JP3624770B2 - File - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a file that is used by interposing a file sheet or the like inside and binding the file sheet or the like using a binding string.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, various files are known in which a file sheet or the like can be bound by inserting a binding string through a binding hole that is opened at a predetermined interval on the file sheet or the like. In such a file, it is usual that the binding string has a substantially rectangular square cross section.
[0003]
[Problems to be solved by the invention]
However, when such a binding string is inserted into and removed from a binding hole such as a file sheet, the corners of the binding string rub against the peripheral edge of the binding hole, and the peripheral edge of the binding hole is cut while repeatedly inserting and inserting. There is a problem that the file paper is damaged. In order to solve such a problem, it is conceivable that the binding string has an overall round cross-sectional shape. When the sheet is inserted into and removed from a binding hole such as paper, the ease of bending the binding string is impaired.
[0004]
[Means for Solving the Problems]
In view of the above problems, the present invention is a file having a binding string in which the peripheral edge of the binding hole is difficult to cut and can be easily bent in the longitudinal direction when the binding string is inserted into and removed from the binding hole of a file sheet or the like. It was decided to constitute.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
That is, in the file of the present invention, the file paper or the like can be bound by inserting the binding string into the binding hole provided in the file paper or the like, and when the binding string is inserted into the binding hole, Forming a curved portion inflated in a convex shape on the downward surface of the binding string facing the binding side edge of the file paper, etc., and the downward direction on the upward surface facing the anti-binding side edge of the file paper, etc. It is characterized by forming a hollow portion that is recessed toward the surface.
[0006]
In such a case, since the square portion is not formed in the binding string, even if the peripheral edge portion of the binding hole and the binding string rub against each other, the binding hole is difficult to cut, and the file paper or the like is effectively prevented from being damaged. be able to. In particular, when inserting and removing file paper etc. with the file spread on a desk, etc., the curved portion is formed on the downward surface of the binding string that is likely to rub against the peripheral edge of the binding hole. The contact area between the peripheral edge portion and the binding string is increased, the binding hole is more difficult to cut, and the binding string can be smoothly inserted and removed. In addition, since the thinning portion is formed on the upward surface of the binding string, the binding string does not become thick, and the binding string can be easily bent to be easily inserted into and removed from the binding hole.
[0007]
Regardless of the number of file sheets or the like to be bound in such a file, in order to facilitate the insertion and removal of the binding string, the bending portion is moved from the proximal end side to the distal end side of the binding string on the downward surface. It is desirable that the curved surface extends continuously.
In addition, if the contact area between the binding string and the binding hole is small, a concentrated force is applied to the part, so that the peripheral edge of the binding hole is easily cut, but the ease of bending the binding string in the longitudinal direction is maintained. In order to increase the smooth contact area with the peripheral edge of the binding hole and make the binding hole more difficult to cut, the cross-sectional shape of the binding string on the curved surface is preferably substantially semicircular. .
[0008]
Furthermore, in order to make the binding string easy to bend in the longitudinal direction and less bend to the side, and to be able to smoothly insert and remove the binding string, It is effective that the groove extends continuously from the proximal end side to the distal end side at the substantially central portion in the width direction. In particular, in order to make the wall thickness of the binding string uniform in substantially the entire region in the longitudinal direction, and to make it durable and difficult to bend in the lateral direction, the cross-sectional shape of the groove serving as the cutout portion is made of the curved surface. A substantially semicircular shape sharing the center with the cross-sectional shape is desirable.
[0009]
In addition, in order to make it easier to bend the binding string in its longitudinal direction without interfering with the loading / unloading of file paper, etc., a predetermined interval along the longitudinal direction of the binding string is provided on the side edge of the downward surface of the binding string. It is desirable to have a notch. Further, by doing so, the peripheral edge of the binding hole of the bound file paper or the like is caught in the notch, and this notch can be used for preventing the file paper or the like from falling off.
