Relatively movable bodies and methods of making them

Abstract

A dial suitable for calculations, demonstrations, teaching and amusements is composed of a front disc, a rear disc and an inner disc rotatable relatively to the other two discs and having indicia visible through a window provided in the front disc and possibly the rear disc. According to the method of the present invention the rotation of the inner disc is made possible by cutting a central circle in the inner disc which, however, is connected to it by thin tabs, gluing the central circle to the front and rear discs and then breaking all the tabs by turning the inner disc. According to another feature, all three discs are initially cut from a single sheet and joined by strips which are folded when the discs are assembled. The fold connected to the rear disc may be extended to form a sheet which may be conveniently glued or stapled inside or outside a magazine or book to form an integral part of the publication. According to a further embodiment two such dials may be joined by a folded sheet portion.

Dependencies are inferred from the claim text.