Book cover corner guard
This is a continuation-in-part of co-pending application No. 08/423,773 filed on Apr. 18, 1995. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates generally to protective corner guards for pages or book covers, especially thin flexible book covers such as is used on paperback books, and more particularly to an improved corner guard configured to allow opposing pages or book covers to slide easily over the guard without catching on its edges, while also helping the protected corner from becoming creased, torn or weakened. 
     2. Description of Related Art 
     Many documents, both bound and unbound, include a cover constructed from paper, cardboard, leather or the like that is designed to protect the enclosed sheets of the document. Unfortunately, covers are themselves susceptible to gradual wear and progressive damage, and once a cover becomes significantly damaged, the enclosed pages are left with less protection and are thus more subject to damage. Invention and use of complete document covers are well known to the public, as there is a wide variety of different paper, plastic and cloth covers available to protect the entire document cover. However, these cover protectors are generally bulky, inconvenient and difficult to properly position over a book cover. In addition, they obscure a book cover and its design. 
     The corners of a document are typically the most susceptible to being bent or torn, which is particularly undesirable since corner damage makes it difficult to easily and quickly turn the pages of the document. Thus, invention and use of protection devices designed expressly to protect page and book corners is well known to the public. Corner protectors are much more light weight and non-obtrusive than full page covers designed to cover the entire document cover. 
     Prior art corner protectors have typically been constructed with one of two different basic configurations. The most common configuration consists essentially of a triangular strip of heavy duty paper, cardboard or metal that fits across the outer surface of a corner providing an edge that is at approximately a 45° angle to the edges of the page or book cover. 
     For example, Leander U.S. Pat. No. 2,728,451 discloses a corner protector that is the shape of a right triangle. A perforation is positioned along the height of the triangle, thereby effectively dividing the protector into two smaller right triangles. To position the protector over the corner, one of the two smaller triangles is placed over the front side of a corner so that the right angle of the protector is aligned with the right angle of the corner and the perforation is aligned with one of the edges of the paper. The protector is then simply folded along the perforation so that the other of the two triangles covers the back side of the corner in the same manner. 
     Moskowitz U.S. Pat. No. 1,676,741 discloses a corner protector that is formed of two pieces of triangular metal. The two pieces are of identical size and shape and are designed to be engaged with a beaded clamping means. Thus, to protect a corner, one piece of metal is aligned with the back of the corner and the other piece is aligned with the front of the corner and the two pieces are then clamped together. 
     Wright et al. U.S. Pat. No. 536,315, Akins U.S. Pat. No. 295,141 and Martin U.S. Pat. No. 318,486 all disclose similar corner protecting means in which the protector covers the front side of the corner at a 45° angle. These protectors differ only in their specific methods of folding and application. 
     While corner covers with this 45° structure may effectively protect the underlying portion of the corner from excessive damage, the protectors themselves often damage the corner. Damage occurs because, with the corner guard in place, the reinforced corner does not tend to bend and flex naturally, but instead always creases sharply along the edge of the guard. Thus, a large, permanent crease gradually forms in the corner along the edge of the guard, which, over time, may actually cause the protected corner to be severed from the rest of the cover. 
     The other major corner protector configuration is essentially L-shaped, with an elongate strip of material aligned with each of the edges of the corner. This type of protector is illustrated in both Milton U.S. Pat. No. 1,773,742 and Weaver U.S. Pat. No. 308,718. Although this configuration appears to improve over the previously described protectors in that it does not cut directly across the corner with a straight edge, it still causes the corner to bend in a linear path. With the L-shaped design this creasing occurs because the terminal ends of the protector become pressure points onto which the forward force generated while turning the corner is transferred. This pressure is then transferred from each of the pressure points directly across the corner, thus causing a linear crease to form in the cover along an imaginary line interconnecting the ends of the protector. In addition, L-shape protector covers and protects only the outermost edges of the corners, thus leaving a much larger surface area uncovered than the prior art employing the 45° design. In addition, the exposed portion of the corner along the edge of the L-shaped protectors is generally very weak and susceptible to puncture. 
     Even further, all of these prior art devices provide sharp, pointed edges and corners, and are thus prone to easily catching on items such as a page or cover of a book, or a fingernail, etc. This is obviously undesirable, and may result not only in scraping or scratching the particular item, but also in tearing or premature wearing of the corner guard itself. 
