Tuned spring-mass vibration absorber

DETAILED DESCRIPTION A primary object of the present invention is to provide an improved tuned spring-mass vibration absorber for use in a helicopter fuselage wherein a dynamic mass is suspended from the fuselage by a plurality of cantilevered leaf spring members having a wide end integrally connected to the mass member and a narrow end pivotally connected directly to the fuselage, so that a substantial portion of the leaf spring mass forms part of the vibration absorber effective mass and so that the leaf spring imposes no reaction moments on the fuselage.
The leaf springs are thus cantilevered from the mass member at their wide ends and pinned to the fuselage at their narrow ends.
In accordance with the present invention, a vibration absorber of reduced damping, weight and maintenance requirements is provided.
It is a further object of this invention to teach such a vibration absorber which is a symmetric system, that is, in which the center of force created by the leaf springs is at the same point or coincident with the dynamic mass center of gravity.
It is still a further object of the present invention to teach such a vibration absorber in which the leaf springs impose a symmetric force on the mass, in which all reaction loads are taken by the mass member, in which no moment reaction loads are imparted to the fuselage, and in which over seventy percent (70%) of the leaf spring mass forms part of the effective mass of the vibration absorber in determining vibration absorber efficiency, thereby increasing the effective mass of the vibration absorber about 10 percent.