WO2004113095A2

WO2004113095A2 - Opening and closing mechanism

Info

Publication number: WO2004113095A2
Application number: PCT/SE2004/001020
Authority: WO
Inventors: Gustaf Unoson Rylander; Karl-Axel Wittsell
Original assignee: Ab Metallmekan
Priority date: 2003-06-24
Filing date: 2004-06-24
Publication date: 2004-12-29
Also published as: WO2004113095A3; SE0301868D0; SE527124C2; SE0301868L; EP1641631A2

Abstract

A binder has a device (10) for opening and closing a binder for storing sheets with an elongate mechanism (20) extending on the inside of the binder in the area of the spine (130) of the binder and along the spine. The mechanism comprises two spaced-apart strips (20a, 20b) which are movably connected to each other by at least one common hinge (30), said strips being connected to the inside of the binder. The mechanism further comprises cooperating forks (60, 70, 80, 90) fixed to the strips.

Description

OPENING AND CLOSING MECHANISM

Field of the Invention

The present invention relates to binders for storing sheets, and more specifically a device for opening and closing a binder with an elongate mechanism extending on the inside of the binder in the area of the spine of the binder and along the spine. The mechanism comprises two spaced-apart strips which are movably connected to each other by at least one common hinge and are connected to the inside of the binder. The mechanism further com- prises cooperating forks fixed to the strips.

Background Art

There are various prior-art mechanisms for opening and closing of binders and also various binder systems. The binders have different types of hinges and sheet- holding means, in many cases in the form of forks or semi-rings, depending on where in the world they are used since there are different national and regional standards regarding hole patterns, sheet sizes, dimensions and sys- terns of measurement. The Swedish binder and hole pattern system differs, for instance, from the European ones which in turn differ from those used in, for example, the USA and Asia. Moreover some countries use several different binder and hole pattern systems. Finland, for instance, uses both the Swedish and European systems. Germany, for instance, uses inter alia a binder system with an opening and closing mechanism having two positions : one position where the binder and the mechanism are closed and one position where the binder is fully open or unfolded and lies essentially flat with the spine in a position for insertion and/or removal of sheets by manual separation of the mechanism holding the sheets in place. This German binder system uses two spring-biased split rings or alternatively mechanically guided rings on to which sheets are slipped, their holes matching the rings, and a fixed plate and a detachable plate which can be displaced along the rings and fasten- ed to them by means of an integrated locking mechanism. In Sweden use is made of a binder system for essentially two types of binders, one type with a divided spine to perform a hinge function, where the spine is in most cases made of wood, plastic or paper, sometimes also metal, and one type with a whole and unbroken spine, where the binder is often and largely made of plastic and where the opening and closing mechanism constitutes the hinge .

The opening and closing mechanism used in the Swedish binder system has the function of providing two extreme positions, open or closed, and one or more intermediate positions where the opening and closing mechanism can be partially open to allow the user to turn over the sheets and facilitate the turning over of the sheets without having to fully open the binder.

In Sweden, for instance a binder model named ERGOGRIP® or alternatively just ERGO^® is available, supplied by KEBA, SWEDEN. This binder is made of plastic and has a divided spine that serves as a hinge for an opening and closing mechanism made of metal. The products AGRIPPA and JOPA provide binders resembling the above-mentioned ERGOGRIP^® binder, except that the spines are made of metal or wood.

The opening and closing mechanism briefly discussed above, which has an opening and closing function and at the same time itself serves as a hinge and takes over the hinge function of the divided spine, is available essentially in two versions: one version called semi-spine with a mechanism for thin binders and one version called full spine with a mechanism for thick binders.

The prior-art mechanisms for opening and closing of binders suffer from several drawbacks. First of all, manufacturers of binders and/or opening and closing mechanisms must design and manufacture different types of mechanisms in different countries and use completely different methods of mounting the mechanisms in the binders. This reduces the possibility of using the same tools, the same knowledge and, in some cases, the same material and very rarely provides synergy effects.

