Abstract:
A ring binder for holding punched paper is configured using two or more curved rotational ring elements (CREs) and corresponding post elements. A linkage mechanism couples the CREs together so that the rotate in unison. When a CRE engages a corresponding post element a ring element is formed for holding punched paper. The interface between the CRE and the post element has features that ensure that the interfaces have minimum gapping and they resist separation in a direction perpendicular to the tangent to the arc of rotation when the rings are closed. The linkage may be latched against rotation. Likewise the interfaces between the CREs and the post elements may be detented to ensure minimum gapping. The mechanism may have features that break the detent before rotation commences. Ring binders with two or more rings may be formed in a variety of sizes.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates in general to ring binder mechanisms for securing and accessing paper in a ring binder notebook. 
       BACKGROUND INFORMATION 
       [0002]    Notebooks are used in large quantities throughout the world for holding paper that has been edge punched with two or more holes. For ring binder notebooks, each of the two or more holes are fitted over corresponding split rings that have a mechanism for separating apart the split rings at an interface point. Once separated, paper may be added or removed from one of the split rings. When a user is through accessing the paper, a mechanism closes and secures the split rings so the paper will remain within the notebook. Most ring binder notebooks use a ring mechanism that rotationally spreads the rings apart such that each of the split rings remains in the same plane. This ring mechanism has a latching structure that has two stable positions, latched open and latched closed. When sufficient force is applied to spread the rings apart, the mechanism snaps into the open position. Likewise an opposite force, when applied, the mechanism snaps into the closed position. While functional this mechanism is prone to cause injury, requires two handed operation, and is prone to come open. The rings may come open because the force that is applied to the rings by stored paper has a vector component that is the same as the force applied to open the split rings. Newer designs have incorporated a one button mechanism to overcome the requirement to use two hands. However, the mechanism is basically the same with the same deficiencies. 
         [0003]    There is, therefore, a need for a new ring binder mechanism that retains the single action operation, has an opening and closing force that is orthogonal to the force applied by store paper, and does not have any snapping action that can cause injury. 
       SUMMARY OF THE INVENTION 
       [0004]    A ring binder mechanism comprises two or more cylindrical post elements and two or more corresponding curved rotational ring elements (CREs) that when in contact each substantially form a ring shape for holding hole punched paper. Each post element and corresponding curved rotational element contact at an interface that has special features for retaining the post element and curved rotational element engaged until they are released by a secondary action which is used to open and close the ring binder mechanism for accessing and retaining punched paper. The two or more curved rotational elements are coupled together with a linkage that ensures that they all rotate in unison. The (CREs) rotate from a first position where all of the CREs are engaged with a corresponding post element at the interface features. The linkage has a feature that allows it to be latched in the closed position where all the CREs and posts form rings for holding punched paper while allowing the paper pages to be flipped by sliding over the cylindrical cross-section of each engaged post and corresponding CRE. The interface feature on each of the rings prevent the formed rings from being pulled apart. The interface is only released when a CRE is rotated away from its corresponding post element. Since the rotation is orthogonal to the direction of force that acts to pull the rings apart, the ring mechanism of the present invention is more secure than conventional ring binder mechanisms. 
         [0005]    In one embodiment of the present invention, the two or more post elements are rigidly mounted to a spring loaded flat rectangular element that allows the post elements to move up and down in a direction parallel to a line through the center and along the length of the post elements. This allows the interface between the post elements and the CREs to be separated and disengaged (in unison) prior to rotating the CREs to open the formed rings of the ring binder mechanism. In this embodiment, the linkage has a slotted section that prevents the rotation of the CREs to start until after the flat rectangular element has been pushed down separating each of the post elements. The linkage then engages the CREs and rotates them to the open position exposing only the posts with any punched paper with holes threaded over the posts. In the open position, paper may be removed or added. To close the ring binder, the linkage is moved in the opposite direction. Features on the linkage again engage the flat rectangular element translating the posts down until the CREs are positioned substantially directly over a corresponding post element. Again the linkage slot disengages the CREs and the features allow the posts to translate up. The interface has mating detent features such that the posts and corresponding CREs are forced into alignment by the spring action of the flat rectangular element. 
