Patent Publication Number: US-7223040-B2

Title: Binder

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a binder, and in particular, to a binder in which first and second binding members for forming closed loops can be rotated in the open/close direction, and the closed loop can be released with a slight operating force. 
   2. Description of the Related Art 
   Conventionally, a binder used for a ring file or the like comprises a base fixed to a back cover or to a position adjacent thereto of the file or the like, a pair of first binding members disposed at two positions in the longitudinal direction on the base, and a pair of second binding members positioned at the opposite sides to these first binding members and are brought into contact with the respective front ends of the first binding members. The first and second binding members are connected respectively at the base side thereof by first and second connecting plates; thereby the first binding members and second binding members are adapted to be capable of rotating in the open/close direction respectively. 
   However, in the known binder as described above, such an arrangement is adopted that, when the binding members are in the closed state where closed loops are formed, the first and second connecting plates act to prop the respective binding members so as to maintain the closed state thereof. Due to this, when opening the binding members, since it is necessary to give a strong external force to the binding members to forcibly open the front ends between the first and second binding members, there resides in such an inconvenience that operation thereof is difficult for a user who is poor in operating force. 
   On the other hand, when the binding members are operated from the open state to the closed state, such an inconvenience that the binding members are closed snapping a large sound is created since the spring force accompanying the angle change of the connecting plates act strongly to maintain the opened state when the binding members are rotated in the close direction exceeding a specific angle, and it causes not only to emit an annoying noise but also to render such a fear that a finger might be pinched during closing operation to the user. 
   SUMMARY OF THE INVENTION 
   The present invention has been proposed in view of the problems, and an object of the invention is to provide a binder capable of opening/closing binding members without requiring a large operating force, and does not emit a noise or render a fear upon closing operation of the binder. 
   To achieve the object, the invention adopts such an arrangement that a binder comprises first binding members supported rotatably by a base to be mounted on a cover body and second binding members supported rotatably by the base for forming closed loops by engaging with the respective front ends of the first binding members: 
   the binder further comprises a first connecting member for connecting the first binding members to each other within the base, a second connecting member for connecting the second binding members to each other within the base, and a releasing means disposed within an area of the respective connecting members to provide a force in a direction that the closed loops are released; and 
   Wherein, by providing the force to the first binding members or the second binding members in the direction that crosses the axial direction thereof, the engagement is released so that the first and second binding members are opened. With this arrangement, an operating force is provided to the first binding members or the second binding members in the direction that crosses the axial direction thereof to release the engagement between the first and second binding members, the binding members are made to rotate in the direction that the same are opened-by the releasing means. Accordingly, it is possible to open the binding members in a state that the operating force is reduced. On the other hand, when operating to make the binding members into the closed state, since the operation is made in the direction opposite to the direction of the force of the releasing means, a noise is not emitted and a fear can be also eliminated, different from the conventional binder, by preventing the binder from closing strongly when the binding members shift into the closed state to form closed loops. 
   Also, the invention may adopt such an arrangement that a binder comprises a pair of first binding members supported rotatably by a base to be mounted to a cover body and a pair of second binding members supported rotatably by the base for forming closed loops by engaging with the respective front ends of the first binding members: 
   the binder further comprises a first connecting member for connecting the first binding members to each other within the base, a second connecting member for connecting the second binding members to each other within the base, and a releasing means disposed so as to cross the respective connecting members to provide a force in a direction that the closed loops are released; and 
   Wherein, by providing the force that makes the first binding members or the second binding members closer to each other, the engagement is released so that the first and second binding members are opened. With this arrangement, the engagement can be released by nipping the first binding members or the second binding members with fingertips to make the same closer to each other, and the binding members is made rotatable in the open direction by the releasing means. 
   In the invention, it is preferred to adopt such an arrangement that the first and second connecting members extend along the base; the inner sides in the smaller width direction of the respective connecting members are positioned lower than the outer sides thereof when the first and second binding members are in the closed position; the inner sides of the respective connecting members are shifted to a position higher than the outer sides thereof by the releasing means so that the first and second binding members are opened when the engagement between the first and second binding members is released. With this arrangement, the force of the releasing means and the position of the connecting members interact with each other, and it becomes possible to maintain the closed position and the opened position of the first and second binding members selectively. Accordingly, the first and second binding members in the opened state are prevented from swinging. 
