Barkermaschine with automatic re-setting device
Inside the Barkersystem (1) a positive pressure (Abstromprinzip) prevails. By operation of the key at the play desk the lever (2) moves downward with switched on Barkermaschine, tail valve (3) opens, scheibenventil (4) closes, and the positive pressure dominant in the Barkerbalg flows outward (Abstromimpuls). Thus the wind force of the system (1) affects the mobile bellows disk of the Barkerbalges, which collapses in itself and pulls on the abstract one (5). (whistle rings out). When releasing the key the Barkerbalg in reverse order moves again upward. (whistle erstummt). During the upward motion a cam (6) accesses into a control nose (7), which is mechanically connected with the key and the complete play mechanics including appropriate key return in resting position. The controlling of the cam (6) takes over with the Barkerbalgplatte connected rocker arm mechanics (8).
Sectional drawing of the Barkermaschine with automatic re-setting device (Patent Nr. DE 4014204 C1)