GB821717A - Metal frame manufacture - Google Patents

Abstract

821,717. Making television tube frames; deforming hoops; stamping; flanging. CORNING GLASS WORKS. Nov. 26, 1956 [Dec. 2, 1955], No. 36110/56. Classes 83 (2) and 83 (4). [Also in Group XL (a)] A method of forming a metal frame for use as a sealing element between glass television tube envelope parts comprises deforming a circular metal hoop into generally rectangular form and then forming it with an inwardly-directed flange. A metal strip is bent into a hoop 12 with the ends abutting, which ends are then welded together and excess weld metal removed. A strip is similarly formed into a hoop 22 and fitted tightly inside the hoop 12 and welded or otherwise secured thereto. The compound hoop is then placed in the lower part of 51, 52 of a forming die, and the section 52 is moved towards the section 51 to deform the hoop to a generally rectangular shape with rounded corners and bulged sides. A punch 55 then descends to flare the edge of the hoop outwardly at 12a, Fig. 9, and the other edge inwardly into a recess 54. This latter edge is then formed into a flange 22a, Fig. 10, by die means 56, 57. The hoop is then inverted and the portion 12a formed into a flare 12b, Fig. 12, by a punch 70 co-operating with a vertically movable cushion plate 66 and spring- urged ring 68. The hoop is finally formed with a rib 12d and flange 12e, Fig. 14, by the punch 70 against a rigidly supported ring 88. In a modification, a single thickness hoop 112, Fig. 15, is brought to rectangular form and, by a chamfered punch 151 co-operating with a twosection die 152, is formed with a flare 113. The hoop is then formed with a horizontal inner flange 114, Fig. 18, by a punch 170 co-operating with a die 166 and spring-urged ring 168. A lip 115, Fig. 21, a rib 292 and outer flange portion 116 are then formed by an inner punch 191 co-operating with a spring-loaded plate 193 and by an outer spring-urged punch section 192 co-operating with a die 196 and outer ring 198. Specification 789,378, [Group XL (a)], is referred to.