[0010]
In addition, as a specific form of a file in which file paper can be bound only by the extra length of the binding string without using a binding tool for binding the file paper from above, the central portion is the boundary. A cover that can be folded into a flat fold or developed in a plane, and a binding portion for binding file paper or the like is formed on the file binding side surface of the cover. The binding string is arranged at positions facing each other across the section and a guide hole through which the binding string can be inserted, and the binding string is inserted into the binding hole such as a file sheet and the guide hole. For example, the file paper can be bound.
[0011]
In such a file, in order to be able to obtain a reliable binding state of a file sheet or the like with a particularly small number of binding points and to manufacture it at a low material cost, the binding unit is arranged at the center of the cover. The positions on the cover where the binding string and the guide hole are provided are opposite to each other across the central portion at the two binding portions. Is preferred. In particular, by doing so, only one binding string is inserted into one binding hole, so that it is possible to increase the thickness of the binding string to increase strength, Even if file sheets or the like are bound, they can be prevented from dripping.
[0012]
Further, in order to be able to bind file paper etc. more reliably and to make file paper etc. easy to put in and out, a pair of binding stoppers are provided with a binding string and guide holes each at the center of the cover. So that the two binding strings can be inserted through the same binding hole with the file paper or the like sandwiched in the center of the cover so that they cross each other. It is desirable to form a plurality of such a pair of binding portions along the center of the cover.
[0013]
Furthermore, when binding easily fragile items such as a transparent bag used by inserting a document or the like into a file, in order to be able to effectively prevent the bending, the binding portion is provided with the central portion. It is effective to form at least both ends of the cover.
[0014]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
(First embodiment)
The file F1 shown in FIGS. 1 to 6 as the first embodiment of the present invention is used by sandwiching the file paper 6 or the like and forming the front and back surfaces thereof and sandwiching the file paper 6 inside. 1 and a binding tool 2 provided along a substantially central portion 13 of the file binding side surface 11 of the cover 1.
[0015]
As shown in FIGS. 1 and 2, the cover can be folded into a valley fold with a pair of valley fold lines 14 provided in the vicinity of the central portion 13 as a boundary. The surface 12 on the anti-file binding side is exposed in the folded state.
As shown in FIGS. 1 to 4, the binding tool 2 includes a base 3 attached to the cover 1 along the valley fold line 14, and a predetermined portion along the valley fold line 14 provided continuously to the base 3. A sandwiching plate portion 4 having a pair of guide holes 43 opened at positions spaced apart from each other, and a binding string 5 provided so as to extend from the base portion 3 to the opposite side of the sandwiching plate portion 4 corresponding to one guide hole 43; The base 3, the sandwiching plate 4 and the binding string 5 are formed by integral molding of a synthetic resin material. In this embodiment, the binding tool 2 having such a configuration is provided so as to be opposed to each other with the central portion 13 of the cover 1 being sandwiched. At that time, the binding string 5 of one binding tool 2 is connected to the other binding tool 2. The binding tool 2 is paired with the guide hole 43 on the side not corresponding to the binding string 5. Therefore, the binding portion X1 is configured by the binding string 5 and the guide hole 43 that is paired therewith.
[0016]
The base 3 is a substantially thin plate having a large number of small protrusions 33 on the back surface, and is adhered along the valley fold line 14 of the file binding side surface 11 of the cover 1 by melting the protrusions 33. It is. Further, the sandwiching plate portion 4 is also in a thin plate shape, and one side edge portion 41 is continued to the side edge portion 31 on the center portion 13 side of the base portion 3. The side edge portions 31 and 41 are slightly thinner than other portions to provide a resin hinge function, and a notch 42 is provided along the side edge portion 41 of the sandwich plate portion 4 so that the base portion 3 and the sandwich plate are provided. By reducing the width dimension in which the portion 4 is continuous, the sandwiching plate portion 4 is bent from a position flush with the base portion 3 to a position where it is overlapped. In addition, the sandwiching plate portion 4 has a binding hole 63 in advance in the binding-side edge portion 61 between the sandwiching plate portion 4 and the opposing sandwiching plate portion 4 sandwiching the central portion 13 of the cover 1 in a state where the sandwiching plate portion 4 stands up with respect to the base portion 3. The provided file paper 6 can be inserted, and the pair of guide holes 43 are provided at positions corresponding to the binding holes 63.
