Paperback-hardcover conversion insert
BACKGROUND OF THE INVENTION 
     Each year millions of paperback books are manufactured and sold. Although these paperbacks are considerably less expensive to buy than the original hard cover editions, the last few years have seen even these inexpensive paperbacks growing in price. Many now exceed $3.00 to $4.00 a book. As price continues to rise, these once thought to be short-term use paperbacks are being kept as the main literary work of many home libraries. 
     Paperback books are usually smaller in size than their original hard covered editions and are printed on less expensive paper. However, they are considered for short-term-use-only, because of the inexpensive binding and paper covers used. These inexpensive paper covers do not stand up to repeated use or long life on library shelves. Paperbacks tend to become very unsightly over time and the paper cover allows it to become easily tattered, torn, and misshapen. 
     I have many paperback novels and have desired a way of salvaging these once thought to be short-term-use books by converting their paper covers to conventional rigid cloth bookcovers. Rigid cloth bookcovers would not only protect the paperbacks from being tattered, torn and misshapen, but also add to their appearance and therefore value to the owner. The invention herein described, when bonded to a rigid cloth bookcover commonly available in the industry, would permit a paperback consumer to easily convert a short-term-use paperback novel to a novel of quality appearance capable of years of use and enjoyment by many people. 
     THE GENERAL DESCRIPTION OF THE INVENTION 
     This invention comprises a central part of an elliptical configuration of foam-type compressible material with one side adhered to a narrow piece of stiff material such as paperboard for rigidity and the other side adhered to a foam-type strip with its outer side having an adhesive covered with a peel-away backing. The outer side of the paperboard as well as the sides of the paperboard and two foam-type materials are adhered to a paper backing with pockets at each end. When the outer two sides of the paper backing of this invention are bonded or otherwise adhered to a conventional rigid cloth bookcover it becomes a means of allowing the ultimate paperback consumer to convert a paperback book with a soft cover to a book with a permanently fastened rigid cloth cover. The consumer simply peels away the paper backing exposing the adhesive underneath. The consumer then holds the paperback novel with its back or spine towards the adhesive strip, and simply centers the book&#39;s spine with respect to the adhesive strip and presses the spine firmly against the adhesive. Then the paper covers of the paperback are fit into their respective pockets of the insert to complete the conversion. 
    
    
     THE DRAWINGS 
     FIG. 1 is a perspective view of a conventional rigid cloth bookcover; 
     FIG. 2 is a perspective view of the materials of construction of an insert or interface in accordance with the present invention for binding a rigid cloth bookcover to a paperback book; 
     FIG. 3 is a perspective view looking at the invention herein described permanently bonded to a rigid cloth bookcover and in a condition to be bonded to a paperback book; 
     FIG. 4 is a lateral cross-sectional view of the rigid cloth bookcover; 
     FIG. 5 is a lateral cross-sectional view illustrating the insert or interface which is positioned between the paperback book and the rigid cloth bookcover; 
     FIG. 6 is a lateral cross-sectional view illustrating the insert or interface connected to the rigid cloth bookcover and also being connected to the paperback book 24; 
     FIG. 7 is a fragmentary elevational view looking at the combination of the paperback book, the insert or interface and the rigid cloth bookcover; and, 
     FIG. 8 is an enlarged fragmentary end view of the spine or center section of the invention depicting the use of only one foam. 
    
    
     THE SPECIFIC DESCRIPTION OF THE INVENTION 
     The object of the invention is to provide an insert or interface 16 between a rigid cloth bookcover 18 and a paperback book. The insert is connected to the rigid cloth bookcover by an adhesive and is connected to the spine of the paperback book by an adhesive. The insert has pockets to receive the paper cover of the paperback book. By means of the insert there results a permanent rigid cloth bookcover for a paperback book which extends the life of the book. A paperback book used without the present invention is subject to damage by tearing and resulting fraying of the paperback bookcover. The invention makes it possible for a person to build a personal library at less cost with paperback books than with hardcover books, since the combination of the paperback book, the insert and a rigid cloth bookcover is less expensive than an original edition, hardcover book. 
     The insert of FIGS. 2 and 5 comprises a stiff material 20 which can be paperboard. As is seen in FIGS. 5 and 6 the material 20 is convex on one side and concave on the other side. In FIGS. 5 and 6 it is seen that this stiff narrow material 20, in lateral cross-sectional configuration, appears in the form of an arc. It is this stiff material 20 which conforms to the configuration of a spine 22 of a paperback book 24 having pages 26. Then an adhesive 28 connects the concave side of the stiff material 20 with one side of a compressible, resilient material 30. One desirable compressible, resilient material is a solid plastic foam such as polyurethane foam, polyethylene foam, polyproplene foam, and polyvinylchloride foam, to name a few appropriate solid plastic foams. The material 30 must be capable of being compressed or expanded and then when the pressure is relieved on the foam, the foam must be capable of expanding back to its moreorless original shape. In other words, the material should have memory. In FIGS. 5 and 6 it is seen that the material 30 in cross-section is of a generally elliptical configuration, i.e., both sides being convex. 