The above-described mechanism having an opening and closing as well as hinge function is also used in binders with an unbroken rigid spine. This mechanism is essentially U-shaped in cross-section with the hinge in the centre of the base of the U and the entire mechanism is fastened by the legs of the U to the inside of the sides or lateral portions of the binder. The problems arising with this type of mechanism in a binder with an unbroken, non-divided spine imply that the mechanism turns about an axis of rotation by means of the hinge function, whose axis of rotation is not aligned with the axis of rotation of the sides of the binder since the binder is manufac- tured in such a manner that it is essentially unfolded to a flat position and, thus, rotates/turns only to some extent. The unbroken/rigid spine of the binder then affords, due to its shape and attachment to the mechanism, resistance to the natural opening motion of the binder when being deformed while the sides of the binder are being unfolded and during the time that the sides are in a lay-flat condition.

The above-mentioned drawbacks have a physical effect on the user who must apply greater force than necessary to open the binder, which is irritating. This also reduces the life and durability of the binder as well as the aesthetical appearance of the spine when the binder is being deformed, which may cause, inter alia, cracking and fatigue to the binder. This also means that any information printed on the outside of the spine can be destroyed and that it can be difficult to perform the printing on the same. This is especially common for binders with a wooden spine since the spine is often coated with fabric that serves as a hinge by holding the spine together. The wooden spine is divided, which also makes printing on the same difficult, decreases the printable surface and has a detrimental effect on the exposure of the print.

In many cases, the prior-art opening and closing mechanisms also use a varying number of sheet-holding means, either in the form of differently curved and mirror-inverted pins or forks that fit into and over- lappingly extend through holes in the sheets, or sheet- holding means in the form of a number of curved and, in some designs, wholly or partly circular spring-biased and split rings. The spring-biased rings are frequently split into two mirror-inverted ring halves and, if more than two rings are used, they are in most cases connected to each other so as cooperate and jointly hold the sheets. The spring mechanism for the rings operates in such a manner that the user of the binder manually opens and closes the rings by grasping the rings and pulling them apart and then pressing them together. These rings can be in two positions, a fully closed position where the sheets are held with the free end faces of the rings in contact with each other and an open sheet-receiving or sheet- releasing position where the free end faces of the rings are positioned at such a distance from each other that the sheets can be slipped on to the rings, the rings extending through holes in the sheets, and/or the sheets can be removed from the rings.

Prior-art opening and closing mechanisms using pins or forks suffer from several drawbacks . The pins or forks will henceforth be referred to merely as forks for the sake of clarity. One drawback is that, when these forks are used in the mechanism with the opening, closing and hinge function in binders with an undivided/rigid spine, the binder is not opened sufficiently due to the pre- viously described force acting against the opening motion as the spine is being deformed. The insufficiently open binder with too small a distance between the outermost freely projecting fork ends implies that it will be very difficult to slip the sheets on to the forks, and the user must often hold the forks apart or press them further apart with one hand while at the same time he tries to fit the holes of the sheets onto the forks with his other hand. Prior-art forks could also be divided in the vertical direction, i.e. perpendicular to the surface plane of the lateral portions or sides of the binder. This vertically divided type of fork has serious drawbacks since it easily gets stuck in the sheets during opening and closing of the binder. It is also unstable in the lateral direction and is therefore easily deformed in the lateral direction.

Summary of the Invention The main objects of the present invention are to provide an opening and closing mechanism and sheet- holding means in the form of pins or forks which are easy to use, durable, reliable, flexible and versatile in such a manner that they can be arranged in many different types of binder for storing of documents, sheets with pockets for holding photographs or storage media in the form of, for instance, CDs, diskettes, especially binders with an unbroken or rigid spine independently of hole pattern and fork type. One object is achieved by providing a device for opening and closing a binder with an elongate mechanism which extends on the inside of the binder in the area of the spine of the binder and along the spine and comprises two spaced-apart strips, which are movably connected to each other by means of at least one common hinge. The strips are connected to the inside of the binder and the mechanism also comprises at least one fork assembly fixed to the strips for holding sheets in the binder. One strip is directly connected to one of the lateral portions of the binder outside the spine and the other strip is free from the binder and connected to the spine by means of a guide bar. The guide bar is movably connected to the other strip, allowing motion of this other strip on the common hinge .

