by toner, and transfer and fixing of the toner onto the sheet. 
     The post processing apparatus  502 A includes a binding part  503 A. The binding part  503 A includes a stapler  1 A and a stacking part  504 A on which a sheet bundle P of the overlapping sheets output from the image forming apparatus  501 A is stacked. 
     &lt;Configuration Example of Stapler of Exemplary Embodiment&gt; 
       FIG. 2A  is a side view illustrating the stapler  1 A of the exemplary embodiment, and  FIGS. 2B and 2C  are perspective views illustrating the stapler of the exemplary embodiment.  FIGS. 3A to 3E  illustrate an operation of binding sheets with a staple.  FIG. 4  is a perspective view illustrating a configuration of parts of the stapler of the exemplary embodiment.  FIG. 5  is a front view illustrating the configuration of parts of the stapler of the exemplary embodiment.  FIG. 6  is an enlarged view of an A part in  FIG. 5 . 
     First, an outline of an operation of binding the sheet bundle P with the stapler  1 A is described with reference to  FIGS. 3A to 3E . As shown in  FIG. 3A , a staple  10 A has staple legs  12 A formed by bending both ends of a crown portion  11 A in one direction. 
     The crown portion  11 A of the staple  10 A is pressed, so that the staple legs  12 A are caused to penetrate the sheet bundle P, as shown in  FIG. 3B . In a state where the staple legs  12 A penetrate the sheet bundle P up to a position in which the crown portion  11 A is in contact with the sheet bundle P, when lengths of the staple legs  12 A protruding from the sheet bundle P exceeds a half of a length of the crown portion  11 A, the staple legs  12 A are overlapped with each other as a result of bending the staple legs  12 A toward each other. 
     At this time, extra portions of the staple legs  12 A overlapped with each other when bending the staple legs  12 A are cut. In the exemplary embodiment, in a process of cutting the extra portions of the staple legs  12 A, before cutting the extra portions of the staple legs  12 A, the pair of staple legs  12 A having penetrated the sheet bundle P is respectively bent inwardly at a first position P 1 , as shown in  FIG. 3C . Then, as shown in  FIG. 3D , predetermined positions of further tip sides of the staple legs  12 A than the first position P 1  are cut as cut staples  13 A. Whether the extra portions of the staple legs  12 A occur is determined based on a sheet thickness and a number of sheets of the sheet bundle P to be bound with the staple  10 A, for example. 
     The staple  10 A of which the staple legs  12 A are cut into predetermined lengths binds the sheet bundle P as the staple legs  12 A having penetrated the sheet bundle P are bent further inwardly at a second position P 2  located on a substantial upper surface of the sheet bundle P, as shown in  FIG. 3E . 
     As shown in  FIGS. 2A, 2B, 2C, 4, 5 and 6 , the stapler  1 A includes a striking unit  2 A configured to supply the staple  10 A and to strike out the staple  10 A toward the sheet bundle P, and a binding unit  3 A configured to cut and bend the staple legs  12 A of the staple  10 A struck out by the striking unit  2 A. Also, the stapler  1 A includes a sheet sandwiching part  4 A for sandwiching the sheet bundle P between the striking unit  2 A and the binding unit  3 A. 
     In descriptions below, a side on which the sheet sandwiching part  4 A is provided is referred to as a front side of the stapler  1 A, and an opposite side to the side on which the sheet sandwiching part  4 A is provided is referred to as a rear side. Also, a side on which the binding unit  3 A is provided is referred to as an upper side of the stapler  1 A, and a side on which the striking unit  2 A is provided is referred to as a lower side of the stapler  1 A. 
     The striking unit  2 A includes a placement part  40 A on which the sheet bundle P can be placed, a cartridge accommodation part  110 A located on a lower rear side of the placement part  40 A and capable of accommodating a staple cartridge  100 A in which a plurality of staple sheets (not shown) (obtained by coupling linear staples into a sheet shape) is stacked, a conveyor part  22 A configured to convey forward the staple sheet accommodated in the cartridge accommodation part  110 A and to expose one staple located at at least a forefront of the staple sheet from a front end face of the staple cartridge  100 A, a forming part configured to form the linear staple exposed from the front end face of the staple cartridge  100 A into a substantial U-shape, and a striking part  20 A disposed to strike out the U-shaped staple  10 A toward the sheet sandwiching part  4 A. 
     The staple cartridge  100 A is detachably attached to the cartridge accommodation part  110 A. 
     The binding unit  3 A includes a cutting part  34 A capable of cutting the staple legs  12 A of the staple  10 A having penetrated the sheet bundle P, and a clincher part  33 A configured to bend the staple legs  12 A of the staple  10 A having penetrated the sheet bundle P inwardly, i.e., toward the sheet bundle P. 
     The sheet sandwiching part  4 A is a space formed between the placement part  40 A of the striking unit  2 A and the clincher part  33 A of the binding unit  3 A, and has a shape opening in three directions of the front side and left and right sides of the stapler  1 A. When binding the sheet bundle P by the stapler  1 A, the sheet bundle is inserted into the sheet sandwiching part  4 A, and the sheet bundle P is placed on the placement part  40 A of the striking unit  2 A. 
     The striking unit  2 A includes a drive part  5 A for vertically moving (opening and closing) the binding unit  3 A relative to the striking unit  2 A. The drive part  5 A includes a motor  50 A, a cam  51 A configured to rotate by drive of the motor  50 A, a link (not shown) configured to transmit an operation of the cam  51 A to the respective parts, and the like. The binding unit is connected to the link and is configured to move downward by rotation of the cam. 
     Also, the stapler  1 A includes a detachable cut staple storing part  6 A provided on the rear side and configured to store the cut staples  13 A cut by the cutting part  34 A. 
     The operation of the cam  51 A is transmitted to the binding unit  3 A via the link and the like, so that the binding unit  3 A is moved away from and toward the striking unit  2 A. While the cam  51 A rotates in one direction, the binding unit  3 A is moved toward the striking unit  2 A, thereby sandwiching the sheet bundle P placed on the placement part  40 A at predetermined timing by the sheet sandwiching part  4 A. While the cam  51 A further rotates in one direction, the binding unit  3 A is moved away from the striking unit  2 A at predetermined timing, thereby releasing the sheet bundle P sandwiched by the sheet sandwiching part  4 A. 
     While the cam  51 A rotates in one direction after the sheet bundle P placed on the placement part  40 A is sandwiched by the sheet sandwiching part  4 A, the striking unit  2 A strikes one staple  10 A at the forefront into the sheet bundle P sandwiched with the sheet sandwiching part  4 A, thereby causing the staple legs  12 A of the staple  10 A to penetrate the sheet bundle P. Also, a second or third linear staple following the forefront is formed into a substantial U-shape in the forming part (not shown). 
     While the operation of the cam  51 A is transmitted via the link and the like and the cam  51 A rotates in one direction, the binding unit  3 A bends and cuts the staple legs  12 A of the staple  10 A having penetrated the sheet bundle P at the first position P 1  and bends the staple legs  12 A at the second position P 2 . 
     The striking part  20 A includes a striking member  21 A configured to press the crown portion  11 A of the staple  10 A and to strike out the same toward the binding unit  3 A. The striking member  21 A is provided at a position facing the crown portion  11 A in a striking direction of the staple  10 A toward the sheet bundle P, and is configured to be movable in the striking direction toward the crown portion  11 A and the sheet bundle P. In a state where the staple  10 A is set at a binding position of the sheet bundle P, the striking member  21 A moves in the striking direction to press the crown portion  11 A, so that the staple legs  12 A are caused to penetrate the sheet bundle P. 