   The releasing means is comprised by a coil spring, and the coil spring is supported by a spring receiving portion formed between the first and second connecting members so as not to drop off. With this arrangement, assembly of the coil spring can be carried out easily, and it is possible to prevent operation failure due to repeated and continuous use from occurring since continuous maintenance of the coil spring at a specific position. 
   It is preferred to adopt such an arrangement that the releasing means is comprised by a leaf spring extending between the first and second connecting members being supported thereby not to drop off. With this arrangement, the leaf spring is maintained at a specific position and it is possible to prevent effectively operation failure from occurring. 
   It is possible that the releasing means is comprised by a wire member, and the wire member is formed of a first portion of the wire member disposed so as to cross the first and second connecting members, and a second portion of the wire member that continues to the first portion of the wire member and the the axis direction thereof is shifted by a predetermined angle with respect to the first portion of the wire member. With this arrangement, it is possible to apply the releasing means to obtain a spring force only by adjusting the axial direction of the wire member. Also, since the wire member can be assembled easily, it is possible to lead to a better productivity of the binder. 
   Further, it is preferred to adopt such an arrangement that the second wire member is formed into a configuration or a size to be generally received within the area of the first connecting member or the second connecting member. 
   Furthermore, such an arrangement is preferably adopted that the wire member is formed along the longitudinal direction of the base into a generally symmetrical configuration with respect to a virtual straight line along the width direction of the base. Owing to this, even if the wire member is used as a releasing means, a force is generated in a state preferably dispersed in the releasing direction of the closed loop, and it is possible to prevent opening failure or the like from occurring. 
   Still furthermore, such an arrangement that the wire member is supported by the base via an anti-drop-off mechanism is adopted. In the arrangement, since there is no possibility that the wire member is shifted unintentionally, it is possible to allow the spring force to act in a stable state. 
   It is preferred to adapt so that the first and second connecting members are, or the first binding members or the second binding members are bent and deformed to release the engagement when a force is given in the direction that the engagement between the first and second binding members is released. Owing to this, since a large operating force is not required for releasing the engagement, it is possible to provide a binder excellent in operation performance. Particularly, when such a structure that the first and second connecting members are bent and deformed is adopted, it is possible to provide a binder excellent in durability since the binding member may be made of a material having rigidity. 
   Further, it is possible to adopt such an arrangement that the first and second connecting members comprises first and second connecting plates extending along the base, and the outer edges of the ends along the longitudinal direction of the respective connecting plates are formed into inclined edges where the width becomes narrower. Owing to the arrangement, since the end areas in the longitudinal direction of the respective connecting plates become to be bent easily, it becomes possible to reduce the force for releasing the engagement between the first and second binding members. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a schematic perspective view of principal parts of a binder according to a first embodiment, which is applied to a file; 
       FIG. 2  is an enlarged schematic perspective view of the binder; 
       FIG. 3  is a front view of  FIG. 2 ; 
       FIG. 4  is a front view of the binder in the opened state; 
       FIG. 5  is a bottom view of the binder; 
       FIG. 6  is an enlarged view of the part-a in  FIG. 5 , in which a coil spring is omitted; 
       FIG. 7  is a sectional view of the binder in the opened state; 
       FIG. 8  is a plan view of the binder; 
       FIG. 9  is an enlarged sectional view taken along an arrow line A—A of  FIG. 8 ; 
       FIG. 10  is an enlarged sectional view taken along an arrow line B—B of  FIG. 8 ; 
       FIG. 11  is an enlarged sectional view taken along an arrow line C—C of  FIG. 8 ; 
       FIG. 12  is an enlarged sectional view taken along an arrow line D—D of  FIG. 8 ; 
       FIG. 13  is a bottom view illustrating a binder according to a second embodiment; 
       FIG. 14  is an enlarged sectional view taken along an arrow line E—E of  FIG. 13 ; 
     FIG.  15  is a sectional view of a binding member that is opened from the state shown in  FIG. 14 ; 
       FIG. 16  is a bottom view of the binder illustrating an example of modification of the second embodiment; 
       FIG. 17  is a bottom view illustrating a binder according to a third embodiment; 
       FIG. 18  is an enlarged view of the principal parts being partially cut off from the binder shown in  FIG. 17 ; 
       FIG. 19(A)  is a plan view of a wire member; 
       FIG. 19(B)  is a front view of the wire member; 
       FIG. 20  is an enlarged sectional view taken along an arrow line F—F of  FIG. 17 ; 
       FIG. 21  is a sectional view illustrating the binding member that is opened from the state shown in  FIG. 20 ; 
       FIG. 22  is an enlarged sectional view taken along an arrow line G—G of  FIG. 17 ; 
       FIG. 23  is a sectional view of the binding member that is opened from the state shown in  FIG. 22 ; and 
       FIG. 24  is a bottom view illustrating an example of modification of the third embodiment. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Preferred embodiments of the invention will be described below with reference to the drawings. 