         [0006]    In another embodiment, the post elements and CREs have the detent features on their side sections such that the post elements do not have to be translated up and down when the linkage rotates the CREs open and closed. In yet another embodiment, the post elements are hollow cylinders that have an internal spring and a ball element. The top of the hollow post elements is sized such that it is slightly smaller that the diameter of the ball element which prevents the ball from escaping while allowing the ball element to be completely depressed into the hollow post element. The tips of the CREs are correspondingly made hollow and shaped to accept the ball element. In this embodiment, when a CRE is rotated into a corresponding post element, the leading edge of the CRE cylinder engages the ball element such that there is a force vector that forces the ball downward into the hollow of the post against the spring. As the ball element moves, the force vector is greater and the ball moves further down into the hollow post element. When the leading edge of the cylinder of the CRE transitions over ½ of the ball element diameter, the ball element starts to come back up into the hollow in the CRE. The action of the spring and the motion of the CRE cause the ball element to act as detent and align the CRE and its corresponding post element. The opening action simply reverses this process. The ball may be made with a flat on the sides perpendicular to the arc of the CRE&#39;s motion when it is engaged to the hollow post element. This assures that when a CRE and corresponding mated hollow post element are engaged, a restraining force will be exerted when one tries to pull them apart in a direction perpendicular to the arc of the motion of the CRE at engagement. Punched paper would exert such a force directing to separating a CRE and corresponding hollow post element that are ball detented according to embodiments of the present invention. 
         [0007]    In yet another embodiment of the present invention, the CRE and a corresponding mating post element have interface features that lock when a force is applied to pull and engaged CRE and corresponding mating post apart in a direction perpendicular to the arc of motion of the CRE when aligned with its post element. These features have a slight interference to insure a minimum gapping or misalignment at detent. 
         [0008]    In one embodiment of the present invention the post elements are fixed to a thin flat metal layer that extends the width of the mechanism and is bent to form a spring segment that acts as a leaf spring. The CREs with their corresponding linkage are assembled into a base element such that the CREs may be rotated in unison within the base element. The linkage and base element aligns the CREs in the correct placement to match with their corresponding posts. The base element is attached to the spring segment so that each CRE aligns with its corresponding mating post element. The spring segment allows the entire CRE assembly to be rotated a few degrees (e.g., 3-5 degrees) so that the CREs transition from engagement with their corresponding post element until their interface is separated allowing the CREs to rotated to allow punched paper to be added or removed from over the post elements. When the CREs are rotated (in unison by the linkage) into alignment with their corresponding post elements, the base element pressed down and a latching element is employed to hold the CREs in engagement with their corresponding post element. When the latch is released, the spring segment automatically rotates the CRE assembly away from their corresponding post element. A user then simply grasps and rotates any one of the CREs and the linkage rotates all the CREs in unison to open the binder mechanism for loading or removing punched paper. 
         [0009]    In another embodiment of the present invention, the interface between the CREs and their corresponding post element uses magnets to aid in aligning the CREs and post elements to minimize gapping of the formed rings. 
         [0010]    In another embodiment of the present invention, the CREs each have a section with gear teeth concentric with the center of the straight portion of the CRE shafts. A linking element comprises a rectangular gear element that has gear teeth for mating with the gear teeth on the gear sections of the CREs. In this manner, when one of the CREs is rotated that action of the mated gear teeth acts to translate the rectangular gear element. Since the other CREs are mated with the rectangular gear element they are also rotated in unison when any one of the CREs is rotated. 
         [0011]    The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0012]    For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which: 
           [0013]      FIGS. 1  is an illustration of CREs and post elements in the closed and open positions according to embodiments of the present invention; 
           [0014]      FIGS. 2A and 2B  illustrate two types of notebooks suitable for practicing embodiments of the present invention; 
           [0015]      FIGS. 3A  illustrates an interface between a CRE and a post element using a cone section on the CRE and a mating depression on the post element; 
           [0016]      FIGS. 3B  illustrates a cross-section an interface between a CRE and a post element where the interface features are on the sides of the CRE and the post element wherein the interface features are rotationally engaged. 