[0017]
As shown in FIGS. 1 to 6, the binding string 5 has a proximal end 51 continuously set on the opposite side to the sandwiching plate portion 4 at a position corresponding to one of the guide holes 43 of the base portion 3. 52 extends toward the side opposite to the center 13 side of the cover 1. The base end 51 is made thinner than the other parts so that the binding string 5 can be bent toward the central portion 13 side. Further, in such a state that it is bent toward the central portion 13 side, the cross-sectional shape of the downward surface of the binding string 5 facing the file binding side surface 11 of the cover 1 is a substantially semicircular shape shown in FIG. In this way, the curved surface 53, which is a curved portion bulging in a convex shape, is formed continuously from the proximal end 51 side to the distal end 52 side. Further, in this state, a groove 55 having a substantially semicircular cross section extending continuously from the base end 51 side to the tip end 52 side is provided at the center in the width direction on the upward surface 54 side of the binding string 5. The groove 55 constitutes a thinned portion that makes the binding string 5 thin. As shown in FIGS. 5 and 6, the semicircular shape of the groove 55 is centered on the curved surface 53 and the center so that the thickness at the portion of the binding string 5 in which the groove 55 that is the thinned portion is formed is substantially uniform. n is shared. In the side edge portion 54a of the upward surface 54, a notch 56 is formed in which concave and convex shapes are continuously formed at a predetermined interval from the base end 51 side to an intermediate position in the longitudinal direction. Note that the front end 52 of the binding string 5 is rounded so as to be gradually tapered.
[0018]
The file F1 of the present embodiment configured as described above is suitable as a file by reducing the number of parts effectively while reducing the thickness of the file F1 itself and without making unnecessary creases in the file paper 6. It is possible to perform various functions.
That is, first, the file sheet 6 provided with the binding holes 63 along the binding side edge 61 at a predetermined interval between the sandwiching plate parts 4 of the binding tool 2 facing each other is connected to the binding side edge 61 of the cover 1. It is inserted toward the file binding side surface 11. Next, the binding string 5 of one binding tool 2 is curved, and the other side of the binding hole 5 that forms a pair with the corresponding guide hole 43 of the binding tool 2, the binding hole 63 of the file paper 6, and the binding string 5 from the tip 52 side. Insert through the guide holes 43 of the binding tool 2 in this order. Further, by similarly inserting the binding string 5 of the other binding tool 2 to the opposite side, the file paper 6 is bound at two locations. Further, when the file F1 is opened with the file paper 6 already bound, and the file paper 6 is inserted and removed from the opened page, one binding string 5 is opened to the other guide hole 43 and the other side. Pull out from the binding hole 63 of the file paper 6 and pull out the other binding string 5 in the same manner, and add or pull out the file paper 6 with the leading end 52 of the binding string 5 opened upward. The file paper 6 can be rebound in the same manner as described above.
[0019]
At that time, in the curved binding string 5, a curved surface 53 that is a curved portion that bulges in a convex shape is formed on the downward surface facing the binding side edge 61 of the file paper 6, and the binding string 5 is squared. Since there is no portion, the binding hole 63 is not cut even if the binding string 5 and the peripheral edge 63a of the binding hole 63 rub against each other, and the file paper 6 can be effectively prevented from being damaged. . In addition, since the upper surface 54 of the binding string 5 is provided with a groove 55 which is a hollowed portion recessed toward the curved surface 53 side, the binding string 5 does not become thick overall, and the strength is increased. It can be easily bent in the longitudinal direction while being maintained.