Another object is achieved by the fork assembly comprising at least two pairs of opposite forks which are bent, divided and connected to the binder by fasteners in the strips. The forks of each pair are positioned in the same plane and are adapted to move relative to each other in the plane. The forks are also adapted to move with overlap during the relative motion and are engaged with/ bear against each other each along a longitudinal guide/ surface for guiding the motion, the guides/surfaces matching and cooperating with each other.

The guiding of the motion of the cooperating forks is provided by means of separate complementary fork cross-sections extending along the respective forks, in the form of at least one recess in a first fork that matches at least one elevation on a second fork.

In addition to the same advantages as those of prior-art opening and closing mechanisms, i.e. allow- ing quick and easy turning over of the documents and the leaves with photographs or storage media without having to remove them, with the risk of their disappearing or becoming disarranged after first being removed from the binder and then being inserted again, the opening and closing mechanism for binders according to the present invention has the advantages that it can be stored and used as a module, i.e. that it can be used both in a binder according to the Swedish binder and hole pattern system and in a binder according to, for instance, the European binder and hole pattern system; that it provides a more aesthetically pleasing appearance for binders with a whole spine since advertisement and text and also labels for these on the outside of the spine are not bent or deformed, and that the printed surface will be unbroken and larger compared with binders having a divided spine; that binders with a whole spine thus will have an increased life; and that the user of this mechanism can open the binder more easily by applying less force. Moreover, modern printing technology can be used for printing in contrast to, for instance, the prior-art binder with a wooden spine. Moreover, functioning forks or pins for Sweden as well as Europe and the USA and other countries are provided, with ensured and improved stability and mutual guiding.

Brief Description of the Drawings The present invention will now be described in more detail with reference to the accompanying drawings, in which

Fig. 1 is a perspective view of a binder mechanism according to the invention in a closed position; Fig. 2 is a perspective view of the binder mechanism according to Fig. 1 in a partially open position,

Fig. 3 is a perspective view of the binder mechanism according to Figs. 1 and 2 in a fully open position,

Figs 4-7 are plan views from the underside of the binder mechanism according to Figs 1-3 during the opening of the same,

Figs 8-10 are side views of sheet-holding means used in the binder mechanism according to Figs 1-7, and Figs 11-16 are detailed views of the sheet-holding means according to Figs 8-10.

Detailed Description of the Invention

An opening and closing mechanism 10 according to the invention for use in a partly shown binder in which perforated documents or plastic and/or paper sheets with pockets for storing photographs or storage media in the form of, for instance, CDs and diskettes can be stored will be described in the following with reference to Figs 1-16.

Figs 1-7 illustrate the opening and closing mechanism 10 mounted on the inside of a binder and will hence- forth for the sake of clarity be referred to as the binder device 10 and, for the same reason, the documents/ storage sheets will be referred to as sheets.

Figs 1-3 show the binder device 10 in three different positions. Fig. 1 shows the binder device in a sheet-storing outer position, i.e. fully closed, Fig. 2 shows at least one partially open intermediate position, and Fig. 3 shows the binder device in an outer position where the sheets can be received to be stored in the binder and/or be removed from the partly shown binder, i.e. in a fully open and lay-flat/unfolded position. For the sake of clarity, the binder is shown to be transparent.