     In the vicinity of the staple legs  12 A having penetrated the sheet bundle P, a bending part  30 A configured to bend portions of the staple legs  12 A before bending the entire staple legs  12 A protruding from the sheet bundle P to bind the sheet bundle P is provided. The bending part  30 A includes a first part disposed on an inner side of the pair of staple legs  12 A and having a first tip portion facing the staple legs  12 A and located at the first position of the staple legs  12 A, a second part disposed on an outer side of each of the staple legs  12 A and having a second tip portion facing the staple legs  12 A and located on a non-sheet bundle side spaced from the sheet bundle P further than the first position of the staple legs  12 A, and moving parts  301 AL and  301 AR configured to move the second part toward the staple legs  12 A. 
     In the exemplary embodiment, the bending part  30 A is configured by the cutting part  34 A. In a process of cutting the staple legs  12 A having penetrated the sheet bundle P, the bending part  30 A (cutting part  34 A) is configured to inwardly bend the pair of staple legs  12 A at the first position P 1  such that the tip sides of the staple legs  12 A are directed inwardly, before cutting the staple legs  12 A. 
     The bending part  30 A (cutting part  34 A) includes a movable member  31 AL on an outer side of one staple leg  12 A and a movable member  31 AR on an outer side of the other staple leg  12 A. Also, the bending part  30 A (cutting part  34 A) includes a receiving part  32 A on an inner side of the pair of staple legs  12 A. 
     The receiving part  32 A is an example of the first part, and is provided to a support member  320 A to which the movable members  31 AL and  31 AR are attached. The receiving part  32 A is configured by providing the support member  320 A integrally with a portion of a convex shape protruding in a predetermined width smaller than a width of the crown portion  11 A of the staple  10 A. 
     The movable members  31 AL and  31 AR are an example of the second part. The movable member  31 AL is supported to the support member  320 A by a shaft  320 AL, and the movable member  31 AR is supported to the support member  320 A by a shaft  320 AR. The shafts  320 AL and  320 AR are attached to an upper surface, which is one surface of the support member  320 A, in such a shape of protruding in a direction perpendicular to the support member  320 A. 
     The shaft  320 AL is inserted into a bearing part  310 AL, so that the movable member  31 AL is attached to the upper surface of the support member  320 A so as to be rotatable about the shaft  320 AL as a support point. The shaft  320 AR is inserted into a bearing part  310 AR, so that the movable member  31 AR is attached to the upper surface of the support member  320 A so as to be rotatable about the shaft  320 AR as a support point. 
     The movable member  31 AL has an operating portion  311 AL provided at an end portion configured to move toward and away from the receiving part  32 A and the staple leg  12 A by a rotation operation about the shaft  320 AL as a support point. The operating portion  311 AL is an example of the second tip portion, and faces an outer surface of one staple leg  12 A having penetrated the sheet bundle P. The movable member  31 AR has an operating portion  311 AR provided at an end portion configured to move toward and away from the receiving part  32 A and the staple leg  12 A by a rotation operation about the shaft  320 AR as a support point. The operating portion  311 AR is an example of the second tip portion, and faces an outer surface of the other staple leg  12 A having penetrated the sheet bundle P. 
     The receiving part  32 A has a first operated portion  321 AL and a second operated portion  322 AL at one end portion. The first operated portion  321 AL is an example of the first tip portion, and faces an inner surface of one staple leg  12 A having penetrated the sheet bundle P. The second operated portion  322 AL faces the inner surface of one staple leg  12 A having penetrated the sheet bundle P. The receiving part  32 A has a first operated portion  321 AR and a second operated portion  322 AR at the other end portion. The first operated portion  321 AR is an example of the first tip portion, and faces an inner surface of one staple leg  12 A having penetrated the sheet bundle P. The second operated portion  322 AR faces the inner surface of the other staple leg  12 A having penetrated the sheet bundle P. 
     A direction perpendicular to a moving direction of the operating portion  311 AL by the rotation operation of the movable member  31 AL about the shaft  320 AL as a support point and a direction perpendicular to a moving direction of the operating portion  311 AR by the rotation operation of the movable member  31 AR about the shaft  320 AR as a support point are denoted with an arrow AZ. In the meantime, the arrow AZ direction is substantially parallel to the extension direction of the staple legs  12 A of the staple  10 A having penetrated the sheet bundle P. 
     Also, a direction along the moving direction of the operating portion  311 AL and a direction along the moving direction of the operating portion  311 AR by the rotation operation are denoted with an arrow AX. 
     The movable member  31 AL is provided on a further upper side than the receiving part  32 A in the arrow AZ direction. Also, the movable member  31 AR is provided on a further upper side than the receiving part  32 A in the arrow AZ direction. In the meantime, herein, the upper side is a direction away from the striking member  21 A. Also, in the state shown in  FIG. 1  and the like in which the sheet bundle P is sandwiched with the sheet sandwiching part  4 A, a side away from the sheet bundle P is a sheet bundle side. 
     The receiving part  32 A has the first operated portion  321 AL and the second operated portion  322 AL on upper and lower sides in the arrow AZ direction. The second operated portion  322 AL is provided on a side, an upper side in this example, on which it is closer to the operating portion  311 AL than the first operated portion  321 AL in the arrow AZ direction. 
     The receiving part  32 A has the first operated portion  321 AR and the second operated portion  322 AR on upper and lower sides in the arrow AZ direction. The second operated portion  322 AR is provided on a side, an upper side in this example, on which it is closer to the operating portion  311 AR than the first operated portion  321 AR in the arrow AZ direction. 
     A tip of the first operated portion  321 AL protrudes toward the staple leg  12 A further than a tip of the second operated portion  322 AL in the AX direction. 
     A tip of the first operated portion  321 AR protrudes toward the facing staple leg  12 A further than a tip of the second operated portion  322 AR in the AX direction. 
     By the above configuration, the second operated portion  322 AL is formed at one end portion of the receiving part  32 A by a corner portion of an upper surface and one side surface of the receiving part  32 A. Also, the first operated portion  321 AL, which is a support point for bending the staple leg  12 A, is formed at one end portion of the receiving part  32 A by a corner portion at a predetermined position spaced from the second operating portion  322 AL in the arrow AZ direction. In the arrow AX direction, the second operated portion  322 AL is provided on a more inner side than the first operated portion  321 AL, and the first operated portion  321 AL protrudes toward the staple leg  12 A further than the second operated portion  322 AL. Also, the first operated portion  321 AL includes an inclined portion  323 AL inclined such that a thickness becomes smaller toward a tip facing one staple leg  12 A. 
