Abstract:
A support structure is disclosed for vertical filing systems to suspend binders horizontally by supporting one end of the binder on an end support fixedly located on the support structure while supporting the binder from another position on the binder remote from the first end by an elongate suspension means coupled at one end to the support structure and extending therefrom to the binder. The support structure provides for easier manual engagement of binders to the support structure and easier disengagement therefrom as compared to prior art support structures.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates generally to clamp binders for holding sheet material such as maps, blueprints and plans. More particularly the invention relates to new configurations for such clamp binders as well as to a new support structure for horizontally suspending new and known clamp binders. 
     In vertical filing systems, clamp binders are used to bind large sheets of material including engineering and architectual plans and drawings, maps, specifications, and blueprints. The clamp binder grasps the sheet-like material along an edge thereof to frictionally hold the material in the binder. The binder may then be suspended in a substantially horizontal position from a support structure whereby the sheet material hangs vertically from the clamp binder. Such vertical filing systems preferably provide for ease of examination, handling and storage of sheet material. 
     Known binders include &#34;three piece binders&#34; such as characterized in Canadian Pat. No. 604,233 to Schneider and U.S. Pat. Nos. 3,891,093 and 3,308,831 to Petrie and Kritske, respectively. These three piece binders include an inverted channel member carrying therein a pair of clamping members. 
     The upper edges of the clamping members are hinged inside the channel and coupled to a threaded bolt extending upwardly through the channel to a wing nut on the exterior top surface of the channel. Turning the wing nut draws the bolt upward, rotating the upper edges of the clamping members about their hinges, and causing the lower edges of the clamping members, which protrude from the channel, to clamp about sheet material to be held. 
     Some &#34;two piece binders&#34; have also been proposed as in U.S. Pat. No. 3,069,737 to Schneider. These two piece binders are characterized by two clamping members hinged together with threaded bolts and wing nuts co-operating to draw complementary edges of the clamping members together to grasp sheet material therebetween. Two piece binders proposed to date have not proved satisfactory and suffer from a number of disadvantages. One disadvantage is that they do not provide a satisfactory hinge between the clamping members. Another disadvantage is that the configurations of the clamping members do not permit efficient transfer of tensioning forces created by the bolt and wing nut into clamping forces acting on the sheet material to be held. 
     A disadvantage common to most two and three piece binders is that the conventional wing nuts used to create the clamping forces are located on the exterior top surface of the binder. Known binders may most conveniently be laid on their side, as on a desk top, to insert sheet material between open clamping members. With binders having wing nuts mounted on the top surface of the binder, the desk top typically interferes with the wing nuts and, in any event, the proximity of the wing nut to the desk top prevents easy and satisfactory manual turning of the wing nuts to tightly clamp the binder onto the sheet material being inserted. 
     Most three piece binders are arranged so that the sheet material will hang straight down from the channel member between symmetrical clamping members. Known two piece binders fail to satisfactorily achieve such a symmetrical arrangement. Those two piece clamps which have attempted to approximate a symmetrical arrangement have found it necessary to locate the adjusting wing nuts on the top surface of a channel like member forming one of the clamping members. Known two piece clamp binders have failed to provide symmetrical grasping members in combination with side mounted wing nuts. 
     Known systems for hanging binders include a simple system comprising two parallel, spaced, horizontal bars across which a binder may be suspended with one end of the binder supported on one bar and another end of the binder supported by the other bar. Such a system is for example referred to in U.S. Pat. No. 3,308,831 to Kritske. Parallel bar systems have the disadvantage that when a number of binders are stored adjacent each other, great difficulty is to be experienced in lifting out any intermediately located binder, particularly having regard to the substantial weight of a loaded binder. 
     To overcome this problem, hinged bracket support systems have been proposed such as in Canadian Pat. No. 671,574 to Schneider and U.S. Pat. No. 3,211,892 to Morcheles. In these systems, a number of adjacent brackets are placed at spaced intervals along a wall with each bracket hinged to rotate about a vertical axis. Each bracket independently receives and supports a binder such that the bracket and binder will rotate as a unit. With binders suspended side-by-side on separate brackets, access to any binder is facilitated by rotating adjacent binders away therefrom. In such systems, coupling means are provided to couple the binder to the bracket, typically coupling the binder to the bracket at two separate points of support. Known hinged bracket support systems have the major disadvantage that, in order to couple the binder to the bracket or disengage the binder from the bracket, substantially the entire weight of the binder must not only be lifted but must also be carefully manipulated. Prior art vertical filing systems thus fail to provide a system in which access to and removal or replacement of the binder can be carried out quickly and with a minimum of effort. 
     Another disadvantage of hinged bracket support systems is that after adjacent binders have been pushed aside to rotate away from the desired binder, no means is provided to automatically swing the binders back to a normal storage position, in which position typically a minimum of space is occupied by the suspended binders. 
