Abstract:
An improved binder formed of two cover portions made of rigid material joined together with a living hinge is disclosed. A closure flap with a second living hinge joins the free ends of the cover opposite the binder spine. An improved method of attaching a pocket to the binder is also disclosed. The use of such a technique on rigid polypropylene material allows roll feeding of materials, eliminates the need for a chipboard, allows existing printing and sealing machinery to be employed in the manufacture of the binder, and provides improved durability and aesthetics at a low cost. One cover portion may be adapted with number design features to properly align one cover portion relative to the other cover portion. A pocket formed of rigid material may also be coupled to one of the cover portions.

Description:
RELATED APPLICATION 
     This is a continuation-in-part application of pending application Ser. No. 09/167,348, filed Oct. 7, 1998, now U.S. Pat. No. 6,030,140, which is hereby incorporated by reference into this application. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of Invention 
     The present invention relates generally to multi-ring binders for the educational market. 
     2. Description of Related Art 
     Three-ring binders made of a flexible outer jacket having a spine with a metal three ring clip are known in the art. The edges of such multi-ring binders are sometimes held together with Velcro or other such hook-and-loop fasteners Many schools have banned such hook-and-loop fastener binders because school children make excessive noise opening and closing these binders. 
     In addition, when mass-producing binders unit costs must be kept as low as possible, while maintaining a high quality look and feel to the binder. One area of cost involves the need to cut and size plastic stock used to make binders on conventional RF welding binder machinery. 
     Further, it has been found that users prefer the texture, thermal conductivity, resiliency and look and feel of certain materials. Consumers are willing to pay a premium for products that are aesthetically pleasing to the touch. Further, consumers are also willing to pay a premium for products that are more durable, and have a sleek look to them, such as for products made from injection molded polypropylene. 
     At the same time, consumers want binders that are easy to use and durable. That is, the injection molded binder should open and close easily and be well constructed to withstand the stress of repeated use by a user. In particular, some injection molded binders have a pocket made of extruded film designed to hold sheets of paper. However, after some use, the pocket made of extruded film is too weak to hold sheets of paper. In other words, the extruded film pocket is not rigid enough to hold sheets of paper. Furthermore, after some use, the extruded film pocket tends to rip. 
     Thus, there still is a need for a binder made of injection molded plastic that is easy to use, reliable, and which has a pocket capable of holding sheets of paper for an extended period of time. 
     SUMMARY OF THE INVENTION 
     Accordingly, the object of the present invention is to provide an improved three-ring binder that solves the above mentioned problems using both improved materials and improved mechanical design. 
     The present invention discloses a plastic binder that is made from plastic material, preferably injection molded polypropylene, in a novel configuration, that is both easier to manufacture in a single pass operation using existing machinery, which holds down unit costs, as well as being aesthetically pleasing. 
     The present design of an embodiment of the present invention, involving a pocket and living hinge latch and fastener, has numerous features and advantages, including but not limited to: 
     a non-Velcro type fastener, which makes less noise when opening; 
     a living hinge fastener or binder closure that is manufactured on the first pass of a production process; 
     the incorporation of a pocket manufactured on a roll process, rather than cut from one or more sheets, to incorporate the pocket into the binder on the first pass of a production process; 
     the use of a perforated mechanism for attachment of a pocket allows a press operator to easily attach the pocket by snapping it to the binder cover during the press operator&#39;s down time, avoiding the need for an additional assembly line process; 
     a contemporary, aesthetically pleasing design is made without excessive weld lines, bumps or creases; 
     the use of a strong, rigid material, such as injection molded polypropylene, combines an impression of durability and aesthetics; 
     the use of a rigid polypropylene shell as one of the binder covers in a unitary, one-piece manner eliminates the need for an underlying inner chipboard for strength; 
     the use of dual soft and hard textures on the cover, which aid to aesthetics and have utilitarian functions; 
     cover portions may be provided with a number of design features to properly align one cover portion to the other cover portion; 
     a pocket formed of injection molded plastic may be ultrasonically welded to one of the covers. 
     The sum total of all of the above advantageous, as well as the numerous other advantages disclosed and inherent from the invention described herein increases consumer satisfaction and helps expand the market for binders throughout, especially from the kindergarten to high school level. 