     Thus there is a significant need for an improved corner protector that can overcome all of the disadvantages of the prior art. Unlike the prior art, such a corner would not cause a linear crease to form in the corner of the cover. 
     The present invention fulfills these needs and provides further related advantages as described in the following summary. 
     SUMMARY OF THE INVENTION 
     The present invention is an improved corner guard designed to more comprehensively protect the corners of a book from excessive wear or damage. In addition to comprehensively protecting a corner, the present invention also protects the surface of the cover, the edges of the cover, and the pages underlying the cover from damage. The corner guard is especially suited for protecting the corner of a book cover, but it may also be used to protect the corner of a wide variety of different objects, such as poster board or sheet metal, as long as the corner to be protected is relatively flat and is formed having two perpendicular edges. The corner guard improves significantly over prior art corner protecting means in that it protects the corner not merely from long-term wear and damage but also from corner bending, creasing or puncturing. 
     The guard of the present invention preferably is made of a heavy paper stock of reinforced, laminated or impregnated material or a rigid plastic sheet material and is cut, in the flat, into a useful shape consisting of a guard body with a bottom surface in contact with and adhered to a book cover, and a top surface facing away from the book cover. Thus, it is a primary object of the invention to rigidize the book corner so that it cannot be easily creased, torn or otherwise damaged. 
     Two orthogonal fold lines define edges of the corner guard when it is folded around a book corner, the fold lines being preferably aligned with the two edges which form the corner of the book cover. In one of the preferred embodiments a fold-over tab, contiguous with the body, extends outwardly from each of the edges of the book cover. These tabs are designed to be folded over the edges of the book corner and adhered to a back surface of the book cover. That portion of the body immediately adjacent to the book cover&#39;s edges are configured as a pair of fixed edge tab portions. These fixed edge tab portions extend along the edges of the corner, thus protecting the top surface of the corner along both of the edges of the corner. The fixed edge tab portions are designed to allow for a degree of corner flexing and shock absorption without bending. They may have a length that is greater than, equal to, or less then that of the fold-over tabs. Thus, it is an object of the present invention to provide a book cover corner protector that includes a pair of fold-over tabs for sandwiching the edges of a book corner between folded-over and fixed edge tabs, thereby reinforcing the book corner on both of its opposing surfaces. In this embodiment, the guard not only effectively protects the top surface of the corner, but also covers and protects the edges and the back surface of the cover from damage 
     A means for folding enhancement, such as a perforation or pre-score, is preferably formed on the fold line along the length of each tab. The folding enhancement means ensures that the tabs are evenly folded forming a smooth edge along the edge of the book cover. Additionally, a dashed line is preferably imprinted on the body&#39;s top surface over the means for folding enhancement, thus providing a visual aid by which to properly fold the tabs. To even further assist in the folding process, the tabs may additionally include one or more curvilinear portions by which to grasp and manipulate the tabs. These curved portions are also effective in preventing inside pages of the book from catching or tearing on the tabs when they are secured against the back of the cover. Preferably, the tabs are configured so that when both are secured in the folded over position, they abut forming a common edge. Thus, it is an object of the present invention to provide a corner guard that is extremely easy to properly apply to a book corner and which has portions which when folded over the edges of the book corner perfect the implementation of the invention. 
     There are numerous other embodiments of the fold-over tabs that may be successfully implemented into the present invention. For example, in other preferred embodiments of the present invention, the fold-over tabs may be torn off once the guard is accurately aligned with the cover corner, or they may be pre-folded at a right angle to the guard so that with the guard positioned in contact with the corner of the cover page, the tabs extend downwardly along the edges of the book pages. In the later embodiment, a key inventive feature is that the tabs act as a natural shock-absorber by virtue of their spring-like action. Even further, the tabs act as a supporting foundation to keep the entire protector in place against the cover and provide additional, dual-sided protection to the corners, thus further reinforcing them against impact. In this preferred embodiment, the tabs may additionally have an inwardly extending linear ridge positioned for contact with the pages of the book so as to catch on these pages and therefore hold the cover flat against the book. Thus it is one object of the invention to provide a corner guard for a book which also holds the covers of a paperback book in a flat and closed position. 
