CONSTANT FORCE SPRING.

In many instances a suspension system is required to protect equipment from the combined effects of both shock and vibration. A new nonlinear spring, the vacuum spring, has been developed which may satisfy both shock and vibration requirements simultaneously. This spring combines high energy absorption and vibration attenuation over a wide range of forcing frequencies. This unusual behavior is produced by a stepwise nonlinearity in its loading curve which is composed of two straight-line segments of differing slopes representing two independent spring rates. The slopes of these line segments and the point of intersection can be adjusted to suit any particular design requirements. A spring-mass system involving this concept has been simulated on an analog computer. Results indicate that it is possible to construct a suspension system which will not resonate at any frequency under certain loading conditions but will absorb large amounts of energy while remaining elastic. Author