     The above described and many other features and attendant advantages of the present invention will become apparent from a consideration of the following detailed description when considered in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Detailed description of preferred embodiments of the invention will be made with reference to the accompanying drawings. 
     FIG. 1 is a perspective plan view of the present invention, a binder. 
     FIG. 2 is top view of the binder shown in FIG. 1; 
     FIG. 3 is a bottom view of the binder shown in FIG. 1; 
     FIG. 4 is a right side view of the binder shown in FIG. 1; 
     FIG. 5 is a left side view of the binder shown in FIG. 1; 
     FIG. 6 is a top end view of the binder shown in FIG. 1; 
     FIG. 7 is a bottom end view of the binder shown in FIG. 1; 
     FIG. 8 is a front view of the binder of FIG. 1 opened; 
     FIG. 9 is a view along the section lines  9 — 9  in FIG. 8; 
     FIG. 10 is a broken view of a pocket inlay for the binder; 
     FIG. 11 is a cross sectional view along the binder closure mechanism; 
     FIG. 12 is an another embodiment of a binder in an open position; 
     FIG. 13 is a cross sectional view along the section line  13 — 13  of the binder in FIG. 12; 
     FIG. 14 is an enlarged perspective view of the bottom end of the binder in FIG. 12; 
     FIG. 15 is an enlarged perspective view of the right side of the binder in FIG. 12; 
     FIG. 16 is a right side view of the binder in FIG. 11 in a slightly open position; and 
     FIG. 17 is a cross sectional view along the section line  17 — 17  of the binder in FIG.  16 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Disclosed herein is a detailed description of the best presently known mode of carrying out the invention. This description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention. The section titles and overall organization of the present detailed description are for the purpose of convenience only and are not intended to limit the present invention. 
     FIGS. 1-11 disclose the binder of the present invention. The binder  10  has a cover  12 , with front or top portion  14 , which has an outside side (as shown in FIG. 1) and an inside side (as shown in FIG.  8 ), and a similar back or bottom portion  16 , with similar outside and inside sides. The cover has a spine  18  in between the two covers, and free open end edges  20 ,  22 , which may be curved into mating end portions  21 ,  23 . A three-ring metal latch or clip  24 , for holding paper, is attached to the back cover  16  to allow the rings to face upwards, as shown, or, alternatively, to the spine. One such metal latch is described in U.S. Pat. No. 5,354,142, incorporated herein. Other designs, such as a clasp or clamp, can be used to hold paper. 
     Crease lines  28 ,  29  form a living hinge between the front and back covers and the spine of the binder. The living hinge lines  28 ,  29  may be formed of the same material as the cover, e.g., in a preferred embodiment injection molded polypropylene material, or, may be formed of a different material fastened to the material forming the cover, such as plastic tape. 
     At the shaded portions shown in FIG. 1, such as shown by dotted shading  25 , a soft, thin layer of vinyl, rubber or thermoplastic material (such as TPR) may be adhesively secured to the underlying polypropylene, to provide a non-skid surface and for aesthetic reasons. Similarly, for aesthetic reasons and to convey information the polypropylene may be imprinted with printed matter or colors. When employing polypropylene as a material, the inks used may be of the same kind used by machinery for imprinting vinyl. 
     The binder has open edges  20 ,  22  held closed by a closure fastener flap mechanism  31 . The open ends  20 ,  22  have flap portions  21 ,  23 , which may be rigid extensions of the covers  14 ,  16  respectively (i.e., the flaps may be the covers  14 ,  16  curved at the open ends to meet together) engaged by the closure flap mechanism  32  to better seal the contends of the binder and prevent documents from falling out. 
     Regarding the closure fastener or binder closure, a lower clasp or semicircular lower flap  32 , which may be formed of the same material as the cover, has a single latch protrusion  36  which extends from the lower flap  32  at right angles. The flap  32  is attached to the lower cover  16  through a living hinge. The living hinge may be formed from the same material constituting the lower cover  16  and lower flap  32 , or, may be formed of a different, more flexible material to join together the more rigid lower cover and flap materials, which in a preferred embodiment are made of injection molded polypropylene material. 