     With an understanding of hinged bracket support systems, a mutual disadvantage of hinged bracket support systems and known two and three piece binders may be pointed out. In many cases where a binder is coupled to a hinged bracket support system, the disadvantage arises that the effective location of the coupling means coupling the binder to the bracket will be such that the center of gravity of the binder and grasped sheet material is not effectively centered about the coupling means. The off-centered weight of the binder and sheet material disadvantageously produces a force moment attempting to rotate the suspended binder about its longitudinal axis. This rotational moment makes coupling and disengagement of the binder more difficult in that in manually manipulating the binder, not only must the weight of the binder be supported but the rotational force must be overcome to achieve a proper orientation of the binder for coupling or disengagement. 
     SUMMARY OF THE INVENTION 
     A first object of the present invention is to at least partially overcome the disadvantages of the prior art by providing a two piece binder having substantially symmetrical clamping members hinged together along first edges thereof so as to be rotated to grasp paper between second edges thereof by the rotation of wing nuts mounted on one side of the two piece binder and operably coupled to the two clamping members. 
     Accordingly, in a first aspect, the present invention provides a clamping device to grasp sheet material along an edge thereof comprising 
     first and second continuous, elongate jaw-like clamping members of substantially identical angle section between first and second longitudinal edges thereof, 
     the clamping members hinged together along their first edges to rotate relative to one another from an open position in which their second edges are sufficiently spaced to permit placement of the sheet material therein to a closed position in which their second edges are brought sufficiently close together to grasp the sheet material therebetween, 
     the clamping members being hinged together with their angle sections opening towards each other to define an interior space bordered by interior surfaces of the first and second members, 
     a depending flange on the first clamping member lying intermediate the first member and second member in the interior space, the flange, in section, extending from the interior surface of the first member towards the interior surface of the second member whereby with the device in the closed position a portion of said flange lies proximate the interior surface of the second member in opposed relation thereto, 
     tensioning means coupling the portion of the flange to the second member for activation to regulate the distance between the portion and the interior surface of the second member opposed thereto for relative rotation of the first and second members between the open and closed positions, and 
     tension activating means located on an exterior side surface of the second member and coupled to the tension means for activating the tension means. 
     In the first aspect of the invention, a novel construction is provided for a two piece binder. The two principal members of the binder comprise complementary jaw-like clamping members of substantially identical angle section between first and second longitudinal edges of each. The clamping members are hinged together along their first edges so as to permit relative rotation of the members about the hinge with respect to each other. Preferably the hinge is provided by one clamping member having a C-shaped section member at its first edge forming a longitudinally extending groove, circular in section, to receive a member of complementary circular section on the first edge of the other clamping member. By rotating the two clamping members about the hinge, their second longitudinal edges may either be separated to permit placement of sheet material therebetween or brought sufficiently close together to effectively grasp the sheet material therebetween. 
     The clamping members are preferably arranged with their angle sections opening towards each other such that an interior space is defined between the jaw-like clamping members. This interior space advantageously permits means to operatively rotate the clamping members relative to one another to be substantially concealed between the clamping members and thereby provide an appealing visual appearance to an assembled binder. In this regard, a first of the clamping members is provided with a depending flange in section extending from an interior surface of the first clamping member within the interior space towards the second clamping member so as to lie proximate an inner surface of the second clamping member when the binder is in a closed position. A tensioning device such as a threaded bolt coupled at one end to the depending flange may extend from the depending flange through the interior space and out a hole through a side-wall of the second clamping member. With a tension activating means such as a wing-nut threaded on the bolt on the exterior side of the second clamping member, turning the wing nut will rotate the first and second clamping members with respect to one another. The first and second clamping members preferably are of a cross section that they may easily be manufactured by extrusion, as for example, from aluminum. Preferably two piece binders according to the invention have a symmetrical appealing appearance and permit ease of insertion of the sheet material plus ease of tightening the clamping members due to provision of a proper hinge between clamping members and due to the location of the tightening wing nuts on a side surface of the binder. 
     A second object of the present invention is to at least partially overcome the disadvantages of the prior art by providing a support structure for vertical filing systems to suspend binders horizontally by supporting one end of the binder on an end support fixedly located on the support structure while supporting the binder from another position on the binder remote from the first end by an elongate suspension means coupled at one of its ends to the support structure and extending therefrom to the binder. 
     Accordingly, in a second aspect, the present invention provides a support structure for suspending an elongate, rigid binder in a substantially horizontal position whereby sheet material grasped in the binder may hang vertically from the binder, 
     the support structure comprising: 
     end support means fixedly secured to the support structure to removably receive a first end of the binder; and 
     elongate suspension means with a first end thereof coupled to the support above the end support means and with a second end thereof adapted to be detachably coupled to the binder spaced from the first end, 
     the suspension means having a length that with a first end of the binder received in the end support means and the second end of the suspension means coupled to the binder, the binder is suspended substantially horizontally, 
     the end support means receiving the first end of the binder to permit at least marginal rotation of the binder relative to the end support means about a first vertical axis passing proximate the first end of the binder; and the suspension means coupled to the support to permit at least marginal rotation of the suspension means thereabout relative to the support structure through a second vertical axis; whereby the first end of the binder received in the end support means and the second end of the suspension means coupled to the binder, the binder may rotate at least marginally about the vertical axis. 
