Ignition device for projectiles having high launching speed - solid backing block carrying sleeve of rigid combustible material has cylindrical cavity contg. detonating fuse of pure sec. explosive

Ignition device has a detonating fuse for a propulsive charge situated around and in its axial extension, and consisting of a rear solid block and an ignition compsn. consisting of a combustible rigid material in the form of a sleeve provided with an internal hollow cylindrical cavity contg. in its axis a detonating fuse comprising a secondary explosive in the pure state. Pref. the rigid combustible ignition material is a cellular material and a layer of a porous unfilled powder with a high rate of combustion is interposed between the ignition compsn. and the detonating fuse inside the cylindrical cavity. The fuse pref. contains a linear charge of 0.8 g/k hexogen. The rigid cellular combustible material is pref. comprised of 60 wt.% KNO3, 5 wt.% microballoons and 35 wt.% foamed polyurethane binder; or 60% granular nitrocellulose and 40 wt.% foamed polyurethane. The porous powder interlayer surrounding the fuse is e.g. of nitricellulose powder or black powder. The detonators give rapid firing along the whole axial length, giving rapid ignition of the charge without causing pressure waves in the combustion chamber. The fuses are esp. useful for firing modern munition projectiles of the 'arrow' type which are launched at speeds of above 1500 m/sec. LA PRESENTE INVENTION CONCERNE UN DISPOSITIF D'ALLUMAGE A CORDEAU DETONANT POUR CHARGE PROPULSIVE DISPOSEE AUTOUR ET DANS PROLONGEMENT AXIAL.IL COMPOSITION D'ALLUMAGE CONSISTANT EN UN MATERIAU COMBUSTIBLE RIGIDE QUI EST UN MATERIAU ALVEOLAIRE 3. ELLE A LA FORME D'UN MANCHON A L'INTERIEUR DUQUEL SONT PREVUS UNE COUCHE DE POUDRE NITROCELLULOSIQUE 5 ET UN CORDEAU DETONANT 4. LE CORDEAU DETONANT EST CONSTITUE D'UN EXPLOSIF SECONDAIRE A L'ETAT PUR.