     When the tabs are configured to permanently remain at right angles to the cover, one or more small, perforated apertures are preferably positioned in the guard so as to accommodate a bookmark leash, adjustable elastic bands, etc. Thus, it is an object of the present invention to provide an easy, convenient means by which to mark a place in the book and/or keep the book covers closed. This is a significant advantage of the present invention, as in the past consumers have been forced to use rubber bands that break and bunch up in an attempt to keep the book covers closed. By threading the bookmark leash or other such elongate, flexible, string-like device through the aperture provided in the fold-over tab, a page or section of the book is easily marked by simply wrapping it vertically around a cluster of pages. Likewise, to keep the book covers firmly closed, the leash is simply wrapped around the entire book, either vertically or horizontally. Thus, the placement of one or more apertures in the fold-over tabs is a novel feature of the present invention in that the consumer can easily install and remove the leash at will without negating any protection features of the guard. 
     Alternately, the corner protector may not include fold-over tabs at all. In this embodiment, the edge of the fixed-edge tabs are simply aligned with the edges of the cover corner in order to properly position the guard. 
     It is a primary object of the present invention to significantly improve over prior art devices by preventing a linear crease from forming across the cover corner. This is accomplished by means of a central portion of the corner guard that extends between the fixed edge tab portions. Unlike prior an devices, the central portion is not designed to extend directly, linearly across the corner at a 45° angle, nor is it designed to transfer force to a pair of pressure points and directly across the corner, as with L-shaped protectors. Instead, it is a key inventive feature of the present invention to configure the central portion of the guard to either extend beyond or inwardly from the imaginary line that extends between the terminal ends of the two fixed tab portions, thus breaking and essentially eliminating any fold path that would otherwise tend to form in the cover. As long as it extends either beyond or inwardly from this line, the peripheral edge of the central portion may take several advantageous configurations. As for example this edge may have two orthogonal portions meeting at an apex, or it may be radiused either outwardly away from the corner, or inwardly toward the corner. Thus, it is an object of the present invention to provide a corner guard that covers substantially more area of the corner than prior L-shaped corners, while also covering the corner in such a way that it does not tend to bend or crease along the edge of the guard. 
     However, the present invention not only provides a design that improves over prior art devices, but it also includes several features that help reduce shelf abrasion, catching and edge fraying of the guard which frequently results from repeated or extended contact with other books, fingers or objects. For example, the edge of the body portion is formed of smooth curves so as not to present a sharp corner to catch on passing paper edges. Additionally, wherever a straight linear edge is provided, such edge is preferably broken by a curved portion. Even further, the perimeter of the entire corner guard preferably has a beveled edge. These features all prevent abutting book pages, book covers and other such objects from catching on the guard, and instead enables objects to easily slide over it. Thus it is an object of the present invention not only to provide a design that improves over prior art devices but also improves the stability and wearability of the corner guard. 
    
    
     Other features and advantages of the present invention will become apparent from the following more detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention. 
     BRIEF DESCRIPTION OF THE DRAWING 
     The accompanying drawings illustrate the instant invention, a book cover corner guard. In such drawings: 
     FIG. 1 is a perspective view of a preferred embodiment of the corner guard, particularly showing the corner guard as positioned over a book corner with fold-over tabs in contact with the rear side of the book corner and a central portion extending outwardly beyond an imaginarly line extending between the two fixed edge tab portions so as to prevent a crease from forming in the cover along the line; 
     FIG. 2 is a top plan view of one embodiment of the guard of FIG. 1 but shown in the flat, particularly showing a pair of fold-over tabs with a length approximately equal to that of a pair of fixed edge tab portions, and a beveled edge along the exterior edges of the guard; 
     FIG. 3 is a view similar to that of FIG. 2, particularly showing the fold-over tabs with a length less than that of the fixed edge tab portions; 
     FIG. 4 is view similar to that of FIG. 3, showing a curved, outwardly extending central portion as an alternate embodiment; 
     FIG. 5 is view similar to that of FIG. 3, showing a curved, inwardly extending central portion as an alternate embodiment; 
     FIG. 6 is an plan view of the reverse side of the book corner demonstrating the positions of the fold-over tabs when positioned thereon; 
     FIG. 7 is a side elevational view of a portion of the corner the guard, particularly showing a means for folding enhancement and the beveled edge of the guard&#39;s perimeter; 
     FIG. 8 is a plan view of one embodiment of the guard of FIG. 1, particularly showing a pair of fold-over tabs designed to be folded at right angles to the guard body for accurate positioning of the guard corner, and then simply torn away; 
     FIG. 9 is a perspective view of another embodiment of the guard of FIG. 1, particularly showing the fold-over tabs fixedly positioned at right angles to the body so as to form a pre-formed tab corner that rests in overlapping adjacency with the corner of the book; 
     FIG. 10 is a cross sectional view of the invention of FIG. 9 taken along line 10--10, particularly showing a rib extending from the delimiting edge of the pre-folded tab portions so as to engage with the pages of the book so as to encourage the shown position of the book cover; 
     FIG. 11 is perspective view of the invention particularly showing an aperture positioned in each of the fold-over tabs so as to hold a bookmark leash captive within the corner guard; and 
     FIG. 12 is an elevational view of the present invention, particularly showing an embodiment in which the invention does not include fold-over tabs. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIGS. 1-10 show several preferred embodiments of the present inventive corner guard designed to protect a corner 5 of a book cover 6 or other sheet product having a corner from excessive wear or damage, provided the corner to be covered is relatively flat and is composed of two perpendicular edges 4. The corner guard can be constructed of a variety of different reinforced flat sheet materials, such as plastic, cardboard, coated paper, sheet metal or stiff leather. The type of material the corner guard is constructed of depends on properties necessary for the intended use of the guard, i.e., strength, flexibility, tear resistance, and so on. In the following description the guard will be described as applied to the corner 5 of a book cover 6, although it is by no means limited to such application. 
