| 摘要 |
<p>1,041,123. Electric igniters. ETABLISSEMENTS DAREY BECKFORD SMITH & CIE S.A. FRANCAISE. April 21, 1964 [May 9. 1963], No. 16480/64. Heading F3A. A method of making electric igniters for detonators for blasting cartridges consists of metallically coating the faces (but not the edges) of a strip of dielectric material, winding a metal filament helically around the strip, depositing a second conductive layer over the first layer and those parts of the filament in contact with the first layer, cutting slots between the filament turns to form a " comb " which is then cut to produce individual igniters. A cardboard sheet, 0À5 mm. thick, is zinc coated by spraying, vacuum deposition or chemical reduction &c., a metallic filament 6, 0À03 mm. diameter, is helically wound round the strip and a second layer of zinc is deposited so as to embed the filament on to the first layer. Slots 8 are then cut out along the edges of the strip between the turns of the filament 6. Cuts are then made along the broken lines 11 to produce individual igniters. Alternative methods include using a strip of only half width and cutting slots along one edge only, or for longer igniters cutting along the lines 11 is excluded while cuts are made along and perpendicular to the median axis 10 passing through the centre of each slot 8.</p> |