     Protrusion  36  is received by a latch aperture or depression  42  found in the mating semicircular recessed depression  40 . The depression  40  contains a thumb well  30  for allowing a user to engage the tip of one&#39;s finger in the thumb well  30  and disengage the binder closure lower flap  32 . The semicircular recessed depression  40  is molded into the upper portion of the binder closure, forming the mating upper fastener portion  38 , and receives the lower latch  32 . Upper fastener  38  is part of the upper cover portion  14  in the upper flap  21 . When protrusion  36  is received within aperture  42 , the binder is snapped shut along the open edges  20 ,  22 . The closure flap  32  forms an aesthetic oval shape when viewed from the top and end, as shown in FIGS. 2 and 4. A thumb recess  30  about the aperture  42  allows easy opening of the flap with one&#39;s fingernail. The lower flap  32  allows the open ends of the binder to close and gives an aesthetically pleasing look to the binder, as well as protecting the binder more completely. 
     Turning attention to FIG. 11, there is shown the end flaps  21 ,  23 , which meet at a ledge  110 , forming a stepped recess. The latch mechanism  31  is shown in the closed position, with lower flap  32  received by the upper fastener portion, and rubber or vinyl surface layer  25  (which has shading as indicated because some of the surface layer  25  is in relief) forming a non-skid and aesthetic surface. 
     The binder  10  is preferably formed of injection molded polypropylene material, a substantially rigid or semi-rigid material. An optional pocket inlay may be attached to the upper cover through a hook and aperture arrangement as described herein, such as shown by section lines  9 — 9  in FIG.  9 . Pocket  44  has raised finger hold  46  and a pen hold recess  48  molded in it. 
     In FIGS. 9-10 show how the binder pocket  44  is attached to the upper half portion  14  of the cover  10  during manufacture, by a tooth and aperture arrangement  50 , to help form a mechanical interlock. Both pocket  44  and the cover  10  are made of substantially hard material, injection molded polypropylene, which also forms the bottom cover  16 . A plurality of hooks or teeth  52  in the cover  14  mate with apertures or recesses  54  in the pocket  44 . The hooks are formed with outward hook portions  56  that have a flat surface engaging the flat portion  58  of the pocket  44 . 
     Turning attention now to FIG. 9, there is shown a cross-section  9 — 9  of a portion of the upper cover  14  of binder  10 , which incorporates the hook and aperture seam  50  for holding the pocket  44  to the upper cover  14 . The pocket may be on either the outside of the upper cover (not shown) or, as illustrated, on the inside of the upper cover. The inside pocket  44  is generally formed of the same material as the cover, preferably injection molded polypropylene, but optionally may be made of a different material. Furthermore, the pocket  44  may be attached to the binder cover by a press operator during the press operator&#39;s down time, in an easy snap fit manner, by taking advantage of the mechanical interlock between the pocket inlay and the cover. 
     Other pocket designs are contemplated by the present invention, such as, in lieu of a pocket inlay sheet  44  that mechanically interlocks with the cover portion, having a pocket flap that is formed from the same stock roll forming the cover, and attached at the bottom side of the cover (e.g., where section line  9 — 9  is shown in FIG. 8) by a living hinge, so that the pocket folds about this living hinge attached at the bottom side of the cover. The pocket flap would be prevented from flapping about by being attached at the top of the pocket to the cover (e.g., at the top where finger hold  46  is) by mating studs and holes. This design eliminates the requirement of a separate pocket inlay, at the cost of having to provide a wider stock of material for the cover during assembly (as the pocket inlay would be attached, at its living hinge portion, to the bottom side of the cover at section line  9 — 9 ). 
     The stock forming the binder  10  itself can be cut to size during manufacture using the RF sealing die. The binder, like the pocket, can also be cut to size and shape by the RF sealing die, as both materials are roll fed together in contiguous layers, avoiding the prior techniques of heat sealing of sheets that are fed together by sheet feeding. 