The binder device 10 is placed on the inside of the binder close to the spine 130 of the binder and is designed to fit in binders of different thicknesses and also constitute a reinforcing construction for the spine of the binder. The binder has sides or lateral portions 50 which function as an extension of the binder device. The binder device comprises an elongate mechanism 20 which in turn comprises two essentially opposite and mirror-inverted elongate strips, one strip 20a to the left and one strip 20b to the right, as shown in Figs 1-7. The right strip 20b is shown partly broken in Fig. 1 for better clarity. The strips are movably con- nected to each other by two common pivots or hinges 30 and positioned at a distance from each other. An alternative solution would be to use only one hinge or more than two according to the desired strength, consumption of material and stability. The strips and the hinges are preferably made of metal, but can also made of other sufficiently durable and rigid materials. Figs 4-7 are plan views, seen from the underside of the binder, of different positions of the lateral portions 50 of the binder as well as the parts of the binder device 10 during opening and closing thereof. Each of the strips 20a, 20b extends along the inside of the binder adjacent to the spine 130 and in the longitudinal direction of the spine and is essentially rectangular in cross-section seen from the underside of the binder, more specifically essentially L-shaped in cross-section. The strips are connected to each other at each end or leg of the L by means of the hinges 30 which are positioned approximately in the middle of the spine of the binder according to Figs 3-7. These strips together form a U section, i.e. an essentially U-shaped cross-section seen from the underside or upper side of the binder, in the fully closed position shown in Figs 1 and 4.

The binder device 10 which is shown in Figs 1-7 is in this embodiment attached to the inside of the right lateral portion 50 of the binder by fastening means 40 in the form of rivets which keep the outside of the punched right strip 20b in direct contact with the inside of the binder. In the binder device according to the invention, only one of the strips is fixed to the inside of the binder, and the other strip 20a is free from the binder. The binder device can be constructed to be mirror-inverted if desired, which means that either the left 20a or the right strip can be fixed to the binder.

The binder device 10 is arranged with two pairs of forks or semi-rings, in the following referred to as pairs of forks, an upper pair of forks 60 and a lower pair of forks 70, as shown in Figs 1-3, attached to the strips 20a, 20b which serve as attachments to the binder. These pairs of forks each consist of two opposite bent forks, an upper first fork 80 and a lower second fork 90, which means that the binder device in this embodiment has a total of two upper forks 80 and two lower forks 90, which are shown in more detail in Figs 4-16. The upper forks 80, which are shown in Figs 1-10 and 14-16, are referred to in this way since they slide over the lower forks 90 during opening and closing of the binder, as clearly shown in Figs 4-10, and are positioned over the lower forks in the closed position as shown in Figs 1 and 4. The upper forks have two ends each, a first end 80a fixed to the inside of the associated strip 20a, 20b and a second end 80b freely projecting from the inside of this strip towards the opposite strip 20a, 20b. The lower forks, which are shown more clearly in

Figs 4-10 and 11-13, also have two ends each, a first end 90a fixed to the inside of the associated strip 20a, 20b and a second end 90b freely projecting from the inside of this strip towards the opposite strip 20a, 20b. The binder device 10 also comprises a guide bar 100 which has a through slot 140, said guide bar being shown in Figs 1-7. The guide bar is designed as an elongate angled plate with a first side 100a movably connected to the left strip 20a in this embodiment of the invention to allow motion of this strip 20a on the hinge 30. If the binder device were mirror-inverted, the guide bar 100 could just as well be movably connected to the other strip 20b. The second side 100b of the guide bar is fixed to the binder, more specifically to the spine 130 of the binder by fastening means 120, in this case in the form of rivets transversely to the strips 20a, 20b. The fastening means can also be some other type, such as detachable screw means or female and male members which are snapped or pressed together similar to press studs; the second side of the guide bar can also be integrated into the spine of the binder.

