CA1185864A - Two piece clamp binder - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
A two piece binder is disclosed having substantially symmetrical clamping members hinged together along first edges thereof so as to be rotated to grasp sheet material 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. The two piece binder disclosed advantageously provides a symmetric two piece binder with a side mounted tensioning wing nut.

Description

us 1 This application is related to the applicant's co-pending Canadian patent application Serial Number 412,471 filed September 29, 1982, BACKGROUND OF THE INTO I ON
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 winders as well as to a new support structure for horizontally suspending new and known clamp binders, In vertical filing systems, clamp winders are used to bind large sheets of material including engineering and architectural plans and drawings, maps, specifications, and blue-prints, The clamp binder grasps the sheet-like material along an edge thereof to frictionally hold the material in the winder, 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 ox examination, handling and storage of sheet material, I Known binders include "three piece binders" such as characterized in Canadian patent 604,233 to Schneider and United States patents 3,891,093 and 3,308,831 to Putter and Kritske, respectively, These three piece binders include an in-vented channel member carrying therein a pair of clamping members.
The upper edges of the clamping members are hinged in-side 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 to!_ 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, 5~6~

1 Some "two piece binders" have also been proposed as in US. patent 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 there between. Two piece binders proposed to date have not So I
f, proved sty Roy 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 I 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 inter-lores 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 hying inserted.
puke out three ~i~rbinders are arranged 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 r horizontal bars across which a binder may be suspended with one end of the binder sup-ported on one bar and another end of the binder supported by the other bar. Such a system is for example referred to in us lo patent 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 listing 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 patent 671,574 to Schneider and US. patent 3,211,892 to rarities. 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 I 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 blinder 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 en-tire weight of the binder must not only be lifted but must 5!3~

1 also be carefully manipulated. Prior art vertical filing systems thus fail to provide a system in which access to and no-moral or replacement of the binder can be carried out quickly and with a minimum ox effort.
Another disadvantage ox 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 automatic ally 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 hinted 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 disk I advantageously 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, no-t only must the weight of the binder be supported but the no-rational force must be overcome to achieve a proper orientation of the binder for coupling or disengagement.
SYRIA OF THE INVENTION
A first object of the present invention is to at least partially overcome the disadvantages ox the prior art by providing a two piece binder having substantially symmetrical clamping 5i86~

1 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 firs-t 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 there between, 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 sun-face 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 there-to, 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 1 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 construe -Tony is provided for a two piece binder. The two principal mom-biers 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 rota-live rotation of the members about the hinge with respect teach other. Preferably the hinge is provided by one clamping mom-bier 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 there-between or brought sufficiently close together to effectively I grasp the sheet material there between.
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 I
1 inner surface of the second clamping member when the binder is in a closed position. tensioning device such as a threaded bolt coupled at one end to the depending flange may extend prom 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 or the exterior snide of the second clamping member, turning the winch nut Wylie rotate -the firs-t and second clamping members with respect to one another. The firs-t 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 I 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 there-from 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 I material grasped in the binder may hang vertically from the binder, ~L~85~

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 Eros 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 an 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 sup-port means which is fixedly secured to the support structure and I
1 adapted to receive a first end of a binder. An elongate suspend soon means is provided with one of its ends coupled to the support structure a-t 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 sub-staunchly horizontal position. Preferably the binder is suspend dyed 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 sup-pension 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 indoor 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.