     Thus, the method of manufacture for the two material binders of the present invention comprises feeding into an RF sealing die a first continuous stock or roll of PVC material, such as injection molded polypropylene. The injection molded polypropylene may come in injection molded form. The injection molded polypropylene forms the cover  10 comprising two cover portions of the binder, covers  14 ,  16 , and spine  18 . Suitable living hinges, such as at fold lines  28 ,  29 , connect the covers and spine. The living hinge may simply comprise crease or score lines  28 ,  29  of the same material as the covers  14 ,  16  and spine (which may be formed of a continuous sheet of material), or, the living hinge may be made of a separate, more flexible material, such as a polypropylene living hinge, which tapes together the three portions of cover  14 , cover  16  and spine  10 . A second roll of injection molded polypropylene is then used to form the pocket, such as pocket  44  in FIG.  8 . As described above, the edges where the two materials forming the cover  14  and pocket  44  meet are joined with mating structures, such as teeth  52  in FIGS. 9-10 mating with apertures  54 . The use of such a perforated mechanism for attachment of a pocket allows a press operator to easily attach the pocket by snapping it to the binder cover during the press operator&#39;s down time, avoiding the need for an additional assembly line process. The two materials, once aligned so that hook and aperture mate, they can, if desired, be radio frequency (RF) welded, heat sealed, ultrasonically welded, mechanically fastened, interlocked or otherwise further secured together. The cover can be printed on, and PVC is easily imprinted on with existing vinyl binder industry inks and machinery. For final assembly, the metal latch is attached to the cover with nuts and bolts or rivets, or other known technologies. 
     Another embodiment of the present invention is illustrated by way of example in FIGS. 12 through 17. Here, a binder  100  has a number of features designed to make the binder more durable and easier to use. As shown in FIGS. 12 and 14, a pair of guides  102  are coupled to the interior side of the spine  18 ′ (hereinafter primed reference numerals are used to indicate similar elements as described in FIGS. 1 through 11 in the previous embodiment). As best shown in FIG. 14, the pair of guides are positioned to mate with the top and bottom rings of the three ring metal latch mechanism  24 ′ as the top cover  14 ′ is closed relative to the bottom cover  16 ′. The guides ensure that the top cover is properly aligned with the bottom cover. In other words, the guides prevent the top cover from over-extending relative to the bottom cover because of the proper spacing between the spine and the three ring metal latch. Preferably, the guides have a predetermined length “L” to provide the proper spacing between the spine and the three ring metal latch, as shown in FIG.  14 . The length “L” of course may be varied depending on the configuration of the spine and the three ring latch mechanism for a particular binder. 
     As further shown in FIG. 14, each of the guides preferably has a notch  104  to accommodate its respective metal ring to ensure that the guides will securely mate with the metal ring. Incidentally, at rest, that is when the binder is not being handled, the guides may or may not be in direct contact with the respective metal rings. However, when the binder is being carried such that the pressure is being applied to the spine or the covers, the guides will engage with its respective metal rings. Once the notch of the guide engages with the metal ring, the spine is prevented from moving side to side relative to the three ring mechanism. That is, the guides not only align the top cover relative to the bottom cover, but they also prevent side to side movement between the top and bottom covers to minimize the stress applied to the fold lines  28 ′,  29 ′. This of course prolongs the life of the fold lines  28 ′,  29 ′. 
     Although this embodiment discloses two guide members, an embodiment with single or more than two guide members is within the scope of the present invention. 
     To further assist in aligning the top cover relative to the bottom cover, FIG. 15 shows a top tooth  108  on the mating end portion  21 ′ of the top cover, and a pair of teeth  106  at the interior side of the bottom cover and near the end of the mating end portion  23 ′. The tooth  108  is positioned to associate in between the pair of teeth  106 . As the top cover closes, the pair of teeth  106  guides the top tooth  108  into proper position so that the mating end portions  21 ′,  23 ′ are properly aligned. Note that the width of the top tooth  108  is substantially similar to the distance between the two teeth  106 . 
     Furthermore, once the top tooth  108  is in position between the pair of teeth  106 , the top tooth is prevented from moving side to side. In other words, like the guides  102 , the top tooth prevents the top cover from moving side to side relative to the bottom cover. Thus, the combination of tooth and the pair of teeth minimizes the stress that may be applied to the score lines  28 ′,  29 ′ as the binder is applied with external forces from handling. Also, once the top tooth is engaged between the pair of teeth, the pair of teeth prevents the end portion  21 ′ from moving laterally toward the three ring mechanism. 
