Patent Publication Number: US-2013236233-A1

Title: Ring mechanism having robust low-profile housing

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a continuation of U.S. application Ser. No. 13/606,209, filed Sep. 7, 2012, which claims priority to Chinese Application Nos. 201110263680.2 and 201120335071.9, both of which were filed Sep. 7, 2011, the entire contents of which are all hereby incorporated by reference. 
    
    
     FIELD OF INVENTION 
     The present invention relates generally to ring binder mechanisms for holding loose-leaf pages and more particularly to ring binder mechanisms in which ring members are mounted on pivoting hinge plates that are supported by a metal housing having openings in its side for receiving the ring members. 
     BACKGROUND 
     Various ring mechanisms for retaining loose-leaf pages are known in the art. One type of prior art ring mechanism includes a plurality of rings made of paired ring members mounted on pivoting hinge plates (which are sometimes referred to as carrier rails, ring supports, or toggle plates). A metal housing has bent under rims extending along its opposite longitudinally extending sides. The hinge plates are arranged side-by-side with one another and extend longitudinally in the housing. The outer side edge of each hinge plate is received in a channel formed by the bent under rims at the side of the housing. The ring members extend from the hinge plates though openings in the housing (e.g., notches extending in from the sides of the housing) so the ring members together form a continuous loop extending above the housing when the rings are closed. The hinge plates are typically dimensioned so the combined width of the hinge plates is greater than the distance between the channels on opposite sides of the housing when the housing is in its un-deformed configuration. The hinge plates pivot through a co-planar position as the rings move between open and closed positions. Consequently, opening or closing the rings requires the housing to be deformed to spread the sides of the housing far enough apart to accommodate the combined width of the hinge plates in their co-planar position. This arrangement of features results in the metal housing providing a toggling spring force that tends to hold the rings in the closed position when the rings are closed and tends to hold the rings in the open position when the rings are open. An example of this type of prior art ring mechanism is described in U.S. Pat. No. 4,552,478. 
     The housings of the ring mechanisms described above are suitably manufactured by forming the housings out of sheet metal. It is desirable to minimize cost by making the housing from sheet metal having the minimum thickness that will still provide the necessary strength. It is also desirable to make the housing so the central portion of the housing between the sides is relatively low to reduce the profile of the ring mechanism. The housing occupies some of the space that could be occupied by loose-leaf pages. Thus, all other things being equal, a ring mechanism having a lower profile housing has the capacity to hold more loose-leaf pages than a ring mechanism having a higher profile housing. 
     However, there are other design constraints that limit the thinness of the housing and/or the extent to which the profile can be lowered. One of these constraints is that the housing has to be strong enough to withstand forces exerted on it by the hinge plates and other objects during operation of the ring mechanism. Another is that the housing has to be strong enough to withstand forces exerted on it during assembly of the ring mechanism. Moreover, it is sometimes desirable to use automated machines to assemble the ring mechanisms. At least some types of machines used to assemble ring mechanisms require the openings in the housing for receiving the ring members to be notches that extend all the way to the edge of the housing so the ring members can be inserted transversely into their respective opening from the side of the opening. However, this results in a relatively weak narrow neck in the housing where the central portion of the housing extends between the openings for a pair of ring members on opposite sides of the housing. This narrow neck portion is one of the weakest points of the housing and makes the housing vulnerable to being bent, particularly during manufacture of the ring mechanism before the housing is reinforced by the relatively stiff hinge plates. 
     Housings made from thicker metal and/or shaped to have a relatively higher profile can be more robust because of the increased strength associated with thicker metal and/or the increased bending moment resulting from the cross sectional shape and/or wider neck between the openings for the ring members that can be achieved using a higher profile housing. The housing would be stronger if the openings for the rings did not extend all the way to the sides of the housing, but this requires the ends of the ring members to be inserted through the opening. This is a more complex assembly step and at least some of the machines that are suitable for use when the openings are notches that extend all the way to the side of the housing cannot be used when the openings do not extend all the way to the side of the housing. Typically, assembly of ring mechanisms in which the openings do not extend all the way to the sides of the housing is done manually rather than with automated machines. Thus, there are additional costs associated with the more complex assembly when the openings for the ring members do not extend all the way to the sides of the housing. 