1 Another object of the present invention is to at least partially overcome the disadvantages of -the prior art by pro-voiding 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 lo structure so as to permit the device to rotate at least margin-ally 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 hoiræontal axis passing through the binder. To permit a suspended binder to assume an advantageous position in which these rotational forces are mini-mixed, 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 espy-Shelley 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 1 appear Eros the following description taken together with the accompanying drawings in which:
Figure 1 is a perspective view of a new binder according to the present invention shown suspended by one form ox a new support structure according to the present invention.
Figure 2 is a cross sectional view of a eeriest clamping member owe a binder.
Figure 3 is a cross sectional view of a second clamping member of a binder.
Figure 4 is a cross sectional end view of a binder according to the present invention in a fully closed position.
Figure 5 is a cross sectional end view similar to that of Figure 4 but with the binder in an open position.
Figure 6 is a pictorial view of a biasing spring.
Figure 7 is a pictorial view of an end cap.
Figure is a schematic side view of a binder suspended from a second form of a new support structure according to the invention.
Figure 9 is a front view of the second form of a new support structure according to the invention showing one binder suspended therefrom.
Figure 10, located on the sheet with Figure 8, is a partial cross sectional view of Figure along axis I-I'.
Figure 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 patent 671,574.
DESCRIPTION OF Toll PREFERRED EMBODIMENTS
. _ , Reference is made first to Figure 1 which shows a vertical filing system including elongate binders 10 suspended 1 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 (snot 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 lo 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 Figure 1, hook 30 has a cylindrical pro-section which extends into a cylindrical interior aperture go I
Jo inside binder 10, with ~4ss 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.
Figures 2 to 5 clearly show the features of a pro-furred embodiment of a new two piece binder according to the present invention. The binder comprises two major pieces, a first ilk clamping member shown in section in Figure 2 and a second jaw-like clamping member 42 shown separately in section in Figure 3. Each comprises a substantially continuous, elongate member, preferably extruded from aluminum.
As shown most clearly in Figures 4 and 5, the first and second members 40, 42 may be hinged together a-t -their upper edges 86~

1 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 Figure 2, the first clamping member bifurcates at point 50 into two separate portions. The firs-t 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 circumferen-trial path around assay 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 Figure 3, the second member 42 is similarly divided a-t point 64 into two arms, a first outermost arm 66 extending from point 64 to extremity 68 and a second arm I 70 extending from pullout 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 has, central aperture 74. The second C-shaped member also 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 ho the first C-shaped member whereby the second C-shaped member of the second member 42 is, for assembly of -the binder, long-tudinally slid able into the first C-shaped member of the first member 40. Inner cylindrical surface 78 on the first 1 Shopped 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 firs-t 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 I
leans are provided on the binder to rotate the first and second member with respect to one another about axis 44.
I 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 con-junction 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 Figure 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. Hoyle is provided through second member 42 passing from the interior surfs 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 mender 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 I of T-bolt 80 so as to permit angular movement of post I with respect to the first and second clamping members 40, 42 as is to be appreciated to take Lucy in relative rotation ox members 40, 42 between the I

Lowe closed position shown in Figure 4 and the open position shown in Figure 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 Figure 5 to a fully closed position as shown in Figure I. In a fully open position, sheet material may be inserted between the lower second edges 90, 92 of clamping members 40, 42 respectively.
10 Roy 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 there between.
so shown in Figures 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 down-warmly from respective points 50, 64 to respective second edges 90, 92 symmetrically about opposite sides of a plane passing through axis 44.
.20 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 Figure 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 off the second member with portions of depending flange 62 lying proximate to and in opposing relation to the inner surface off 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 I
1 from first clamping member 40 and to comprise an arcuate extension of the innermost arm 56 of firs-t member 40. Alternatively, the depending flange could be provided -to extend from virtually any portion of ether the interior surface 96 of the first member 40 or the interior surface By 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, I towards the interior Sirius 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 there-to. 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 - advantageously are located on an exterior side surface of such one of members 40, 4-2 to activate the tensioning means.
Preferably a stop flange 98 extends radially inward . from inner surface 78 of the first C-shaped member. Advent-easily 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 Figure 5, stop flange 98 will abut extremity 68 to prevent rotation of members 40, 42 past a fully open position. Similarly as seen in Figure 4, stop flange I 98 will effectively abut extremity 72 -to prevent rotation past a fully closed position.

