Patent GB-189800807-A (GB)
Title: Improvements in Pneumatic Devices for Playing Keyboard Musical Instruments.
Inventor: THOMPSON WILLIAM PHILLIPS
Filed: 1898-01-11
Granted: 1898-04-09
Abstract: 807. Thompson, W. P., [Wilshire, H. G.]. Jan. 11. Automatic i n s t r uments.-The invention relates to pneumatic devices for playing keyboard instruments. The apparatus is situated underneath the keyboard, andis for the most part concealed from view. Fig. 1 shows the parts immediately operating the keys. Stickers P, which act upon the inner ends of the keys so as to lift them from underneath, are actuated by levers G operated by the collapse of bellows D. These bellows are situated upon each side of a rail B for economy of space. Wind is admitted by holes in a tune-sheet to tubes K, from which the air is normally kept exhausted, and thus pneumatics h, situated in a vacuum chest I, are caused to expand. This opens a flap M situated in a chest L, and closes a relief valve t. Wind is thus exhausted from the chest L, and therefore from the bellows D, which communicates with it through tubes O. The pneumatics h are made by folding over a piece of thin leather and gluing their covering-boards outside it. A small hole is made in one of the covers to allow air admitted through the tune-sheet perforation to be subsequently exhausted. The flaps M consist of boards loosely faced with leather. Piano pedals may be operated in a similar way, but, to avoid long holes in the tune-sheet where the pedal has to be kept down for a considerable time, a catch is employed to engage with the pedal lever when depressed by its bellows. The catch is released by a bellows of its own. Fig. 15 shows the tune-sheet operating- device, B' being the storage roller and B<3> the takeup roller, to which the end of the tune-sheet is attached by a hook 51. The roller B<3> is driven from a spindle 37, which can be shifted by a slide 39 engaging with a collar 38 so as to vary the distance of its driving-disc 36 from the centre of a disc 35 driven by a motor. The speed of the roller B<3> can thus be regulated. The slide 39 is actuated by a pull 41 by means of a lever 40. The rollers can be reversed for re-winding by a belt 47 passing over a pulley 48 on the axle of the drum B', and a pulley 45 loose on the spindle 37. When the pull 41 is drawn out as far as it will go, pins 46, 46¢ on the spindle and pulley 45 engage ; at the same time the lever 40 shifts the lower bearing of the spindle so as to disconnect the gearwheels 52 and 54. This action also moves a crank 44, thus opening a valve in the wind chest, so that the vacuum, which would otherwise be maintained therein by the continued operation of the motor, is destroyed, and the notes are thus prevented from sounding. The same motor is employed for exhausting and for driving the tune-sheet. If it is an electric motor, the outer end of the pull 41 is pivoted on the inner end, and is used as the movable part of a switch for turning on the current. The construction of the tracker board is shown in Figs. 8 and 9, the former being a section of the latter on the line G-H. It consists of a thin central board a' notched at the top so as to form a comb. Two other boards a<2> and a<3>, grooved as shown, are glued on either side and complete the wind passages.