     SUMMARY 
     One aspect of the invention is a ring mechanism for holding loose-leaf pages. The mechanism includes an elongate housing having a central portion and longitudinally extending sides on opposite sides of the central portion. First and second hinge plates are supported by the housing for pivoting movement relative to the housing. The mechanism has rings for holding the loose-leaf pages. Each ring includes a first ring member and a second ring member. The first ring member is mounted on the first hinge plate and moveable with the pivoting motion of the first hinge plate relative to the second ring member between a closed position and an open position. The first and second ring members form a substantially continuous closed loop in the closed position. The first and second ring members form a discontinuous open loop in the open position. The housing has an opening for receiving one of the first ring members. The opening extends laterally inward toward a longitudinal centerline of the elongate housing. The housing has a vault-forming portion at the inner margin of the opening. The vault-forming portion of the housing is spaced from a longitudinal centerline of the housing and raised above longitudinally adjacent portions of the housing spaced the same distance from the centerline. 
     Another aspect of the invention is a ring mechanism for holding loose-leaf pages. The ring mechanism includes an elongate housing having a central portion and longitudinally extending sides on opposite sides of the central portion. First and second hinge plates are supported by the housing for pivoting movement relative to the housing. The mechanism has rings for holding the loose-leaf pages. Each ring includes a first ring member and a second ring member. The first ring member is mounted on the first hinge plate and moveable with the pivoting motion of the first hinge plate relative to the second ring member between a closed position and an open position. The first and second ring members form a substantially continuous closed loop in the closed position. The first and second ring members form a discontinuous open loop in the open position. The housing has an opening for receiving one of the first ring members. The opening extends laterally toward a longitudinal centerline of the elongate housing. The housing having an upturned lip at the inner margin of the opening. 
     Another aspect of the invention is a ring mechanism for holding loose-leaf pages. The ring mechanism includes an elongate housing having a central portion and longitudinally extending sides on opposite sides of the central portion. First and second hinge plates are supported by the housing for pivoting movement relative to the housing. The mechanism has rings for holding the loose-leaf pages. Each ring includes a first ring member and a second ring member. The first ring member is mounted on the first hinge plate and moveable with the pivoting motion of the first hinge plate relative to the second ring member between a closed position and an open position. The first and second ring members form a substantially continuous closed loop in the closed position. The first and second ring members form a discontinuous open loop in the open position. The housing has an opening for receiving one of the first ring members. The opening extends laterally toward a longitudinal centerline of the elongate housing. The housing has a raised bump at the inner margin of the housing. The bump is configured to extend over a segment of said one of the first ring members when the rings are in the closed position. The housing further comprising a dimple positioned along the longitudinal centerline of the housing and extending downward toward the hinge plates to protect the housing from being damaged by the hinge plates as the rings move into the open position. The dimple is offset axially on the housing the ring members. 
     Other objects and features will in part be apparent and in part pointed out hereinafter. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective of one embodiment of a ring mechanism mounted on a notebook cover; 
         FIG. 2  is a top plan view of the ring mechanism illustrated in  FIG. 1 ; 
         FIG. 3  is a bottom plan view of the ring mechanism illustrated in  FIG. 1 ; 
         FIG. 4  is an exploded perspective of the ring mechanism illustrated in  FIG. 1 , 
         FIG. 5  is a perspective of the ring mechanism illustrated in  FIG. 1  sectioned on a plane including line  5 - 5  on  FIG. 2  to show internal features; 
         FIG. 6  is a perspective similar to  FIG. 5  but showing the rings in their open position; 
         FIG. 7  is an enlarged perspective of a portion of the ring mechanism illustrated in  FIG. 1  showing an opening in the housing of the ring mechanism for one of the ring members; 
         FIG. 8  is an enlarged perspective of the ring mechanism illustrated in  FIG. 1  similar to  FIG. 7  but with the ring member in an open position; 
         FIG. 9  is a cross section of the ring mechanism illustrated in  FIG. 1  taken in a plane including line  9 - 9  on  FIG. 2 ; 
         FIG. 10  is an enlarged side view of a portion of the housing of the ring mechanism illustrated in  FIG. 1  showing one of the openings in the housing for a ring member; and 
         FIG. 11  is an enlarged perspective of another embodiment of a ring mechanism having an opening for a ring member that does not extend all the way to the side of the housing of the ring mechanism. 
