Improvements in or relating to devices for converting electrical into acoustic oscillations or vice versa

摘要

376,705. Gramophone pick - ups. NAAMLOOZE VENNOOTSCHAP PHILIPS' GLOEILAMPENFABRIEKEN, 13D, Emmasingel, , Eindhoven, Holland. Jan. 6, 1931, No. 480. Convention date, Feb. 15, 1930. Void [Published under Sect. 91 of the Acts]. [Class 40 (iv).] A gramophone pick-up comprises a casing 1 in which are arranged magnets 2, 3 provided with pole-shoes 4 .. 7. An armature 8 surrounded by a coil 12 is arranged between the pole-shoes, the lower end of the armature carrying a needle-holder 9 whilst its upper end is resiliently supported by helical springs 14, 15 arranged in recesses in the pole-shoes 4, 7. The armature spindle 17 is arranged with some play between the pole-shoes 5, 6, copper tubes 18 internally provided with a leather covering 19 being slid on the ends of the spindle and partly surrounded by leather 20 provided on the pole-shoes 5, 6. The casing is filled with a mixture 21 of the material known under the Registered Trade Mark " Vaseline," and paraffin oil, the opening in the casing where the needleholder passes through it being closed on the inside by a member 22, which may be a piece of intestinal wall. The opening is also preferably closed on the outside by a piece of leather 23.