Improvements in and relating to Tempo Control Gear for Pneumatically Operated Piano Players and the like

26,179. Atkinson, H. W. Nov. 14. Tempo-regulating means; blowing and exhausting air.-The tempo is controlled by varying the tension of a spring acting upon the motor governor, which comprises a valve adjusted automatically by the suction operating either through a bellows or directly upon the valve. The manual controlling-device comprises a member which may be tilted in either direction against the action of a spring, and provided with a cam or the like which mav be adapted to vary the initial position of the lever controlled by it. In this way, the normal tempo is adjusted without varying the normal position of the controlling-device. The pipe j is connected to the motor and connects with the windchest k through a port l controlled by a valve l. The valve l is connected to the moving-board of the bellows i, which has a spring connexion ,q to a lever f, rotatably mounted on a spindle having loosely mounted arms c connected by springs e to a fixed member b and co-operating with pins d on a member a. The member a is mounted concentrically with the lever f, and is adapted to be tilted in one direction or the other to vary the tension of the spring g and thus alter the tempo. When the member a is released, it is returned to the normal position by the springs e acting through the arms c and pins d. Stops m, n limit the movements of the arms c and pins d respectively. A rotatable cam o, or a sliding member, is provided to adjust the initial position of the lever f and thus the normal tempo. A throttle-valve may be provided between the valve l and the motor. In the form shown in Fig. 3, the bellows i is dispensed with, the valve l being so formed that it is opened or closed by the variations in suction. The valve l is provided with a downward extension to prevent the current of air from producing a whistling noise.