     The second operated portion  322 AR is formed at the other end portion of the receiving part  32 A by a corner portion of the upper surface and the other side surface of the receiving part  32 A. Also, the first operated portion  321 AR, which is a support point for bending the staple leg  12 A, is formed at the other end portion of the receiving part  32 A by a corner portion at a predetermined position spaced from the second operating portion  322 AR in the arrow AZ direction. In the arrow AX direction, the second operated portion  322 AR is provided on a more inner side than the first operated portion  321 AR, and the first operated portion  321 AR protrudes toward the staple leg  12 A further than the second operated portion  322 AR. Also, the first operated portion  321 AR includes an inclined portion  323 AR inclined such that a thickness becomes smaller toward a tip facing the other staple leg  12 A. A portion of one staple leg  12 A having penetrated the sheet bundle P, which is in contact with the first operated portion  321 AL, is the first position P 1  becoming a support point of the bending. Also, a portion of the other staple leg  12 A having penetrated the sheet bundle P, which is in contact with the first operated portion  321 AR, is the first position P 1  becoming a support point of the bending. Also, the receiving part  32 A is a fixed cutter configured to cut one staple leg  12 A with the second operated portion  322 AL and the operating portion  311 AL of the movable member  31 AL and to cut the other staple leg  12 A with the second operated portion  322 AR and the operating portion  311 AR of the movable member  31 AR. The receiving part  32 A configures a first cutting edge by the second operated portions  322 AL and  322 AR located on the non-sheet bundle side than the first operated portions  321 AL and  321 AR. 
     The operating portion  311 AL is provided on the non-sheet bundle side, which is a further upper side than the second operated portion  322 AL in the arrow AZ direction. Also, the operating portion  311 AR is provided on the non-sheet bundle side, which is a further upper side than the second operated portion  322 AR in the arrow AZ direction. 
     The movable member  31 AL is configured such that the operating portion  311 AL is moved by the rotation operation about the shaft  320 AL as a support point from a state, in which a predetermined gap through which the staple leg  12 A is to pass is formed between the operating portion  311 AL and the first operated portion  321 AL and second operated portion  322 AL of the receiving part  32 A, to a position in which the operating portion  311 AL passes the second operated portion  322 AL. 
     The movable member  31 AR is configured such that the operating portion  311 AR is moved by the rotation operation about the shaft  320 AR as a support point from a state, in which a predetermined gap through which the staple leg  12 A is to pass is formed between the operating portion  311 AR and the first operated portion  321 AR and second operated portion  322 AR of the receiving part  32 A, to a position in which the operating portion  311 AR passes the second operated portion  322 AR. The movable member  31 AL is a movable cutter configured to cut one staple leg  12 A with the operating portion  311 AL and the second operated portion  322 AL of the receiving part  32 A as the operating portion  311 AL moves toward one staple leg  12 A. The movable member  31 AL configures a second cutting edge by the operating portion  311 AL. Also, the movable member  31 AR is a movable cutter configured to cut the other staple leg  12 A with the operating portion  311 AR and the second operated portion  322 AR of the receiving part  32 A as the operating portion  311 AR moves toward the other staple leg  12 A. The movable member  31 AR configures a second cutting edge by the operating portion  311 AR. 
     The bending part  30 A includes moving parts  301 AL and  301 AR configured to move the movable members  31 AL and  31 AR toward the staple legs  12 A. The moving parts  301 AL and  301 AR are configured to move the pair of movable members  31 AL and  31 AR away from and toward each other as the operation of the cam  51 A shown in  FIG. 1  and the like is transmitted via the link and the like. The moving part  301 AL is configured to move one movable member  31 AL toward one staple leg  12 A located on an inner side of the movable member  31 AL. The moving part  301 AR is configured to move the other movable member  31 AR toward the other staple leg  12 A located on an inner side of the movable member  31 AR. The clincher part  33 A includes bending members  33 AL and  33 AR each of which is configured to bend one staple leg  12 A, which has penetrated the sheet bundle P, of the staple  10 A struck out by the striking member  21 A. The bending members  33 AL and  33 AR are configured to linearly move toward and away from each other, and to rotate toward the sheet bundle P. 
       FIG. 7  illustrates a preferred manner of bending the staple legs  12 A. The first operated portion  321 AR ( 321 AL) and second operated portion  322 AR ( 322 AL) of the receiving part  32 A are configured such that an angle α between an extension line Ln 11  of a virtual line Ln 1  connecting the second position P 2  of the staple legs  12 A located on the upper surface of the sheet bundle and the first operated portion  321 AR ( 321 AL) and an extension line Ln 21  of a virtual line Ln 2  connecting the first operated portion  321 AR ( 321 AL) and the second operated portion  322 AR ( 322 AL) is preferably 15° or greater, and is more preferably within a range from 15° to 45°. When the angle α is 15° or less, the legs return by an amount of elastic deformation of a bent amount of the staple legs  12 A bent at the first position P 1 , so that the bending is hardly formed. 
     Also, a length Ls 10  of the virtual line Ln 2  connecting the first operated portion  321 AR ( 321 AL) and the second operated portion  322 AR ( 322 AL) is preferably 3 mm or less. When a length from a bending portion of the staple leg  12 A at the first position P 1  to an end side increases, a spacing of the bending portion at the first position P 1  from the surface of the sheet bundle P in a bound state also increases and a height of the staple leg  12 A at the first position P 1  upon the binding increases. 
     &lt;Operation Example of Stapler of Exemplary Embodiment&gt; 
       FIGS. 8A to 8D  are perspective views illustrating an operation example of the stapler of the exemplary embodiment, and  FIGS. 9A to 9D  are front views illustrating an operation example of the stapler  1 A of the exemplary embodiment. Also,  FIG. 10A  is an enlarged view of an A part in  FIG. 9A ,  FIG. 10B  is an enlarged view of an A part in  FIG. 9B ,  FIG. 10C  is an enlarged view of an A part in  FIG. 9C , and  FIG. 10D  is an enlarged view of an A part in  FIG. 9D . In the below, the operation of the stapler  1 A of the exemplary embodiment is described with reference to the respective drawings. 
       FIGS. 8A, 9A and 10A  illustrate a state where the movable members  31 AL and  31 AR are moved to a standby position. In the state where the movable members  31 AL and  31 AR are moved to the standby position, the movable member  31 AL forms a predetermined gap between the operating portion  311 AL and the first operated portion  321 AL and second operated portion  322 AL of the receiving part  32 A. Also, the movable member  31 AR forms a predetermined gap between the operating portion  311 AR and the first operated portion  321 AR and second operated portion  322 AR of the receiving part  32 A. The predetermined gap is a gap through which the staple  10 A struck out by the striking member  21 A can pass. 
     In the state where the movable members  31 AL and  31 AR are moved to the standby position, the binding unit  3 A shown in  FIG. 1  and the like is moved toward the striking unit  2 A, so that the sheet bundle P is sandwiched in the sheet sandwiching part  4 A. 
     The striking member  21 A of the striking part  20 A provided to the striking unit  2 A presses the crown portion  11 A of the formed staple  10 A to strike out the staple  10 A in the state where the sheet bundle P is sandwiched by the sheet sandwiching part  4 A. The staple legs  12 A of the staple  10 A struck out by the striking member  21 A penetrate the sheet bundle P. At this time, as shown in  FIGS. 8A, 9A and 10A , one staple leg  12 A passes between the operating portion  311 AL and the first operated portion  321 AL and second operated portion  322 AL, and the other staple leg  12 A passes between the operating portion  311 AR and the first operated portion  321 AR and second operated portion  322 AR. 
