 In 1872, de Bange designed the "de Bange system", a new type of obturator for cannons.His system used a breech block made of three parts; an interrupted screw locking mechanism at the rear, a doughnut-shaped grease-impregnated asbestos pad that sealed the breech, and a rounded movable "nose cone" at the front.When the gun fired, the nose was driven rearward, compressing the asbestos pad and squeezing it so it expanded outward to seal the breech.