[0020]
Further, since the curved surface 53 is provided continuously from the proximal end 51 side to the distal end 52 side of the binding string 5, the binding string 5 can be attached regardless of the number of file sheets 6 bound to the file F1. It is possible to smoothly insert and remove from the binding hole 63. In addition, since the cross-sectional shape of the curved surface 53 is substantially semicircular, the contact area between the binding string 5 and the peripheral edge 63a of the binding hole 63 can be increased, and the binding string 5 can be bent. While maintaining easiness, the force applied to the peripheral edge 63a by the binding string 5 can be dispersed to improve the difficulty of cutting the binding hole 63.
[0021]
On the other hand, the groove 55 constituting the thinned portion is provided continuously from the proximal end 51 side to the distal end 52 side of the binding string 5, and is substantially half sharing the center n of the cross-sectional shape with the curved surface 53. Since it is circular, the thickness of the binding string 5 is substantially uniform, the binding string 5 is easily bent in the longitudinal direction, is not easily bent to the side, and is not easily bent or wrinkled. The guide hole 43 can be easily inserted into and removed from the guide hole 43, and can be suitable for long-term use.
[0022]
Moreover, since the notch 56 which continues along the longitudinal direction is provided in the side edge part 54a of the said upward surface 54 of the binding string 5, the binding string 5 shall be further easily curved in the longitudinal direction. Can do. In addition, when the binding string 5 is inserted into and removed from the binding hole 63 or the guide hole 43, the curved surface 53 of the binding string 5 mainly includes the binding hole 63 or the like, as shown in a schematic cross-sectional view in FIG. Therefore, even if the notch 56 is formed on the upward surface 54 side as described above, it does not hinder the insertion and removal. On the other hand, in the state where the file paper 6 is bound, the binding string 5 that is bent and curved toward the opposite side is slightly lifted from the surface 11 on the opposite side of the cover 1 due to its own elasticity. As shown in a schematic cross-sectional view in FIG. 6, the notch 56 is caught above the peripheral portion 43 a of the guide hole 43 and the like, so that the file paper 6 once bound cannot be easily dropped off. it can.
[0023]
Further, the file F1 of the present embodiment sets the binding portions X1 composed of the binding string 5 and the guide hole 43 that are opposed to each other with the central portion 13 of the cover 1 interposed therebetween, and the binding portions X1 are set in only two places. The binding string 5 and the guide hole 43 at the stop portion X1 are disposed at positions opposite to each other with the central portion 13 interposed therebetween so that the two binding strings 5 extend from opposite sides and the file paper 6 is Since the binding is performed, the file paper 6 can be bound very easily and reliably. In particular, the file F1 has only two binding strings 5, and only one binding string 5 is inserted into each binding hole 63. Therefore, the binding string 5 is relatively thick. Even if it is a thing, inconvenience does not arise in the insertion to the binding hole 63, and not only the material cost can be kept low, but even if a large number of file sheets 6 are bound, they can be made difficult to sag.
[0024]
(Second embodiment)
As a second embodiment of the present invention, a file F2 shown in FIGS. 7 and 8 has a cover 201 similar to the file F1 of the first embodiment, and a valley fold line 214 is formed on the surface 211 on the file binding side. A pair of binding tools 202 are arranged at positions facing each other across the central portion 213, and two binding strings 205 are provided in each binding tool 202.