I
1 Stop flange 98 may be seen to extend radially inward but only -to an extent that i-t 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 I owe the binder as shown in Figure 7 is adapted to frictionally slide in-to aperture 74 at either end of the binder.
Whorl 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.

lo Preferably, spring means are provided to bias the first and second member 40, 42 to an open position. Biasing spring 104 as shown in Figure 6 has a coil 105 of a diameter sufficiently small to be slid ably 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 ln4 is inserted into cylindrical aver-lures 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 firs-t and second members, 40, 42 towards an open position.
reference is now made to Figures 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 I elements in the -first form of the support structure shown in I

1 Figure 1 and like reference number are used to indicate similar elements.
Figure 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 ion this embodiment coupling to the binder at a location between first end 16 and the bounds center of gravity marked as the upward arrow COG on Fig. 8.
As more specifically shown in Figures 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 118 with interior surfaces including end wall 120 and cylindrical 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 interface of ahuttment 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 12~.
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 so 1 end 32. Rod 26 its 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 owe 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 Lund 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 slid ably 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 hall 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 pivoting 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 13~ of opening 36, and enter aperture I With hook 30 1 guided into place in aperture I by the other hand, the operators one hand permits binder 10 to rotate downward whereby cylindrical protrusion 130 becomes receivable engaged in aperture 74 and the binder it suspended horizontally from support structure 12.
Removal of binder 10 from suspension is easily accomplished by rotatincJ the second remote end 132 of binder 10 upwardly with one hand until hook 30 clears opening 36 and may be removed there-from. 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.
Figures 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 slid ably 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 slid ably 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 Figures 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 trough the center of ball 126. The end cap 18 on -the first end 16 of binder 10 is received in 136~
1 recession 118 so as to permit rotation of the binder about a vertical axis passing proximate first end 16. secession 118 and end cap 18 are provided with complementary surfaces for abutment whereby the first end of the binder will pivot about interfaces of abutment between interior surfaces owe recess 118 and exterior surfaces of cap 18.
Wyeth 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 Figure 10 is free to be rotated side-to-side about a vertical axis passing proximate its first end 16.
In the embodiment shown in Figure 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 pro-vise for the self-centering of a suspended binder such that after rotation to one side or another a binder will automatically no-turn to a suspended position extending perpendicularly outward from plate loathes result is obtained in embodiments of figure 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 Figure 8 urging end cap 18 upwardly into feces-soon 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 1 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 It was 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 Solon-Dracula 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.
I The selE-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 I at-tempting to assume the lowest central portion in the cylindrical recession 118.
Another method by which self-centering may be accom-polished 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 51!36~

1 extending arc, the lowest point of which arc will coincide with the position of the second end 132 when binder 10 is hung per-pendicular 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 Figure 1 with a flexible strap 26, made for example, of DACRON* synthetic polyester fiber, sideways 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 sup-port structure for suspension from the support structure sub-staunchly free from restrain-t from rotation of the device as a unitary body about axis 44. As has been seen, first and second clamping members 40 t 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 owe its ends 16 and 132, were to be Herr zontally suspended between two suitably spaced, parallel, horizontal bars (not shown) with a first end cap 18 resting on a firs-t 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 eeriest and second members 40, 42.

A similar free rotation suspension, may be achieved by the manner in which cylindrical protrusion 130 of hook 30 on *Trade Mark -23-1 bar 26 is received within central cylindrical aperture I inside the binder. As has been seen, aperture 74 has an inner Solon-Dracula 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 Figure 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 lo I 42 from the exterior of binder 10 into interior aperture I
As to be appreciated from Figure 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 Howe 30 may pass through opening 36. Secondly, for advantageous "free-rotation" suspension, the circumferential extent of opening 36 must be sufficient that hook 30 does not contact the side I
walls of aperture so as to prevent free rotation of the binder I about axis 44. If a binder 10 grasping sheet material is sup-penned as shown in Figure 10 and a vertical plane were drawn through axis I 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 I 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 Wyeth sufficient circumferential extension.

