US3885500A - Percussion igniter for projectiles and projectile embodying the same - Google Patents

Abstract

A percussion igniter for projectiles, having a striker located up-stream of a thin walled primer and having in line with an annular bottom of a primer carrier, an annular and concave lower face, which centrally draws out into a coaxial protruding part.

Description

United States Patent 1 Bornand [451 May 27, 1975 PERCUSSION IGNITER FOR PROJECTILES AND PROJECTILE EMBODYING THE SAME [75] Inventor: Robert M. Bornand, Meyrin,

Switzerland [73] Assignee: Valinor Anstalt, Vaduz,

Liechtenstein [22] Filed: Oct. 16, 1973 [21] Appl. No.: 406,930

[30] Foreign Application Priority Data Oct. 5, 1973 Switzerland 14241/73 [52] US. Cl 102/45; 102/56 [51] Int. Cl. F42c 1/00 [58] Field of Search 102/45, 78, 38, 44, 70, 102/5 6 {56] References Cited UNITED STATES PATENTS 624,145 5/1899 Young 102/45 UX 2,415,803 2/1947 Abel] 102/45 2,421,266 5/1947 Honger 102/78 2,926,607 3/1960 Muller, Jr. et al.. 102/45 3,114,290 12/1963 Harvey et a1. 102/38 X 3,396,658 7/1968 Scanlon, Jr. et a1. 102/45 Primary Examiner-Robert F. Stahl Attorney, Agent, or Firm-Young & Thompson 57 ABSTRACT A percussionigniter for projectiles, having a striker located up-stream of a thin walled primer and having in line with anannular bottom of a primer carrier, an annular and concave lower face, which centrally draws out into'a coaxial protruding part.

5 Claims, 6 Drawing Figures P ENTEnHmmrs 3,885,500

SHEET 1 Ezgtf 5 7 PERCUSSION IGNITER FOR PROJECTILES AND PROJECTILE EMBODYING THE SAME The present invention relates to a percussion igniter for igniting the propulsive charge of projectiles.

The purpose of the invention is to provide such a percussion igniter, which will be quite simple and capable of ensuring the tightness of the igniting system in both directions, that is to say, capable of preventing the penetration of and the escape of, the high pressure gases.

Various solutions have already been proposed for achieving the protection of propulsive powders during the storing of projectiles and for ensuring a high pressure combustion gas tightness.

Most of said solutions have consisted either in doubling the priming cup or in using comparatively thick walled cups. This has resulted in a heightening of the sensitivity threshold of the primer, respectively in an increase of the force required for igniting the primer. Another solution has also been to provide, downstream of the primer, a non-retum valve of a ball, cone or other type. Such a means makes the construction appreciably more intricate, increases the cost of same and offers a comparatively poor reliability.

The percussion igniter according to the present invention allows at the same time to ensure in the known way the moisture tightness and through a quite simple means to avoid the escape of gases, whilst lowering the working threshold down to the known limits for the most sensitive of primers. To this end, the percussion primer according to this invention is characterized in that the striker, which is located up-stream of the thin walled primer has, in line with the annular bottom of the primer carrier, an annular and concave lower face, which centrally draws out into a coaxial protruding part. The latter may be hollow, solid or even elastic The gas sealing function is carried over to the comparatively light striker located up-stream of the primer, which may be highly sensitive. Without any loss of efficiency whatsoever, this percussion igniter may be combined with any chamber, a casing or also be an integral part of a projectile, for instance a finned projectile.

As a non-limiting example, embodiments are described hereinafter with reference to the attached drawings in which the same reference numerals designate equivalent components in each of the described constructions.

FIG. 1 shows a radial section of the components of the percussion igniter in a restor storage position;

FIG. 2 is similar to FIG. 1, the igniter being shown in ignition position;

FIG. 3 is similar to FIGS. 1 and 2, the igniter being shown in post firing position;

FIGS. 4, and 6 show radial sections of various applications and embodiments of the igniter according to the invention.

