The pneumatic player, the regulation and repair of some modern types . when the roll deviatestoo far to the right or left; and this air, destroy-ing the vacuum in one or two of the power pneu-matics, the other being still under vacuum, pushesthe roll into correct alignment again. There is the usual sustaining pedal duct,—alarge square orifice which, by means of a leverand switch (the latter just beneath the key bed),operates a triple valved pneumatic at the bassend of the piano. The advantage of the triplevalve is that a very small pulse of air is suffi-cient to lift the primary, which instant
The pneumatic player, the regulation and repair of some modern types . when the roll deviatestoo far to the right or left; and this air, destroy-ing the vacuum in one or two of the power pneu-matics, the other being still under vacuum, pushesthe roll into correct alignment again. There is the usual sustaining pedal duct,—alarge square orifice which, by means of a leverand switch (the latter just beneath the key bed),operates a triple valved pneumatic at the bassend of the piano. The advantage of the triplevalve is that a very small pulse of air is suffi-cient to lift the primary, which instantly lifts thelarger secondary, which again immediately liftsthe much larger tertiary and the pneumatic iscollapsed. This sustaining pneumatic is alsooperated by a button, one of four, situated on thelockboard. The half throw hammer liftingdevice is operated by a similarly valved these pneumatics are screwed to the sides ofthe piano, beneath the key bed, from which theycan be unscrewed and cleaned with the minimumof trouble. 28 THE PNEUMATIC PLAYER A. VV/XA/VAAA/ -boM (floor of f>l*l>0/ y&lve hlock. screwed to kev beJ Y^ Accei\tQ jvn<utntitn Fig. I. Normal Condition. On the floor of the piano, just against thesepneumatics, are the expression boxes containingthe accenting and re-roll valves ; and betweenthem is the main bellows, which can be taken outfor repairs after withdrawing four screws and slip-ping off the two large exhaust tubes. The Stradola possesses a peculiarity which Ihave endeavoured to portray in the accompanyingsketches by indicating those portions under ex-haust as dotted regions. The peculiarity is this :That we have a pouch which is not under per-petual exhaust during the playing period, but onlywhen its chamber is exhausted by a quite inde-pendent valve. In Fig. I., it will be noticed that only the cham-ber beneath the valve (C) is, with its tube, underexhaust. (The expression box hardly concerns usnow ; it must be understood that it i
Size: 2946px × 849px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1920, bookidpneumaticpla, bookyear1921
