Showing papers on "Active vibration control published in 1972"

Vibration absorbing device for rotorcraft

Abstract: In a vibration absorbing device for rotorcraft, of the type having at least one vibration weight provided in the proximity of a structural member of the rotorcraft through which exciting forces are transmitted to the fuselage, and arranged in such a position and direction of vibration that a selected one of a plurality of forces and moment exciting forces may be offset by the force of inertia of said vibration weight, hydraulic means for imparting vibrations to said vibration weight and means for controlling said hydraulic means to impart desired vibrations to said vibration weight are provided.

Sensing device of acceleration and vibration

Abstract: The acceleration and vibration sensing device of the present invention comprises in a casing a sensor means consisting of a cylindrical weight and a holding member attracting thereunder the sensor means by magnetic force. The sensor means detects external acceleration and vibration such as of an earthquake and permits the cylindrical weight to drop at a predetermined level of acceleration and vibration. This dropping motion is transmitted to an operating means connected to the sensor casing to actuate the valves or cocks, or electrical switches or air-operated microswitches either to open or close so as to avoid the danger caused from vibration of an earthquake or like accident. The sensing device can be provided so as to measure the gradient of inclination, as well as acceleration and vibration of the intensity as predetermined.