       FIGS. 8B, 9B and 10B  illustrate a state where the movable members  31 AL and  31 AR are moved to a cutting end position. In the state where the movable members  31 AL and  31 AR are moved to the cutting end position, the rotation of the movable member  31 AL about the shaft  320 AL as a support point causes the operating portion  311 AL to move to a position in which the operating portion  311 AL passes the second operated portion  322 AL. Also, the rotation of the movable member  31 AR about the shaft  320 AR as a support point causes the operating portion  311 AR to move to a position in which the operating portion  311 AR passes the second operated portion  322 AR. 
     As shown with an arrow F 1  in  FIGS. 8A, 9A, 10A, 8B, 9B and 10B , while the movable member  31 AL moves from the standby position toward the cutting end position, the operating portion  311 AL of the movable member  31 AL first contacts an outer surface of one staple leg  12 A. Also, while the movable member  31 AR moves from the standby position toward the cutting end position, the operating portion  311 AR of the movable member  31 AR first contacts an outer surface of the other staple leg  12 A. 
     An interval L 1  between the first operated portions  321 AL and  321 AR of the receiving part  32 A is smaller than a width L of the crown portion  11 A. Thereby, force of pushing inwardly the portions of the pair of staple legs  12 A protruding from the sheet bundle P is applied from the respective outer sides of the pair of staple legs  12 A, so that the pair of staple legs  12 A is respectively bent inwardly at the second position P 2  of the staple legs  12 A located closer to the sheet bundle P than the first position P 1  on the upper surface of the sheet bundle P as a support point of the bending. 
     When the portions of the pair of staple legs  12 A protruding from the sheet bundle P are respectively bent inwardly at the second position P 2 , one staple leg  12 A is contacted to the first operated portion  321 AL and the other staple leg  12 A is contacted to the first operated portion  321 AR. 
     An interval L 2  between the second operated portions  322 AL and  322 AR of the receiving part  32 A is smaller than the interval L 1  between the first operated portions  321 AL and  321 AR. Also, in the state where the portions of the pair of staple legs  12 A protruding from the sheet bundle P are bent inwardly at the second position P 2  on the upper surface of the sheet bundle P as a support point and portions on further tip sides than the second position P 2  are linear, the staple legs  12 A are not in contact with the second operated portions  322 AL and  322 AR. 
     Thereby, in the state where one staple leg  12 A is in contact with the first operated portion  321 AL while the movable member  31 AL is moved from the standby position toward the cutting end position, the force of pushing inwardly the one staple leg  12 A is further applied, so that one staple leg  12 A is further bent inwardly on the further tip side than the first position P 1  by using the first operated portion  321 AL as a support point and the portion in contact with the first operated portion  321 AL as the first position P 1 . Also, in the state where the other staple leg  12 A is in contact with the first operated portion  321 AR while the movable member  31 AR is moved from the standby position toward the cutting end position, the force of pushing inwardly the other staple leg  12 A is further applied, so that the other staple leg  12 A is further bent inwardly on the further tip side than the first position P 1  by using the first operated portion  321 AR as a support point and the portion in contact with the first operated portion  321 AR as the first position P 1 . 
     When the portions of the pair of staple legs  12 A protruding from the sheet bundle P are further bent inwardly at the first position P 1  by using the first operated portions  321 AL and  321 AR as support points, one staple leg  12 A is contacted to the second operated portion  322 AL and the other staple leg  12 A is contacted to the second operated portion  322 AR. 
     In the state where the staple leg  12 A is sandwiched between the operating portion  311 AL of the movable member  31 AL and the second operated portion  322 AL of the receiving part  32 A, the movable member  31 AL is moved to the cutting end position, so that the staple leg  12 A is sheared by the second cutting edge consisting of the operating portion  311 AL and the first cutting edge consisting of the second operated portion  322 AL, so that one staple leg  12 A is cut. Also, in the state where the staple leg  12 A is sandwiched between the operating portion  311 AR of the movable member  31 AR and the second operated portion  322 AR of the receiving part  32 A, the movable member  31 AR is moved to the cutting end position, so that the staple leg  12 A is sheared by the second cutting edge of the operating portion  311 AR and the first cutting edge of the second operated portion  322 AR, so that the other staple leg  12 A is cut. The cut staples  13  are stored in the cut staple storing part  6 A shown in  FIG. 1  and the like. 
     One staple leg  12 A of which the further tip side than the portion in contact with the second operated portion  322 AL is cut has such a shape that the further tip side than the portion in contact with the first operated portion  321 AL is bent inwardly at the first position P 1  about the first operated portion  321 AL as a support point. Also, the other staple leg  12 A of which the further tip side than the portion in contact with the second operated portion  322 AR is cut has such a shape that the further tip side than the portion in contact with the first operated portion  321 AR is bent inwardly at the first position P 1  about the first operated portion  321 AR as a support point. 
       FIGS. 8C, 9C and 10C  illustrate a state where the bending members  33 AL and  33 AR are moved to a bending start position. The bending members  33 AL and  33 AR are linearly moved toward each other, as shown with an arrow F 2 , thereby moving to the bending start position in which they are in contact with the outer surfaces of the staple legs  12 A. The support member  320 A is moved rearward in conjunction with the movement of the bending members  33 AL and  33 AR to the bending start position, so that the movable members  31 AL and  31 AR and the receiving part  32 A are retreated from between the staple legs  12 A and the bending members  33 AL and  33 AR. 
       FIGS. 8D, 9D and 10D  illustrate a state where the bending members  33 AL and  33 AR are moved to a bending end position. The bending members  33 AL and  33 AR are further moved linearly from the bending start position toward each other, as shown with the arrow F 2 , thereby pushing the staple legs  12 A inwardly. While the bending member  33 AL moves from the bending start position toward the bending end position, the force of pushing the staple leg  12 A inwardly is applied, so that the portion, which protrudes from the sheet bundle P, of one staple leg  12 A is further bent inwardly at the second position P 2  on the upper surface of the sheet bundle P as a support point. Also, while the bending member  33 AR moves from the bending start position toward the bending end position, the force of pushing the staple leg  12 A inwardly is applied, so that the portion, which protrudes from the sheet bundle P, of the other staple leg  12 A is further bent inwardly at the second position P 2  on the upper surface of the sheet bundle P as a support point. 
     After the bending members  33 AL and  33 AR are linearly moved toward each other, the bending members  33 AL and  33 AR are rotated toward the sheet bundle P, as shown with an arrow F 3 . Thereby, the bending member  33 AL presses one staple leg  12 A to the sheet bundle P, and the bending member  33 AR presses the other staple leg  12 A to the sheet bundle P. 
     In the stapler  1 A of the exemplary embodiment, while the staple legs  12 A are cut by the movable members  31 AL and  31 AR, the staple legs  12 A on the further tip side than the portions in contact with the first operated portions  321 AL and  321 AR are bent inwardly at the first position P 1  about the first operated portions  321 AL and  321 AR as support points. Thereby, the tips of the staple legs  12 A are difficult to float from the surface of the sheet bundle P. 
     &lt;Modified Examples of Stapler of Exemplary Embodiment&gt; 
     In the stapler  1 A, the movable members  31 AL and  31 AR and the receiving part  32 A have the functions of bending and cutting the tip sides of the staple legs  12 A of the staple  10 A. In contrast, in modified examples below, the movable member and the receiving part do not have the function of cutting the staple leg. 