[0025]
The binding tool 202 includes a base portion 203 and a sandwiching plate portion 204 similar to those of the first embodiment, and sandwiches the base portion 203 corresponding to a pair of guide holes 243 provided in the sandwiching plate portion 204. These are provided on the side opposite to the plate portion 204. A total of four binding portions X2 are configured by the binding strings 205 and the guide holes 243 provided at opposite positions with the central portion 213 interposed therebetween. That is, the pair of binding portions X2 are formed so as to face each other with the central portion 213 of the cover 201 sandwiched therebetween, and such a pair of binding portions X2 are formed at two locations along the central portion 213. It will be provided. The configurations of the binding strings 205, the sandwiching plate portion 204, the base portion 203, and the cover 201 have the same configurations as the respective members in the first embodiment, and thus detailed description thereof is omitted here. And
[0026]
Therefore, in the file F2 of the present embodiment having such a configuration, the binding strings 205 extending from opposite directions are inserted so as to intersect the common binding hole 63 in the pair of opposing binding portions X2. Therefore, the file paper 6 can be bound more reliably. Further, when the file F2 is opened with the file paper 6 already bound, and the file paper 6 is inserted and removed from the opened page, the pair of binding strings 205 are pulled out from the other guide hole 243 and the binding hole 63, respectively. When the leading end 252 of the binding string 205 is opened upward, the binding string 205 is inserted into the guide hole 243 and the binding hole 63, respectively. Operations such as drawing out or adding the paper 6 can be performed very easily. In addition, the file F2 of the present embodiment can exhibit the same operations and effects as the file F1 of the first embodiment such that the binding hole 63 is not easily broken depending on the binding string 205 and the binding string 205 is easily bent. Therefore, explanation is omitted here.
[0027]
(Third embodiment)
A file F3 shown in FIGS. 9 and 10 as a third embodiment of the present invention has two upper end portions 315, lower end 316 portions and intermediate portions thereof along the valley fold line 314 of the file binding side surface 311 of the cover 301. A binding tool 302 is provided at each location. However, here, for convenience of explanation, the vertical direction of the file is set when the long side of the file paper or the like is used in the vertical direction. When used in the direction, it is set as the left-right direction.
[0028]
Thus, the upper end portion 315 and the lower end portion 316 are connected to the base portion 303 attached to the file binding side surface 311 along the valley fold line 314 and the side edge portion 331 of the base portion 303 on the central portion 313 side. And a single binding string 304 provided on a side edge portion 332 of the base portion 303 opposite to the sandwiching plate portion 304 corresponding to the guide hole 343. 305. Such a binding tool 302 is provided at the upper end portion 315 and the lower end portion 316 so as to face each other with the central portion 313 interposed therebetween, and the binding portion X3 is formed by the binding string 305 and the guide hole 343 facing each other. Is configured.
[0029]
Further, the binding tools 302 arranged at two positions in the intermediate portion are also the same as the binding tools 302 arranged at the upper end portion 315 and the lower end portion 316, respectively, and are arranged along one valley fold line 314. Is provided. Then, at a position facing the binding tool 302 with the central portion 313 interposed therebetween, a part of the cover 1 is cut and raised in a substantially half donut shape on the file binding side surface 311, and the cut and raised portion has a guide hole 345. The sandwiching plate portion 344 is used. That is, the cut-and-raised guide hole 345 of the sandwiching plate portion 344 constitutes the binding portion X3 by the binding string 305 of the binding tool 302 that is opposed thereto. The configuration of each binding string 305 is the same as that of the first and second embodiments, and the description thereof is omitted.
[0030]
In the file F3 of the present embodiment having such a configuration, the binding portion X3 is formed at least at the upper end portion 315 and the lower end portion 316 of the file F3 and in addition to the intermediate portion thereof. For example, when using a bag-like transparent bag body 6A that has a binding hole 63A along the edge 61A on the binding side as shown in FIG. It is possible to effectively prevent the drooping of the water. That is, such a transparent bag body 6A is usually a thin thin film made of a transparent synthetic resin, and the edge side 62A on the side opposite to the binding side is relatively thick and heavy when a document or the like is put therein. The binding-side edge portion 61A that is relatively thin and easily bent tends to hang down. Therefore, if such a transparent bag body 6A is bound in the file F3 of the present embodiment, it is possible to effectively prevent the transparent bag body 6A from drooping even at a small number of binding points. Further, this file F3 is less likely to break the binding hole 63A of the file paper 6A by the binding string 305, and is easy to bend the binding string 305, like the files F1 and F2 of the first and second embodiments. The file hole 6A can be easily inserted and removed from the binding hole 63A and the guide holes 343 and 345, and the file paper 6A can be easily loaded and unloaded in a spread state.
