GB1156830A - Delay Device Particularly for Producing Artificial Reverberation. - Google Patents

Abstract

1,156,830. Spring delay device. AKUSTISCHE & KINO-GERATE G.m.b.H. 7 Dec., 1966 [10 Dec., 1965], No. 54768/66. Heading H4R. In an artificial delay device comprising at least two helical springs which have different dimensions and in which torsional vibration is induced by a common vibratory driving element, a torsionally elastic coupling and suspending system is provided to suspend the input end of the larger spring and to couple it to the driving system. The larger spring may surround the smaller, they may be end to end with their axes aligned or their axes may be parallel, and the output end of the larger spring may be coupled to the pick-up system by a torsionally elastic coupling and suspension system. The smaller spring may be coupled to the driving system and the pick-up system by U-shaped end portions engaging two diametrically opposite grooves in the respective output and input members. The torsionally elastic coupling may be provided by a wire which extends along the axis of the spring. In the concentric arrangement the motor and smaller spring are anchored by a wire extending along the axis, and the larger spring has a U-shaped end portion attached at the centre of the U to a point along the anchoring wire. In the parallel axis arrangement the two springs have wire anchors, the smaller of the two is driven, and the free driven end is connected by a wire to the end of the larger. In the in-line arrangement the driving system is introduced at a point between the two springs and the pick-up system is included between the end of the smaller spring and its wire anchor, axial extensions of the larger in this case providing the torsional elasticity. The arrangements are said to prevent change in vibrating mode above a critical frequency, and couplings could include a plastics material.