     In the second aspect of the invention, a novel support structure is provided to preferably support binders, such as known two and three piece binders, in substantially horizontal positions. As with known vertical filing systems, suspending a binder horizontally from the support structure of the present invention permits sheet material which may be grasped in the binder to hang vertically downward from the suspended binder. The support structure of this invention has an end support means which is fixedly secured to the support structure and adapted to receive a first end of a binder. An elongate suspension means is provided with one of its ends coupled to the support structure at a position located above the end support means. The suspension means extends from its end coupled to the support structure to its other end where it is adapted to be detachably coupled to the binder at a location on the binder spaced from the end of the binder received in the end support means. Upon choosing the elongate structure to be of a suitable length, with the first end of the binder received in the end support means and the suspension means coupled to the binder, the binder may be suspended from the support structure in a substantially horizontal position. Preferably the binder is suspended so that the binder may be rotated, while maintaining its substantially horizontal position, about a vertical axis passing near the first end of the binder. This may be accomplished, firstly, by having the first end of the binder received in the fixed end support means to permit at least some rotation of the binder about a vertical axis passing proximate the end support means and, secondly, by having the elongate suspension means coupled to the support structure to permit the elongate suspension means to also be rotatable about a vertical axis. 
     The preferred embodiments of the support structure according to the present invention facilitate ease of insertion of a binder into the support structure with the end support means receiving the first end of the binder so as to prevent relative vertical downward movement of the first end of the binder with respect to the end support means. The preferred embodiments provide a simplified construction for the support structure as compared to known support structures particularly when simple rods or straps are used as the elongate suspension means. 
     Another object of the present invention is to at least partially overcome the disadvantages of the prior art by providing a novel method for suspending elongate binders which comprises suspending the binders from a support structure such that the binders are free to rotate about an axis passing longitudinally through the binder. 
     Accordingly, in a third aspect the present invention provides an improved method of suspending an elongate clamping device, adapted to grasp sheet material therein, from a support structure so as to permit the device to rotate at least marginally about an axis passing longitudinally through the device. 
     In the third aspect of the invention, the applicant has appreciated that force moments may disadvantageously act on suspended binders due to the sheet material hanging therefrom tending to rotate the binder about a hoirzontal axis passing through the binder. To permit a suspended binder to assume an advantageous position in which these rotational forces are minimized, the present invention provides for supporting the binder from the support structure such that the binder is substantially free from restraint to rotate about a longitudinal axis. While both sectionally symmetrical and sectionally non-symmetrical binders may be suspended so as to permit such preferred rotation of the binder with respect to the support structure, suspension according to the third aspect of the present invention is especially preferable in clamping binders, such as two or three piece binders, in which two clamping members are hinged together about an axis and the binder is suspended to be free to rotate about this axis. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further objects and advantages of the invention will appear from the following description taken together with the accompanying drawings in which: 
     FIG. 1 is a perspective view of a new binder according to the present invention shown suspended by one form of a new support structure according to the present invention. 
     FIG. 2 is a cross sectional view of a first clamping member of a binder. 
     FIG. 3 is a cross sectional view of a second clamping member of a binder. 
     FIG. 4 is a cross sectional end view of a binder according to the present invention in a fully closed position. 
     FIG. 5 is a cross sectional end view similar to that of FIG. 4 but with the binder in an open position. 
     FIG. 6 is a pictorial view of a biasing spring. 
     FIG. 7 is a pictorial view of an end cap. 
     FIG. 8 is a schematic side view of a binder suspended from a second form of a new support structure according to the invention. 
     FIG. 9 is a front view of the second form of a new support structure according to the invention showing one binder suspended therefrom. 
     FIG. 10, located on the sheet with FIG. 8, is a partial cross sectional view of FIG. 9 along axis I--I&#39;. 
     FIG. 11, is a perspective view showing a third form of the support structure of the present application adapted for use with a known three piece binder as described in Canadian Pat. No. 671,574. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Reference is made first to FIG. 1 which shows a vertical filing system including elongate binders 10 suspended in a substantially horizontal position from first preferred form of a support structure generally designated 12 whereby sheet-like material 14 grasped by each binder 10 may freely hang vertically from the binder. Support structure 12 is affixed by known means to a support (not shown) such as a wall or a movable stand. 