[0031]
Note that the present invention is not limited to the above-described embodiments, and, of course, for example, a binding portion including a binding string and a guide hole may be formed on the same side along the valley fold line of the cover. In addition, the specific configuration of each part, such as how to attach the binding tool to the cover, is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
[0032]
【The invention's effect】
The present invention is implemented in the form as described above, and has the following effects.
That is, in the file of the present invention, when a binding string is inserted into a binding hole opened in a file sheet or the like and the file sheet or the like is bound, the file sheet is inserted when the binding string is inserted into or extracted from the binding hole. Since the curved portion that is inflated in a convex shape is formed on the downward surface of the binding string facing the edge of the binding side, etc., even if the peripheral edge of the binding hole rubs against the binding string, it will not be damaged. Can be effectively prevented. In addition, since the thinning portion is formed on the upward surface of the binding string, it is possible to prevent the binding string from being thickened as a whole, and to be easily bent when being inserted into and inserted into the binding hole. Therefore, according to the file having such a binding string, the file paper and the like can be taken in and out very smoothly.
[0033]
In particular, when the curved portion is a curved surface formed continuously in the longitudinal direction of the binding string, even when a large number of file sheets are bound, it is possible to smoothly put in and out the file sheets. Further, if the cross-section of the curved surface is substantially semicircular, the contact area between the binding string and the binding hole can be increased, so that it is possible to further improve the prevention of the binding hole from being damaged. is there.
[0034]
Furthermore, when the thinning portion is a groove that is continuous in the longitudinal direction provided in the substantially central portion in the width direction of the binding string, not only can the bending string be easily bent, but it can be used for a long time. It is also possible to construct a file with useful binding strings that are not easily bent or wrinkled. Furthermore, if the cross-sectional shape of the groove is a substantially semi-circular shape that shares the center with the substantially semi-circular cross-sectional shape of the curved surface, the thickness of the binding string becomes substantially uniform, and the binding string has greater strength. Can be granted.
[0035]
Further, if the notches are provided at predetermined intervals along the side edge of the upward surface, it is possible to effectively prevent the file paper from falling out without interfering with the loading / unloading of the file paper.
The file having the above-described configuration includes the binding string as described above that is disposed opposite to the surface of the cover on the file binding side, and a guide hole through which the binding string can be inserted. This is extremely useful when the binding hole is constituted by the guide hole and the file hole is bound by the extra length of the binding string by inserting the binding string through the binding hole and the guide hole. is there. That is, such a file does not require a binding tool or the like for pressing and binding the file paper from above, so the file paper is not folded and the file paper is easily and reliably bound with a small number of parts. This is because it can be included.
[0036]
Particularly in such a file, the binding portions are provided at two locations along the central portion of the cover, and the positions where the binding strings and the guide holes are provided are opposite to each other with the central portion interposed therebetween. If it is, the file paper or the like can be securely bound with very few binding locations. Further, in this case, it is possible to make the binding string relatively thick while keeping the material cost low and to give strength to the binding string so that even if a large number of file sheets or the like are bound, they are unlikely to sag. .
[0037]
In a file in which a pair of binding portions are formed so as to face each other across the central portion, and a plurality of such a pair of binding portions are provided along the central portion, Since a pair of binding strings can be crossed and inserted through a common binding hole at the stop location, it is possible to bind file paper or the like more reliably. Moreover, even if one of the binding strings is pulled out from the binding hole and the guide hole at the opposite position in a state where the file is opened, the binding string is inserted into the binding hole of the file paper or the like on the side where the binding string is provided. In this state, the binding holes for a plurality of file sheets and the like are continuous, and the re-binding operation can be performed very easily.