           [0017]      FIGS. 4  illustrates the cross-section of the interface of  FIG. 3B  showing the cross-section of a CRE at various angles of rotation according to embodiments of the present invention; 
           [0018]      FIGS. 5  illustrates four positions of a CRE and post element with a ball type of interface as the CRE is rotated into engagement with the post element according to embodiments of the present invention; 
           [0019]      FIG. 6  illustrates a CRE and post with a ball type interface wherein the ball element has flats on the sides that assure the ball can rotate only in one axis hence providing denting locking according to embodiments of the present invention; 
           [0020]      FIG. 7  illustrates two isometric views of a ring binder assembly according to embodiments of the present invention; 
           [0021]      FIGS. 8A-8F  illustrate various exploded views of the ring binder assembly of  FIG. 7 ; 
           [0022]      FIG. 9  illustrates an exploded view of the ring binder assembly of  FIG. 7 ; 
           [0023]      FIGS. 10A-10E  illustrate various exploded views of the embodiment of  FIG. 7 ; 
           [0024]      FIGS. 11A-11E  illustrate various exploded views of the embodiment of  FIG. 7  showing the rotational positions of the CREs according to embodiments of the present invention; 
           [0025]      FIG. 12A  illustrates a linkage element according to embodiments of the present invention; 
           [0026]      FIG. 12B  illustrates a top view of linked CREs and their corresponding post elements when the CREs are rotated to the open position according to embodiments of the present invention; 
           [0027]      FIG. 12C  illustrates a top view of the linked CREs and their corresponding post elements of  FIG. 12B  when the CREs are rotated to the closed position according to embodiments of the present invention; 
           [0028]      FIG. 13A  illustrates a linkage element for a six ring binder mechanism according to embodiments of the present invention; 
           [0029]      FIG. 13B  illustrates a top view of a six ring linked CREs and their corresponding post elements when the CREs are rotated to the open position according to embodiments of the present invention; 
           [0030]      FIG. 13C  illustrates a top view of the linked CREs and their corresponding post elements of  FIG. 13B  when the CREs are rotated to the closed position according to embodiments of the present invention; 
           [0031]      FIG. 14  illustrates linked CREs and their corresponding post elements where the interface between the CREs and post elements employ magnets to minimize gapping when the CREs are rotated to the closed position; 
           [0032]      FIG. 15A  illustrates another ring binder assembly according to embodiments of the present invention; 
           [0033]      FIG. 15B  illustrates the CRE assembly of  FIG. 15A  rotated to separate the interface between the CREs and their corresponding post elements; 
           [0034]      FIG. 15C  is magnified view showing detail of a portion of the ring binder assembly of  FIG. 15A ; 
           [0035]      FIG. 16A  is a side view of another ring binder assembly according to embodiments of the present invention employing geared CREs and their linkage element; and 
           [0036]      FIG. 16B  is a top view illustrating the coupling between the geared CREs and their linkage element in the ring binder assembly of  FIG. 16A . 
       
    
    
     DETAILED DESCRIPTION  
       [0037]    In the following description, numerous specific details are set forth to provide a thorough understanding of the present invention. However, it will be obvious to those skilled in the art that the present invention may be practiced without such specific details. In other instances, well-known mechanisms may be shown in block diagram form in order not to obscure the present invention in unnecessary detail. For the most part, details concerning materials, processes and the like have been omitted inasmuch as such details are not necessary to obtain a complete understanding of the present invention and are within the skills of persons of ordinary skill in the relevant art. 
         [0038]    Refer now to the drawings wherein depicted elements are not necessarily shown to scale and wherein like or similar elements are designated by the same reference numeral through the several views. 
         [0039]      FIG. 1  is a simple view of a three ring binder mechanism according to embodiments of the present invention. A base  102  holds CREs  106 - 108  and their corresponding post elements  105 - 103 . Each of the CRE/post element pairs have an interface  110  that engages when the CREs are rotated into their closed position. CREs  106 - 108  may be individually rotated from an open position to a closed position where they engage their corresponding post element. Also a linkage may be used wherein CREs  106 - 108  are forced to rotate in unison from their open to closed positions. A punched piece of paper  101  is shown with its punched poles placed over a post element. 
         [0040]      FIG. 2A  illustrates one traditional notebook  200  suitable for practicing embodiments of the present invention. Notebook  200  has three cover sections  201 ,  206  and  207 . The base  204  of a ring binder mechanism according to embodiments of the present invention is mounted to section  207 . A ring  203  form by a CRE and a corresponding post element is coupled through punched holes of punched paper  202 . 
         [0041]      FIG. 2B  illustrates one traditional notebook  220  suitable for practicing embodiments of the present invention. Notebook  220  has three cover sections  210 ,  216  and  217 . The base  204  of the ring binder mechanism according to embodiments of the present invention is mounted to section  217 . A ring  203  form by a CRE and a corresponding post element is coupled through punched holes of punched paper  202 . In notebook  220  the ring binder mechanism remains fixed when cover  210  is opened. 
