Patent ID: 8414366
Filing Date: 2013-04-09
Classification: B60H,F16K

Abstract:
1. A pressure relief valve adapted for use with and for modifying a condition of an interior compartment of a vehicle, said valve comprising: a housing defining an opening in fluid communication with the compartment and an external environment; a flap pivotally connected to the housing, so as to be caused to swing between open and closed conditions, and configured to cover at least a portion of the opening in the closed condition and not to obstruct the opening, so as to allow fluid flow between the compartment and environment, in the open condition: and an actuator drivenly coupled to the flap, and including an active material element effective to undergo a reversible change in fundamental property when exposed to an activation signal, wherein the change is operable to cause the flap to swing between the open and closed conditions, so as to achieve a modified condition, said actuator further comprising a load limit protector coupled to and configured to present a secondary output path for the element, when the flap is unable to swing between open and closed conditions, wherein the protector includes a stretched spring connected in series to the element and a lever intermediate the element and spring, the lever defines first and second arms and a pivot axis, the element is attached to one of said arms and spaced from the axis a first distance, and the spring is attached to the other of said arms and spaced from the axis a second distance greater than the first.