Radial flextures, beam-columns and tilt isolation for a vibration

Abstract

The present invention provides improvements in the design of radial flexures and beam-columns used in vibration isolation systems which rely on a principle of loading a particular elastic structure which forms the isolator or a portion of it to approach the elastic structure's point of elastic instability. The improved radial flexure includes a region along the flexure in which there is reduced stiffness than the stiffness substantially along the length of the flexure. In one preferred form of the invention, the region of reduced stiffness is created by machining or forming a notch near each end of the flexure. Likewise, the improved design of the beam-column includes a region in which the stiffness of the beam-column in less than the stiffness along substantially the length of the beam-column. In one preferred embodiment, the region of reduced stiffness of the beam-column is formed by machining or otherwise forming notches near the ends of the beam-column. Those regions of reduced stiffness provide the necessary bending flexibility of the beam-column and radial flexure while increasing their local crippling strengths. The present invention is also directed to an improved tilt-motion isolator which utilizes a single damper pad or a plurality of damper pads to provide tilt isolation on an isolator which includes vertical and/or horizontal motion isolation. An outer stiffening jacket which increases the initial stiffness of the beam-column can be incorporated for applications in which the initial stiffness of the beam-column must be increased, or to provide a simple method for changing the stiffness of the beam-column.