| CPC F16K 17/403 (2013.01) [F16K 17/383 (2013.01); F17C 13/04 (2013.01); F17C 13/06 (2013.01); F17C 13/12 (2013.01); F17C 13/123 (2013.01); F17C 2201/056 (2013.01); F17C 2205/0314 (2013.01); F17C 2205/032 (2013.01); F17C 2205/0323 (2013.01); F17C 2205/0326 (2013.01); F17C 2205/0329 (2013.01); F17C 2205/0332 (2013.01); F17C 2205/0335 (2013.01); F17C 2205/0385 (2013.01); F17C 2221/012 (2013.01); F17C 2270/0168 (2013.01); F17C 2270/0184 (2013.01)] | 15 Claims |

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1. A multifunction valve for a tank containing high-pressure hydrogen of an automotive fuel cell system, comprising:
a valve body applicable to the tank, internally having a by-pass duct in communication upstream with the tank and an evacuation duct in communication downstream with an external environment and upstream with the by-pass duct;
a thermal safety device operative between the by-pass duct and the evacuation duct, provided with a bulb, which is breakable when exposed to a temperature higher than a threshold safety temperature;
an auxiliary device adapted to act mechanically on the bulb to break the bulb, the auxiliary device comprising a hammer that is movable between an advanced position, in which the hammer impacts against the bulb, and a backward position, in which the hammer does not influence the bulb;
a trigger group, which, in a configuration of normal operation of the multifunction valve, retains the hammer in the backward position and, in a configuration of remote emergency, is disengaged from the hammer, so that the hammer is brought into the advanced position, in which the hammer breaks the bulb;
wherein the trigger group comprises a stop movable between an advanced position, in which the stop mechanically engages the hammer holding the hammer in the backward position and a backward position, in which the stop is disengaged from the hammer; and
wherein the trigger group further comprises a heat sensitive element, extending along a rectilinear trigger axis beyond the multifunction valve, the heat sensitive element being operatively connected to the stop, and comprising at least one heat sensitive section consisting of a wire made of a shape-memory material, which tends to shorten above a critical temperature, moving the stop into the backward position.
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