         [0042]      FIG. 3A  illustrates interface  110  of one embodiment of the present invention wherein CRE  108  employs a cone section  301  to interface with a corresponding cone shaped depression  302  in post element  103 . In this embodiment, post element  103  would first be translated in direction shown by vector  304  to separate cone sections  301  and  302 . CRE  108  is then rotated according to embodiments of the present invention in a tangential direction shown as vector  305  at it the CRE&#39;s in a closed rotational position. 
         [0043]      FIG. 3B  is a top section view of another embodiment of the interface  110 . In this embodiment post  103  has a side feature  311  wherein a section with a shape substantially like  310  removed from its tip to form a one-half of interface  110 . Likewise, CRE  108  has a section with a shape substantially like  310  removed from its tip to form the other half of interface  110 . The shape of feature  310  and  311  allow them to “detent” when they come into engagement as CRE  108  rotates into post element  103 . When engaged, interface  110  resists forces that act in the direction illustrated by vector  330 . 
         [0044]      FIG. 4  is another top section view of the embodiment of  FIG. 3B  showing additional rotational positions of CRE  108  and interface  110  when CRE  108  rotates to engage post element  103  along arc vector  305 . Again, the shape of feature  310  and  311  allow them to “detent” when they come into engagement as CRE  108  rotates into post element  103 . 
         [0045]      FIG. 5  illustrates a CRE  108  as it engages a post element  103  with a ball and cavity interface  110 . Post  103  has a hollow section holding a spring  502  and a ball  501 . The tip of post  103  is formed such that it is slightly smaller than the diameter of ball  501 , therefore, as spring  502  pushes ball  501  upward its diameter will interfere with the inside diameter of the hollow of post  103  retaining ball  501 . As CRE  108  rotates into post  103 , the leading edge of the tip of CRE  108  has a force vector directed to push ball  501  downward, in direction  503 . The force vector in the direction of vector  305  will cause ball  501  to rotate relieving any side thrust on post  103 . The more CRE  108  is rotated into post  103  the greater the force vector becomes in direction  503 . In this manner, ball  501  is pressed down into the hollow of post  103 . After the leading edge of CRE  108  passes the mid-point of the diameter of post  103 , ball  501  starts to move up in the direction  504 . When CRE  108  is directly over post  103  the ball  501  is “detented” resisting further rotation of CRE  108  according to embodiments of the present invention. Reversing the rotation of CRE  108  reverses the above process. 
         [0046]      FIG. 6  illustrates a top of the embodiment of  FIG. 5  wherein the ball  501  has flats  601  and  602  formed on ball  501 . When ball  501  is assembled into post  103 , ball  501  can only rotate orthogonal to radial vectors. When CRE  108  and post  103  are engaged at position  603 , any force in vector direction  630  can only separate CRE  108  and post  103  is ball  501  is free to rotate in direction  630 . If the flats  601  and  602  are in contact with mating flats inside of post  103 , ball  501  is not free to rotate in direction  630 , thus CRE  108  and post  103  are locked against motion that would try to open their formed ring. In this manner, only rotational force would freely separate CRE  108  and post element  103 . 
         [0047]      FIG. 7  illustrates two isometric view of a three ring binder assembly according to embodiments of the present invention. CREs  106 - 108  are engaged with corresponding post elements  105 - 103  at interfaces  110 . A cover  708  is fitted over base  102  (not shown). Slots  704 - 706  allow cover  708  to be fitted over the base with integrated CREs  106 - 108 . Holes  702 - 703  are used to attached ring binder assembly  700  to a notebook cover section(e.g., covers sections  204  and  216 ). The tip of linkage  701  is shown extending from cover  708  allowing a user to rotate the CREs ( 106 - 108 ) according to embodiments of the present invention. 
         [0048]      FIGS. 8A-8F  illustrate various views of ring binder assembly  700 .  FIG. 8A  is a side view of CRE  108  and corresponding post element  103  with cover  708 .  FIG. 8B  is a top view of ring binder assembly  700  illustrating CREs  106 - 108 , holes  702 - 703 , and a portion of linkage  701 .  FIG. 8C  is a detail of the section (A) view showing cover  708  coupled to base  102  and a portion of CRE  108  and linkage  701 .  FIG. 8D  is the section (A) view illustrating a cross-section of the base assembly and CRE  108  and post element  103 .  FIG. 8E  is a view from the back of assembly  700  showing CREs  106 - 108  and cover  708  over the base assembly.  FIG. 8F  is a bottom view of assembly  700  showing holes  702 - 703  and the bottom of base  102 . 