       FIGS. 11A and 11B  are configuration views illustrating a modified example of the stapler of the exemplary embodiment. An overall configuration of a stapler  1 B is equivalent to the configuration shown in  FIGS. 2A, 2B and 2C . The stapler  1 B includes a bending part  30 B configured to bend the staple legs  12 A at the first position P 1  such that the tips of the staple legs  12 A having penetrated the sheet bundle P are directed inwardly. 
     The bending part  30 B includes a movable member  31 BL on the outer side of one staple leg  12 A, and a movable member  31 BR on the outer side of the other staple leg  12 A. Also, the stapler  1 B includes a receiving part  32 B between the pair of staple legs  12 A. 
     The receiving part  32 B is an example of the first part, and has an operated portion  321 BL at one end portion. The operated portion  321 BL is an example of the first tip portion, and a portion thereof, which faces the inner surface of one staple leg  12 A having penetrated the sheet bundle P, is formed to have a planar shape. The receiving part  32 B has an operated portion  321 BR at the other end portion. The operated portion  321 BR is an example of the first tip portion, and a portion thereof, which faces the inner surface of the other staple leg  12 A having penetrated the sheet bundle P, is formed to have a planar shape. 
     The movable members  31 BL and  31 BR are an example of the second part, and are configured to move toward and away from the receiving part  32 B. The movable member  31 BL has an operating portion  311 BL at an end portion configured to move toward and away from the receiving part  32 B. The operating portion  311 BL is an example of the second tip portion, and a portion thereof, which faces the outer surface of one staple leg  12 A having penetrated the sheet bundle P, is formed to have a planar shape. The movable member  31 BR has an operating portion  311 BR at an end portion configured to move toward and away from the receiving part  32 B. The operating portion  311 BR is an example of the second tip portion, and a portion thereof, which faces the outer surface of the other staple leg  12 A having penetrated the sheet bundle P, is formed to have a planar shape. 
     In the arrow AZ direction, the movable member  31 BL is provided on a further upper side than the receiving part  32 B, and the operating portion  311 BL of the movable member  31 BL is provided on a further upper side than the operated portion  321 BL of the receiving part  32 B. Also, in the arrow AZ direction, the movable member  31 BR is provided on a further upper side than the receiving part  32 B, and the operating portion  311 BR of the movable member  31 BR is provided on a further upper side than the operated portion  321 BR of the receiving part  32 B. 
       FIG. 11A  illustrates a state where the movable members  31 BL and  31 BR are moved to the standby position. In the state where the movable members  31 BL and  31 BR are moved to the standby position, the movable member  31 BL forms a predetermined gap between the operating portion  311 BL and the operated portion  321 BL of the receiving part  32 B. Also, the movable member  31 BR forms a predetermined gap between the operating portion  311 BR and the operated portion  321 BR of the receiving part  32 B. 
     The staple legs  12 A of the staple  10 A struck out with the striking member  21 A penetrate the sheet bundle P, in which one staple leg  12 A passes between the operating portion  311 BL and the operated portion  321 BL and the other staple leg  12 A passes between the operating portion  311 BR and the operated portion  321 BR. 
       FIG. 11B  illustrates a state where the movable members  31 BL and  31 BR are moved to the bending end position. In the state where the movable members  31 BL and  31 BR are moved to the bending end position, the movable member  31 BL is moved to a position in which the operating portion  311 BL passes the operated portion  321 BL. Also, the movable member  31 BR is moved to a position in which the operating portion  311 BR passes the operated portion  321 BR. 
     As shown with the arrow F 1  in  FIGS. 11A and 11B , while the movable member  31 BL moves from the standby position toward the bending end position, the operating portion  311 BL of the movable member  31 BL first contacts the outer surface of one staple leg  12 A. Also, while the movable member  31 BR moves from the standby position toward the bending end position, the operating portion  311 BR of the movable member  31 BR first contacts the outer surface of the other staple leg  12 A. 
     An interval L 1  between the operated portions  321 BL and  321 BR of the receiving part  32 B is smaller than the width L of the crown portion  11 A. Thereby, the force of pushing inwardly the portions of the pair of staple legs  12 A protruding from the sheet bundle P is applied from the respective outer sides of the pair of staple legs  12 A, so that the pair of staple legs  12 A is respectively bent inwardly at the second position P 2  of the staple legs  12 A located closer to the sheet bundle P than the first position P 1  on the upper surface of the sheet bundle P as a support point of the bending. 
     When the portions of the pair of staple legs  12 A protruding from the sheet bundle P are respectively bent inwardly, one staple leg  12 A is contacted to the operated portion  321 BL and the other staple leg  12 A is contacted to the operated portion  321 BR. 
     Thereby, in the state where one staple leg  12 A is in contact with the operated portion  321 BL while the movable member  31 BL is moved from the standby position toward the bending end position, the force of pushing inwardly the one staple leg  12 A is further applied. Therefore, one staple leg  12 A is further bent inwardly on the further tip side than the first position P 1  by using the operated portion  321 BL as a support point and the portion in contact with the operated portion  321 BL as the first position P 1 . Also, in the state where the other staple leg  12 A is in contact with the operated portion  321 BR while the movable member  31 BR is moved from the standby position toward the bending end position, the force of pushing inwardly the other staple leg  12 A is further applied. Therefore, the other staple leg  12 A is further bent inwardly on the further tip side than the first position P 1  by using the operated portion  321 BR as a support point and the portion in contact with the operated portion  321 BR as the first position P 1 . The operation of bending the entire staple legs  12 A from the second position P 2  is similar to that shown in  FIGS. 8C, 8D, 9C, 9D, 10C and 10D . 
       FIGS. 12A and 12B  are configuration views illustrating a modified example of the stapler of the exemplary embodiment. An overall configuration of a stapler  1 C is equivalent to the configuration shown in  FIGS. 2A, 2B and 2C . The stapler  1 C includes a bending part  30 C configured to bend the staple legs  12 A at the first position P 1  such that the tips of the staple legs  12 A having penetrated the sheet bundle P are directed inwardly. 
     The bending part  30 C includes a movable member  31 CL on the outer side of one staple leg  12 A, and a movable member  31 CR on the outer side of the other staple leg  12 A. Also, the stapler  1 C includes a receiving part  32 C between the pair of staple legs  12 A. 
     The receiving part  32 C is an example of the first part, and has an operated portion  321 CL at one end portion. The operated portion  321 CL is an example of the first tip portion, and a portion thereof, which faces the inner surface of one staple leg  12 A having penetrated the sheet bundle P, is formed to have a curved surface shape. The receiving part  32 C has an operated portion  321 CR at the other end portion. The operated portion  321 CR is an example of the first tip portion, and a portion thereof, which faces the inner surface of the other staple leg  12 A having penetrated the sheet bundle P, is formed to have a curved surface shape. 
     The movable members  31 CL and  31 CR are an example of the second part, and are configured to move toward and away from the receiving part  32 C. The movable member  31 CL has an operating portion  311 CL at an end portion configured to move toward and away from the receiving part  32 C. The operating portion  311 CL is an example of the second tip portion, and a portion thereof, which faces the outer surface of one staple leg  12 A having penetrated the sheet bundle P, is formed to have a curved surface shape. The movable member  31 CR has an operating portion  311 CR at an end portion configured to move toward and away from the receiving part  32 C. The operating portion  311 CR is an example of the second tip portion, and a portion thereof, which faces the outer surface of the other staple leg  12 A having penetrated the sheet bundle P, is formed to have a curved surface shape. 
