GB416071A - Improvements in and connected with draw stops, stop keys, pistons and like control devices for musical instruments - Google Patents

Abstract

416,071. Organs &c. WALKER & SONS, Ltd., J. W., Southfield Road, Acton, London, and SYMONDSON, A. H., 69, Jersey Road, Osterley, Hounslow, Middlesex. March 8, 1933, No. 7049. [Class 88 (ii).] Draw stops, stop keys, pistons, &c. are provided with preferably permanent magnets offering a momentary sticky ' resistance to the initial portion of a movement, so that a plucking actuation is required. Magnets may retain the stops in " on," as well as in " off," positions ; in double-touch stops, magnets may resist the second-touch operation and subsequently restore the parts to their position after first touch operation. In Fig. 1, the simple draw stop a carries a block c to which is affixed a bar (or electro) magnet g which in the " off " position is in contact with a stationary magnet (or armature) g<1>. Other magnets k, k<1> may, if desired, be arranged to contact in the " on " position. A rod f may be connected to a solenoid core for electromagnetic operation of the stop. When the draw stop is constructed for double-touch actuation (Fig. 4, not shown), the magnets g, g<1>, k, k<1> are omitted and in the " on " position the block c contacts with an arm of a cranked lever the other arm of which carries a magnet lying in contact with a stationary magnet. The " on " position is indicated by the tip of an indicator rod appearing at an aperture in the panel. Second-touch actuation then separates the magnets. In the second touch stop key shown in Fig. 5, first-touch actuation separates the magnets g, g<1>, the tail l<2> of the key, which is influenced by a deadcentre spring device n, being arrested by a flap 3 hinged at 4 and held down by magnets g<2>, g<3> whose resistance is overcome in the second - touch actuation. Specifications 253,594, [Class 88 (ii)], and 351,558 are referred to.