     Each end of the binder 10 has a cylindrical end extension or cap 18 extending therefrom. The end cap 18 at one end of the binder is received within a circular opening 20 in a substantially hollow square rod-like member 22 formed in support structure 12. The end surface of end cap 18 abuts a rear surface 24 in square rod-like member 22. A flexible strap 26 is secured at a first end 28 thereof to support structure 12 vertically above opening 20. Flexible strap 26 has a hook 30 at its second end 32. While not clearly shown in FIG. 1, hook 30 has a cylindrical projection which extends into a cylindrical interior aperture inside binder 10, with ingress and regress of the cylindrical projection being accomplished via opening 36 through top of binder 10. Strap 26 is of length that with the first end of the binder received in opening 20 to abut against the rear interior surface of square rod-like member 22, binder 10 is disposed in a substantially horizontal position. 
     FIGS. 2 to 5 clearly show the features of a preferred embodiment of a new two piece binder according to the present invention. The binder comprises two major pieces; a first jaw-like clamping member 40 shown in section in FIG. 2 and a second jaw-like clamping member 42 shown separately in section in FIG. 3. Each comprises a substantially continuous, elongate member, preferably extruded from aluminum. 
     As shown most clearly in FIGS. 4 and 5, the first and second members 40, 42 may be hinged together at their upper edges to rotate with respect to one another about an axis indicated at 44. This is accomplished in the present embodiment by a first C-shaped member being provided at the first edge of the first clamping member 40 to receive therein a second C-shaped member generally being provided at the first edge of the second member 42. 
     As seen in FIG. 2, the first clamping member bifurcates at point 50 into two separate portions. The first C-shaped member comprises a first outer most arm 52 extending from point 50 to extremity 54 and a second inner most arm 56 extending from point 50 to point 58 where in the curvature diverges from a circumferential path around axis 44. As discussed later, the extension from point 58 to extremity 60 is to be referred to as the depending flange 62. The first C-shaped member may be seen to define therein, by its interior surface 78, a longitudinally extending groove 61 of part-circle section. 
     As may be seen in FIG. 3, the second member 42 is similarly divided at point 64 into two arms, a first outermost arm 66 extending from point 64 to extremity 68 and a second arm 70 extending from point 64 to extremity 72. The first and second arm 66 and 70 form the second C-shaped member in section defining therein a longitudinally extending substantially cylindrical central aperture 74. The second C-shaped member also has an outer surface 76 of part circle section. The diameter of outer cylindrical surface 76 on the second C-shaped member is marginally smaller than the diameter of groove 61 of part-circle section formed by the first C-shaped member whereby the second C-shaped member of the second member 42 is, for assembly of the binder, longitudinally slidable into the first C-shaped member of the first member 40. Inner cylindrical surface 78 on the first C-shaped member cooperates with the outer cylindrical surface 76 of the second C-shaped member so as to hinge the first member and second member together for rotation about axis 44. 
     Preferably groove 61 of the first C-shaped member encircles the second C-shaped member to an extent greater than 180° to prevent removal of the second C-shaped from groove 61 by movement in a radial direction with respect to axis 44. 
     Means are provided on the binder to rotate the first and second member with respect to one another about axis 44. These means include depending flange 62, T-bolt 80 and nut 82. Depending flange 62 is preferably located on the first clamping member 40 to extend from point 58, the designated end of second arm 56, to extremity 60. Depending flange 62 forms in section a third C-shaped member (also designated as 62) whereby in conjunction with the first C-shaped member may be seen to form an S-shape in section (or of inverted S-shape). As best seen in FIG. 5, depending flange 62 is provided with one narrow slot 63 extending upwardly from extremity 60 through which center post 84 of T-bolt 80 may pass. A hole 65 is provided through second member 42 passing from the interior surface 88 of the second member 42 to its exterior side surface, in section, in alignment with the slot 63 in the depending flange 62. With the cylindrical rod-like head 86 of T bolt 80 located within the third C-shaped member 62, center post 84 may extend through both U-shaped slot 63 and hole 65 to outside the binder 10. Preferably U-shaped slot 63 and hole 65 have sufficient dimension having regard to the diameter of central post 84 of T-bolt 80 so as to permit angular movement of post 84 with respect to the first and second clamping members 40, 42 as is to be appreciated to take place in relative rotation of members 40, 42 between the closed position shown in FIG. 4 and the open position shown in FIG. 5. 
     A threaded portion of post 86 is engaged within threaded nut 82 located along the side of the binder over hole 65. Turning nut 82 will rotate first and second members, 40, 42, relative to one another from a fully open position as shown in FIG. 5 to a fully closed position as shown in FIG. 4. In a fully open position, sheet material may be inserted between the lower second edges 90, 92 of clamping members 40, 42 respectively. The first and second members may then be rotated towards a closed position whereby sheet material is grasped between the second edges 90, 92 of members 40, 42 respectively, to be frictionally held therebetween. 
     As shown in FIGS. 4 and 5, clamping members 40, 42 are preferably of substantially identical angle section. Thus, first member 40 and second member 42, in section, extend downwardly from respective points 50, 64 to respective second edges 90, 92 symmetrically about opposite sides of a plane passing through axis 44. 
