Abstract:
The invention relates to a device for holding sheets in a binder which form a folded stack, comprising a holding element ( 3 ) connected to the spine ( 2 ) of the binder ( 1 ). According to the invention, the holding element ( 3 ) engages behind the innermost sheet of the stack ( 4 ) at its fold ( 9 ).

Description:
BACKGROUND OF THE INVENTION 
     The invention concerns a device for holding sheets that form a folded stack in a binder, with a holding element connected with the spine of the binder. 
     WO 01/89859 A1 discloses a sheet binding system in which a folded stack of sheets is joined with a retaining rod that extends along the outside of the fold of the stack. This retaining rod in turn can be detachably joined with the aforesaid holding element, and several holding elements for holding one stack of sheets each can be provided in the binder. The retaining rod stabilizes the stack of sheets, so that it can also be detached from the binder, e.g., as a notebook or calendar. 
     SUMMARY OF THE INVENTION 
     The objective of the invention is to create a new holding device of the aforementioned type, which has a simplified design compared to the sheet binding system described in WO 01/89859 A1. 
     The device of the invention which achieves this objective is characterized by the fact that the holding element grips behind the innermost sheet of the stack at the fold. 
     In accordance with the invention, the holding element, which is preferably directly joined with the binder, directly grips the folded stack. To stabilize the stack, its sheets can be attached by staples in the area of the adjacent folds. 
     The section of the holding element that grips behind the innermost sheet has a strand-like design and in a holding position, it borders the fold along its length. This strand, which is designed, e.g., as a thin wire or thin strip, is attached on the inside against the fold of the innermost sheet and holds the stack in the binder. 
     The holding element can grip the stack around and behind its edge. 
     In a preferred embodiment of the invention, at least one opening that passes all the way through is formed in the stack or, as is especially preferred, a peripheral recess is formed in it, into which enters a section of the holding element that extends perpendicularly to the fold. The holding element grips behind the stack of sheets, i.e., it either grips behind at the edge or grips behind a passage formed in the stack. As a result of the engagement of the aforesaid section in the peripheral recess or passage, the stack is secured against displacement perpendicularly to the fold, which is advantageous especially when the stack is opened together with the binder, and the opened stack could be laterally displaced towards the binder without this engagement. 
     The opening or peripheral recess is preferably formed symmetrically to the fold, i.e., to a plane which perpendicularly intersects the stack on the fold line in the opened state. 
     In a further refinement of the invention, the holding element comprises a carrier rail, which is joined with the spine of the binder and can also be integrated in the binder. 
     The aforementioned perpendicular section of the holding element can be joined with this carrier rail and/or it can be formed as an angled section of the aforesaid strand-like section. 
     The strand-like section preferably can be removed from its holding position, in which it borders on the fold and extends parallel to it, to allow removal of the stack of sheets from the binder by, for example, swiveling the section into a position perpendicular to the fold or displacing it parallel to the fold. The strand-like section preferably can be removed from the holding position against the action of spring tension, such that the strand-like section itself can be elastically deformed and can be formed, e.g., by a rubber band. 
     The invention is explained in greater detail below with reference to the specific embodiments illustrated in the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a folded block, which is held in a leather binder by a device in accordance with the invention, 
         FIG. 2  shows details of the holding device of  FIG. 1 , 
         FIGS. 3 to 9  show schematic representations of further embodiments of holding devices of the invention, 
         FIG. 10  shows a partial view of another embodiment of a holding device of the invention, and 
         FIGS. 11 and 12  show further embodiments of holding devices according to the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The leather binder  1  shown in  FIG. 1  has holding elements  3  mounted on the inside on the binder spine  2  for holding a stack of sheets  4  folded at  9  inside the leather binder. 
     In the illustrated embodiment, two holding elements  3  are provided in the leather binder  1 . One of these holding elements  3  holds the stack of sheets  4  shown in the drawing. Another stack of this type could be held by the other holding element. In a modification of this specific embodiment, additional holding elements could be provided. 
