Projectiles containing combination fuses explode after the lapse of a predetermined period, unless contact occurs earlier. If the shell fires upon contact A is forced in to explode detonator, which burns through vent AA to the magazine charge. The shock of firing ignites the time train B, which burns for desired period up to 5 seconds, after which the fire, through vent 88, can reach the magazine charge (2), igniting it. The fire goes through the flash tube (3) to the base charge (4), exploding a charge of black powder, which forces the diaphragm (5), head (6), and combination fuse (1) out of the case, carrying shrapnel balls with it. Burning of the matrix gives off a cloud of smoke which enables observers to determine accuracy of fire.

Evening Post, Volume CXXIX, Issue 111, 11 May 1940, Page 18

Projectiles containing combination fuses explode after the lapse of a predetermined period, unless contact occurs earlier. If the shell fires upon contact A is forced in to explode detonator, which burns through vent AA to the magazine charge. The shock of firing ignites the time train B, which burns for desired period up to 5 seconds, after which the fire, through vent 88, can reach the magazine charge (2), igniting it. The fire goes through the flash tube (3) to the base charge (4), exploding a charge of black powder, which forces the diaphragm (5), head (6), and combination fuse (1) out of the case, carrying shrapnel balls with it. Burning of the matrix gives off a cloud of smoke which enables observers to determine accuracy of fire.