         [0049]      FIG. 9  is an exploded view of assembly  700 . Cover  708  has holes  702 - 703  which extend through the assembly through base  102 . CREs  106 - 108  are shown with their corresponding levers  922 - 920  that couple with linkage  701  via slots  941 - 940 . Linkage  701  also has cam elements  906 - 908 . Post elements  103 - 105  are coupled to bail  901  which attaches to base  102 . 
         [0050]      FIG. 10A  is an exploded view of a portion of assembly  700  illustrating linkage  701 , bail  901  and base  102 .  FIG. 10B  is a detail C showing the interface  110  of post  104  and CRE  107  along with lever  921  on CRE  107 .  FIG. 10C  is an exploded view of CREs  106 - 108  with their corresponding levers  922 - 920  and bail  901  with post elements  103 - 105  coupled into base  102 .  FIG. 10D  is an exploded view of cover  708  with holes  702 - 703  in position to be place over the base assembly of assembly  700 . CREs  106 - 108  and bail  901  with post elements  103 - 105  are integrated into base  102 . Linkage  701  is shown with clearance slots  930 - 931  that allow an attachment means (e.g., screw or rivet) for mounting assembly  700  to a note book cover (e.g.,  204  and  216  to clear the motion of lever  701  when operated to rotate the CREs open and closed according to embodiments of the present invention.  FIG. 10E  is a detail of hole  702 . 
         [0051]      FIGS. 11A-11E  illustrate assembly  700  (with cover  708  removed) in various stages of operation according to embodiments of the present invention.  FIG. 11A  illustrates the CREs ( 106 - 108  in the closed position engaging post elements  105 - 103  respectively. Linkage engaged with levers  921 - 923  is positioned inside of base  102 . In  FIG. 11B , linkage  701  is pull out to start the process of opening the rings formed by CREs  106 - 108  and post elements  105 - 103 . Cams  906 - 908  are disposed in slots in linkage  701 . After linkage  701  is pulled out cams  906 - 908  engage bail  901  and cause a downward force that flexes bail  901  and resulting in post elements  103 - 105  translating down separating interfaces  110  positioning the CREs to be rotated. A corresponding slot in linkage  701  allows the levers  920 - 922  to remain in their home position until posts  103 - 105  are depressed. 
         [0052]    In  FIG. 11C , linkage  701  is extended farther and the CREs  106 - 108  are rotated open away from corresponding post elements  105 - 103 . In  FIG. 11D , the CREs  106 - 108  are rotated completely open. Pushing linkage  701  back into base  102  reverses the process above. The spring force of bail  901  minimizes the gap in the interfaces  110 .  FIG. 11E  is a top view of the assembly  700  with the cover  708  removed showing the open and close motion directions  1010  of linkage  701 , CREs  106 - 108 , levers  920 - 922  and their corresponding slots  930 - 932 . 
         [0053]      FIG. 12A  is a side view of a linkage  1202  according to embodiments of the present invention with corresponding cylindrical elements  1203 - 1205  that engage corresponding levers  1206 - 1208  coupled to CREs  108 - 106 .  FIG. 12B  illustrates base  1202  and linkage  1202  coupled to CREs  108 - 106  with levers  1206 - 1208  in the fully open position away from post elements  103 - 105 .  FIG. 12C  illustrates base  1202  and linkage  1202  coupled to CREs  108 - 106  with levers  1206 - 1208  in the fully closed position over post elements  103 - 105 . 
         [0054]      FIG. 13A  illustrates a linkage  1302  for a six ring binder mechanism with cylindrical elements  1303 - 1208  that engage corresponding levers  1310 - 1315  coupled to CREs  1330 - 1335  according to embodiments of the present invention.  FIG. 13B  illustrates base  1350  and linkage  1302  coupled to CREs  1330 - 1335  with levers  1310 - 1315  in the fully open position away from post elements  1340 - 1345 .  FIG. 13C  illustrates base  1350  and linkage  1302  coupled to CREs  1330 - 1335  with levers  1310 - 1315  in the fully closed position over post elements  1340 - 1345 . 
