Attenuator apparatus

The present invention relates to attenuators such as shock absorbers or energy management systems for absorbing or reducing shock or vibration forces produced by various devices, including vehicles, guns, heavy machinery, prosthetic devices, and electronic equipment. An attenuator apparatus has an outer housing with a first chamber filled with a first fluid, and a bellows member of elastomeric material mounted in the first chamber and having a second chamber filled with a second fluid, the bellows member having a first end facing away from the first chamber. A piston is slidably mounted in the housing at the first end of the bellows member for acting on the bellows member in response to a force applied to the piston so as to expand the bellows member in the first chamber and cushion the force. The bellows member returns to its original configuration and biases the piston back in a second direction opposite to the first direction on removal of the force.