     Each holding element consists of a carrier rail  5  sewn together with the spine  2  of the leather binder  1 . An angled section  6  is formed at each end of the carrier rail  5 . The angled sections  6  extend through peripheral recesses  7  formed in the stack of sheets  4 . An end piece  8  is formed at the free end of each angled section  6  and can swivel about a joint  10 . Along its length, the end piece  8  borders the fold  9  opposite the stack of sheets  4  and holds the stack of sheets on the carrier rail. The joint  10  can have a stiff design or it can lock in the swivel position shown in  FIG. 2 . 
     As a result of the angled sections  6  that engage the peripheral recesses  7  and extend perpendicularly to the fold  9 , the stack of sheets  4  is secured in the direction perpendicular to the fold  9 , which prevents an undesired lateral displacement of the stack of sheets  4 , especially in the folded-up state. 
     In the illustrated embodiment, the peripheral recess  7  is semicircular. It could also be triangular or it could be adapted to the cross-sectional shape of the peripheral angled section that engages it. 
     By bringing the end pieces  8  into a position perpendicular to the fold  9  of the stack of sheets  4 , the stack of sheets can be detached from the holding device  3  to allow it to be used independently of the binder. In this position of the end pieces  8 , the stack of sheets can also be reinserted and reattached to the carrier rail  5  by swiveling the end pieces  8  into the position shown in  FIG. 2 . 
     In the following figures, parts that are the same or have the same function are labeled with the same reference numbers as in  FIGS. 1 and 2  but with an appended letter a, b, c . . . , etc. 
     The holding element  3   a  shown in  FIG. 3  has a carrier rail  5   a  that is joined, e.g., with a leather binder. The carrier rail  5   a  is constructed as a tube that is open at its ends and is connected with a retaining clip  11  made of spring wire, and a folded stack of sheets  4   a  is enclosed between the retaining clip  11  and the carrier rail  5   a.    
     The retaining clip  11  made of spring wire has a section  8   a , which rests against the stack of sheets  4   a  at its fold and to which angled sections  6   a  and  6   a ′ are attached. The angled sections  6   a  and  6   a ′ extend perpendicularly to the fold of the stack of sheets  4   a , and peripheral recesses of the stack of sheets  4   a  engage corresponding peripheral recesses  9 . 
     Attached to the angled section  6   a  is an end piece  12 , which is arranged at an angle of 90° to the angled section  6   a  and enters an opening at the end of the tubular rail  5   a . The angled section  6   a ′ is connected with a loop  13 , which makes a transition into an end piece  12 ′, which, like the end piece  12 , enters an opening at the end of the tubular rail  5   a.    
     To release the connection between the stack of sheets  4   a  and the rail  5   a , the user grips the loop  13  and pulls the end piece  12 ′, which is much shorter than the end piece  12 , out of the tubular carrier rail  5   a . The retaining clip  11  can now be bent aside to release the stock of sheets  4   a  from the carrier rail  5   a  and moved in the opposite direction, which causes the end piece  12  to come out of the rail. 
       FIG. 4  shows a holding element  3   b  that is similar to the holding element of  FIG. 3 . In this case, a clip  11   b  made of spring wire with angled sections  6   b  and  6   b ′ has a loop  14  in the longitudinal center of a section  8   b  that rests against a stack of sheets  4 , which makes it possible to stretch section  8   b  in the direction indicated by the arrow  15 . Reference number  12   b  indicates the end piece. 
     To release the retaining clip  11   b  from the carrier rail  5   b , a user can pull a strip  16  connected with the retaining clip  11   b  in the direction of the arrow  15 . 
     A retaining element  3   c  shown in  FIG. 5  has a retaining wire  17  made of spring steel, which is laid over most of its length through a tubular carrier rail  5   c  and is wound to form a spring segment  18  inside the carrier rail. End pieces  8   c  angled once again 90° from angled sections  6   c  hold a stack of sheets  4   c  on the carrier rail  5   c . When a user pulls the pull strip  16   c , the stack of sheets  4   c  is released from the clasp of the respective end piece  8   c  and can then be removed from the binder. 