     Each member 40 42 are preferably of overall angle section with the angle sections opening towards one another whereby an interior space 94 is seen in FIG. 4 to be provided defined by interior surfaces 96 of the first member 40 and interior surfaces 88 of the second member 42. Depending flange 62 may be seen to extend from a portion of the interior surface 96 of the first member towards the inner surface 88 of the second member with portions of depending flange 62 lying proximate to and in opposing relation to the inner surface 88 of the second member when the first and second member 40, 42 are in a substantially closed position. 
     To facilitate manufacture by extrusion, depending flange 62 as shown in the figures has been selected to extend from first clamping member 40 and to comprise an arcuate extension of the innermost arm 56 of first member 40. Alternatively, the depending flange could be provided to extend from virtually any portion of either the interior surface 96 of the first member 40 or the interior surface 88 of the second member 42. The depending flange should lie intermediate the first and second members 40, 42 in the interior space 94 with the depending flange in section extending from the interior surface of one of clamping members 40, 42 towards the interior surface of the other of clamping members 40, 42. With the binder in a closed position, a portion of the depending flange advantageously should lie proximate the interior surface of such other of clamping members 40, 42 in opposed relation thereto. Tensioning means, exemplified in the figures by a threaded T-bolt, coupling such portion of the depending flange to such other of clamping members 40, 42 may then be provided for activation to regulate the distance between such portion and the interior surface of such other of clamping members 40, 42 opposed thereto whereby the clamping members 40, 42 may be rotated relative to one another. Tension activating means, exemplified in the figures by threaded nut 82, advantageously are located on an exterior side surface of such one of members 40, 42 to activate the tensioning means. 
     Preferably a stop flange 98 extends radially inward from inner surface 78 of the first C-shaped member. Advantageously stop flange 98 is located at a circumferential location on surface 78 to lie intermediate extremities 68 and 72 on the second C-shaped member. As shown in FIG. 5, stop flange 98 will abut extremity 68 to prevent rotation of members 40, 42 past a fully open position. Similarly as seen in FIG. 4, stop flange 98 will effectively abut extremity 72 to prevent rotation past a fully closed position. 
     Stop flange 98 may be seen to extend radially inward but only to an extent that it does not protrude into the central aperture 74 in the second C-shaped member. Central aperture 74 may thus include a space completely circular in section. Cap 18 of the binder as shown in FIG. 7 is adapted to frictionally slide into aperture 74 at either end of the binder. When interior portion 100 of end cap 18 is inserted into aperture 74, the outer portion 102 comprises a longitudinal extension of the binder with a cylindrical surface 103 coaxial with axis 44. 
     Preferably, spring means are provided to bias the first and second member 40, 42 to an open position. Biasing spring 104 as shown in FIG. 6 has a coil 105 of a diameter sufficiently small to be slidably received inside central cylindrical aperture 74 in the second C-shaped member. Spring 104 also has two radial extensions one on each of its extremities extending radially from the coil. With the first and second members 40, 42 in a fully open position, the spring 104 is inserted into cylindrical apertures 74 with the two radial extensions 106, 108 located between one side of stop flange 98 and extremity 72 on the second inner arm 70 of the second C-shaped member. On rotating the first and second members 40, 42 towards the closed position, the stop flange 98 will engage one radial extension 106 while extremity 72 will engage the other radial extension 108 drawing them towards each other, winding the spring 104 and thereby developing a bias tending to urge the first and second members, 40, 42 towards an open position. 
     Reference is now made to FIGS. 8, 9 and 10 which show a second preferred form of a support structure according to this invention. Many elements of this second form have equivalent elements in the first form of the support structure shown in FIG. 1 and like reference number are used to indicate similar elements. 
     FIG. 8 schematically shows binder 10 suspended from support structure 12 with a first end 16 of the binder received in end support means 116 and a second end 132 remote therefrom. Elongate suspension means 26 extends from support structure 12 to the binder in this embodiment coupling to the binder at a location between first end 16 and the binders center of gravity marked as the upward arrow CG on FIG. 8. 
     As more specifically shown in FIGS. 9 and 10, the support structure generally indicated at 12 comprises a spacer or structural plate 110 for attachment to a wall 112 by fastening means such as screws 114. A number of spaced end receiving means generally indicated as 116 are provided at the lower end of plate 110. Each end receiving means 116 has a horizontally disposed cylindrical recess herein referred to as recess or recession 118 with interior surfaces including end wall 120 and cylindrrcal side walls 122. Recession 118 opens forwardly as a circular opening 20. 
     Recession 118 is a depth which is less than the length of the outer portion 102 on end cap 18 so that with cap 18 received in recession 118, end face 124 of cap 18 may abut against end wall 120. Recession 118 has a diameter whereby with cap 18 received therein, room is provided for rotation of binder 10 about axis formed at the interface of abuttment between the interior surfaces of recession 118 and the exterior surfaces of the outer portion 102 of cap 18, namely cylindrical surface 103 and end face 124. 
