GB1164306A - Loudspeaker Diaphragm Basket Assembly. - Google Patents

Abstract

1,164,306. Making loud-speaker baskets. GENERAL ELECTRIC CO. 21 Nov., 1966 [21 Dec., 1965], No. 52084/66. Heading B3A. [Also in Division H4] In making a diaphragm basket for a moving- coil loud-speaker, a depression is formed in a single piece of material to accommodate a loudspeaker diaphragm, an aperture is formed in the depression by removing material from the area which is to form the aperture, and the material removed from the area but integral with the remaining material forming the depression is shaped to form an element in which a permanent magnet can be placed so that the element provides a magnetic flux path. A sheet (1), Fig. 1 (not shown), of low carbon steel is drawn to form a central depression (2). The depression is reverse drawn (Fig. 3, not shown) to approximately double the gauge of the walls of the depression (2) while halving its length. The depression (2) is pierced to form a central aperture (3), Fig. 4 (not shown). The depression is shaped by a die, the lower end being crimped to form an annular collar (5), Fig. 5 (not shown), of reduced diameter to provide close contact with the magnet 9 (Fig. 7). The diaphragm basket (7), Figs. 6, 8 (not shown), is shaped in cylindrical form, four windows (8) being blanked out and four apertures (10) providing means for attaching the loud-speaker to a housing. Alternatively, a metal sheet is formed with a depression 16 (Fig. 12) pierced to provide a central aperture and reverse drawn to form an annular collar 18. The sheet is next shaped to form a conical basket 19 and pierced to provide four apertures 20, 21, 21<SP>1</SP> (20<SP>1</SP>), Fig. 11 (not shown). Apertures 21, 21<SP>1</SP> are so pierced to leave T-shaped tabs 22, 22<SP>1</SP> each of which is bent downwardly into a half of a tube. After further bending back, tabs 22, 221 form intimate contact with depression 16 and form double-thickness walls (Fig. 13, not shown).