GB191421796A - Improvements in or relating to Mechanical Piano Players and the like. - Google Patents

Abstract

21,796. Mowbray, F. H. Oct. 30. Actions; tracker-bars.-Two sets of connexions, in reverse order between primary pneumatics, and a single row of apertures or contacts in a tracker-bar, are controlled by a device such as a multiple slide valve or switch so that either set can be rendered operative for use with tune-sheets designed for horizontal or vertical tracker-bars, and having the treble perforations respectively to the left or right of the direction of travel. In the arrangement shown, the tracker ducts a<1> are forked and communicate by parallel tubes d and by crossing tubes d<1> with two sets of ports b<4>, b<5> in a bar b<1>. This bar is carried by a radius-arm and a lever e so that either set of ports can be caused to register with a single set of ports in a bar b<2>, the latter ports being connected to the primary pneumatics. In a modification, the movable valve bar b<1> has a single set of ports, and the stationary bar b<2> two sets of ports, each primary pneumatic having a forked connecting-nipple. A disk valve may replace the valve described. An analogous arrangement, with contacts instead of ports, may be employed in electrically-controlled instruments. According to the Provisional Specification, the tracker-bar may have two sets of ducts.