     The support structure includes an elongate suspension means 26, in this embodiment, being an integral rod 26 with a ball 126 at a first end 28 and a hook member 30 at its second end 32. Rod 26 is coupled via ball 126 at its first end 28 to a ball-socket means on the support structure generally indicated as 128 so as to permit rotation of the rod with respect to the ball-socket means 128. The hook 30 on the second end 32 of rod 26 has a cylindrical protrusion 130 which is adapted to pass into and out of opening 36 in the top surface of binder 10 and to be received within central cylindrical aperture 74 of the second C-shaped member of binder 10. Rod 26 is selected to have a length such that with end cap 18 received in recession 118, and hook 30 engaged inside aperture 74, the binder 10 will be suspended substantially horizontally. 
     Attachment and removal of binder 10 to support structure 12 is easily accomplished as now described. To hang binder 10 from the support structure, firstly, with all the weight of the binder being carried by the person inserting the binder, end cap 18 of binder 10 is slidably inserted into recession 118. Recession 118 prevents vertical downward movement of the first end 16 of the binder and accordingly by manually lifting merely at the second remote end 132 of the binder, a person inserting the binder may support it in a substantially horizontally position in cooperation with recession 118. This may typically be accomplished with one hand by the inserting person, thus leaving the other hand free. The other hand may be used to grasp rod 26 which in an unused position will hang vertically downward from ball-socket means 128. With rod 26 swung to a position above opening 36 by the other hand, the one hand may lift the remote end of binder 10 thus pivotting the binder upward about its first end 16. As is to be appreciated, with binder 10 rotated sufficiently upward about its first end, the cylindrical protrusion 130 of hook 30 may be allowed to clear the inner edge 134 of opening 36, and enter aperture 74. With hook 30 guided into place in aperture 74 by the other hand, the operators one hand permits binder 10 to rotate downward whereby cylindrical protrusion 130 becomes receivably engaged in aperture 74 and the binder is suspended horizontally from support structure 12. Removal of binder 10 from suspension is easily accomplished by rotating the second remote end 132 of binder 10 upwardly with one hand until hook 30 clears opening 36 and may be removed therefrom. Only then is the first end of binder 10 disconnected from recession 118 and the full weight of the binder 10 carried by the person removing the binder. 
     FIGS. 9 and 10 show a convenient method of mounting the recession 118 and ball-socket means 128 to the support structure. A plurality of modular end receiving means 116 containing recessions 118 are slidably received on a square bar 136 which is secured to plate 110 by fasteners 138. Similarly, a plurality of modular ball-socket means 128 are slidably received on a similar square bar 140 secured to plate 110 by fasteners 142. Each ball-socket means 128 has a front circular opening 144 which forms a seat to retain ball 126. Advantageously the ball-socket means may have a forward angled surface 148 above the ball-socket adapted to receive an indication tag to identify the binder to be hung therefrom. 
     The support structure of FIGS. 9 and 10 permit a suspended binder 10 to be swung from side to side to aid access to and removal of any binder hung between adjacent binders. Ball 126 and ball-socket means 128 couple rod 26 to the support structure so as to permit rotation of rod 26 thereabout. The freedom of rotation of rod 26 includes freedom to rotate about a vertical axis passing through the center of ball 126. The end cap 18 on the first end 16 of binder 10 is received in recession 118 so as to permit rotation of the binder about a vertical axis passing proximate first end 16. Recession 118 and end cap 18 are provided with complementary surfaces for abuttment whereby the first end of the binder will pivot about interfaces of abuttment between interior surfaces of recess 118 and exterior surfaces of cap 18. 
     With rod 26 free to rotate freely about a vertical axis passing through ball 126 and the binder 10 free to rotate about a vertical axis passing proximate its first end 16, it is to be seen that binder 10 when suspended as in FIG. 10 is free to be rotated side-to-side about a vertical axis passing proximate its first end 16. 
     In the embodiment shown in FIG. 1 using a flexible strap as the suspension means 26, the flexibility of strap 26 permits rotation of the strap about a vertical axis proximate its juncture with support structure 12. 
     Advantageously the binder and support structure provide for the self-centering of a suspended binder such that after rotation to one side or another a binder will automatically return to a suspended position extending perpendicularly outward from plate 110. This result is obtained in embodiments of FIG. 1, 9 and 10 by the interaction of the interior surfaces of recession 118 with the exterior surfaces of end cap 18. With hook 30 coupled to the binder on the side of the center of gravity of binder 10 closest to first end 16, the weight of binder 10 provides a force moment urging binder 10 to rotate clockwise about the hook as seen in FIG. 8 urging end cap 18 upwardly into recession 118. With the binder extending perpendicularly outward from plate 110, the axis of the cylindrical surface 122 of recess 118 and the axis 44 will lie in the same vertical plane. As the end cap 18 is of a diameter less than the diameter of recession 118, the end cap may assume the highest possible position in the central top portion of recession 118 with contact between surfaces taking place at a single point in the vertical upward center of recession 118. The relative diameters of recession 118 and cap 18 are chosen such that as binder 10 is progressively rotated towards one side about a vertical axis, the sectional area of the end cap 18 as seen in a plane normal to the axis of recession 118 will progressively increase. The exterior surface 103 of a cap 18 so rotated will no longer be able to retain single point contact with cylindrical surface 122 of recession 118 at its top center point. Cylindrical surface 103 of a cap 18 will come to contact the cylindrical surfaces 122 of recession 118 at two points and effectively, by rotation of binder 10, cam end cap 18 to a lower position in recession 118 against a force moments tending to urge the end cap 18 upwardly. Accordingly, once the binder has been rotated to one side, binder 10 will in response to this force moment, attempt to return to the lowest energy state with the end cap 18 in the highest point in recession 18. 