   [First Embodiment] 
     FIG. 1  shows a schematic perspective view of principal parts of a binder according to a first embodiment applied to a file;  FIG. 2  shows an enlarged perspective view of the binder. In these drawings, a file  10  comprises a cover body  14  provided with a front cover  12  and a rear cover  13  continued thereto through a back cover  11  therebetween and a binder  15  mounted on the inside face of the back cover  11 . 
   The binder  15  comprises a base  18  extending in the upper and lower (longitudinal) direction of the back cover  11  and being mounted on the inner face of the back cover  11  by rivets  17 ,  17 , a pair of first binding members  19 ,  19  supported by the end portions at the rear cover  13  side of the base  18  respectively, and a pair of second binding members  20 ,  20  supported by the end portions at the front cover  12  side of the base  18  respectively to form a closed loop being engaged with the respective front ends of the first binding members  19 ,  19  together with the base  18 . Here, respective members constituting the binder  15  are formed of a metallic material such as stainless or the like. 
   As shown in  FIGS. 3–12 , the base  18  is formed into a curvature in configuration having a maximum height at the center thereof and being opened at the bottom thereof. Both end sides in the longitudinal direction of the base  18  are respectively pressed to have step so as to form mounting face portions  21 ,  21  for being mounted to the back cover  11 , and generally at the central area within the face of the respective mounting face portions  21 ,  21 , rivet holes  22 ,  22  are formed respectively (refer to  FIGS. 5 and 8 ). Also, at two locations in the longitudinal direction of the base  18 , four slots  24  for allowing the base sides of the first and second binding members  19 ,  20  to pass through are formed at both sides along the smaller width direction. As shown in  FIG. 9 , each slot  24  is formed from a point near the central area in the smaller width direction of the base  18  to the side end thereof; thereby, a large rotational angles of the first and second binding members  19 ,  20  are ensured respectively. 
   The first binding members  19  are formed into a generally semi-arc configuration viewed from the front thereof; while the second binding members  20  are formed into a generally U-letter type viewed from the front thereof; and are such adapted that a closed state is maintained by forming a closed loop via engagement portions  27  formed at the front ends of the respective binding members  19 ,  20 , and that the front ends of the respective binding members  19 ,  20  can be opened by releasing the engagement. As shown in  FIG. 8 , the engagement portion  27  includes an outwardly hook-shaped portion  28  formed at the front end of the first binding members  19  and an inwardly hook-shaped portion  29  formed at the front end of the second binding members  20  and is capable of engagement with the outwardly hook-shaped portion  28 . The engagement portions  27  are such adapted that, when an operation force directed in the direction of the arrows-P in  FIG. 2  is applied to make the front ends of the first binding members  19 ,  19  closer to each other, the first binding members  19 ,  19  can be inclined in a direction that the both thereof become closer to each other in a state that the front ends of the first binding members  19 ,  19  do not interfere with the second binding members  20 ,  20  and the first binding members  19 ,  19  generally maintain their own configuration. 
