GB245766A - Safety device for very sensitive percussion fuses - Google Patents

Abstract

245,766. Schneider et Cie. Jan. 6, 1925, [Convention date]. Void [Published under Sect. 91 of the Acts]. Projectile fuzes.-Sensitive direct-action percussion fuzes, especially those acting by a combination of direct impact and momentum as described in Specifications 172,326 and 238,186, are provided with means for preventing premature explosion on leaving the muzzle of a gun by accidental light impact, for example against a tree branch. The safety device covers the fuze, or prevents its backward movement, or shuts off the flash passage, and is removed a short time after discharge as a result of the rotation of the projectile. In Fig. 1, the fuze B is covered by a cap C made in two halves secured in a groove a by a binding of lead wire D, which gradually gives way to the centrifugal force on the two halves of the cap when the projectile is discharged. In a modification, the cap is made in one piece and is screwed over the fuze and locked in place by a bolt situated in a substantially longitudinal direction. When the projectile is discharged, the bolt sets back, releasing the cap, and the cap is unscrewed by the action of the air on inclined ribs on the cap. Air is also admitted between the cap and the fuze, preferably by oblique ducts, and the cap is eccentrically weighted to facilitate its detachment. In Fig. 8, the backward movement of the fuze B is prevented by a transverse bolt F, which under centrifugal force when the projectile is discharged gradually stretches a lead wire G and moves radially away from behind the fuze B. A similar arrangement of bolt may be used to shut off the flash passage A<2>. In Figs. 9 and 11, the flash passage A<2> is shut off by a transverse bolt H, which is dislodged radially by centrifugal force when the projectile is discharged, this movement being delayed by the gradual ejection of sand, vaseline, lime soap, or other fluid from a chamber a<4>. The bolt is retained in its extreme positions by a yielding spring catch H<2>. In a modification, the fluid from the chamber a' is not ejected, but is forced into an empty space within the bolt H. In still another modification, the flash passage is normally closed by a pair of centrifugal segments bound round with lead wire, which gradually yields to the centrifugal force on the segments.