Pyrotechnic devices

Claim 2

A pyrotechnic article, comprising a substantially gas-tight casing provided with an opening; a pyrotechnic device interiorly of said casing; and a valve member cooperating with said casing so as to define a unidirectional flow path for a gas in a direction from the interior of said casing to the exterior thereof, said valve member comprising a body of resilient, substantially gas-impermeable material having a first portion extending through said opening with clearance, a second portion exteriorly of said casing completely overlying said opening and normally sealingly engaging said casing circumferentially of said opening, and a third portion interiorly of said casing engaging the same so as to prevent withdrawal of said body from said opening and only in part overlying the latter, said opening, said first portion and said third portion cooperating to define a passage extending from the interior of said casing to said second portion so that when the gas pressure interiorly of said casing exceeds the pressure exteriorly thereof the seal between saId second portion and said casing is temporarily broken to thereby permit gas to flow through said passage from the interior of said casing to the exterior thereof until the pressure interiorly of said casing substantially equals the pressure exteriorly thereof.

Claim 3

A pyrotechnic article as defined in claim 1, wherein said second portion is of part-spherical configuration.

Claim 4

A pyrotechnic article as defined in claim 1, said second portion having a peripheral region provided with an edge section which normally sealingly engages said casing; and wherein the thickness of said second portion increases in a direction inwardly from said edge section so as to impart increased flexibility to said peripheral region.

Claim 5

A pyrotechnic article as defined in claim 3, wherein said second portion is of concavo-convex configuration.

Claim 6

A article articl as defined in claim 1, wherein said third portion is of frustoconical configuration.

Claim 7

A pyrotechnic article as defined in claim 1, wherein said casing constitutes an integral part of said article and is adapted to retain said device when the latter is fired.

Claim 8

A pyrotechnic article as defined in claim 1, wherein the cross sections of said second and third portions as viewed in a plane normal to the axial direction of said opening are of substantially circular configuration, said second portion having a cross-sectional area which is greater than the cross-sectional area of said third portion.

Claim 9

A pyrotechnic article, comprising a substantially gas-tight casing provided with an opening of substantially polygonal configuration; a pyrotechnic device interiorly of said casing; and a valve member cooperating with said casing so as to define a unidirectional flow path for a gas in a direction from the interior of said casing to the exterior thereof, said valve member comprising a body of a resilient, substantially gas-impermeable material having a first portion of substantially circular cross-section extending through said opening and being su0stantially tangential to said casing within the confines of said opening, a second portion exteriorly of said casing completely overlying said opening and normally sealingly engaging said casing circumferentially of said opening at locations radially outwardly of said opening so as to define with said casing a substantially annular space, and a third portion interiorly of said casing engaging the same so as to prevent withdrawal of said body from said opening, said third portion only in part overlying said opening, and said first portion, said third portion and said opening cooperating to define a passage extending from the interior of said casing to said annular space so that when the gas pressure interiorly of said casing exceeds the pressure exteriorly thereof the seal between said second portion and said casing is temporarily broken to thereby permit gas to flow through said passage and said annular space from the interior of said casing to the exterior thereof until the pressure interiorly of said casing substantially equals the pressure exteriorly thereof.

Claim 10

A pyrotechnic article, comprising a substantially gas-tight casing provided with an opening of substantially polygonal configuration; a pyrotechnic device interiorly of said casing; and a valve member cooperating with said casing so as to define a unidirectional flow path for a gas in a direction from the interior of said casing to the exterior thereof, said valve member comprising a body of a resilient, substantially gas-impermeable material having a first portion of substantially circular cross-section extending through said opening and being su0stantially tangential to said casing within the confines of said opening, a second portion exteriorly of said casing completely overlying said opening and normally sealingly engaging said casing circumferentially of said opening at locations radially outwardly of said opening so as to define with said casing a substantially annular space, and a third portion interiorly of said casing engaging the same so as to prevent withdrawal of said body from said opening, said third portion only in part overlying said opening, and said first portion, said third portion and said opening cooperating to define a passage extending from the interior of said casing to said annular space so that when the gas pressure interiorly of said casing exceeds the pressure exteriorly thereof the seal between said second portion and said casing is temporarily broken to thereby permit gas to flow through said passage and said annular space from the interior of said casing to the exterior thereof until the pressure interiorly of said casing substantially equals the pressure exteriorly thereof.

Claim 11

A pyrotechnic article as defined in claim 8, wherein said opening is of substantially triangular configuration.

Claim 12

A pyrotechnic article as defined in claim 1, wherein said first portion is integrally formed with said second and third portions.