Abstract: A fuse having a protective jacket is utilized, for example, in petroleum exploration at large depths where the fuse must withstand high temperatures and pressures. The jacket is produced from a shrinkable hose that is shrink-fitted onto the unfinished cord which latter contains an explosive. The hose consists preferably of radiation-crosslinked polyethylene. The use of a shrink-fitted hose eliminates long preparation and curing times for the synthetic resin jacket. The process temperatures required during heat shrinking are no threat to the safety against ignition of the explosive. It is possible in accordance with the process to manufacture, in particular, fuses for high pressures and high ambient temperatures, without any problems.

Abstract: In the manufacture of explosive fusecord stranded reinforcing wrapping material is helically spun around an encased fusecord core by advancing the fusecord core axially through at least one supply reel of wrapping material and training at least one strand of wrapping material from the reel around the fusecord core by means of a driven flyer rotating around the fusecord core. Strands of wrapping material may be trained from two or more supply reels preferably mounted in line co-axially with the path of the fusecord core. The method permits faster production than can be achieved by the conventional method wherein the wrapping material is applied from supply reels rotating orbitally around the path of the fusecord core.

Abstract: A method and apparatus for the manufacture of explosive fusecord the method comprising continuously advancing and convoluting a carrier tape into hollow tubular form, feeding a stream of explosive material into the tubular carrier tape to form an explosive core encased by the carrier tube and subsequently applying reinforcing materials around said carrier tube, said carrier tape being convoluted by passing through shaping guide means, the passage of the carrier tape through the guide means being assisted by pulling an auxiliary transport belt through the guide means, said transport belt being in frictional contact with said carrier tape.The method facilitates higher fusecord production speeds by preventing stretching or rupture of the carrier tape.

Abstract: A method and apparatus is provided for the manufacture of dry spun explosive fusecord, the method comprising continuously advancing a carrier tape in a horizontal linear path, partially convoluting the tape to form a longitudinal open trough portion extending over a feed zone of said path, continuously feeding a stream of explosive material into the trough portion at a controlled rate appropriate to the formation of the desired explosive core, said stream being elongated and extending longitudinally over a portion of said feed zone, further convoluting the loaded tape to form a closed tube surrounding the explosive core and subsequently applying reinforcing materials around the closed tube. The carrier tape is preferably convoluted by carrying it through guides while the tape is supported on an auxiliary transport tape of stronger material.