The movable connection between the guide bar 100 and the associated strip 20a, 20b is provided by means of a guide/sliding device or a slide means 110 in the form of a pin 160 which runs in and is guided by the slot 140 of the guide bar during opening and closing of the binder. The purpose of the guide bar 100 which is shown in Figs 1-7 is to connect the spine of the binder to the binder device 10 according to the invention and enable, when a user of the binder is to open or close the same, the binder to be "flattened out" as much as possible in the fully open position according to, inter alia, Fig. 3 and at the same time help to pull apart or press together the binder device when the user manually opens or closes the binder. The advantage of a movably connected strip 20a and a strip 20b directly connected to or fixed to the binder outside the spine 130 of the binder is that the binder device 10 allows the binder to be opened and laid flat without the spine of the binder being deformed since the link connection in the form of the guide bar 100 and the guide bar pin 160 lets the binder device keep its rotary motion and axis of rotation while at the same time the binder keeps its rotary motion and axis of rotation and shape, and thus these different motions do not counteract each other and the shape of the binder does not make resistance due to deformation while the binder is being fully opened. The guide bar and its slot 140 are designed so that the guide bar pin and, thus, the strip 20a are guided when closing the binder in such a manner that the centre axis of the guide bar pin only instantaneously coincides with the closing motion of the binder and the centres of the axes of rotation of the hinges 30, and no "locking" of the closing motion of the binder occurs since the guide bar pin is not "pressed through" the centre of rotation of the hinges, but accompanies the guide bar.

The guide bar pin 160 has a shape resembling a pin, dowel or rivet with an edge or flange extending round a first end to provide a head and a second headless end which is fixed to a fastening means in the form of a plate 150 projecting approximately from the centre of and along the left strip 20a. The guide bar pin 160 can be fixedly connected to the plate 150 by a welded joint, soldered joint, glue joint or alternatively shrink fit or be detachably and/ or rotatably connected to this plate by different fasten- ing means (not shown) , such as bearings, a threaded end which is attached by screwing and locked to a corresponding threaded part of the plate or a snap fastener with a male and female member engaging each other.

The guide bar 100 and the guide bar pin 160 could also change places, i.e. the guide bar can be fixed to the left strip 20a and the guide bar pin can be fixed to the spine 130 and be placed at a distance from the spine so as to project from the spine along the same, which will be appreciated by a person skilled in the art. The guide bar pin 160 has a diameter slightly smaller than the width of the slot or opening 140 of the guide bar and extends perpendicular to and through the guide bar 100 and its slot with the head end as an axial stop in the longitudinal direction of the strips 20a and 20b. In this embodiment, the guide bar pin need not have a head as an axial stop since the guide bar and the strips 20 are already fixed in relation to each other, but has this shape for safety's sake so as not to "jump out" of the slot of the guide bar if the binder device 10 is deformed by the strips being displaced relative to the guide bar.

The shape of the guide bar 100 is most distinctly shown in profile in Figs 4-7. The first guide bar side 100a projecting perpendicular from the plane of the binder is bent and the second guide bar side 100b fixed to the binder is straight. The bending of the first guide bar side is necessary due to the different motions of the strips 20a and 20b relative to the binder and the axes of rotation, which are offset relative to each other and thus different, of the binder device 10 and the binder, respectively. This distance between the axes of rotation is changed since the spine 130 of the binder is essen- tially rotated/turned outwards and inwards while the left strip 20a in the binder device 10 is turned/rotated and at the same time moved/raised along the inside of the spine during the same motion. This means that the left strip 20b must run freely past the first side 100a of the guide bar and is guided along the same, and that the guide bar pin 160 is moved from the inside of the spine 130 of the binder along the guide bar slot 140 during opening of the binder and towards the inside of the binder during closing of the binder. The spine is rotated through about 90° while the left strip 20a is turned or rotated through slightly less than 90°. The spine and the left lateral portion of the binder seen in Figs 1-7 move away from the hinges 30, i.e. the distance between the spine and the hinges increases when opening the binder and decreases when closing the binder.

In the closed position of the binder according to Figs 1 and 4, the guide bar pin 160 is positioned next to the second side 100b of the guide bar and the spine 130. In the practically fully open position of the binder in Figs 3 and 7, the guide bar pin is positioned furthest away from the second side of the guide bar and the spine.