     
    
    
     Corresponding reference numbers indicate corresponding parts throughout the drawings. 
     DETAILED DESCRIPTION 
     Referring to the drawings,  FIGS. 1-10  illustrate one embodiment of a ring mechanism, generally designated  101 , that is suitable for holding loose-leaf pages (not shown). As illustrated, the mechanism  101  is mounted on a cover  103  (e.g., a notebook cover) adapted to selectively cover or expose any loose-leaf pages retained on the rings  105 . For example, the cover  103  in  FIG. 1  includes a spine  107  and front and back cover portions  109 ,  111  hingedly attached to opposite sides of the spine. The ring mechanism  101  can be mounted in various positions on the cover  103 . For example, it is common to mount ring mechanisms on the spine or on one of the cover portions adjacent the spine, although it is possible to mount the ring mechanism elsewhere within the scope of the invention. In  FIG. 1 , the mechanism  101  is mounted on the spine  107  of the cover  103 . The ring mechanism  101  can also be mounted on different kinds of covers or substrates within the scope of the invention. For instance, the cover may be a flexible sheet that operates similarly to the cover illustrated in  FIG. 1  except that the flexing between the spine and cover portions is spread out over a larger area or over multiple pseudo hinge lines such that the movement between the spine and the cover portions is not constrained to a single well-defined pivot axis. Similarly, the ring mechanism  101  can be mounted on other objects, such as clip boards, brief cases, etc. within the scope of the invention. 
     The mechanism  101  includes an elongate housing  115  ( FIG. 4 ). The housing  115  is suitably formed by stamping a piece of flat sheet metal. The type of metal used to make the housing  115  can vary within the scope of the invention. For example, the metal housing  115  can be made of stainless steel, which can be nickel plated if desired to limit corrosion. Also, the housing can be made of polymeric materials or other non-metal materials if desired within the scope of the invention. The housing  115  includes a raised central portion  117  and longitudinally extending sides  119  extending down from the central portion on opposite sides of the central portion. Bent under rims  121  are formed along the sides  119  of the housing  115  to form a pair of opposed channels  123  on opposite sides of the housing extending along the length of the housing. The housing  115  suitably has one or more longitudinally-extending ribs  125  along the central portion  117  of the housing. For example, the housing  115  in the illustrated embodiment has a pair of ribs  125 , one of which extends along each side of the central portion  117  along substantially the entire length of the housing  115 . Additional shorter longitudinally extending rib segments  127  are suitably formed in the housing  115  adjacent the rings  105  that are adjacent the ends of the housing  115  and at a location spaced laterally outward from the full-length ribs  125 . 
     A pair of hinge plates  131  ( FIGS. 3-6 ) are supported by the housing  115  for pivoting movement relative to the housing. In particular, a pair of elongate generally flat, stiff hinge plates  131  (e.g., made of stainless steel that is thicker than the sheet metal used to make the housing  115 ) are positioned side-by-side in the housing between the sides  119  and under the central portion  117  so the outer edges of the hinge plates are received in the channels  123  formed by the bent under rims  121  extending along the sides of the housing. The combined width of the hinge plates  131  exceeds the distance between the channels  123  formed in the sides  119  of the housing by the bent under rims  121  when the housing is in a relaxed un-deformed configuration. The hinge plates  131  have tabs  133  ( FIGS. 3 and 4 ) along their inner edges which retain the hinge plates in side-by-side relation as they pivot relative to one another along a hinge line  135  where the inner edges of the hinge plates meet. 