In the various drawings, on one of the ends of an envelope 1, which may be a chamber (FIGS. 1 4), or a casing (FIG. 5), or the corresponding part of a finned projectile (FIG. 6), is screwed or otherwise attached the body 2 of the igniter. The latter is provided with bores defining two annular shoulders 3-4. In the first bore, limited at the bottom by said annular shoulder 3, is fixed the primer carrier 5, housing the primer proper 6, jacketed by a thin wall 7 and an additional charge or primer 8. On the upper edge of said igniter body is located a washer or disc 9, limiting in this way the lower part of the combustion chamber 10, the upper part of which is limited by the corresponding part of the projectile 11. In the bore limited in its lower part by the shoulder 4 is located the striker 12, which in the present case consists of a cylindrical body 13, the upper face of which is centrally provided with a protrusion or needle 14 whilst, according to the principal characteristic of the invention, its annular bottom face 15 is con cave. The central part of the said concave annular face 15 is drawn out into a protruding part 16. This part is hollow and has in the example of the FIGS. 1 to 4 a comparatively thin wall; it is solid in the example of FIG. 5, but, in the part which is adjacent to the concave annular face; it has a reduced diameter or a groove 17; in the example of FIG. 6, said protruding part 16 is a helicoidal spring firmly attached to the central part of said concave inferior face of the striker. The free end of the protruding part 16 is slightly sunk with respect to the lower face 18 of igniter body 2.

In those embodiments, tightness against the entry of moisture into the combustion chamber 9 is ensured, as known, by the fact that the primer is housed in a thin walled jacket, pressed into the primer carrier 5.

According to the invention, the tightness in preventing combustion gases from escaping after firing is ensured by the fact that as the striker 12 is violently loaded by the gases under pressure, its concave annular face 15 is deformed whilst being forcibly seated on said shoulder 4 (FIG. 3), thereby ensuring a perfect tightness, preventing any passage of gas under pressure.

The drive of the striker 12 towards the primer 6 may be obtained by an infinite variety of means, generally determined by the kind of projectile concerned and also by the percussion mechanism proper, which are not an internal part'of the invention and are quite schematically illustrated by the percussion component 19.

In the example of the FIGS. 1-4, when the striker 12 is loaded by the gases under pressure after firing, the

' hollow protruding part with comparatively thin wall gives way through crushing against the percussion component 19 in such a way that the concave lower face 15 of the striker 12 is violently pressed, whilst being deformed on theshoulder 4, thus absolutely preventing any passage of gas under pressure. In the embodiment of FIG. 5, due to the presence of the groove 17, the protruding part 16 gives way to rupture. In the embodiment of FIG. 6, they giving way function is ensured by the compression of the elastic protruding part, the load characteristic and pitch of which can be easily determined in relation to the type of projectile to be equipped.

The dimensions of the respective components are variable in relation to the applications contemplated.

The invention relates both to the percussion igniter device and to any projectile associated therewith.

What we claim is:

1. In a percussion igniter for projectiles, comprising an igniter body ,'a primer within said igniter body, a striker disposed in said igniter body for movement toward and away from said primer, said body having an annular internal shoulder thereon that surrounds an opening through the bottom of said primer to provide access to said striker, said body and primer and striker and shoulder being coaxial; the improvement in which said striker has a concave surface confronting said annular shoulder whereby upon combustion of said primer, said striker is forced against said annular shoulder to flatten out said concave surface against said anbase to promote collapse of said projection upon impact.

4.-An igniter as claimed in claim 1, and a coil compression spring extending axially from said striker into said opeing.

5. A projectile having an explosive charge therein and a percussion igniter therefor as claimed in claim 1.

Claims (5)

1. In a percussion igniter for projectiles, comprising an igniter body, a primer within said igniter body, a striker disposed in said igniter body for movement toward and away from said primer, said body having an annular internal shoulder thereon that surrounds an opening through the bottom of said primer to provide access to said striker, said body and primer and striker and shoulder being coaxial; the improvement in which said striker has a concave surface confronting said annular shoulder whereby upon combustion of said primer, said striker is forced against said annular shoulder to flatten out said concave surface against said annular shoulder thereby to seal against the escape of gas under pressure through said opening.

2. An igniter as claimed in claim 1, and a hollow thin-walled protrusion extending axiAlly from said striker into said opening.

3. An igniter as claimed in claim 1, and a solid projection extending axially from said striker into said opening, said projection being reduced in diameter at its base to promote collapse of said projection upon impact.

4. An igniter as claimed in claim 1, and a coil compression spring extending axially from said striker into said opeing.

5. A projectile having an explosive charge therein and a percussion igniter therefor as claimed in claim 1.

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