GB375964A - Improvements in or relating to loose-leaf visible indexes - Google Patents

Abstract

375,964. Visible card indexes. POWER, R. F., 18, Chesterford Gardens, Hampstead, London. May 28, 1931, No. 15700. [Classes 16 and 146 (i).] In visible indexes arranged in loose-leaf book-form the thickness of paper in the marginal area is regulated to compensate for the thickness of the binding devices and so that the top cover can be parallel to the bottom cover. As applied to sheets adapted to be mounted in a loose-leaf binder as described in Specification 356,452, the sheets are cut away adjacent to the binding edge 2 so as to leave lugs 1 perforated or notched to engage binding studs mounted on backing sheets one of which is provided for each set of sheets. The total width of the lugs 1 relatively to the overlap between adjacent sheets determines the maximum thickness of paper along the margin adjacent to the binding devices. The sheets may be similarly treated at the free edges to compensate for the thickening effect of index tabs. In order that each unit carried on a backing sheet may be of uniform thickness, the backing sheet is provided or formed on both faces with protuberances increasing in thickness towards the top and bottom edges thereof by affixing embossed strips thereto in the manner described in Specification 337,468, [Class 146 (i), Filing paper &c. sheets]. The binding studs may be mounted on strips instead of backing sheets. The edges 1a of the lugs may be perpendicular or inclined relatively to the sheet edge.