     The mechanism  101  also includes a plurality of rings  105  for holding the loose-leaf pages. Each ring  105  includes a pair of ring members  141 . At least one of the ring members  141  for each ring  105  is mounted on one of the hinge plates  131  and is moveable with the pivoting motion of the hinge plate relative to its corresponding ring member between a closed position ( FIG. 5 ) and an open position ( FIG. 6 ). In the closed position, the ring members  141  of each ring  105  form a substantially continuous closed loop for retaining loose-leaf pages. In the open position, the ring members  141  form a discontinuous open loop for adding and/or removing loose-leaf pages from the mechanism  101 . In the illustrated embodiment, both ring members  141  in each pair are mounted on a corresponding one of the hinge plates  131 . As the hinge plates  131  and ring members  141  pivot between the open and closed positions, the hinge plates pass through a co-planar orientation with one another at which point the hinge plates have deformed the housing  115  to spread the sides  119  of the housing far enough apart to accommodate the combined width of the hinge plates. This toggling action results in the housing  115  applying a spring biasing force tending to hold the rings  105  in the closed position when the rings are closed and tending to hold the rings in the open position when the rings are in the open position. 
     The housing  115  has openings  151  in its sides  119  for receiving the ring members  141 . The openings  151  extend laterally inward toward the longitudinal centerline  153  of the elongate housing  115 . The openings  151  are suitably notches that extend laterally inward from the sides  119  of the housing, as illustrated in  FIGS. 4 ,  7 , and  8 . Because the notches  151  extend all the way to the sides  119  of the housing  115 , it is possible during assembly of the ring mechanism  101  to insert the ring members  141  into the notches transversely from alongside of the housing (e.g., using an automated machine) without requiring the end of the ring member to be inserted through the opening. The longitudinally-aligned openings  151  for each ring  105  create a relatively narrow neck  161  in the housing  115  where the width W 1  ( FIG. 9 ) of the housing is significantly less than the overall width W 2  of the housing between the sides  119 . When the openings  151  are notches, as in the illustrated embodiment, the relatively narrow neck portion  161  of the housing  115  provides the only resistance to accidental bending of the housing at the neck. 
     The openings  151  do not extend as far inward toward the longitudinal centerline  153  of the housing  115  as the openings do in some conventional ring mechanisms. The housing  115  suitably has a vault-forming portion  165  ( FIGS. 7-9 ) at the inner margin of at least one of the openings  151 . As illustrated in  FIG. 4 , there is a substantially identical vault-forming housing portion  165  at the inner margin of each opening  151  in the housing for the ring members  141 , but this is not required within the broad scope of the invention. If desired, some of the advantages of the invention can be attained by including vault-forming housing portions at less than all of the openings for the ring members, including without limitation all of the openings on only one side of the housing, only a pair of openings on opposite sides of the housing for the ring members of a just one or more but less than all of the rings, or even just a single one of the openings. 
     The vault-forming portion  165  of the housing  115  is suitably spaced from the longitudinal centerline  153  of the housing so the inner margin of the opening is offset from the longitudinal centerline. For example, as illustrated in  FIGS. 7 and 8 , one of the full-length longitudinally extending ribs  125  is positioned between each vault-forming portion  165  of the housing and the longitudinal centerline  153  of the housing. The vault-forming portion  165  is raised above longitudinally adjacent portions  167  of the housing spaced the same distance from the centerline  153 . The vault-forming portion  165  is also spaced from the centerline  153  of the housing  115  by a non-vault forming portion  173  of the housing that is axially aligned with the opening  151  for the adjacent ring member  141  and that is not raised above axially adjacent portions  175  of the housing spaced the same distance from the centerline as the non-vault forming portion  173 . 