     The self-centering has been described with binder 10 coupled to rod 26 on the side of the center of gravity closest to the first end of the binder. If binder 10 were coupled to rod 26 on the remote side of the center of gravity from the first end, a similar self-centering would occur with the end cap 18 attempting to assume the lowest central portion in the cylindrical recession 118. 
     Another method by which self-centering may be accomplished is to have the center of ball 126 located farther forward from vertical plate 110 than the effective vertical axis about which the first end of binder 10 rotates in recession 118. In such an arrangement, the second end 132 of binder 10 will on rotation of the binder side-to-side describe an upwardly extending arc, the lowest point of which arc will coincide with the position of the second end 132 when binder 10 is hung perpendicular to plate 110. In such an arrangement, the binder 10 will tend to assume the lowest energy position, the low point in the arc whereby returning to a centered position. 
     In the embodiment shown in FIG. 1 with a flexible strap 26, made for example, of DACRON* synthetic polyester fiber, sideway rotation of binder 10 will distort the strap such that the strap, will tend to return the binder to a centered position. 
    
     The binders are advantageously provided with rotation permitting means adapting the binders to be coupled to the support structure for suspension from the support structure substantially free from restraint from rotation of the device as a unitary body about axis 44. As has been seen, first and second clamping members 40, 42 are hinged together to rotate about axis 44. Cap 18 is co-axially received in central cylindrical apertures 74 inside the second C-shaped member of second clamping member 42 so that the exterior surface 103 of end cap 18 is coaxial with axis 44. In the event binder 10 having end caps 18 received in each of its ends 16 and 132, were to be horizontally suspended between two suitably spaced, parallel, horizontal bars (not shown) with a first end cap 18 resting on a first bar and a second end cap 18 resting on a second bar, then binder 10 would be free to rotate about axis 44 as a unitary body. The binder 10 would then, with uniform, flexible sheets grasped therein, be free to rotate about axis 44 so as assume a position with the sheets extending vertically downward between the first and second members 40, 42. 
     A similar &#34;free-rotation&#34; suspension, may be achieved by the manner in which cylindrical protrusion 130 of hook 30 on bar 26 is received within central cylindrical aperture 74 inside the binder. As has been seen, aperture 74 has an inner cylindrical surface co-axial with axis 44. With the coefficient of friction between cylindrical protrusion 130 and the inner cylindrical surface of aperture 74 being minimal, advantageously a binder 10 when suspended as in FIG. 10 will be free to rotate about axis 44 to adopt a free-hanging position having regard to the nature of the sheet material grasped therein. 
     Opening 36 provides communication through members 40, 42 from the exterior of binder 10 into interior aperture 74. As to be appreciated from FIG. 10, opening 36 is formed by the overlap of an opening in first C-shaped member of member 40 and an opening in second C-shaped member of member 42. The circumferential extension of opening 36 about axis 44, firstly, should be sufficient that cylindrical protrusion 130 of hook 30 may pass through opening 36. Secondly, for advantageous &#34;free-rotation&#34; suspension, the circumferential extent of opening 36 must be sufficient that hook 30 does not contact the side walls of aperture 74 so as to prevent free rotation of the binder about axis 44. If a binder 10 grasping sheet material is suspended as shown in FIG. 10 and a vertical plane were drawn through axis 44, in section, the point at which this plane passes through the circumference of the first and second C-shaped members will vary depending upon the number of sheets grasped by the binder (i.e. the extent to which first member 40 and second member 42 have been rotated relative to one another). The two openings through the first and second C-shaped members are preferably to be of a size that for any number of sheets grasped by the binder, the openings overlap to define opening 36 with sufficient circumferential extension. 
     Many other means for permitting free rotation of binder 10 about axis 44, when coupled to the support structure 12, may occur to a person skilled in the art which effectively serve to hinge binder 10 to support structure 12 permitting free rotation therebetween thereabout axis 44. 