     There is an adhesive 32 on the outer side of the foam 30. The adhesive 32 bonds to the material 30 and to another soft compressible resilient material such as latex foam 34. The foam 34 may be a strip of material. 
     Then, there is an adhesive 36 applied to the outer or free side of the foam 34. This adhesive is covered with a paper backing 38 capable of being peeled away and exposing the adhesive 36. However, the adhesive 36 is protected by the paper backing 38 until it is appropriate to contact the adhesive with the spine 22 of the paperback book 24. 
     In a mass production manufacturing stage one foam piece 70 can be used as depicted in FIG. 8 rather than two foam pieces for material 30 and foam 34 shown in FIGS. 5 and 6. 
     There is a backing sheet 40 which is a flexible, limber sheet, usually of paper. This backing sheet is folded back on itself at the two extreme ends to form pockets 42 having an outer sheet 43. At the junction of the backing sheet 40 and the outer sheet 43 there is an edge 45. An adhesive 44 bonds the respective outer edges of the pocket 42 and the backing sheet 40. 
     Then, adhesive 46 connects the pocket side of the paper backing sheet 40 to the outer or convex side of the stiff material 20 and to the outer edges of the stiff material 20. 
     In FIG. 7 there is illustrated a front elevational view of the insert 16. The compressible material 30 has a lateral upper guide 60 and a lateral lower guide 62. The guides 60 and 62 are not covered by the foam 34 and are not covered by the adhesive 32 and 36. With the guides 60 and 62 it is possible to more easily position the spine 22 with respect to the foam 34 of the insert 16. 
     The free or non-pocket sides of backing sheet 40 are bonded by adhesive 44 to the inside surface of the two sides 48 of the conventional rigid cloth book cover 18. The sides 48 can be paperboard. On the outside of the paperboard sides 48 is a fabric cover 52 which may be of cloth. In FIGS. 6 and 7 it is seen that the fabric cover 52 extends around the outer edges of the stiff paperboard 48 and, partially overlies the exposed surface of the stiff paperboard 48 at 53 and has an edge 55. A center or spine section 41 of the backing sheet 40 is not adhered to a center section 52a of the fabric bookcover 52. The adhesive 44 is applied at the opposing ends opposite each pocket and continues inward up to but not including the center section 41. When bonded, the insert 16 becomes an integral part of the rigid cloth bookcover and is permanently secured to the cover except for the center section 41 which has free movement. The free movement of the center section 52a of the fabric cover 52 allows the combination of the rigid cloth bookcover 18, the insert 16, and the paperback book 24 to be opened and closed with ease. 
     The paperback book 24 has a flexible cover 54 which may be of paper. The outer parts of the paper cover 54 are inserted into the pockets 42. This partially assists in positioning of the paperback book spine 22 with respect to the insert 16. The result is that in a few minutes and with a few steps, a paperback book can be converted, permanently, into a hardcover book. 
     A manufacturer unites the insert 16 and the rigid cloth hard cover 18. For example, the manufacturer of the hardcover 18 can apply the insert 16 to the hardcover to form a combination interface-and-hardcover. The combination can be packaged. A person having a paperback book could purchase the combination in a package and combine the paperback book and the combination to have a book with a hardcover or the entire package including the paperback prebonded to the insert with hardcover could be sold to a purchaser. 
     More, explicitly, the book maker would manufacture the insert 16 and bond the insert to the hardcover 18 to make the combination interface-and-hardcover. The manufacturer would sell the combination in various sizes, to retail book outlets. The public would purchase a paperback and also purchase the combination, i.e., a hard cover for paperbacks, for permanent conversion of the paperback at the time of the purchaser&#39;s choosing. The concept is that the paperback consumer would have the choice and the ability to convert the desired paperback books to hardcover books. The insert 16 and the rigid bookcover 18 can be made in appropriate sizes to fit any size paperbook to the hardcover in a minute or two. 
     In FIG. 6 it is seen that edge 45 at the junction of backing sheet 40 and the outer sheet 43 is juxtapositioned to the edge 55 of the overlaying portion of the rigid cloth cover 18 at 53 when the insert 16 and the rigid cloth book cover 18 are united. 
     Also, in FIG. 6 there is illustrated the step of uniting the insert 16 and the paperback book 24. The paper backing 38 of the insert 16 is being peeled away from the adhesive 36 and the paperback book 24 is being pressed against the adhesive 36 and is being permanently bonded to the adhesive 36. 
     Although but one specific embodiment of this invention is herein shown and described it will be understood that details of the construction or materials used may be made by those skilled in the art without departing from the spirit and scope of the invention. 
     From the foregoing description of the invention, it is seen that the invention provides an inexpensive apparatus to combine a paperback book with a rigid cloth book cover so as to have a hard cover book. The apparatus makes it possible for many people to convert a paperback book to a hard cover book.