     A holding element  3   d  shown in  FIG. 6  for holding a stack of sheets  4   d  has a carrier rail  5   d  that is formed as a single piece with a retaining clip  11   d  made of spring steel wire. The retaining clip  11   d  can be hung on an angled end section  6   d  of the carrier rail  5   d  at  19  in the manner of a safety pin. 
     A holding element  3   e  shown in  FIG. 7  has a carrier rail  5   e  with an angled end section  6   e , whose free end is connected with an elastically stretchable band  8   e , e.g., a rubber band. A pin  21  is attached to the end of the rubber band  8   e  that faces away from the angled end section  6   e . The pin  21  can be pushed into an opening in the end of the tubular carrier rail  5   e  under tension of the rubber band  8   e  and placement of the rubber band against the inner fold of the stack of sheets  4   e.    
     A holding element  3   f  shown in  FIG. 8  for holding a stack of sheets  4   f  is formed as a single piece from spring wire to form a carrier rail  5   f  with angled sections  6   f  and with end pieces  8   f  further angled from the angled sections  6   f.    
     Reference is now made to  FIG. 9 , which shows an embodiment of a holding element  3   g  for holding a folded stack of sheets  4   g , in which two passages  23  are formed in the stack of sheets  4   g  instead of the peripheral recesses provided in the preceding embodiments. A pin  6   g  that extends perpendicularly to the fold  9   g  and is connected with the carrier rail  5   g  fits into each of the passages  23 . An end piece  8   g  can be swiveled about a joint  10   g , so that it rests against the fold  9   g  of the stack of sheets  4   g  and grips behind the stack of sheets to connect it with the rail  5   g.    
     Naturally, instead of swiveling end pieces  8   g , a band, possibly one that is elastic, which connects the projecting pins  6   g , could be used to hold the stack of sheets  4   g  on the carrier rail  5   g.    
     Reference is now made to  FIG. 10 . A partially drawn carrier rail  5   h  has a pin  6   h  with a spherical head  24 . Another pin of this description (not shown) is arranged some distance from the pin  6   h . A rubber band  8   h  stretched between the spherical heads  24  of the pins holds the stack of sheets  4   h  on the carrier rail  5   h.    
     Passages  23   h  with a width equal to the diameter of the spherical heads  24  are formed in the stack of sheets  4   h.    
     Some of the sheets in the stack of sheets  4   h  have only the hole  23   h  visible in  FIG. 10   c , these being the sheets facing the spine of the binder. The sheets of the stack that follow these sheets have holes  26  symmetrical to the fold  9   h  with a width that increases from sheet to sheet. 
     In the state in which the sheets are folded by 90°, the spherical head  24  fills the cavity formed by the holes  26  in the stack of sheets  4   h . In the folded-up state, after the rubber band  8   h  has been removed, the stack of sheets  4   h  can be detached from the carrier rail  5   h  by passing the spherical heads  24   h  through the holes  23   h.    
     Another holding element  3   i  shown in  FIG. 11  has a carrier rail  5   i  with angled sections  6   i . Each of these angled sections follows two other angled sections, which include angled end sections that are formed as eyes  27 . An elastically stretchable band  8   i  can be hung in the eyes  27 , and spherical end pieces  28  grip behind the eyes  27 . The eyes form a seat for the end pieces which centers the end pieces. 
       FIG. 12  shows a holding element  3   j  that consists exclusively of a stretchable, closed band  29 . The band engages peripheral recesses  7   j  in a stack of sheets  4   j . The ends of a spine  2   j  of a binder  1  have corresponding peripheral recesses  30  for receiving the band  29 . In the open state of the binder  1   j  and the stack of sheets  4   j , the peripheral recesses  7   j  and 30 prevent both the band  29  and the stack of sheets  4   j  from shifting laterally on the binder  1   j . As  FIG. 12   b  shows, several peripheral recesses  30  are formed on the spine of the binder, corresponding to the number of stacks of sheets to be held in the binder. 
     The band  29  can be enclosed between two layers of the spine of the binder, so that it is not visible from the outside. 
     In particular, the inner layer of the two layers could be detachably fastened to the other layer, e.g., by snap fasteners. 
     The band  29  does not have to be closed. The ends of an open band could be firmly connected with the spine of the binder.