GB295266A - Improvements in or relating to the manufacture of safety fuses for use in mining or blasting - Google Patents

Abstract

295,266. Fritzsche, J. Feb. 7, 1927. Blasting fuzes.-Consists in the provision, in a machine for making mining or blasting fuzes, of the kind comprising a core of powder contained in a wrapping formed from a strip of paper, &c., of means for ensuring uniformity in the charge of powder by controlling the flow of powder as it is fed into the wrapping, in such a manner as to prevent undue crowding of the particles. Fig. 1 shows part of a machine for the purpose, in which powder is contained in a flat-bottomed receptacle 1 through which a strip 3 of paper is drawn. The strip is guided into the vessel 1 by a suitable nipple (not shown) and assumes a trough-like shape as it passes through the powder. As it emerges, the strip is formed by a nozzle 2 into a tube with overlapping edges, and near the point of emergence a member 7 is adjustably fixed, with its end 8, shaped like a scoop, projecting into the paper trough. The " ejector " 7 regulates the quantity of powder passing out of the container with the paper wrapping. Fig. 3 shows another construction in which the paper strip 4, instead of passing through the powder container 1, moves below it, the powder falling on to it at a point between the shaping members 14, 2. Excess of powder is directed by a fixed scoop 7, and falls into a vessel 17. Fig. 3 also shows spinning mechanism for covering the filled tube with jute threads in the usual manner. A further alternative is shown in Fig. 5. In this construction, the paper strip 3 retains a troughshaped formation as it passes through the flatbottomed container 1, and a stirrer is provided to prevent crowding of the particles at the lower end of the receptacle 1. Escape of superfluous powder from within the strip is thus facilitated. The stirrer comprises arms 26 carried by a powerdriven rotating part 24 within which the stationary guide 14 for the strip is located. A worm 29 mav be rotated within the passage 28 through which the powder passes to the receptacle 1. The nozzle 2 through which the charged wrapper emerges is flared as shown. The wrapper filled with powder may be enclosed by a sheath of paper &c., to close the longitudinal slot, this sheath being applied simultaneously with the winding of the threads. Fig. 11 shows still another device for displacing excess powder as the core is being formed, an adjustable needleshaped rod 140 being in this case so placed that the wrapper 4 passes round it during its passage through the powder receptacle. More than one strip of paper may be used in the formation of the first wrapper for the core. The strip may be waterproofed or otherwise impregnated, and may be formed of the substance known under the registered Trade Mark " Cellophane."