The first guide bar side 100a of the guide bar 100, which is shown in Figs 1-7, is divided into three por- tions, a wider portion 101 which extends from a third guide bar side 100c and passes, via an intermediate portion 102 which is angled to the second guide bar side 100b, into a narrower portion 103 which extends up to a fourth guide bar side lOOd. The third guide bar side 100c and the fourth guide bar side lOOd which are shown in Figs 1-7 constitute in this embodiment the short sides of the guide bar while the first guide bar side 100a and the second guide bar side 100b constitute the long sides of the guide bar. The lower edge of the strip 20a, facing the guide bar pin 160, is in contact with the first side 100a of the guide bar, i.e. accompanies, by engagement, the intermediate angled portion 102 and the narrower portion 103 along a sliding surface indicated by a thick line on the contour of the guide bar and arrows in Figs 6 and 7 and is guided by these portions and the sliding sur- face during opening and closing of the binder in order to facilitate these motions.

The slot 140 of the guide bar, as shown in Figs 1-7, has an even width and a bent shape which at a distance, preferably a practically constant distance, from the edge of the guide bar 100 essentially follows the bent shape of the first side 100a of the guide bar. The design of the guide bar and the slot depends on their geometric motion and location inside the binder relative to the strips_, 20a and 20b and the hinges 30 as well as the design of the binder.

The pairs of forks 60 and 70 and the associated different forks 80 and 90 differ from traditional prior-art forks by their design. The common cross-section of the forks largely resembles that of a fork which is essen- tially circular in cross-section and which is divided essentially along the same plane or longitudinal direction as the strips 20a and 20b into two separate halves which are practically semicircular in cross-section. In this embodiment, the division of the forks has preferably occurred in a plane or a direction running essentially in a bend along the direction or plane of the opening and closing motion, i.e. the horizontal plane if the binder lies horizontally or the vertical plane if the binder stands upright. The upper half/fork 80 is essentially concave in cross-section with a slot, recess or notch that extends along the centre of its inside or underside and steers, by engagement, against a matching elevation, rib or bead which extends along the centre of the outside or upper side of the lower half or fork 90. These forks are made by rolling by a suitable method to provide greater strength and the correct radius of curvature and also complementary cross-sections or shaping or surfaces for guiding their motion. Such rolling also forges the forks by deformation when they are made of round bars as starting material in this embodiment, but can of course be made of other suitable starting materials of other cross-sections.

Figs 4-10 clearly show that the forks 80 and 90 run with overlap and have a contact surface along which they slide during the relative displacement or motion in the same plane. This contact surface consists of the inside of the slot of the upper fork 80 and the outside of the bead of the lower fork 90 and also neighbouring support or contact surfaces which form the joint surface between the upper fork 80 and the lower fork 90 in the common cross-section along the strips 20a, 20b. Figs 1-3 show each of the two upper forks 80, i.e. one upper fork 80 in the upper pair of forks 60 fixed to the left strip 20a and the other upper fork 80 in the lower pair of forks 70 fixed to the right strip 20b. Each of the two lower forks 90, i.e. one lower fork in the upper pair of forks 60, is fixed to the right strip 20b and the other lower fork in the lower pair of forks 70 is fixed to the left strip 20a. This "overlap" of upper and lower forks, which are arranged on different sides or strips, implies that guiding in the vertical direction out of and into the longitudinal plane of the binder is effected by the forks "making resistance" to each other during the opening and closing motion. If the two upper forks were placed on the same strip or side, this double guiding in the vertical direction would not exist and no resistance effect would be achieved. The upper fork 80 in the upper pair of forks 60 could, as an alternative, be placed on the right strip 20b and the lower fork 90 be placed on the left strip 20a. The same would be applicable to the lower pair of forks 70, as will be realised by a person skilled in the art.

