Patent GB-162340-A (GB)
Title: Improvements in or relating to pianolas, piano-players, & similar pneumatically actuated musical instruments
IPC: G10F5/06
Filed: 1919-12-29
Abstract: 162,340. Scurfield, G. G. Dec. 29, 1919. Tracker-bars; transposing-means.- A laterally - movable transposing tracker-bar in one piece is provided with additional holes so as to enable the production of fully accentuated music in the various keys. The pedal and themodist actions are maintained in normal operation by the use of change-over valves, similar valves also operating in the case of the end noteholes. Means are also described for maintaining the themodist action of the central note-pneumatics. The laterally-movable tracker-bar C (of which the bass end only is shown in Fig. 14), in order to transpose four semitones either way, has four extra holes 1 at each end, and by being rigidly connected or by other means such as gearing, the tracker-bar and the parts A of a slide valve are caused to move to the same extent or proportionately to the distances between the holes on each. Fig. 9 shows the lower face of the upper movable valve-part A, the top plan of part of which is shown in Fig. 14. Fig. 8 shows the stationary intermediate strip B of the valve, and Fig. 10 is a top plan of the lower movable part A. The eleven endholes at the bass end of the tracker-bar, comprising the four additional holes 1, the normal pedal hole 5, themodist holes 6, 7 and four end note-holes 8 are permanently connected to eleven holes L<1> at the left-hand end of the upper part A which lead to slots L, Fig. 9, in the lower face thereof. The ten end-holes (there being no pedal hole) at the treble end of the tracker-bar are similarly connected to ten holes L<2> and slots L at the right-hand end of the upper part A. The holes may be staggered as shown at L<2> to give more landing at the edges. The intermediate eighty note-holes of the tracker-bar are connected directly to the note-pneumatics in the ordinary way. The slots L co-operate with holes G, J, H on the stationary part B, Fig. 8. These holes in turn co-operate with a slot P connected to the pedal action, slots O connected to the themodist actions, and holes n<1>, n<2> connected to the four note-pneumatics at each end. Successive movement of the tracker-bar and parts A to the right to transpose the key downwards bring the extra holes at the bass end of the tracker-bar, normally not in use, successively into operation, firstly under pedal perforation of the tune-sheet, and then under the two themodist perforations; in the fourth position, the first additional hole is under the bottom note-perforation but is now, with the original pedal and themodist holes, out of operation. Seven only of the eleven end-holes are thus in operation at any one time. Meanwhile, at the treble end of the tracker-bar further holes have been put out of operation, holes originally operating the end note-pneumatics taking over the operation of the themodist. To overcome the difficulty due to the lateral distance between the pedal perforations and the bass themodist-holes being usually slightly more than that between the note-perforations, nine auxiliary holes S are arranged overlapping the end nine (equidistant) holes at the bass end of the trackerbar, these being connected by tubes S<1> to a set of holes S<2> arranged at the middle of the upper movable valve part A and co-operating with a hole T in the stationary part B, the hole T leading to a groove V in the lower movable part A and being connected by a T-piece to the outlet from the slot P connected to the pedal action. The effect of a wider pedal hole is thus obtained but only one hole S is open at a time in combination with an adjacent hole in the main row. To maintain the themodist action of the eight centrol note-pneumatios when transposing, four extra divisions with flap-valves opening outwardly only, are arranged one on either side at a distance of two pneumatics of the central divisions of the two wind-chests. The central divisions may be omitted, or cut out by opening a valve in a bye-pass. The trackerbar may be traversed separately from the valvebox, means to indicate when they are set for the same key being provided. A scale may be provided to show the extent of key-transposition corresponding to the different positions of the tracker-bar. One Provisional Specification refers to the division of the tracker-bar into three portions, only the centre portion carrying the note-holes (end ones omitted) being movable. Or cocks or valves with more than one outlet may be connected to the end note-holes and to the pedal and themodist slots, some valves being used for shut-off, and others with more than one outlet, for change-over, purposes. The other Provisional Specification states that a valve, cocks, or a sliding division, for controlling the themodist action of the central note-pneumatics, may be connected to the shut-off and change-over cocks or valves so as to be automatically operated.