     The sheet material is cut, in the flat, so that the corner guard preferably includes a guard body 10, comprised of a pair of fixed edge tab portions 50 and a central body portion 60, and a pair of fold-over tabs 40. The guard body has a top surface 22 and a bottom surface 24. The top surface 22 is designed to face away from the book cover 6 and may be laminated or otherwise reinforced. Additionally, the top surface 22 may include printed indicia, graphics, instructions for proper application of the corner guard, etc. The guard body&#39;s bottom surface 24, on the other hand, is designed to contact and permanently attach to an upfacing surface 6A of the book cover&#39;s corner 5. Thus, the bottom surface 24 is coated with an adhesive layer 26, preferably a hot melt rubber adhesive such as emulsion acrylic adhesive. Either an active or a non-active adhesive layer 26 can be successfully implemented within the scope of the present invention. When an active adhesive layer 26 is implemented, a sheet of non-stick material 28 covers the adhesive layer 26 so that the sheet 28 can be simply peeled from the guard body 10, thus exposing the active adhesive layer 26 when it is desired to adhere the guard to a book cover 6. Alternately, a non-active adhesive layer 26 may be implemented, preferably of the type activated by contact with water or alcohol, etc. 
     The guard body 10 also includes a pair of mutually orthogonal fold lines 30 that intersect at a point 21, thus forming a guard corner 17. The orthogonal fold lines 30 are designed to align with the edges 4 of the book cover corner 5 so that the guard corner 17 covers the top surface 6A of the corner 5 when the fold lines 30 are properly aligned with the edges 4. Preferably, as illustrated in FIG. 2, the point 21 at which the fold lines 30 intersect is rounded so as to keep the point 21 from catching on items while also giving the guard corner 17 added strength against abrasion. 
     The fixed edge tab portions 50 of the guard body abut the fold lines 30 and extend inwardly from them. Each of the fixed edge tab portions 50 preferably includes at least one curvilinear portion 56, as illustrated in the figures. The curvilinear portions 56 effectively prevent other book covers, clothing, skin or the like from catching or scratching on the guard, as the curvilinear portions 56 allow items to slip easily and smoothly over the guard&#39;s edges. The fixed edge tab portions 50 can be constructed to any desired fixed length, preferably not to exceed more than half the width of the book cover 6. 
     The central portion 60 of the guard body 10 extends between the fixed edge tab portions 50. There are numerous possible embodiments of the central portion 60 that can be implemented successfully within the scope of the present invention. However, in all of the different possible embodiments, it is essential that the arrangement of the central portion 60 is such that it does not urge a linear crease to form in the corner 5 along an imaginary line 86 that extends directly between the fixed edge tab portions 50. To prevent creasing from occurring, the central portion 60 of the present invention extends inwardly from or outwardly beyond the imaginary line 86 in a way that breaks any potential fold path and thus does not urge a crease to form along line 86. FIG. 1 illustrates an embodiment in which the central portion 60 extends outwardly beyond line 86. 