     To lock the top and bottom covers together, FIG. 15 shows a pair of latching protrusions  110  positioned to associate with an opening  112  at the mating end portion  21 ′. That is, the closure flap mechanism  32 ′ is flipped over to engage the pair of latching protrusions  110  into the opening  112 . Having a pair of latching protrusions independent of one another provides a more positive latching mechanism and strength to resist the covers from being pulled off unintentionally. As shown in FIGS. 16 and 17, all the features discussed above in this embodiment ensures that the front cover self-adjusts relative to the back cover for proper alignment. That is, as shown in FIG. 16, as the front cover is closed relative to the back cover, the guides  102  ensure that the front cover does not over-extend beyond the back cover. Furthermore, the guides also allow the spine to rest against the three ring metal latch to provide additional support for the front cover when the binder is compressed, handled or carried. As the front cover moves closer to the back cover, the pair of teeth  106  in conjunction with the upper tooth  108  help to further assist in aligning the front cover to the back cover, to ensure that there is no lateral misalignment between the two covers. Once the front and the back covers are in the closed position, the closer flap mechanism  32  is flipped over to lock the front and back covers together via the pair of latching protrusions  110  engaging with the opening  112  as shown in FIG.  17 . Thus, the guides, the upper tooth, the pair of teeth, all work together to properly align the front and back covers together. 
     As shown in FIG. 14, the spine  18 ′ is curved like the upper left quadrant of a quarter circle. As such, the transition between the spine and the top cover is much smoother than the transition between the bottom cover and the spine. Accordingly, as the top cover is opened and closed relative to the bottom cover, the hinged line  29 ′ has a greater play than the hinged line  28 ′. In other words, the binder  100  with the curved spine  18 ′ pivots mostly along hinged line  29 ′. One of the advantages of having a top cover that pivots substantially about the hinged line  29 ′, rather than both hinged lines  28 ′,  29 ′, is that the top cover is more surely constrained to align with the bottom cover as they are closed. For example, a box with a single hinged top will always close in the same position; but if there were two equally active hinged lines, there is greater chance of misalignment. Thus, where there is a single hinge where most of the pivoting occurs, there is more accuracy in aligning the top cover relative to the bottom cover. 
     Of course, a spine with a plainer surface is within the scope of this invention. Preferably, in this instance, one hinge has greater play over the other hinge line, so that the two covers will align more accurately. 
     With regard to the pocket  44 ′, as discussed above, the pocket  44 ′ is preferably ultrasonically welded to the front cover  14 , along the contact areas  114  as shown in FIG.  13 . That is, the pocket  44 ′ is ultrasonically welded to the cover  14  along the contact areas rather than being snapped on as disclosed in one of the previous embodiments. Preferably, a continuous ultrasonic weld is used; however, periodic spot welds are within the scope of this invention. One advantage to the ultrasonic weld is that it provides a strong coupling effect between the pocket and the cover. Strong coupling provides rigidity to the pocket itself so that it is better able to hold sheets of paper within the pocket, so that even if the binder is held upside down, the paper will not fall out. Preferably, outer edges of the pocket  44 ′ is coupled to the cover along the bottom and the left-hand sides  116 ,  118 , respectively, as shown in FIG.  12 . This allows a user to easily insert and remove papers from the pocket, and allows the pocket to expand to hold more papers. Alternatively, a combination of mechanical interlocks, as shown in FIGS. 9-10, and ultrasonic weld may also be used to couple the pocket to the cover. 
     With regard to the material and welding process, any combination of material and the welding process may be used that is known to one of ordinary skill in the art. For example, materials may include (but are not limited to): rigid or semi-flexible polyvinyl chloride (PVC), ethylene vinyl acetate (EVA), polyurethane and nylon. With regard to the welding process, the pocket may be welded to the binder via a radio frequency welding or ultrasonic welding, for example. Additional coupling means such as heat sealing and adhesive may also be used. Also, the pocket need not be made of the same material as the binder. 
     Although the present invention has been described in terms of the preferred embodiments above, numerous modifications and/or additions to the above-described preferred embodiments would be readily apparent to one skilled in the art. Thus, by way of example but not of limitation, the mechanical interlock for holding the pocket in place could be an enlarged stud or mushroom shaped stem mating with a slightly smaller opening in the pocket. Also, a binder without the latching mechanism is within the scope of the present invention. Furthermore, where the three ring latching mechanism is coupled to the spine, the guides may protrude from one of the top or bottom covers to associate with the ring mechanism. With respect to the claims, it is applicant&#39;s intention that the claims not be interpreted in accordance with the sixth paragraph of 35 U.S.C. §112 unless the term “means” is used followed by a functional statement.