Abstract: A vibration isolation system includes a seismic restraint assembly that attenuates forces above a chosen magnitude transmitted to a unit from a support during a seismic event. Vertical friction elements on a vertical frame engage and support a vertical damper element. Horizontal friction elements on a horizontal frame engage and retain a horizontal damper element. One frame is connected to the unit, the other to the support. The vertical and horizontal damper elements interconnect, but lost motion spacing between these elements ordinarily prevents low level vibrations being communicated therethrough. Each of the vertical and horizontal friction elements is spring biased into a predetermined frictional engagement with its associated damper element. The force of the engagement is adjustable to adjust the level at which higher than ordinary forces that are being transmitted through the assembly will begin to be attenuated by slippage of the frictionally engaged elements.

Abstract: A forging hammer is isolated from a foundation by a shock and vibration control system composed of an inertia block and a multiplicity of shock-vibration isolators that are installed on pedestals spaced a dimension X below the bottom of the inertia block that is substantially equal to the sum of the loaded height H of an isolator and the height S of one or more permanent load-supporting spacers installed between the top of each isolator and the bottom of the inertia block.

Abstract: The force transmitted to vibration-isolated equipment during a seismic event can be essentially limited to the force generated by the floor input acceleration by a combination of friction restraining devices and energy-absorbing stops constructed into the vibration isolators which support the equipment. The friction restraint devices permit essentially undamped vibration of the equipment during normal operation but provide a frictional force which restrains vibration of the equipment at amplitudes greater than a selected value. Any movement of the equipment in excess of the selected amplitude that results from a floor input force that exceeds the frictional restraining force of the friction restraint devices is limited by the energy-absorbing stops, which transmit to the equipment with a small amplification only the residual of the input force over the frictional force.