   In the internal space of the base  18 , a first connecting plate  30  as a connecting member, which is a thin and long rectangular plate in configuration, is disposed along the longitudinal direction of the base  18  between the respective base sections of the first binding members  19 ,  19 ; and also, a second connecting plate  31  as a connecting member of the generally same configuration is disposed along the longitudinal direction of the base  18  between the second binding members  20 ,  20 ; thereby it is adapted so that the first binding members  19  and the second binding members  20  forming units respectively can be rotated simultaneously. These first and second connecting plates  30 ,  31  are fixed by caulking the base sections of the first and the second binding members  19 ,  20  being passed through them. Further, the outer sides in the smaller width direction of the first and the second connecting plates  30 ,  31  are supported by the caulking portions  18 A formed at both ends in the smaller width direction of the base  18  so as not to drop off. 
   The inner ends of the first and second connecting plates  30 ,  31 , which come to the inner side in the smaller width direction thereof, are adapted to be generally brought into contact with each other; and in the central area of the contact edge portion, a notch  35  as a spring receiving section, which supports a coil spring  33  to be incapable of dropping off as a releasing means, is formed. As shown in  FIG. 6  being enlarged, the notch  35  has a configuration which is provided with protruding pieces  36  protruding toward the inside of the notch  35  and is adapted to support the coil spring  33  not to drop off in such manner that the protruding pieces  36  are located within the respective edges of the coil spring  33 . Further, on the contact edge portions of the first and second connecting plates  30 ,  31 , a plurality of small protruding pieces  37  pressed to have steps so as to position slightly upper with respect to the position of the faces of the connecting plates  30 ,  31  are formed, and are adapted to be coupled so that these small protruding pieces  37  ride on the mating contact edge portion to regulate the position of the faces of the first and second connecting plates  30 ,  31 . Furthermore, the first and second connecting plates  30 ,  31  are such formed that the outer edges of the end portions in the longitudinal direction become gradually narrower in the narrower width direction thereof; i.e., into inclined edges  30 A,  31 A. Owing to this, the end side areas in the longitudinal direction of the respective connecting plates  30 ,  31  can be bent easily. In addition, the first and second connecting plates  30 ,  31  can be such mounted that, when the first and second binding members  19 ,  20  are closed, the inner sides in the smaller width direction are positioned slightly lower than the outer sides; while when the first and second binding members  19 ,  20  are opened, the inner sides are positioned higher than the outer sides to deform into a generally L shape. 
   The coil spring  33  is such disposed that one end side thereof rides on the first connecting plate  30 , while the other end side thereof rides on the second connecting plate  31 . The coil spring  33  is adapted to, ordinarily, provide a force in the direction that the first and second binding members  19 ,  20  are opened; i.e., in the direction that the closed loop is released. In this case, the spring force of the coil spring  33  is adapted to be smaller than the engagement force in the engagement portion  27 . Owing to this, unless the operating force is given to the first binding members  19 ,  19 , the closed loop by the first and second binding members  19 ,  20 ; i.e., the closed state is maintained to prevent unintentional opening thereof from occurring. 
   In the arrangement, when disengaging to open a closed state in which the first and second binding members  19 ,  20  form the closed loop together with the base  18 , the engagement portions  27 ,  27  can be disengaged by, for example, positioning the thumb and the forefinger on the respective front ends of the first binding members  19 ,  19  so as to stride them, and applying an operation force in the direction that both fingers come closer to each other (the direction indicated by the arrows P, P in  FIG. 2 ). Owing to this, the spring force of the coil spring  33  acts on the first and second connecting plates  30 ,  31  to make an angle change so that the inner sides thereof shift upward (refer to  FIG. 7 ); resulting in opening the front ends of the respective binding members  19 ,  20  supported by the connecting plates  30 ,  31 . Here, it is adapted that, when the operating force is given to the first binding members  19 ,  19 , the first connecting plate  30  in the base area of the first members  19 ,  19  is bent and deformed, and at the same time, slightly inclined so that the front end side of the first binding members  19 ,  19  come closer to each other. Owing to this, the first binding members  19 ,  19  is allowed to make an angle change to release the engagement while maintaining generally the configuration of them. 
   On the other hand, when restoring the closed state by forming the closed loop by the first and second binding members  19 ,  20 , the front ends of the first and second binding members  19 ,  20  are rotated against the spring force of the coil spring  33  in the direction that the front ends comes closer to each other. Owing to this, the outwardly hook-shaped portion  28  and the inwardly hook-shaped portion  29  of the respective engagement portions  27 ,  27  slide and engaged with each other to form the closed loop. 
