Abstract: A purging and recharging system improves the repeating of detonations from a detonation device 10 having a detonation chamber 20 separated from an ignition chamber 25 by a detonation plate 22 having an opening 23 through which a flame jet can pass from ignition chamber 25 to detonation chamber 20. A differential piston 30 driven by a detonation in a differential cylinder 31, 32 around detonation chamber 20 affords a fluid passageway between differential piston 30 and detonation chamber 20. On a power stroke, differential piston 30 compresses recharging air and draws in cooling and exhaust purging air to surround detonation chamber 20. On a return stroke, differential piston 30 forces cooling and purging air into detonation chamber 20 and then admits compressed recharging air into detonation chamber 20.

Abstract: A purging and recharging system improves the repeating of detonations from a detonation device 10 having a detonation chamber 20 separated from an ignition chamber 25 by a detonation plate 22 having an opening 23 through which a flame jet can pass from ignition chamber 25 to detonation chamber 20. A differential piston 30 driven by a detonation in a differential cylinder 31, 32 around detonation chamber 20 affords a fluid passageway between differential piston 30 and detonation chamber 20. On a power stroke, differential piston 30 compresses recharging air and draws in cooling and exhaust purging air to surround detonation chamber 20. On a return stroke, differential piston 30 forces cooling and purging air into detonation chamber 20 and then admits compressed recharging air into detonation chamber 20.

Abstract: Three-dimensional preformed fabric devices for painting, dyeing, silk screening, or other surface design finishing are disclosed. One or more raised ridges or lines is formed on the surface in a predetermined geometric design. The fabric is folded and held in place by stitching. Stiffening members can be inserted in the ridges to define certain shapes or stiffen the ridges.