     In the arrow AZ direction, the movable member  31 CL is provided on a further upper side than the receiving part  32 C, and the operating portion  311 CL of the movable member  31 CL is provided on a further upper side than the operated portion  321 CL of the receiving part  32 C. Also, in the arrow AZ direction, the movable member  31 CR is provided on a further upper side than the receiving part  32 C, and the operating portion  311 CR of the movable member  31 CR is provided on a further upper side than the operated portion  321 CR of the receiving part  32 C. 
       FIG. 12A  illustrates a state where the movable members  31 CL and  31 CR are moved to the standby position. In the state where the movable members  31 CL and  31 CR are moved to the standby position, the movable member  31 CL forms a predetermined gap between the operating portion  311 CL and the operated portion  321 CL of the receiving part  32 C. Also, the movable member  31 CR forms a predetermined gap between the operating portion  311 CR and the operated portion  321 CR of the receiving part  32 C. 
     The staple legs  12 A of the staple  10 A struck out with the striking member  21 A penetrate the sheet bundle P, in which one staple leg  12 A passes between the operating portion  311 CL and the operated portion  321 CL and the other staple leg  12 A passes between the operating portion  311 CR and the operated portion  321 CR. 
       FIG. 12B  illustrates a state where the movable members  31 CL and  31 CR are moved to the bending end position. In the state where the movable members  31 CL and  31 CR are moved to the bending end position, the movable member  31 CL is moved to a position in which the operating portion  311 CL passes the operated portion  321 CL. Also, the movable member  31 CR is moved to a position in which the operating portion  311 CR passes the operated portion  321 CR. 
     As shown with the arrow F 1  in  FIGS. 12A and 12B , while the movable member  31 CL moves from the standby position toward the bending end position, the operating portion  311 CL of the movable member  31 CL first contacts the outer surface of one staple leg  12 A. Since the operating portion  311 CL is formed to have a curved surface shape, an apex of the curved surface becoming a convex shape contacts the staple leg  12 A. Also, while the movable member  31 CR moves from the standby position toward the bending end position, the operating portion  311 CR first contacts the outer surface of the other staple leg  12 A. Since the operating portion  311 CR of the movable member  31 CR is formed to have a curved surface shape, an apex of the curved surface becoming a convex shape contacts the staple leg  12 A. 
     An interval L 1  between the operated portions  321 CL and  321 CR of the receiving part  32 B is smaller than the width L of the crown portion  11 A. Thereby, the force of pushing inwardly the portions of the pair of staple legs  12 A protruding from the sheet bundle P is applied from the respective outer sides of the pair of staple legs  12 A, so that the pair of staple legs  12 A is respectively bent inwardly in the second position P 2  of the staple legs  12 A located closer to the sheet bundle P than the first position P 1  on the upper surface of the sheet bundle P as a support point of the bending. 
     When the portions of the pair of staple legs  12 A protruding from the sheet bundle P are respectively bent inwardly, one staple leg  12 A is contacted to the operated portion  321 CL and the other staple leg  12 A is contacted to the operated portion  321 CR. Since the operated portion  321 CL is formed to have a curved surface shape, an apex of the curved surface becoming a convex shape contacts the staple leg  12 A. Also, since the operated portion  321 CR is formed to have a curved surface shape, an apex of the curved surface becoming a convex shape contacts the staple leg  12 A. 
     Thereby, in the state where one staple leg  12 A is in contact with the operated portion  321 CL while the movable member  31 CL is moved from the standby position toward the bending end position, the force of pushing inwardly the one staple leg  12 A is further applied. Therefore, one staple leg  12 A is further bent inwardly on the further tip side than the first position P 1  by using the operated portion  321 CL as a support point and the portion in contact with the operated portion  321 CL as the first position P 1 . Also, in the state where the other staple leg  12 A is in contact with the operated portion  321 CR while the movable member  31 CR is moved from the standby position toward the bending end position, the force of pushing inwardly the other staple leg  12 A is further applied. Therefore, the other staple leg  12 A is further bent inwardly on the further tip side than the first position P 1  by using the operated portion  321 CR as a support point and the portion in contact with the operated portion  321 CR as the first position P 1 . The operation of bending the entire staple legs  12 A from the second position P 2  is similar to that shown in  FIGS. 8C, 8D, 9C, 9D, 10C and 10D . 
       FIGS. 13A and 13B  are configuration views illustrating a modified example of the stapler of the exemplary embodiment. An overall configuration of a stapler  1 D is equivalent to the configuration shown in  FIGS. 2A, 2B and 2C . The stapler  1 D includes a bending part  30 D configured to bend the staple legs  12 A at the first position P 1  such that the tips of the staple legs  12 A having penetrated the sheet bundle P are directed inwardly. 
     The bending part  30 D includes a movable member  31 DL on the outer side of one staple leg  12 A, and a movable member  31 DR on the outer side of the other staple leg  12 A. Also, the stapler  1 D includes a receiving part  32 D between the pair of staple legs  12 A. 
     The receiving part  32 D is an example of the first part, and has an operated portion  321 DL at one end portion. The operated portion  321 DL is an example of the first tip portion, and a portion thereof, which faces the inner surface of one staple leg  12 A having penetrated the sheet bundle P, is formed to have a planar shape. The receiving part  32 D has an operated portion  321 DR at the other end portion. The operated portion  321 DR is an example of the first tip portion, and a portion thereof, which faces the inner surface of the other staple leg  12 A having penetrated the sheet bundle P, is formed to have a planar shape. 
     The movable members  31 DL and  31 DR are an example of the second part, and are configured to move toward and away from the receiving part  32 D. The movable member  31 DL has an operating portion  311 DL at an end portion configured to move toward and away from the receiving part  32 D. The operating portion  311 DL is an example of the second tip portion, and a portion thereof, which faces the outer surface of one staple leg  12 A having penetrated the sheet bundle P, is configured as an apex of a convex portion protruding in an acute angle shape. The movable member  31 DR has an operating portion  311 DR at an end portion configured to move toward and away from the receiving part  32 D. The operating portion  311 DR is an example of the second tip portion, and a portion thereof, which faces the outer surface of the other staple leg  12 A having penetrated the sheet bundle P, is configured as an apex of a convex portion protruding in an acute angle shape. 
     In the arrow AZ direction, the movable member  31 DL is provided on a further upper side than the receiving part  32 D, and the operating portion  311 DL of the movable member  31 DL is provided on a further upper side than the operated portion  321 DL of the receiving part  32 D. Also, in the arrow AZ direction, the movable member  31 DR is provided on a further upper side than the receiving part  32 D, and the operating portion  311 DR of the movable member  31 DR is provided on a further upper side than the operated portion  321 DR of the receiving part  32 D. 
       FIG. 13A  illustrates a state where the movable members  31 DL and  31 DR are moved to the standby position. In the state where the movable members  31 DL and  31 DR are moved to the standby position, the movable member  31 DL forms a predetermined gap between the operating portion  311 DL and the operated portion  321 DL of the receiving part  32 D. Also, the movable member  31 DR forms a predetermined gap between the operating portion  311 DR and the operated portion  321 DR of the receiving part  32 D. 
     The staple legs  12 A of the staple  10 A struck out with the striking member  21 A penetrate the sheet bundle P, in which one staple leg  12 A passes between the operating portion  311 DL and the operated portion  321 DL and the other staple leg  12 A passes between the operating portion  311 DR and the operated portion  321 DR. 
