GB347642A - Improvements in, or relating to, electrical sound reproducing apparatus - Google Patents

Abstract

347,642. Telephone instruments. COLASSI, W. L., 26, Burnham Court, Bayswater, London. Jan. 29, 1930, No. 30734. Divided on 337,094, [Class 40 (iv), Telephones &c.]. [Class 40 (iv).] For adjusting the relative positions of the armature and magnet, the latter is pivotally mounted and springs are provided on both sides of the pivot so that the magnet is held constantly pressed either towards or away from the reed. A further adjustment is provided by making the pivots movable. In the preferred form the magnet is held pressed towards the armature, as the spring pressure on the pivot is then added to the magnetic pull. The magnet platform 5, Fig. 3, is pivoted by pins 6, in the holes 7, in pillars 3 fixed to a baseplate 2. Located in recesses in the plates 2, 5 are springs 9, 10 and another, not shown, making a pair with 9, and acting in opposition to 10 which is stronger than the pair in conjunction. For adjustment a bolt 11 fixed to the platform 5 passes through the plate 2 and carries an adjusting nut 12 bearing against a distance-piece 13 secured to the plate 2. An adjustable stop 15 is provided to prevent the pole-pieces being pressed heavily against the armature. The pivot pins 6, Fig. 5, may be adjustably mounted in hollow supporting pillars 19, being pressed on to springs 24, by members 25 with inclined lower ends and engaged at the upper end by set-screws 26. Shims or washers may be provided for adjustment of the pillars 19 relative to the baseplate. The armature is mounted to move as a whole, on wires clamped at both ends. Specification 337,094 is referred to.