The two upper forks 80, which are shown in Figs 1-10 and in more detail in Figs 14-16, are bevelled on the upper side of their freely protruding ends 80b. The two lower forks 90, which are also shown in Figs 1-10 and in more detail in Figs 11-13, are bevelled on the underside of their freely protruding ends 90b. The above-described bevels at the ends 80b, 90b of the forks 80, 90 have the function of ensuring, when inserting the forks into the holes of the sheets, that the outer tip of each fork end 80b, when meeting the opposite fork end 90b, does not hit the sheet, but is inserted into or enters the sheet hole in the free space, i.e. where no front face of any of the opposite fork ends is in contact with or abuts against the sheet during insertion into the same. The underside of the upper fork 80 can be in contact with the sheet when the upper side of the lower fork 90, i.e. the upper side of the bead, is in contact with the sheet. This means that the free space into which the end 80b of the upper fork must be inserted is positioned below the upper surface/point/area of the bead for the end 90b of the lower fork, and therefore the upper fork is bevelled on the upper side so that its first two front terminal or tip points made by bevelling are inserted into the two free spaces close to the sheet- free areas in the front views of the lower fork in Figs 11-13. The free space into which the front terminal/ tip point of the lower fork 90 is to be inserted is positioned above the lower surfaces, facing the lower fork 90, of the upper fork 80b, and therefore the lower fork is bevelled on the underside so that its bead is inserted in connection with the sheet-free area in the front views of the upper fork in Figs 14-16.

Figs 1-3 illustrate a mechanism adjacent to the lower hinge 30. The mechanism serves to allow a user of the binder to open and close the binder, in a manner known to a person skilled in the art, by connectible and disconnectible engagement and will therefore not be explained in more detail. One of the strips 20a and 20b in the binder device 10 as shown in Figs 1-7 can, in another embodiment, be fixed by glue, screw means, melting to the plastic of the lateral portions of the binder if they are made of ther- moplastic, or by similar fastening means and methods. In one embodiment of the binder device, the attached strip 20b is formed with a pattern on its outside facing and being in contact with the inside of the lateral portion 50 of the binder in the form of projecting material, for instance by sharp, pointed burrs of metal extending into the lateral portion of the binder and being produced in the strip in the manufacture thereof, or a pattern formed in the surface thereof by knurling, rolling or some kind of machining, such as milling. The purpose of this pat- tern is to increase friction as well as form-fit and force-positive engagement between the attached strip and the binder, especially in connection with adhering of the strip by gluing or melting.

All parts included in the binder device 10 can be quenched blue, lacquered, painted or coated in some other way with a protective surface, as is easily realised by a person skilled in the art.

The guide bar 100 according to the invention can be formed with, instead of a through slot 140, a slot which is machined in the surface of the guide bar and in which the guide bar pin 160 runs during opening and closing of the binder. This requires, however, the guide bar to be thicker and the end of the guide bar pin to be provided with a head to be shaped in a suitable manner. It is also possible to use two or more guide bars to increase stability and facilitate opening and closing of the binder, if desired.

The forks 80 and 90 and their longitudinal slot and bead, respectively, can have a varying longitudinal sec- tion to improve the mutual guiding and decrease the risk of the free fork ends 80b and 90b not entering the holes in the sheets or even missing them or, besides, in some cases, being prevented from entering the holes by reducing the risk of colliding with the sheets. The cross- ' section of the forks can increase from the free ends to the fixed ends 80a, 90a, for instance with a conical shape, so that the smaller end face of the free fork ends does not collide with the sheet round the hole. The increasing cross-section of the longitudinal slot and bead, respectively, can also produce a stop effect by the length of the bead or the slot being adjusted so that the bead or the slot "touches bottom" in a stop position of the closing movement of the binder.

The forks 80 and 90 can also be divided in a direction other than essentially parallel to the strips 20a, 20b, for instance inclined relative to the horizontal or vertical plane if the binder is lying or standing, respectively. The pairs of forks 60, 70 can also be divided in different directions inclined to each other to provide a resistance effect as described above. The guide surfaces of the forks can also be arranged as notches or recesses on one fork that match projections or points on the other fork and, by sliding engagement, help to hold the binder in its intermediate positions, such as the position for turning over sheets.