[0038]
Furthermore, in a file in which binding portions are formed at both ends of the cover in the central portion, a transparent bag body that is easily bent especially at the binding side edge is firmly secured without bending. It is possible to bind.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a usage state of a first embodiment of the present invention.
FIG. 2 is a plan view showing the embodiment in a developed state.
FIG. 3 is an enlarged plan view showing the binding tool of the embodiment.
FIG. 4 is a side view of the same.
FIG. 5 is an operation explanatory view showing an enlarged schematic cross-sectional view of a part of the embodiment.
FIG. 6 is an explanatory diagram of the operation.
FIG. 7 is a plan view showing a second embodiment of the present invention in an unfolded state.
FIG. 8 is a perspective view showing a usage state of the embodiment.
FIG. 9 is a plan view showing a third embodiment of the present invention in an unfolded state.
FIG. 10 is a perspective view showing a usage state of the embodiment.
[Explanation of symbols]
1, 201, 301 ... cover
2, 202, 302 ... binding tool
5, 205, 305 ... Binding string
6, 6A ... File paper
11, 211, 311, file binding side surface
13, 213, 313 ... central part
43, 243, 343, 345 ... guide holes
53 ... curved portion (curved surface)
54 ... Upward
54a ... side edge
55. Meat extraction part (groove)
56 ... notches
61, 61A ... edge of binding side
62, 62A ... Edge on the anti-binding side
63, 63A ... Binding hole
315, 316 ... end (upper end, lower end)
F1, F2, F3 ... file
X1, X2, X3 ... Binding section
n ... Center

Claims (10)

In what is capable of binding the file paper or the like by inserting a binding string through a binding hole provided in the file paper or the like,
When the binding string is inserted through the binding hole, a curved portion is formed in a convex shape on the downward surface of the binding string facing the binding side edge of the file paper, etc., and the anti-binding side edge of the file paper, etc. The file | surface characterized by forming the hollow part hollowed toward the said downward surface in the upward surface which faces a part. The file according to claim 1, wherein the curved portion is a curved surface continuously extending from the proximal end side to the distal end side of the binding string on the downward surface. The file according to claim 2, wherein the cross-sectional shape of the binding string on the curved surface is substantially semicircular. The file according to claim 1, 2 or 3, wherein the lightening portion is a groove continuously extending from the proximal end side to the distal end side at a substantially central portion in the width direction of the binding string. The thinned portion is a groove continuously extending from the proximal end side to the distal end side in the substantially central portion in the width direction of the binding string, and the cross-sectional shape of the groove substantially shares the center with the cross-sectional shape of the curved surface. 4. A file according to claim 3, wherein the file is semicircular. 6. The file according to claim 1, 2, 3, 4, or 5, wherein notches are provided at predetermined intervals along a longitudinal direction of the binding string at a side edge portion on a downward surface of the binding string. This cover has a cover that can be folded or flattened in a valley fold with the central portion as a boundary, and a binding portion for binding file paper or the like is formed on the file binding side surface of the cover, and this binding is performed. The binding string is composed of the binding string arranged at positions facing each other across the central part, and a guide hole through which the binding string can be inserted, and the binding string is a binding hole such as a file sheet and the guide 7. The file according to claim 1, wherein the file paper or the like can be bound by being inserted into the hole. The binding portions are formed at two locations separated by a predetermined distance along the center portion of the cover, and the positions on the cover where the binding string and the guide hole are provided are opposite to each other across the center portion in the two binding portions. The file according to claim 7, wherein the relationship is as follows. The pair of binding portions are formed such that the binding strings and the guide holes face each other with the center portion of the cover interposed therebetween, and the same binding is performed with the file paper or the like sandwiched between the center portions of the cover pages. A plurality of such a pair of binding portions are formed along the center of the cover so that the two binding strings can be inserted through the hole so as to cross each other. 7. The file described in 7. The file according to claim 7, 8 or 9, wherein a binding portion is formed at least at both ends of the cover in the central portion.

Images