         [0055]      FIG. 14  illustrates another embodiment of the present invention. A base  1402  has fixed post elements  1403 - 1405  and corresponding CREs  1408 - 1406  rotationally coupled to base  1402 . Levers  1409 - 1411  are coupled to linkage  1401  that assures the CREs rotate in unison. Interfaces  1420  employ magnets to aid in aligning posts and CREs during closure. The natural detent action of the magnets will pull the tips of the CREs and corresponding posts independently into alignment when they are in a close proximity. By shaping the tips, the only force that freely allows the rings to be opened is the rotational motion of the CREs according to embodiments of the present invention. If the rotary motion is latched, the normal forces that try to pull the rings apart meet with a strong restraining force while the force for opening the rings with rotary motion is only the sheer force of the magnets in the interface. As one magnetic force is broken then the applied force works one fewer magnet for easy opening.  FIG. 14  also an exploded view of CRE  1408  with lever  1409  and linkage  1401 . Post  1403  is shown in base  1402 . A hole  1412  receives the cylinder of CRE  1408  allowing it to rotate while remaining secured in base  1402 . 
         [0056]      FIGS. 15A-15C  illustrate another embodiment of the present invention. In  FIG. 15A , a CRE  1508  and corresponding post element  1503  are shown with interface  1510 . CRE  1508  is rotationally coupled to base assembly  1520  that is coupled to a spring element  1502 . Lever  1507  (e.g., like lever  1206  in  FIG. 12 ) is coupled to the cylinder of CRE  1508  and is coupled to linkage  1509  (like linkage  1202  in  FIG. 12 . Element  1511  retains CRE  1508  with washer  1512  so that CRE  1508 , element  1511 , lever  1507 , and linkage  1509  are coupled together forming base assembly  1520 . A flat spring element  1502  has a flat portion  1522  that extends and rigidly couples to post element  1503  joint  1505 ) and a leaf spring portion  1523  (see  FIG. 15C ) that folds over the flat portion  1522  and hinges about bend  1521 . Base assembly  1520  is coupled to leaf spring portion  1523  (joint  1514  in  FIG. 15C ). When leaf spring portion  1523  is free to pivot about bend  1521  it lifts and rotates base assembly  1520  a few degrees and thereby cause the interface  1510  to separate allowing CRE  1508  to be rotated with linkage  1509  and lever  1507  according to embodiments of the present invention. The flat portion  1522  of the spring element may be mounted to a notebook cover (e. g., cover  204  and  216  in  FIG. 2 ) to secure the ring binder mechanism  1500  to the notebook. A cover piece  1501  may be snapped over the edges of the spring element to cover up the mechanism and to present a smooth surface for stored paper coupled to post element  1503 . While only one CRE  1508  and post  1503  were shown coupled to base assembly  1520  it is understood that embodiments of the present invention use two or more CREs for normal operation. 
         [0057]      FIG. 15B  illustrates base assembly and coupled CRE  1508  rotated (vector  1506 ) an angle  1513  to cause the interface  1510  to separate allowing CRE  1508  to be rotated open according to embodiments of the present invention. 
         [0058]      FIG. 15C  is an expanded view of base assembly  1520  with coupled CRE  1508 . Element  1511  receives the shaft of CRE  1508  and the bottom of lever  1507  contacts its top surface. A washer  1512  is pressed over the shaft of CRE  1508  and contacts a bottom surface of element  1511 . This secures CRE  1508  to element  1511  while allowing CRE  1508  to rotate. The surfaces  1514  of element  1511  are attached to leaf spring portion  1523 . Linkage  1509  is coupled to lever  1507 . 
         [0059]      FIG. 16A  is a view of a portion of a ring binder mechanism according to another embodiment of the present invention. A base element  1602  has post element  1603 . Base element  1602  has a cavity for receiving rectangular geared element  1605  that mates with the gear teeth on the gear portion  1606  of CRE  1608 . When geared element  1605  is moved in a direction perpendicular to the page, it acts to rotate CRE  1608 . A snap ring  1608  is used to rotationally couple CRE  1608  to base  1602 . A cover  1601  is place over the cavity. Interface  1610  is configured so that CRE  1608  and post element  1603  resist separation from forces acting perpendicular to the tangent to the arc of motion of CRE  1608  when rotated. 
         [0060]      FIG. 16B  is a top view of the ring binder mechanism in  FIG. 16A . The gear portions  1606  on multiple CREs  1608  are shown. Multiple mating post elements  1603  are also shown . When geared element  1605  is move laterally, all of the CREs  1608  move in unison according to embodiments of the present invention to rotationally open and close the ring formed by each CRE  1608  and corresponding post element  1603 . 
         [0061]    The present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.