       FIG. 13B  illustrates a state where the movable members  31 DL and  31 DR are moved to the bending end position. In the state where the movable members  31 DL and  31 DR are moved to the bending end position, the movable member  31 DL is moved to a position in which the operating portion  311 DL passes the operated portion  321 DL. Also, the movable member  31 DR is moved to a position in which the operating portion  311 DR passes the operated portion  321 DR. 
     As shown with the arrow F 1  in  FIGS. 13A and 13B , while the movable member  31 DL moves from the standby position toward the bending end position, the operating portion  311 DL of the movable member  31 DL first contacts the outer surface of one staple leg  12 A. The operating portion  311 DL contacts the staple leg  12 A at the apex of the convex portion protruding in an acute angle shape. Also, while the movable member  31 DR moves from the standby position toward the bending end position, the operating portion  311 DR of the movable member  31 DR first contacts the outer surface of the other staple leg  12 A. The operating portion  311 DR contacts the staple leg  12 A at the apex of the convex portion protruding in an acute angle shape. 
     An interval L 1  between the operated portions  321 DL and  321 DR of the receiving part  32 D is smaller than the width L of the crown portion  11 A. Thereby, the force of pushing inwardly the portions of the pair of staple legs  12 A protruding from the sheet bundle P is applied from the respective outer sides of the pair of staple legs  12 A, so that the pair of staple legs  12 A is respectively bent inwardly at the second position P 2  of the staple legs  12 A located closer to the sheet bundle P than the first position P 1  on the upper surface of the sheet bundle P as a support point of the bending. 
     When the portions of the pair of staple legs  12 A protruding from the sheet bundle P are respectively bent inwardly, one staple leg  12 A is contacted to the operated portion  321 DL and the other staple leg  12 A is contacted to the operated portion  321 DR 
     Thereby, in the state where one staple leg  12 A is in contact with the operated portion  321 DL while the movable member  31 DL is moved from the standby position toward the bending end position, the force of pushing inwardly the one staple leg  12 A is further applied. Therefore, one staple leg  12 A is further bent inwardly on the further tip side than the first position P 1  by using the operated portion  321 DL as a support point and the portion in contact with the operated portion  321 DL as the first position P 1 . Also, in the state where the other staple leg  12 A is in contact with the operated portion  321 DR while the movable member  31 DR is moved from the standby position toward the bending end position, the force of pushing inwardly the other staple leg  12 A is further applied. Therefore, the other staple leg  12 A is further bent inwardly on the further tip side than the first position P 1  by using the operated portion  321 DR as a support point and the portion in contact with the operated portion  321 DR as the first position P 1 . The operation of bending the entire staple legs  12 A from the second position P 2  is similar to that shown in  FIGS. 8C, 8D, 9C, 9D, 10C and 10D . 
       FIGS. 14A and 14B  are configuration views illustrating a modified example of the stapler of the exemplary embodiment. An overall configuration of a stapler  1 E is equivalent to the configuration shown in  FIGS. 2A, 2B and 2C . The stapler  1 E includes a bending part  30 E configured to bend the staple legs  12 A at the first position P 1  such that the tips of the staple legs  12 A having penetrated the sheet bundle P are directed inwardly. 
     The bending part  30 E includes a movable member  31 EL on the outer side of one staple leg  12 A, and a movable member  31 ER on the outer side of the other staple leg  12 A. Also, the stapler  1 E includes a receiving part  32 E between the pair of staple legs  12 A. 
     The receiving part  32 E is an example of the first part, and has an operated portion  321 EL at one end portion. The operated portion  321 EL is an example of the first tip portion, and a portion thereof, which faces the inner surface of one staple leg  12 A having penetrated the sheet bundle P, is formed to have a planar shape. The receiving part  32 E has an operated portion  321 ER at the other end portion. The operated portion  321 ER is an example of the first tip portion, and a portion thereof, which faces the inner surface of the other staple leg  12 A having penetrated the sheet bundle P, is formed to have a planar shape. 
     The movable members  31 EL and  31 ER are an example of the second part, and are configured to move toward and away from the receiving part  32 E. The movable member  31 EL has an operating portion  311 EL at an end portion configured to move toward and away from the receiving part  32 E. The operating portion  311 EL is an example of the second tip portion, and a portion thereof, which faces the outer surface of one staple leg  12 A having penetrated the sheet bundle P, is configured as an apex of a convex portion protruding in an acute angle shape. The movable member  31 ER has an operating portion  311 ER at an end portion configured to move toward and away from the receiving part  32 E. The operating portion  311 ER is an example of the second tip portion, and a portion thereof, which faces the outer surface of the other staple leg  12 A having penetrated the sheet bundle P, is configured as an apex of a convex portion protruding in an acute angle shape. 
     In the arrow AZ direction, the movable member  31 EL is partially provided on a further upper side than the receiving part  32 E, and the operating portion  311 EL of the movable member  31 EL is provided on a further upper side than the operated portion  321 EL of the receiving part  32 E. Also, in the arrow AZ direction, the movable member  31 ER is partially provided on a further upper side than the receiving part  32 E, and the operating portion  311 ER of the movable member  31 ER is provided on a further upper side than the operated portion  321 ER of the receiving part  32 E. 
       FIG. 14A  illustrates a state where the movable members  31 EL and  31 ER are moved to the standby position. In the state where the movable members  31 EL and  31 ER are moved to the standby position, the movable member  31 EL forms a predetermined gap between the operating portion  311 EL and the operated portion  321 EL of the receiving part  32 E. Also, the movable member  31 ER forms a predetermined gap between the operating portion  311 ER and the operated portion  321 ER of the receiving part  32 E. 
     The staple legs  12 A of the staple  10 A struck out with the striking member  21 A penetrate the sheet bundle P, in which one staple leg  12 A passes between the operating portion  311 EL and the operated portion  321 EL and the other staple leg  12 A passes between the operating portion  311 ER and the operated portion  321 ER. 
       FIG. 14B  illustrates a state where the movable members  31 EL and  31 ER are moved to the bending end position. In the state where the movable members  31 EL and  31 ER are moved to the bending end position, the movable member  31 EL is moved to a position in which the operating portion  311 EL passes the operated portion  321 EL. Also, the movable member  31 ER is moved to a position in which the operating portion  311 ER passes the operated portion  321 ER. 
     As shown with the arrow F 1  in  FIGS. 14A and 14B , while the movable member  31 EL moves from the standby position toward the bending end position, the operating portion  311 EL of the movable member  31 EL first contacts the outer surface of one staple leg  12 A. The operating portion  311 EL contacts the staple leg  12 A at the apex of the convex portion protruding in an acute angle shape. Also, while the movable member  31 ER moves from the standby position toward the bending end position, the operating portion  311 ER of the movable member  31 ER first contacts the outer surface of the other staple leg  12 A. The operating portion  311 ER contacts the staple leg  12 A at the apex of the convex portion protruding in an acute angle shape. 
     An interval L 1  between the operated portions  321 EL and  321 ER of the receiving part  32 E is smaller than the width L of the crown portion  11 A. Thereby, the force of pushing inwardly the portions of the pair of staple legs  12 A protruding from the sheet bundle P is applied from the respective outer sides of the pair of staple legs  12 A, so that the pair of staple legs  12 A is respectively bent inwardly in the second position P 2  of the staple legs  12 A located closer to the sheet bundle P than the first position P 1  on the upper surface of the sheet bundle P as a support point of the bending. 
