Pyrotechnical devices and methods of making the same

Claim 1

A PYROTECHICAL DEVICE COMPRISING AN EXTERNAL CANISTER OF GENERALLY TUBULAR SHAPE, SAID CANISTER HAVING A CLOSED BOTTOM WALL AND A CONTINUOUS SIDE WALL, A SOLID PYROTECHNICAL MASS WHICH IS SUBSTANTIALLY SIMILAR IN GEOMETRICAL SHAPE TO THE INTERIOR OF THE CANISTER AND BEING SMALLER IN CROSS-SECTIONAL DIMENSION THAN THE CORRESPONDING INSIDE CROSS-SECTIONAL DIMENSION OF THE CANISTER BY AN AMOUNT IN THE RANGE OF 0.005 TO 0.125 INCH IN ALL LATERAL DIRECTIONS WHEREBY TO PROVIDE AN ANNULAR SPACE BETWEEN THE SIDE WALL OF THE CANISTER AND THE PYROTECHNICAL MASS, SAID ANNULAR SPACE HAVING A WIDTH WHICH IS SUBSTANTIALLY UNIFORM AND IS IN THE RANGE OF 0.005 TO 0.125 INCH, SAID PYROTECHNICAL MASS ALSO HAVING A BOTTOM SURFACE PROXIMATE TO THE BOTTOM WALL OF THE CANISTER AND DISPOSED IN MATERIAL DISPOSED BETWEEN THE CANISTER AND THE PYROTECHNICAL MASS, SAID SEMI-SOLID NON-PYROTECHNICAL MATERIAL BEING ONLY IN CONTACT WITH THE BOTTOM WALL AND CYLINDRICAL SIDE WALL OF SAID MASS.