   Thus, according to the first embodiment, it makes possible to release the closed state between the first binding members  19  and the second binding members  20  only by giving a slight operation force to the first binding members  19 ; while when restoring the same to the closed state, it makes possible to perform a smooth engagement preventing a possibility of emitting a noise. 
   Next, referring to  FIGS. 13–15 , embodiments of the invention other than the first embodiment will be described. In the following descriptions, the component parts, which are the same or equivalent to those of the first embodiment, will be given with the same symbols, and the description will be omitted or simplified. 
   [Second Embodiment] 
   A second embodiment is characterized in that a leaf spring  40  is adopted as a releasing means in place of the coil spring  33 . That is, the leaf spring  40  comprises a generally rectangular metal plate extending in the smaller width direction of the base  18 . The leaf spring  40  is disposed being inserted through the notch  35  formed between the contact edge portion between the first and second connecting plates  30 ,  31  and extends to the outside and the inside thereof. A half of the leaf spring  40  is positioned at the bottom side of the first connecting plate  30 ; while the other half is positioned at the topside of the second connecting plate  31 . The leaf spring  40  is such adapted that the initial configuration thereof is a bent shape as shown in  FIG. 15 , and when the first and second binding members  19 ,  20  are made into the closed state, the bending direction is slightly inverted as shown in  FIG. 14 . Accordingly, the leaf spring  40  maintains a state that a force is given in the direction that the first and second binding members  19 ,  20  are opened. Like the first embodiment, when an operating force that makes the first binding members  19 ,  19  closer to each other is given, the closed state is immediately released. 
   Accordingly, owing to the arrangement of the second embodiment, it makes possible to obtain the same action and effect as the first embodiment and, further, the assembly thereof can be carried out easier than the first embodiment. 
   In the second embodiment, although a case in which the leaf spring  40  is disposed to go through the notch  35  is given, the entire leaf spring  40  may be positioned at the outside of the first and second connecting plates  30 ,  31  as shown in  FIG. 16 . In this case, the formation of the notch  35  between the first and second connecting plates  30 ,  31  is unnecessary. 
   [Third Embodiment] 
     FIGS. 17–23  show a third embodiment of the invention. The third embodiment is characterized in that a wire member  50  is used as the releasing means. The wire member  50  is formed into a configuration or a size to be stored generally within the area of the first and second interconnecting plates  30 ,  31 , and is disposed within the area of the first and second connecting plates  30 ,  31 . Further detailed description of the wire member  50  will be made with reference to  FIG. 18 ,  FIGS. 19(A) and 19(B) . The wire member  50  includes first portions of the wire member  51 ,  51  that are disposed to cross the first and second connecting plates  30 ,  31 , and are positioned along the longitudinal direction of the base generally symmetrically with respect to the virtual central straight line along the width direction of the base  18 ; and of a second portion of the wire member  53  that is formed to be connected to one end side of these first portions of the wire member  51 ,  51 , i.e., to the left side end in  FIG. 18  being interposed by middle portions  52 ,  52 , that is oriented toward the axis line which is shifted by a predetermined angle with respect to the axis line of the first portion of the wire member  51 , and that is positioned generally symmetrically with respect to the central straight line C. Here, the second portion of the wire member  53  comprises inner portions of the wire member  53 A,  53 A extending parallel to each other, and a connecting portion of the wire member  53 B that connects these inner portions of the wire member  53 A,  53 A. As shown in  FIG. 18 , the shaft length of the inner portions of the wire member  53 A,  53 A is adapted to generally a half or so of the first portion of the wire member  51  so that the connecting portion of the wire member  53 B is positioned adjacent to the contact edge portion between the first and second connecting plates  30 ,  31 . In the present embodiment, the inner portions of the wire member  53 A,  53 A are adapted to a length that, when the same is disposed to cross the second connecting plate  31  in the width direction, the connecting portion of the wire member  53 B reaches a little to the area of the first connecting plate  30 . 