     The vault-forming portion  165  of the housing  115  forms a vault  171  in the lower surface of the housing at the inner margin of the opening  151 . The vault  171  is a space in the ceiling formed by the underside of the housing  115  that extends above the underside of the housing at locations longitudinally adjacent the vault and spaced the same distance laterally from the longitudinal centerline  153  of the housing as the vault. The vault  171  is sized and shaped to receive at least a portion of segment of the ring member  141  associated with the corresponding opening  151 . The vault  171  extends laterally inward from the inner margin of the opening  151  For example, when the rings are closed as illustrated in  FIG. 7 , a portion of the segment of the ring member  141  adjacent the opening  151  is received in the vault  171 . The vault-forming portion  165  of the housing  115  provides additional clearance for the ring members  141 , especially in the closed position. For example, the vault  171  formed under the vault-forming portion  165  of the housing  115  allows the ring members  141  to pivot to the closed position notwithstanding a relatively low-profile of the housing and/or without requiring an unduly narrow neck  161  in the central portion  117  of the housing. 
     For example, the width W 1  ( FIG. 9 ) of the neck  161  is suitably at least about 40 percent of the width W 2  of the housing, more suitably at least about 50 percent of the width W 2  of the housing, and still more suitably at least about 65 percent of the width W 2  of the housing. Thus, the vault-forming portion  165  of the housing  115  can facilitate use of a lower profile housing without restricting the range of motion of the ring members  141  and can facilitate making the housing from a thinner piece of sheet metal or other material because the extra width at the neck  161  created by vault-forming portion(s)  165  of the housing augments the housing&#39;s resistance to bending at the neck between the openings  151 . Also, referring to  FIG. 9 , the vault forming portion  165  is disposed at an angle relative to the non-vault forming portion  173  of the housing at the inner margin of the vault forming portion and this can also increase resistance of the housing to bending at the neck  161  by increasing the bending moment of inertia of the housing  115  at the neck. 
     The vault-forming portion  165  of the housing is suitably a relatively small structure that does not extend very far from the opening  151 . The vault-forming portion  165  suitably does not extend above the central portion  117  of the housing  115 . For example, the vault-forming portion  165  of the housing  115  suitably extends no farther than about the diameter of the cross-sectional shape of the ring members  141  from the margins of the adjacent opening  151 . Accordingly, the vault-forming portion  165  of the housing  115  does not increase overall height of the housing. The vault-forming portion  165  also adds little or nothing to the amount of material needed to make the housing  115 . 
     The vault-forming housing portion  165  can have various shapes or configurations within the scope of the invention. As illustrated in  FIGS. 7-10 , for example, the vault-forming portion  165  of the housing has an upper surface  177  ( FIG. 10 ) having a convex curvature in the longitudinal direction of the housing  115 . In this embodiment the vault-forming portion  165  of the housing  115  comprises an arch formed at the inner margin of the corresponding opening  151 . The arch has feet  179  at its opposite ends at opposite sides of the opening  151  and on opposite sides of the adjacent ring member  141 . The vault-forming arch  165  has an apex  181  that is aligned axially on the housing  115  with the adjacent ring member  141 . Moreover, the vault-forming arch  165  extends laterally of the housing  115  and has crest  183  extending transversely inward of the elongate housing  115  from the apex  181  of the outer end of the arch  165  to the non-vault forming portion  173  of the housing ( FIGS. 7-8 ). The vault  171  formed by the vault-forming portion  165  of the housing  115  suitably forms a short tunnel extending from the inner margin of the opening  151  toward the centerline  153  of the housing  115 . As illustrated in  FIG. 9 , which is a cross section taken in a plane including a line extending along the crest  183 , the highest point of the crest is suitably at the outer end of the vault forming arch  165 . Moreover, the crest  183  can also be level or inclined downward toward the outer end of the vault-forming portion  165  within the scope of the invention, or have other configurations within the scope of the invention. 
     A suitable arch-shaped or other vault-forming housing portion  165  can be made by forming an upturned arch-shaped lip on the housing  115  at the inner margin of the opening  151 . As used herein the phrase “upturned” does not require the feature to actually extend upward. Instead, a feature such as the lip  165  is also considered “upturned” when it is curved so it does not slope downwardly as rapidly as adjacent portions  167  of the housing  115 . Moreover, the phrase “upturned” is intended to describe the end shape of the feature and does not require any particular method of manufacture. Referring again to  FIGS. 7 and 8 , the vault-forming portion  165  of the housing  115  can also be recognized in this embodiment as a feature that results in a raised bump at the inner margin of the opening  151 . The bump  165  is configured to extend over the segment the corresponding ring member  141  when the rings are in the closed position. 