I

58~

1 Many other means for permitting free rotation of binder 10 about axis I 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 -there between thereabout axis I
any different coupling systems may he adopted -to couple the first end 16 of binder 10 to the support structure. Pro-Eerably the coupling system will at least provide means to pro-vent substantial vertically downward displacement of the first I 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 Figure 10 the ahuttment 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 Figure 10, as discussed above, abutment 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 Figure 10, this is accomplished by side walls of recession 118 abutting against side surfaces of end cap 118. Advantageously, ~L851~

1 the coupling siesta 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 hinder. This is also provided in the embodiment of Figure 10 by -the abutment of corresponding surfaces of recession 118 and end cap 18 providing interfaces about which the binder 10 may rotate. Such rotation is ad-I
voltages when engaging hook 30 within aperture 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 firs-t end 16 and the center of gravity of the binder creates a force moment acting to rotate the first end upward about aperture . 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.

1 In the embodiment shown in Figure 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.
Figure 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 patent 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 Figure 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 fist 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 *Trade Mark -27-1 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 abutment with the top surface of rod 15~. The embodiment shown in Figure l] may be swung Eros side-tweezed. It may be seen to be easy to mount with thy first end 16 received on top of the rod and the binder rotated Yen-ti.cally upward until loop 172 can be received in bracket 17~.
In the preferred embodiments shown in Figure 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 preread arrange-mint 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 relieve the ball.. Further coupling systems according to this invention include as an end support I means the simple horizontal rod as shown in Figure 11.
though 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.

Claims (30)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. 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, said 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 said sheet material therein to a closed position in which second edges are brought sufficiently close together to grasp the sheet material therebetween, said clamping members being hinged together with their angle sections opening towards each other to define an interior space bordered by interior surfaces of said first and second members, a depending flange on said first clamping member lying intermediate the first member and second member in said interior space, said flange, in section, extending from the interior surface of said first member towards the interior sur-face of said second member whereby with the device in said closed position a portion of said flange lies proximate the interior surface of the second member in opposed relation thereto, tensioning means coupling said portion of said flange to said second member for activation to regulate the distance between said portion and the interior surface of the second member opposed thereto for relative rotation of said first and second members between said open and closed positions,
1. Claim 1 continued ...
   
   tension activating means located on an exterior side surface of said second member and coupled to the tension means for activating the tension means.
2. 2. A clamping device as claimed in claim 1 wherein said first and second clamping members being hinged together by:
   a first substantially C-shaped section member provided on the first edge of said first clamping member defining therein a longitudinally extending groove of part-circle section of a first diameter, and a substantially circular section on the first edge of said second clamping member of a second diameter marginally smaller than the first diameter, said circular section longitudinally slidably receivable in said groove of the C-shaped section member to be rotatable therein between said open and closed positions, said groove of said C-shaped section member encircling said circular section to an extent greater than 180° to prevent radial removal therefrom.
3. 3. A clamping device as claimed in claim 2 wherein said depending flange extends from an extremity of said C-shaped section member within said interior space.
4. 4. A clamping device as claimed in claim 1 or 2 wherein said portion of said depending flange is of C-shaped section opening away from the opposing interior surface of the second clamping member.
   
   5. A clamping device as claimed in claim 3 wherein said portion of said depending flange is of C-shaped section opening
5. Claim 5 continued ...
   
