GB469980A - Improvements in ring binders for books - Google Patents

Abstract

469,980. Bending metals. TRUSSELL MFG. CO. June 10, 1936, No. 16244. Convention date, April 11. [Class 83 (iv)] [Also in Group XV] A method of forming ring binders for books comprising perforated sheets consists in bending the intermediate portion of a length of material such as wire to the curvature of the ring to be formed, as at 16, Fig. 2, rounding the ends 18, 19, Fig. 3, and bending the intermediate part of the material back to substantially the original condition as at 17 to effect a hinging portion about which the material will bend in the closing operation of the binder. The same method may be employed on a length of material which is preformed in zigzag shape to form a ring binding element with double prong elements 20 connected by spacing loops 21, as shown in Fig. 8. The perforated sheets are placed on the binding element when the latter is in the condition shown in Fig. 3, and the last bending operation may be performed between a stationary and a movable die. The ends of the prongs 20 and the loops 21 of the binding element may be overlapped by offsetting them and, where book covers are threaded on the prongs, the overlap is arranged immediately below one cover to be concealed thereby.. Specifications 422,409 and 447,231 are referred to.