The forks 80 and 90 in other embodiments with a lon- gitudinally varying cross-section and/or the forks divided in a direction which is inclined relative to the longitudinal plane of the strips 20a, 20b are manufactured by embossing, punching or pressing that forges the forks to the desired shape, curvature and cross-section or pro- file with increased strength, such as in the first embodiment of the fork.

The forks 80 and 90 according to the invention can, of course, also be used/attached in prior-art opening and closing mechanisms for binders, as will be appreciated by a person skilled in the art. The opening and closing mechanism 10 according to the invention can also use prior-art cooperating forks 60 70, 80, 90 for holding sheets to be stored in the binder.

Claims

1. A device (10) for opening and closing a binder for storing sheets with an elongate mechanism (20) which extends on the inside of the binder in the area of the spine (130) of the binder and along the spine and which comprises two spaced-apart strips (20a, 20b) which are movably connected to each other by at least one common hinge (30) , said strips being connected to the inside of the binder, the mechanism further comprising at least one fork assembly (60, 70, 80, 90) fixed to the strips for holding sheets in the binder, c h a r a c t e r i s e d in that one strip ( 20b) is directly connected to one of the lateral portions (50) of the binder outside the spine (130) of the binder, and the other strip (20a) is free from the binder and connected to the spine (130) of the binder by means of a guide bar (100) in such a manner that the guide bar allows this other strip to move on the common hinge (30) .

2. A device (10) for opening and closing binders for storing sheets as claimed in claim 1, wherein a first side (100a) of the guide bar (100) is movably connected to the other strip (20a) by at least one means (110) which projects from said other strip and which is movably engaged with the guide bar and the second side (100b) of the guide bar is directly connected to the spine (130) of the binder transversely to the strips (20a, 20b) .

3. A device (10) for opening and closing binders for storing sheets as claimed in claim 1, wherein a first side (100a) of the guide bar (100) is fixedly connected to said other strip (20a) and the second side (100b) of the guide bar is movably connected to the spine (130) of the binder transversely to the strips (20a, 20b) by at least one means (110) which projects from the spine of the binder and which is movably engaged with the guide bar.

4. A device (10) for opening and closing binders for storing sheets as claimed in claim 2 or 3, wherein the projecting means (110) comprises a pin (160), which extends along the other strip (20a) and the spine (130) and is displaceably engaged with a guide (140) arranged in the guide bar (100) and extending along the same.

5. A device (10) for opening and closing binders for storing sheets as claimed in any one of the preceding claims, wherein the one strip (20b) directly connected to the inside of the binder has a frictional- force-increasing and form-fit-improving pattern on the surface which is in contact with the inside of the binder.

6. A device (10) for opening and closing binders for storing sheets as claimed in any one of the preceding claims, wherein the fork assembly (60, 70, 80, 90) comprises at least two pairs of opposite forks (60, 70, 80, 90) which are bent, divided and connected to the binder by fasteners in the strips (20a, 20b) , the forks (80, 90) of each pair (60, 70) being positioned in the same plane and adapted to move with overlap relative to each other in the plane and are engaged with each other each along a longitudinal guide for guiding the motion, the guides matching and cooperating with each other.

7. A fork assembly (60, 70, 80, 90) for holding sheets together in a binder, said fork assembly comprising at least two pairs of opposite forks (60, 70, 80, 90) which are bent, divided and connected to fasteners for fastening to the binder, the forks (80, 90) of each pair (60, 70) being positioned in the same plane and adapted to move relative to each other in the plane, c h a r a c t e r i s e d in that the forks (80, 90) are adapted to move with overlap during the relative motion, and the forks are engaged with each other each along a longitudinal guide for guiding the motion, the guides matching and cooperating with each other.

8. A fork assembly (60, 70, 80, 90) for holding sheets together in a binder, in which fork assembly the guide guiding the motion of the cooperating forks (80,

90) comprises separate complementary fork cross-sections extending along each fork in the form of at least one recess in a first fork (80) matching at least one elevation on a second fork (90) .