   away from the opposing interior surface of the second clamping member.
6. 6. A clamping device as claimed in claim 5 wherein said tensioning means comprises a T-shaped bolt with the top of the received in said C-shaped section of said portion of the depending flange, the portion having a first hole therethrough in said C-shaped section in alignment with a second hole in the opposing interior surface of said second clamping member, the center post of the T-bolt extending from the C-shaped section of the portion through the first hole and through the second hole to outside the second clamping member, said tension activating device comprising a wing nut threadably received on the center post of the T-bolt.
7. 7. A clamping device as claimed in claim 2 wherein said C-shaped section member comprises two arcuate arms extending from the angle section with a first of said arms lying in the interior space, said depending flange comprising an extension from an extremity of said first arm.
8. 8. A clamping device as claimed in claim 7 wherein said extension comprising the depending flange comprises an arcuate extension of C-shaped section opening away from the opposed in-terior surface of said second clamping member.
9. 9. A clamping device as claimed in claim 8 wherein said C-shaped section member and said arcuate extension of C-shaped section together comprise in section a substantially S-shape,
10. 10. A clamping device as claimed in claim 1 further com-prises spring means acting on the first and second clamping members to bias them to an open position.
11. 11. A clamping device as claimed in claim 2 wherein said substantially circular section on the first edge of said second clamping member comprises a second C-shaped section member comprising two arcuate arms.
12. 12. A clamping device as claimed in claim 2 wherein said substantially circular section on the first edge of said second clamping member comprises a second C-shaped section member defining an aperture of substantially circular section therein.
13. 13. A clamping device as claimed in claim 12 including an end extension member slidably receivable in said aperture of circular section at a longitudinal end of said second clamping member.
14. 14. A clamping device as claimed in claim 13 wherein said end extension member is of cylindrical section.
15. 15. A clamping device as claimed in claim 12 further com-prising an end extension member comprising a first cylindrical segment frictionally held in said aperture of circular section at one longitudinal end of said second clamping member and a second cylindrical segment extending beyond said end of the second clamping member, said first and second cylindrical sections being co-axial with each other and with an axis about which said first and second clamping members are hinged to rotate with respect to each other.
    
    16. A clamping device as claimed in claims 12 or 15 wherein
16. Claim 16 continued ...
    a first opening is provided radially through the first C-shaped section member, a second opening is provided radially through the second C-shaped section member, whereby with the first and second clamping members in longitudinal alignment, the first and second openings align and provide for access from a top of an assembled binder into the aperture of circular section throughout all open and closed positions of the binder.
17. 17. A clamping device as claimed in claim 12 wherein a longitudinal, radially inward extending stop flange is provided on an interior surface of said groove positioned at a circum-ferential location to abut an extremity of one arm of the second C-shaped section member thereby limiting the extent of rotation of said first and second clamping members with respect to one another.
18. 18. A clamping device as claimed in claim 17 wherein spring means are received in said aperture of circular section,with two radial projections extending from said aperture to both lie between said extremity of said one arm of said second C-shaped section member and said stop flange, one projection abutting said extremity and the other said stop flange whereby said spring means biases the extremity circumferentially away from the stop flange thereby biasing the first and second clamping members towards the open position.
    
    19. A clamping device as claimed in claim 1 in combination with a support structure for suspending the device in a substan-tially horizontal position with sheet material grasped in the device to hang vertically downward therefrom the device being
19. Claim 19 continued ...
    
    detachably supported from the support structure with the device substantially free to rotate as a unitary body about the axis through which the first and second clamping members are hinged for rotation with respect to one another.
20. 20. A clamping device as claimed in claim 19 wherein the device includes cylindrical surfaces co-axial with the axis and the device is substantially supported from the structure by contact therebetween on said cylindrical surfaces.
21. 21. A clamping device as claimed in claim 1 wherein said device is adapted for substantially horizontal suspension from a support structure with the sheet material grasped in the clamping device to hang vertically downward therefrom, said device including rotation permitting means on said device whereby with said device supported by the support structure said rotation permitting means permitting rotation of the device as a unitary body about the axis through which said first and second clamping members are hinged for rotation with respect to one another.
    