     Several possible embodiments of the central portion are illustrated in the figures, although the invention is in no way limited to the illustrated embodiments. In a first preferred embodiment, illustrated in FIGS. 2 and 3, the central portion 60 forms an apex 67 pointing away from the corner 5 of the book cover 6. The apex 67, which is preferably rounded (FIG. 2), effectively serves as an extended strength point of the guard so that when the corner 5 is slightly bent, as is necessary for turning the book cover 6 by grasping the corner 5, the apex 67 transfers the force downwardly toward the center of the cover 6, thus effectively preventing the corner 5 from being creased or torn. In this embodiment, the central portion 60 also preferably includes at least one curvilinear portion 66 on each side of the apex 67. These curvilinear portions 66 give the guard improved structural stability while also helping to reduce shelf abrasion, catching and edge fraying of the guard that can result from repeated or extended contact with other books or items when they are shelved or stacked against the book cover 6. Alternately, the central portion 60 is outwardly curved (FIG. 6), or inwardly curved (FIG. 7). It should be noted that in all these embodiments, the point at which the central portion 60 and the fixed edge tab portions 50 intersect is at least slightly radiused, again to prevent catching and allow objects to move smoothly over the guard. 
     Preferably, a pair of fold-over tabs 40 are attached to and extend laterally from the fold lines 30, each tab thus being foldable along one of the fold lines 30. The fold-over tabs 40 each have a delimiting edge 44 that defines the shape of the tabs 40. The tabs may be rounded, square, rectangular or any other feasible, desired shape. It should be noted that the tabs 40 can be located at any desired position along the fold lines 30. Both tabs 40 may be positioned near the guard corner 17 so that they abut one another in the folded position, or, alternately, they may be spaced apart from one another. The positioning of the tabs 40 may also vary according to the intended placement of each tab. For example, the tabs 40 may be configured so that the tabs on the guard designed to be positioned over the front cover are offset from the tabs on the guard designed to be positioned over the back cover of the book, or they may be configured so that the tabs 40 on the front and back guards align with one another. 
     A fold enhancing means 37 is formed consonant with the fold lines 30 so as to ensure that the tabs 40 are easily and properly folded along the fold lines 30. Preferably the means for folding enhancement 37 is a perforated or pre-scored line (FIG. 7). Such a pre-scored line is produced by indenting the top surface 22 so as to bias the tab 40 to fold along the pre-score, and not elsewhere. The means for folding enhancement 37 must have a width approximately equal to the thickness of the of the cover 6 so that the means for folding enhancement 37 conforms to the edges 4 of the corner 5 when the tabs 40 are folded-over. Additionally, a dashed line (not shown) may be imprinted on the guard&#39;s top surface 22 over the means for folding enhancement 37, thus providing a visual aid by which to properly fold the tabs 40 along the fold lines 30. 
     There are numerous possible embodiments of the fold-over tabs 40 that can be successfully implemented within the scope of the present invention, several of which are illustrated in the figures. For example, the tabs 40 may be designed to fold over the corner edges 4 and adhere to a back surface 6B of the corner, they may be designed to be permanently positioned at right angles to the body for alignment of the guard with the book, they may be designed to extend straight out beyond the edges 4 of the cover 6 without being bent in any direction or they may be designed to be torn off after alignment of the guard with the corner 5 of the book. 
     When the fold-over tabs 40 are designed to be adhered to the back surface 6B of the book cover 6, the cover is effectively sandwiched between the fold-over tabs 40 and the fixed edge tabs 50. As illustrated in FIGS. 1-5, when the guard corner 17 is properly aligned with the book cover corner 5, the fold-over tabs 40 are easily folded over the cover&#39;s corner edges 4 and adhered to the back surface 6B of the book cover 6. In this embodiment, as seen in FIG. 7, a bottom surface 40B of the tab portions 40 include an adhesive layer 26 by which to adhere the tabs 40 to the back surface 60B of the book cover 6. When an active adhesive layer 26 is implemented, a single sheet of non-stick material 28 may cover the bottom surfaces 24 and 40B of both the guard body 10 and the tabs 40, as shown in FIG. 7, or, alternately, a separate sheet 28 of the non-stick material may be placed over each tab 40 and the guard body so that the sheets 28 are removable in an order corresponding with the steps for proper application of the guard. 
