Delay action electric fuse

416,349. Blasting - fuses. SOSSON, C. E., 13, Eglinton Street, Saltcoats, Ayrshire, BARLOW, H., Thurlstone, Major's Loam, Falkirk, and IMPERIAL CHEMICAL INDUSTRIES, Ltd., Millbank, London. Feb. 7, 1933, No. 3758. [Class 9 (i).] A delay-action electric blasting- fuse comprises in combination an inner metal tube 1 enclosing at one end a delay element 2 and communicating at the other end through a hole 8 with a surrounding cooling sleeve 9, one or more finely milled ribs 6, 7 or other filtering means in the cooling sleeve, and an electric igniter 5 in close proximity to the inner surface of the delay element 2, the length of the inner tube 1 being such as to afford a relatively large space sufficient to ensure the effective deposition therein of solid products of combustion to avoid choking of the filtering means. The leads 4 of the electric igniter pass through a rubber plug 3, and this end of the device is coated with pitch 10. The vent hole 8 may be temporarily closed by a strip of thin paper shellacked on the tube and coated with a waterproofing dope.