    22, 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;
    said clamping members hinged together along their first edges to pivot relative to one another from an open position in which their second edges are sufficiently spaced to permit placement of said sheet material therein to a closed position in which their second edges are brought sufficiently close together to grasp said sheet material therebetween;
    said clamping members being hinged together with their angle sections opening towards each other to define an interior space bordered by interior surfaces of said first and second clamping members;
    tensioning means extending through said interior space coupling said first clamping member to said second clamping member for activation to regulate the distance therebetween for relative pivoting of said first and second clamping members between said open and closed positions;
    tension activating means located on an exterior surface of one of said first and second clamping members and coupled to the tensioning means for activating the tensioning means;
    said first and second clamping members being hinged together by:
22. Claim 22 continued a first substantially C-shaped section member provided on the first edge of said first clamping member defining therein a longitudinally extending groove of part-circle section, a second substantially C-shaped section member on the first edge of said second clamping member defining an aperture of substantially circular section therein; said second C-shaped section member longitudinally slidably receivable in said groove of the first C-shaped section member to be pivotable therein between said openand closed positions;
    a longitudinal, radially inward extending stop flange provided on an interior surface of said groove positioned at a circumferential location to abut an extremity of one arm of the second C-shaped section member thereby limiting the extent of pivoting of said first and second clamping members with respect to one another;
    spring means received in said aperture of circular section, two radial projections on said spring means extending from said aperture to both lie between said extremity of said one arm of said second C-shaped section member and said stop flange, one projection abutting said extremity and the other projection abutting said stop flange whereby said spring means biases the extremity circumferentially away from the stop flange thereby biasing the first and second clamping members towards the open position,
23. 23. A clamping device as claimed in claim 22 further comprising:
    a depending flange on said first clamping member lying intermediate the first clamping member and second clamping member in said interior space, said depending flange in section extending from the interior surface of said first clamping member towards the interior surface of said second clamping member whereby with the device in said closed position a portion of said depending flange lies proximate the interior surface of the second clamping member in opposed relation thereto;
    said tensioning means coupling said portion of said depending flange to said second clamping member for activation to regulate the distance between said portion of said depending flange and the interior surface of the second clamping member opposed thereto for relative pivoting of said first and second clamping members between said open and closed positions; and wherein said groove of said first C-shaped section member encircling said second C-shaped section member to an extent greater than 180° to prevent radial removal therefrom.
    24. A clamping device to grasp sheet material along an edge thereof in combination with a support structure for suspending the device in a substantially horizontal position with sheet material grasped in the device to hang vertically downward therefrom, the clamping device comprising:
    first and second continuous, elongate jaw-like clamping members of angle section between first and second longitudinal edges thereof, said clamping members hinged together along their first edges to pivot relative to one another about an axis for movement from an open position in which their second edges Claim 24 continued are sufficiently spaced to permit placement of said sheet material therein to a closed position in which their second edges are brought sufficiently close together to grasp said sheet material therebetween, said clamping members being hinged together with their angle sections opening towards each other to define an interior space bordered by interior surfaces of said first and second clamping members, tensioning means extending through said interior space coupling said first clamping member to said second clamping member for activation to regulate the distance therebetween for relative pivoting of said first and second clamping members between said open and closed positions, tension activating means located on an exterior surface of one of said first and second clamping members and coupled to the tensioning means for activating the tensioning means, said first and second clamping members being hinged together by:
    a first substantially C-shaped section member pro-vided on the first edge of said first clamping member defining therein a longitudinally extending groove of part-circle section of a first diameter, and a second part-cylinder member on the first edge of said second clamping member having a part-cylindrical exterior surface of a second diameter marginally smaller than the first diameter, said second part-cylinder member defining an aperture of substantially circular section therein
24. Claim 24 continued coaxial with said axis; said second part-cylinder member longitudinally slidably receivable in said groove of the first C-shaped section member to be pivotable therein about said axis between said open and closed positions;
    a first opening provided radially through the first C-shaped section member;
    a second opening provided radially through the the second part-cylinder member;
    whereby with the first and second clamping members in longitudinal alignment, the first and second openings align and provide for access from a top of an assembled device into the aperture of circular section throughout all open and closed positions;
    said clamping device being detachably supported from the support structure with the clamping device substantially free to pivot as a unitary body about said axis through which the first and second clamping members are hinged for pivoting with respect to one another;
    pivoting permitting means coupling the support structure to the device and permitting pivoting of the device as a unitary body about said axis, said pivoting permitting means passing through said first and second openings and contacting interior surfaces of said aperture proximate said first and second openings.
25. 25. The combination of claim 24 wherein said pivoting permitting means comprising a hook-like member to extend through said first and second openings and locate a protrusion of part-circular section within said aperture.
    