     In this embodiment, one preferred tab configuration includes angled portions 45 that are co-linear with one another and terminate at the intersection point 21 of the fold lines 30, when the guard is laid-out in the flat (FIGS. 2 and 5). When the tabs 40 are folded over against the back surface 6B of the cover 6, as illustrated in FIG. 6, the angled portions 45 nearly abut with one another. As also illustrated in FIGS. 2-5, at least one portion of each of the delimiting edges 44 is preferably curvilinear, thus forming curvilinear portions 46. However, as illustrated in FIG. 2, each of the delimiting edges 44 may include additional curvilinear portions 47. All of these curvilinear portions 46 and 47 allow pages of the book to slip easily over the tabs 40 instead of catching or tearing on them, while also aiding a user in properly folding the tabs 40 against the back surface 6B of the corner 5. 
     When the tab portions 40 are designed to be removable, illustrated in FIG. 8, rather than having angled portions 45 that are in co-linear alignment, the tabs 40 preferably have a relatively rectangular shape so that when the tabs are folded at right angles to the guard body, the angled portions 45 abut one another. This allows the guard corner 17 to be precisely aligned with the cover corner 5 by simply sliding the guard over the corner until the edges 4 of the corner 5 contact the tabs 40. Once the tabs have been used to aid in quickly and easily aligning the guard corner precisely with the corner of the book cover, the fold-over tabs 40 can simply be torn along the fold lines 30 and removed. 
     In yet another embodiment, illustrated in FIG. 9, the fold-over tabs 40 are designed to permanently remain at right angles to the guard body 10. In this embodiment the tabs 40 are designed not only to aid in properly aligning the guard body with the cover corner 5, but also to help protect the edges of the book pages, as the tabs act as natural shock-absorbers that minimize any applied force. To properly position the corner guard so that the guard corner 17 is precisely aligned with the cover corner 5, the guard is slid over the cover corner 5 until the edges 4 of the cover contact the fold-over tabs 40. Preferably, as illustrated in FIG. 10, in this embodiment each of the fold-over tabs includes a rib 75 positioned along the delimiting edge 44. The ribs 75 extend inwardly toward the pages 3 of the book, thus engaging the fold-over tabs 40 with the book pages 3 so that the cover 6 is maintained in a closed position. As illustrated, the tabs 40 may be shaped so that they abut, and preferably the tabs 40 are secured together so that they cannot move apart from one another, thus forming a sturdy, pre-formed tab corner 48. In this embodiment, illustrated in FIG. 10, when the guard body 10 is positioned in contact with the corner of the cover, the tab corner 48 is in overlapping adjacency with the corner of the book pages 3, thus shielding the pages from exposure and other damage. Alternately, as detailed above, the tabs 40 may be spaced apart from one another in any desired manner. It should be noted that while the tabs 40 are preferably pre-formed to extend at right angles to the cover 6, they may also be constructed in alignment with the rest of the guard, so that the user must simply manually fold the tabs 40 to the proper angle. 
     As shown in FIG. 11, preferably, one or more small apertures 80 are positioned in the fold-over tabs 40 so as to allow a bookmark leash 82, such as a rubber band, or other similar elongated, flexible string-like device, to be inserted and retained in the tab 40. With one or more of the leashes 82 captured in one or more of the apertures 80, any leash 82 is simply placed or stretched around the book so as to ensure that the covers 6 remain closed at all times. Likewise, a leash 82 may be vertically wrapped around a cluster of pages in order to mark a particular page or section of the book. The apertures 80 may be pre-punched, or they may be merely perforated so that the user manually may punch out the aperture 80. 
     It should be noted that although the fold-over tabs 40 provide for easy and accurate alignment of the guard, the corner guard may also be constructed without any fold-over tabs 40, as shown in FIG. 12. In this embodiment, the user properly positions the guard by simply aligning the outer edges of the fixed edge tab portions 50 with the edges 4 of the cover&#39;s corner. 
     In all of these embodiments, the fold-over tabs 40 can be constructed to any desired fixed length, preferably equal or less than that of the fixed edge tab portions 50. In FIGS. 3-5 the tabs 40 are smaller in area than the edge tab poritons 50 whereas in FIG. 2 the fold-over tabs 40 are approximately equal in area to the edge tab portions 50. 
     To ensure that book pages, book covers and other such objects do not catch on the guard but rather slip easily over it, the perimeter of the entire corner guard preferably has a beveled edge 70 which forms a down-sloping perimeter, as illustrated in FIG. 7. 
     While the invention has been described with reference to a preferred embodiment, it is to be clearly understood by those skilled in the art that the invention is not limited thereto. Rather, the scope of the invention is to be interpreted only in conjunction with the appended claims.