   In the first portions of the wire member  51 ,  51 , the ends opposite to the middle portions  52 ,  52  are bent portions  51 A,  51 A, and these bent portions  51 A,  51 A are received within the notches  56 ,  56  formed in the outer edge of the first connecting plate  30 . On the other hand, the middle portions  52 ,  52  are adapted so as to be, in the respective spaces, strongly tightened or enclosed by a step-pressed portion  57  formed in a part of the caulking portion  18 A. Here, an anti-drop-off mechanism of the wire member  50  is constituted of the bent portions  51 A, the notches  56  and the step-pressed portion  57 . 
   As for the wire member  50 , a wire member having such a configuration as the initial configuration before being mounted that the width W 1  between the bent portions  51 A,  51 A of the first portions of the wire member  51 ,  51  is wider than the width W 2  at the middle portions  52 ,  52  side is used. To mount the wire member  50 , in a state that the step-pressed portion  57  has been formed before hand, when the middle portions  52 ,  52  of the wire member  50  are pressed to engage into the caulking portion  18 A until a sound “click” is emitted, the first portions of the wire member  51 ,  51  are positioned respectively at the positions indicated with the chain double-dashed lines in  FIG. 18 . Then, by carrying out a work in such a manner that the first portions of the wire member  51 ,  51  are nipped with fingertips and shifted to become generally parallel to each other, it is made possible to assembled the bent portions  51 A,  51 A being received by the notches  56 . 
   In the third embodiment, in a state that the wire member  50  is mounted within the area of the first and second connecting plates  30 ,  31  and the first and second binding members  19 ,  20  are closed, as shown in  FIGS. 20-23 , the second portion of the wire member  53  becomes into a state being pressed down forcibly to be positioned on a plane generally even with respect to the first wire member. At the same time, a state that the inner sides in the width direction of the first and second connecting plates  30 ,  31  are positioned at a position slightly lower than the outer sides and propped up by each other is obtained. Here, when an operation is made in the direction that the first binding members  19 ,  19  are made to be closer to each other, the engagement with the second binding members  20  is released, and the second portion of the wire member  53  tends to rise up with respect to the first portion of the wire member  51  to return to the original configuration. Accordingly, owing to the restoring force, the inner sides of the first and second connecting plates  30 ,  31  shift to a position higher than the outer sides thereof and bent into a generally L shape; and it makes possible to open the first and second binding members  19 ,  20 . 
   Consequently, according to the third embodiment also the same effect as that of the embodiments aforementioned can be obtained and, in addition, such an effect that assembly work of the wire member  50  can be carried out much easily and swiftly is obtained. 
   Although the best arrangement, method and the like to carry out the invention have been disclosed in the above descriptions, the invention is not limited thereto. 
   That is to say, although the invention has been described about mainly specific embodiments while particularly illustrating them in the figures, it is possible for a person skilled in the art to add various modifications with respect to the configuration, material, quantity, position, layout or the like to the embodiments without departing from the scope of the technical ideas and object of the invention. 
   Accordingly, the defined descriptions about the disclosed configuration or the like are given illustratively only to make the invention be understood easily, but the descriptions do not limit the invention thereto. Therefore, any descriptions about components, of which name may partially or entirely depart from the definition of the configuration or the like, are all included in the invention. 
   For example, in the embodiment 3, a case, in which the inner portion of the wire member  53 A in the second portion of the wire member  53  is shorter than the first portion of the wire member  51 , is described. However, as shown in  FIG. 24 , the same may be adapted to be the same length or so as that of the first portion of the wire member  51 . By adopting the structure also, when the engagement between the first and second binding members  19 ,  20  is disengaged, rotation in the direction to open them is made possible. Further, although the wire member  50  is located at the central area in the longitudinal direction of the base  18 , for example, such a design change that, using two wire members  50 , the same may be located separately at two positions along the longitudinal direction, and so on is possible. Furthermore, although the wire member  50  having a symmetrical configuration with respect to the centerline C is used, an symmetrical one may be used. 
   In the respective embodiments, although the cases, in which the first binding members  19 ,  19  are structured so that the closed state is released by giving the operation force in the direction that the same come closer to each other, have been illustrated and described, the invention is not limited thereto. For example, the second binding members  20 ,  20  may be such adapted that the closed state is released by parting the same away from each other. Also, such a structure, in which the closed state is released by giving the operating force in the direction that the second binding members  20 ,  20  are made to come closer to each other, or by parting the first binding members  19  away from each other, may be adopted. In that case, it is enough to form the hook configurations of the front ends of the first binding members  19  and the second binding members  20  in the reversed manner of the embodiments. Further, a couple of first binding member  19  and second binding member  20  forming a closed loop may be such structured that, for example, same as the case that a mutual engagement between two protruding portions provided on the rims of a purse is released, the closed loop is released by making a twist or twirl operation. 