    26. A combination of:
    A: a substantially symmetrical 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, said clamping members hinged together along their first edges to pivot relative to one another about an axis for movement 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, on pivoting of the clamping members about said axis each clamping member assuming a position symmetrical with respect to the other clamping member about a plane of symmetry passing through said axis and intermediate the second edges of the clamping members;
    said clamping members being hinged together with their angle sections opening towards each other to define an interior space bordered by interior surfaces of said first and second clamping members;
    tensioning means extending through said interior space coupling said first clamping member to said second clamping member for activation to regulate the distance therebetween for relative pivoting of said first and second clamping members between said open and closed positions;
26. Claim 26 continued tension activating means located on an exterior surface of one of said first and second members and coupled to the tensioning means for activating the tensioning means;
    and B: a support structure for suspending the clamping device in a substantially horizontal position with the clamping device detachably supported from the support structure and with the clamping device substantially free to pivot as a unitary body about said axis, whereby with said clamping device suspended from said support structure free to pivot about said axis and with any thickness of planar sheet material grasped in the clamping device, the clamping device assuming an orientation with the sheet material hanging vertically downward parallel to said plane of symmetry.
    27. The combination claimed in claim 26 wherein said first and second clamping members being hinged together by:
    a first substantially C-shaped section member pro-vided on the first edge of said first clamping member defining therein a longitudinally extending groove of part-circle section of a first diameter, and a second part-cylinder member on the first edge of said second clamping member having a part-cylindrical exterior surface of a second diameter marginally smaller than the first diameter, said second part-cylinder member being longitudinally slidably receivable in said groove
27. Claim 27 continued of the first C-shaped section member to be pivotable therein about said axis between said open and closed positions.
28. 28, The combination claimed in claim 27 including support surfaces on said device co-axial with said axis, and the device being supported from the structure free to pivot about said axis by contact of said support surfaces with surfaces of said support structure.
29. 29. The combination claimed in claim 28 wherein said second part-cylinder member defining an aperture of substantially circular section therein coaxial with said axis, an end extension member slidably receivable in said aperture at a longitudinal end of said second clamping member, said end extension member having a segment with surfaces coaxial with said axis extending beyond said end of the second clamping member to contact surfaces of said support structure and permit pivoting of said device about said axis, a first opening provided radially through the first C-shaped section member, and a second opening provided radially through the second part-cylinder member, whereby with the first and second clamping members in longitudinal alignment, the first and second openings align and provide for access to said aperture from the top of an assembled device throughout all open and closed positions of the device, a hook-like member of said support structure passing through said first and second openings to contact interior surfaces of said aperture and permit pivoting of said device about said axis.
30. 30, 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;
    said clamping members hinged together along their first edges to pivot relative to one another about an axis for movement from an open position in which their second edges are sufficiently spaced to permit placement of said sheet material therein to a closed position in which their second edges are brought sufficiently close together to grasp said sheet material therebetween;
    said clamping members being hinged together with their angle sections opening towards each other to define an interior space bordered by interior surfaces of said first and second clamping members;
    said first and second clamping members being hinged together by:
    a first substantially C-shaped section member provided on the first edge of said first clamping member defining therein a longitudinally extending groove of part-circle section of a first diameter; and a second part-cylinder member on the first edge of said second clamping member having a part-cylindrical exterior surface of a second diameter marginally smaller than the first diameter, Claim 30 continued said second part-cylinder member being longitudinally slidably received in said groove of the first C-shaped section member to be pivotable therein about said axis between said open and closed positions, a depending flange extending, from an extremity of said first C-shaped section member within said interior space, into said interior space in a substantially radial direction with respect to said axis, with the clamping device in said closed position said flange lying proximate an interior surface of said second clamping member in opposed relation to a hole passing through said second clamping member, an elongate bolt member coupled to said flange to extend substantially normal to said flange through said hole for activation by tension activating means on an external surface of said second member to regulate the distance between said flange and the second member for relative pivoting of said first and second members between said open and closed positions.