Abstract: An Extensile Fluidic Muscle Actuator (FMA) that changes the normal direction of force and motion, achieving compressive force generation and extensile motion output with just a small increase in friction, weight, and cost is disclosed. The motion conversion is accomplished by a pushrod that is attached to the inside end of one of the actuator's end fittings, and extends through the actuator body and slidably out through the other end fitting. The other end fitting is held stationary by a seal housing that contains a sealing element to retain internal fluid pressure as the actuator moves. A linear bearing may also be installed to keep the rod aligned and centered properly in the seal. Upon pressurization of the actuator, the flexible body of the actuator will expand radially, causing relative contractile motion between the two end fittings. However, as the two end fittings are drawn towards each other, the pushrod is extended.

Abstract: An Extensile Fluidic Muscle Actuator (FMA) that changes the normal direction of force and motion, achieving compressive force generation and extensile motion output with just a small increase in friction, weight, and cost is disclosed. The motion conversion is accomplished by a pushrod that is attached to the inside end of one of the actuator's end fittings, and extends through the actuator body and slidably out through the other end fitting. The other end fitting is held stationary by a seal housing that contains a sealing element to retain internal fluid pressure as the actuator moves. A linear bearing may also be installed to keep the rod aligned and centered properly in the seal. Upon pressurization of the actuator, the flexible body of the actuator will expand radially, causing relative contractile motion between the two end fittings. However, as the two end fittings are drawn towards each other, the pushrod is extended.