     When the portions of the pair of staple legs  12 A protruding from the sheet bundle P are respectively bent inwardly, one staple leg  12 A is contacted to the operated portion  321 EL and the other staple leg  12 A is contacted to the operated portion  321 ER 
     Thereby, in the state where one staple leg  12 A is in contact with the operated portion  321 EL while the movable member  31 EL is moved from the standby position toward the bending end position, the force of pushing inwardly the one staple leg  12 A is further applied. Therefore, one staple leg  12 A is further bent inwardly on the further tip side than the first position P 1  by using the operated portion  321 EL as a support point and the portion in contact with the operated portion  321 EL as the first position P 1 . Also, in the state where the other staple leg  12 A is in contact with the operated portion  321 ER while the movable member  31 ER is moved from the standby position toward the bending end position, the force of pushing inwardly the other staple leg  12 A is further applied. Therefore, the other staple leg  12 A is further bent inwardly on the further tip side than the first position P 1  by using the operated portion  321 ER as a support point and the portion in contact with the operated portion  321 ER as the first position P 1 . The operation of bending the entire staple legs  12 A from the second position P 2  is similar to that shown in  FIGS. 8C, 8D, 9C, 9D, 10C and 10D . 
       FIGS. 15A and 15B  are configuration views illustrating a modified example of the stapler of the exemplary embodiment. An overall configuration of a stapler  1 F is equivalent to the configuration shown in  FIGS. 2A, 2B and 2C . The stapler  1 F includes a bending part  30 F configured to bend the staple legs  12 A at the first position P 1  such that the tips of the staple legs  12 A having penetrated the sheet bundle P are directed inwardly. 
     The bending part  30 F includes a receiving part  32 FL on the outer side of one staple leg  12 A, and a receiving part  32 FR on the outer side of the other staple leg  12 A. Also, the stapler  1 F includes a movable member  31 FL on the inner side of one staple leg  12 A, and a movable member  31 FR on the inner side of the other staple leg  12 A. 
     The movable members  31 FR and  31 FL are an example of the first part. The movable member  31 FL is configured to move toward and away from the receiving part  32 FL, and the movable member  311 R is configured to move toward and away from the receiving part  32 FR. The movable member  31 FL has an operating portion  311 FL at an end portion configured to move toward and away from the receiving part  32 FL. The operating portion  311 FL is an example of the first tip portion, and a portion thereof, which faces the inner surface of one staple leg  12 A having penetrated the sheet bundle P, is configured as an apex of a convex portion protruding in an acute angle shape. The movable member  31 FR has an operating portion  311 FR at an end portion configured to move toward and away from the receiving part  32 FR. The operating portion  311 FR is an example of the first tip portion, and a portion thereof, which faces the inner surface of the other staple leg  12 A having penetrated the sheet bundle P, is configured as an apex of a convex portion protruding in an acute angle shape. 
     The receiving parts  32 FL and  32 FR are an example of the second part. The receiving part  32 FL has an operated portion  321 FL at an end portion facing the movable member  31 FL. The operated portion  321 FL is an example of the second tip portion, and a portion thereof, which faces the outer surface of one staple leg  12 A having penetrated the sheet bundle P, is configured as an apex of a convex portion protruding in an acute angle shape. The receiving part  32 FR has an operated portion  321 FR at an end portion facing the movable member  31 FR. The operated portion  321 FR is an example of the second tip portion, and a portion thereof, which faces the outer surface of the other staple leg  12 A having penetrated the sheet bundle P, is configured as an apex of a convex portion protruding in an acute angle shape. 
     In the arrow AZ direction, the receiving part  32 FL is provided on a further upper side than the movable member  31 FL, and the operated portion  321 FL of the receiving part  32 FL is provided on a further upper side than the operating portion  311 FL of the movable member  31 FL. Also, in the arrow AZ direction, the receiving part  32 FR is provided on a further upper side than the movable member  31 FR, and the operated portion  321 FR of the receiving part  32 FR is provided on a further upper side than the operating portion  311 FR of the movable member  31 FR. 
       FIG. 15A  illustrates a state where the movable members  31 FL and  31 FR are moved to the standby position. In the state where the movable members  31 FL and  31 FR are moved to the standby position, the movable member  31 FL forms a predetermined gap between the operating portion  311 FL and the operated portion  321 FL of the receiving part  32 FL. Also, the movable member  31 FR forms a predetermined gap between the operating portion  311 FR and the operated portion  321 FR of the receiving part  32 FR. 
     The staple legs  12 A of the staple  10 A struck out with the striking member  21 A penetrate the sheet bundle P, in which one staple leg  12 A passes between the operating portion  311 FL and the operated portion  321 FL and the other staple leg  12 A passes between the operating portion  311 FR and the operated portion  321 FR. 
       FIG. 15B  illustrates a state where the movable members  31 FL and  31 FR are moved to the bending end position. In the state where the movable members  31 FL and  31 FR are moved to the bending end position, the movable member  31 FL is moved to a position in which the operating portion  311 FL passes the operated portion  321 FL. Also, the movable member  31 FR is moved to a position in which the operating portion  311 FR passes the operated portion  321 FR. 
     As shown with an arrow F 4  in  FIGS. 15A and 15B , while the movable member  31 FL moves from the standby position toward the bending end position, the operating portion  311 FL of the movable member  31 FL contacts the inner surface of one staple leg  12 A. The operating portion  311 FL contacts the staple leg  12 A at the apex of the convex portion protruding in an acute angle shape. Also, the outer surface of one staple leg  12 A contacts the operated portion  321 FL of the receiving part  32 FL. The operated portion  321 FL contacts the staple leg  12 A at the apex of the convex portion protruding in an acute angle shape. 
     While the movable member  31 FR moves from the standby position toward the bending end position, the operating portion  3111 R of the movable member  31 FR contacts the inner surface of the other staple leg  12 A. The operating portion  311 FR contacts the staple leg  12 A at the apex of the convex portion protruding in an acute angle shape. Also, the outer surface of the other staple leg  12 A contacts the operated portion  321 FR of the receiving part  321 R. The operated portion  321 FR contacts the staple leg  12 A at the apex of the convex portion protruding in an acute angle shape. 
     Thereby, force of pushing outwardly the portions of the pair of staple legs  12 A protruding from the sheet bundle P is applied from the respective inner sides of the pair of staple legs  12 A, so that the pair of staple legs  12 A is respectively bent outwardly at the second position P 2  of the staple legs  12 A located closer to the sheet bundle P than the first position P 1  on the upper surface of the sheet bundle P as a support point of the bending. Also, since one staple leg  12 A is in contact with the operated portion  321 FL on the outer side of the tip thereof, the further tip side than the first position P 1  is bent inwardly by using the operating portion  311 FL as a support point and the portion in contact with the operating portion  311 FL as the first position P 1 . Since the other staple leg  12 A is in contact with the operated portion  321 FR on the outer side of the tip thereof, the further tip side than the first position P 1  is bent inwardly by using the operating portion  311 FR as a support point and the portion in contact with the operating portion  311 FR as the first position P 1 . The operation of bending the entire staple legs  12 A from the second position P 2  is similar to that shown in  FIGS. 8C, 8D, 9C, 9D, 10C and 10D .