Patent attributes
Active pressure relief valves and methods of use for regulating atmospheric conditions within an interior compartment of a vehicle generally include an active material to effect movement of a flap relative to an opening. The active material has the ability to remember its original at least one attribute such as dimension, shape, and/or flexural modulus, which can subsequently be recalled by applying or removing an external stimulus, as will be discussed in detail herein. Suitable active materials include, without limitation, shape memory alloys, ferromagnetic shape memory alloys, shape memory polymers, piezoelectric materials, electroactive polymers, magnetorheological fluids and elastomers, electrorheological fluids, composites of one or more of the foregoing materials with non-active materials, combinations comprising at least one of the foregoing materials, and the like. Depending on the particular active material, the activation signal can take the form of, without limitation, an electric current, a temperature change, a magnetic field, a mechanical loading or stressing, or the like.
