Patent ID: 8172269
Filing Date: 2012-05-08
Classification: B42D

Abstract:
1. A file comprising: a cover body including a front cover portion, a back cover portion, and a spine portion provided between the front cover portion and the back cover portion; a binding body which is superimposed with a plurality of binding sheets superimposed on the binding body; a curved retaining portion adhered or bonded to an end edge of the binding body such that the binding body extends therefrom and which is curved in a direction away from an inner side of the spine portion when the cover body is opened; and a curved subsidiary portion arranged to fix a back portion thereof in a desired configuration in a region on the spine portion, a region on a side of the front cover portion between a folding portion of the front cover portion and the spine portion, and a region on a side of the back cover portion between a folding portion of the back cover portion and the spine portion; wherein the binding body is provided adjacent to the curved retaining portion and has an arch-shape in a direction away from an inner side of the front cover portion and an inner side of the back cover portion extending from the inner side of the spine portion; the curved retaining portion includes a hinge portion on a front cover side connected to the front cover portion, a hinge portion on a back cover side connected to the back cover portion, and an interjacent connecting portion interposed between the hinge portion on the front cover side and the hinge portion on the back cover side; a distance between the folding portion of the front cover portion and the folding portion of the back cover portion and the spine portion is substantially equal to or less than a distance between the hinge portion on the front cover side of the connecting body curved retaining portion and the inner surface of the front cover portion and between the hinge portion on the back cover side and the inner surface of the back cover portion; the hinge portion on the front cover side and the hinge portion on the back cover side are positioned adjacent to an end edge of the spine portion when the cover body is closed; and a region on the front cover side extending to the hinge portion on the front cover side and a region on the back cover side extending to the hinge portion on the back cover side intersect at substantial right angles with the interjacent connecting portion when a load is not applied and move the interjacent connecting portion in the direction away from the inner side of the spine portion as the direction in which the plurality of binding sheets extend so as to be lifted as a result of expanded angles between the interjacent connecting portion and the regions of the front cover side and the back cover side, a resiliency of a material from which the curved retaining portion is made, and an elasticity adjacent to the hinge portion on the front cover side and the hinge portion on the back cover side, which move on an opposite side of the spine portion and become narrower than the spine portion and are located on an inner side of the folding portion of the front cover side and the folding portion of the back cover side when the cover body is opened.