GB361285A - An improved mounting or support for sound boxes and their associated tone-arms, or for electrical pick-ups, of gramophones or like sound reproducing apparatus, or for stylus holders or cutting tool holders of sound recording apparatus - Google Patents

Abstract

361,285. Gramophones. LOWNDES, J., 38, Thompson Road, Sheffield. July 14, 1930, No. 21316. [Class 40 (ii).] Comprises a mounting, for a sound-box and its tone-arm or for an electric pick-up, which is designed to maintain the direction of the needle or stylus always substantially tangential to the record grooves during its traverse thereover. As shown in Fig. 1, applied to an electric pick-up, supporting arms 2, 3 are separately pivoted at 4, 5 to a fixed mounting 6 and at their ends 8, 9 to a movable cross-bar 7, the pivots 8, 9 being adjustable in their distance apart. The pick-up 11 is mounted on an arm 13 pivoted to the cross-bar 7 to permit the pick-up to be raised clear of the record. According to the invention, the distance from the needle point 12 to a line joining the pivots 8, 9 is made equal to half the distance between this line and a line joining the pivots 4, 5. The pick-up 11 may be detachably connected to the arm 13 at 21, Fig. 4, to render it adjustable as indicated in chain lines, or the arm 13 may be pivoted as at 22, Fig. 5, for lateral adjustment while the pick-up 11 is pivoted as 23 to permit it to be raised clear of the record. As applied to a sound-box and tone-arm, Fig. 3, the tone-arm 16 is adapted to swivel on ball bearings and is pivoted to the cross-bar 7 by a coupling member 17a and pivot pin 18, the coupling being connected to the cross-bar 7 by a pin 20. The sound-box 11 is connected to the member 17a by a swan-neck 19.