Heat transfer delay

Abstract

A heat transfer delay for providing a delay time in propellant, pyrotechnic, and explosive devices, and a method of delaying production of a non-detonating thermal output with the heat transfer delay. A representative delay is in the form of a housing having a first heat source cavity, a second heat source cavity, and a heat transfer cavity connecting the first and second heat source cavities. A pyrotechnic heat source is placed in thermal contact with the first heat source cavity, and a non-detonating autoignition material is placed in thermal contact with the second heat source cavity. Upon ignition and combustion or reaction, the pyrotechnic heat source generates an amount of heat sufficient to heat the first heat source cavity to a temperature sufficiently high to cause a transfer of a sufficient amount of heat through the heat transfer cavity to the second heat source cavity to heat it to a temperature sufficiently high to ignite the non-detonating autoignition material, and produce a non-detonating thermal output therefrom, where the heat transfer bridge conducts heat at a rate such that a delay time of at least about 0.5 second elapses between ignition of the heat source and ignition of the non-detonating autoignition material.