     Many different coupling systems may be adopted to couple the first end 16 of binder 10 to the support structure. Preferably the coupling system will at least provide means to prevent substantial vertically downward displacement of the first end 16 of the binder with respect to the support means. Vertical support of the first end 16 by the support structure facilitates the manual operation of coupling the binder 10 to the support structure as discussed above. In the embodiment of FIG. 10 the abuttment of the lower surfaces of recession 118 with the lower surfaces of end cap 18 prevents vertical displacement of end 16 with respect to support structure 12. 
     Preferably the coupling system between the first end of the binder and the support structure will also permit at least rotation of the first end of the binder about a vertical axis passing proximate the first end of the binder. This will permit side-to-side rotation of the binder. In the embodiment of FIG. 10, as discussed above, abuttment of corresponding surfaces of recession 118 and end cap 18 provide interfaces about which the binder may rotate. 
     Advantageously the coupling system between the first end of the binder and the support structure will provide means to prevent substantial horizontal movement of first end of the binder with respect to the support structure. In the embodiment of FIG. 10, this is accomplished by side walls of recession 118 abutting against side surfaces of end cap 118. Advantageously, the coupling system will also provide means to permit rotation of the first end 16 of the binder about a horizontal axis normal to the longitudinal of the binder. This is also provided in the embodiment of FIG. 10 by the abuttment of corresponding surfaces of recession 118 and end cap 18 providing interfaces about which the binder 10 may rotate. Such rotation is advantageous when engaging hook 30 within aperture 34 in the top of the binder, however, devices other than hook 30 may be provided so as to permit coupling without requiring binder 10 to be rotated about a horizontal axis. 
     The coupling system between the first end of the binder and the support structure is seen in the preferred embodiments to inherently have restraining means to restrain the first end of the binder within end support means in opposition to force moments acting on the binder due to its suspension via rod 26, which force moments in the absence of such restraining means would act to substantially move the first end of the binder with respect to the end support means. For example, in the suspension structure of FIG. 10, the upper most surface of recession 118 may be seen to act as a reaction surface abutting on surface 103 of end cap 18 and retaining end cap 18 within recession 118. This is because the suspension of binder 10 by rod 26 coupled to opening 36 between the first end 16 and the center of gravity of the binder creates a force moment acting to rotate the first end upward about aperture 74. Similarly, end wall 120 of recession 118 acts as a reaction surface abutting on end face 124 of cap 18 to restrain cap 18 from movement further into recession 118. This is because the suspension of binder 10 by rod 26 with rod 26 hinged at ball-socket means 128 creates a force moment acting to rotate the binder about ball-socket 128 into recession 118. PG,28 
     In the embodiment shown in FIG. 10, the lower half of recession 118 could be removed to leave a U-shaped downward opening recession which would retain the first end of the binder therein. However, such a downward opening U-shape would have the disadvantage of not providing means to prevent vertically downward movement of the first end 16 advantageous when attempting to manually couple binder 10 to support structure 12. 
     In the event the opening 36 is moved to a point beyond the center of gravity from first end 16, the binder would have a tendency to rotate its first end downward and the upper half of recession 118 could satisfactorily be removed leaving an upward opening U-shaped recession. 
     FIG. 11 shows a third form of the support structure according to this application specifically adapted to suspend known three piece binder 10 such as those shown in Canadian Pat. No. 671,574. In this embodiment the end receiving means comprises the simple horizontally disposed rod 154 and the support means comprising a DACRON strap 26 similar to that shown in FIG. 1. The strap has a squared end loop 172 which is received in a bracket 174 on the top of the binder on the side of the center of gravity of the binder remote from its first end 16. Each end of the binder 10 has an extension 156 of the inverted channel. The end extension 156 at a first end rests on the top of rod 154. End faces 158 of the two clamping members 160 at the first end abut the side of the rod. While not necessary, means not shown could be provided to prevent substantial horizontal movement of the first end of the binder along rod 154. Preferably, the squared end caps on the binder may have a marginal downward extension or lip 164 at their extremities so that in the event the binder is rotated a substantial extent to one side, this downward extending lip will prevent rotation of the binder to an extent that it may become disengaged from abuttment with the top surface of rod 154. The embodiment shown in FIG. 11 may be swung from side-to-side. It may be seen to be easy to mount with the first end 16 received on top of the rod and the binder rotated vertically upward until loop 172 can be received in bracket 174. 
     In the preferred embodiments shown in FIG. 1 and 10 the coupling system between the first end 16 of the binder and the support structure has comprised in effect a ball-in-socket type arrangement with end cap 18 analogous to a ball and the end support means on the support structure analogous to a socket. An obvious adaptation of this preferred arrangement is to provide a fixed ball member, as for example a ball on a short rod fixed to and extending outward from the support structure in cooperation with, for example, a recession in one end of the binder to receive the ball. Further coupling systems according to this invention include as an end support means the simple horizontal rod as shown in FIG. 11. 
     Although this disclosure describes and illustrates preferred embodiments of the invention, it is to be understood that the invention is not limited to these particular embodiments. Many variations and modifications will now occur to those skilled in the art. For a definition of the invention reference is made to the appended claims.