Method and apparatus for the manufacture of fusecord

An apparatus for the manufacture of explosive fusecord comprising draw means to advance a carrier tape in horizontal linear path, guide means to convolute said carrier tape to form a longitudinal open trough portion at a feed zone, an auxiliary transport belt trained through the guide means and drive means to pull the auxiliary transport belt through the guide means in the same direction and substantially at the same speed as the carrier tape, said transport belt being adapted to conform to the shape of the guide surfaces and frictionally to engage the carrier tape, feed means to deliver a stream of explosive material to said trough portion at a rate controlled to provide only the exact amount required for the formation of the fusecord core, said feed means having an outlet whereby said stream is elongated in cross section to extend over a longitudinal portion of said feed zone of greater length than the diameter of the core of material to be formed by the apparatus and is uniformly distributed along said longitudinal portion, further guide means to further convolute said carrier tape to form a closed tube around the explosive material fed into said trough portion and means to apply reinforcing material around said closed tube, said means including at least one reel of stranded wrapping material, the reel having a tubular centre and being mounted for rotation around an axis coaxial with the path of the carrier tape and, in association with the reel, a rotatably driven flyer guide adapted to train at least one strand from the reel helically around the closed tube surrounding the fusecord core as the encased core passes axially through the reel and to rotate the reel by the pull on the wrapping material.

A method for the production of explosive fusecord which comprises continuously advancing a carrier tape in a horizontal linear path partially convoluting said tape to form a longitudinal open trough portion extending over a feed zone of said path, continuously feeding a stream of explosive material into said trough portion at a rate controlled to provide only the exact amount required for the formation of the desired explosive core, said stream being elongated and extending longitudinally over a portion of the feed zone of greater length than the diameter of the core to be formed and having uniform distribution of the powdered explosive material along the longitudinal extent of said portion, further convoluting said tape in a zone subsequent to said feed zone to form a closed tube surrounding and conveying the thus-produced core of explosive material, said partial and further convoluting steps being effected by passing the carrier tape through shaping guides comprising a trough-shaped guide for the partial convolution and a tubular guide for completion of the convolution of the tape into tube form, the passage of the carrier tape through the shaping guides being assisted by pulling an auxiliary transport belt through the guides in frictional contact with the carrier tape, and subsequently applying reinforcing stranded wrapping materials to said closed tube by spinning the materials around said closed tube from at least one supply reel mounted co-axially with the path of the carrier tape, said closed tube passing axially through the centre of the supply reel, at least one strand from the reel being trained helically around said closed tube by means of a driven flyer rotating around said closed tube.