     The housing  115  also has at least one dimple  191  positioned along the longitudinal centerline  153  of the housing in the central portion  117  of the housing. For example, the illustrated embodiment includes four such dimples  191  as may be seen in  FIG. 2 . Those skilled in the art will recognize the purpose of these dimples  191  is to form a sturdy dome-shaped structure that extends downward from the central portion  117  of the housing  115  toward the hinge plates  131 . Analogous dimples are provided in axial alignment with the rings of at least some prior art ring mechanisms. The dimples  191  protect the housing  115  from being damaged by the stiff hinge plates  131  as the rings  105  move into the open position by providing a relatively sturdy dome-shaped engagement surface on the underside of the housing to absorb the impact of the hinge plates as they snap into the open position under the influence of the spring force from the housing. As illustrated in  FIGS. 2 and 4 , each of the dimples  191  is suitably spaced longitudinally of the housing from the necks  161  and the openings  151  in the housing  115  associated with the necks. Accordingly, each dimple  191  is offset longitudinally of the housing  115  from the ring members  141 . None of the dimples  191  is aligned axially on the housing  115  with any of the necks  161 , openings  151 , or ring members  141 . Accordingly, the transverse cross sections of the housing taken in a plane including a line axially aligned with the rings (e.g.  FIG. 9 ) does not section any portion of any of the dimples  191 . Further, each of the necks  161  is substantially free of dimples  191  that are impacted by the hinge plates  131  when the rings  105  open. This protects the housing  115  from being impacted by the hinge plates  131  at the relatively thin necks  161  and causes the impact forces from the hinge plates to be absorbed by a more robust portion of the housing  115  away from the necks. 
     The additional resistance to bending of the housing  115  resulting from the vault-forming housing portions(s)  165  is particularly advantageous during manufacture and assembly of the ring mechanism  101  because the housing is most vulnerable to accidental bending before the hinge plates  131  are assembled in the housing. Accordingly, the vault-forming portions  165  can decrease the precautions that are needed during manufacture and assembly of the ring mechanism  101  to protect the housing  115  from damage. The vault-forming portions can also reduce yield loss associated with damage accidentally inflicted on the housings  115  during manufacture. After the housing  115  is combined with the hinge plates  131 , the relatively stiff hinge plates provide substantial reinforcement that greatly reduces the vulnerability of the housing to accidental bending or other damage. Nevertheless, the ring mechanism  101  still benefits from the additional strength in the housing  115  after assembly is complete. 
       FIG. 11  illustrates a second embodiment of a ring mechanism. This mechanism is identical to the ring mechanism  101  described above except that for at least one of the ring member openings  251  (e.g., all of the ring member openings, the ring member openings along one side, or only a single ring member opening) of the housing  215  includes a strip  293  of material extending around the opposite side of the ring member  141  so the housing extends completely around the ring member. The strip  293  is suitably produced by forming the opening  251  from an opening near the side edge of a sheet metal blank used to make the housing that is spaced the width of the strip inward from the edge of the blank by the width of the strip. Accordingly, when the sheet metal blank is stamped or otherwise formed into the housing, portion of the blank between the opening and the side edge of the blank becomes the strip  293  of material at the side  119  of the housing (e.g., as part of the bent under rim  121 ). The housing  215  includes one or more vault-forming portions  165  as described above. The additional strip  293  of material makes the housing more resistant to bending than the housing would be without this strip of material. During assembly, the ring member  141  is inserted end first through the opening (e.g., manually or using machines that do not rely on the ability to insert the ring member into the opening through the open side of a notch). In all other respects, the mechanism operates as described for the mechanism  101  above. 
     When introducing elements of the present invention of the preferred embodiments thereof, the articles “a”, “an”, “the”, and “said” are intended to mean that there are one or more of the elements. The terms “comprising”, “including”, and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. 
     In view of the foregoing, it will be seen that the several objects of the invention are achieved and other advantageous results attained. 
     As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.