   Further, in the embodiments, although such a structure is adopted that the engagement with the second binding members  20 ,  20  is disengaged by operating the first binding members  19 ,  19  in the direction that the same come closer to each other, the operation direction is not limited thereto. Such an arrangement that the disengagement is made by giving a force that operate the binding members in the direction that the same crosses the axial direction may be adopted. 
   In the invention, although the number of the first and second binding members  19 ,  20  is total four, which are coupled into the respective pairs, the number thereof may be further increased. Also, in case that the number of the binding members is increased, the front ends of the increased binding members at one side may be formed into such a shape that the same are brought into contact with the front ends of the binding members at the opposite side. Owing to this, it is made possible to open the binding members without increasing the number of binding members to be operated by fingertips when disengaging the engagement. 
   In the third embodiment, a case, in which the releasing means for giving the force in the direction that the closed loop is released is disposed at a generally symmetrical position with respect to the virtual centerline C, has been illustrated and described. The invention is not limited thereto, but such cases, in which the releasing means is disposed within the area along the longitudinal direction of the base  18 , or a plurality of releasing means different from each other, for example, the coil spring  33  and the wire member  50  are used simultaneously, are included in the conception of the invention. 
   As described above, according to the invention, the engagement is released only by giving an operating force to the first binding members or the second binding members, and the binding members are made to rotate in the direction that the same are opened by the releasing force of the releasing means. And when operating to make the binding members into the closed state, since it is such arrangement that the operation is made in the direction opposite to the direction of the force via the releasing means, a noise is not emitted when the binding members shift into the closed state to form closed loops. And further, since the operation force is given in the direction opposite to the direction that the spring force acts, it makes possible to regulate the speed of the first and second binding members when the same are closed, and a fear rendered by the conventional binder, which closes instantly, can be also eliminated. 
   Also, since it is adapted so that the coil spring comprising the releasing means is supported by the notch not to drop-off, assembly of the coil spring can be carried out easily, and since the spring is maintained at a specific position, it is possible to prevent operation failure from occurring. 
   Since also the leaf spring constituting the releasing means extends between the first and second connecting members and is supported not to drop-off, it is possible to maintain the leaf spring at a specific position and to effectively prevent operation failure from occurring in the same manner as the coil spring. 
   The wire member constituting the releasing means comprises the first portion of the wire member disposed crossing the first and second connecting member, and the second portion of the wire member, which has been shifted by a predetermined angle with respect to the first portion of the wire member. Therefore, it is possible to apply the releasing means to obtain a spring force only by adjusting the axial orientation of the wire member and, since the wire member can be assembled easily, it is possible to lead to a better productivity also. 
   Further, since the wire member is disposed to be generally symmetrical with respect to the virtual straight line, in the structure that the wire member is used as the open/close means, the force in the direction that the first and second binding members are opened is generated being preferably dispersed. Accordingly, it is possible to prevent the open failure from occurring. 
   Furthermore, since the wire member is supported by the base via an anti-drop-off mechanism, there is no possibility that the wire member is shifted unintentionally. Accordingly, it is possible to allow the spring force to act in a stable state. 
   Since it is such arrangement that the first and second connecting members are, or the first binding members or the second binding members are bent and deformed, and thereby the engagement between the first and second binding members is disengaged, it is possible to reduce the operation force for releasing the binding members. Particularly, in the structure that the connecting members are bent and deformed, it is possible that the binding member is arranged of a material having rigidity, resulting in providing a binder excellent in durability. 
   Owing to the structure that the inclined edges are formed on the outer edges of the end portions along the longitudinal direction of the first and second connecting plates constituting the first and second connecting members, it is possible to make the end areas in the longitudinal direction of the respective connecting plates be bent easily, making it possible to reduce the force for disengaging the engagement between the first and second binding members.