US3572246A

US3572246A - Detonating fuze system

Info

Publication number: US3572246A
Application number: US770029A
Authority: US
Inventors: George F Hare; Bruce W Travor
Original assignee: US Department of Army
Current assignee: US Department of Army
Priority date: 1968-10-23
Filing date: 1968-10-23
Publication date: 1971-03-23
Anticipated expiration: 1988-03-23

Abstract

A MILD DETONATING FUZE SYSTEM HAVING AN ASSURED CONTINUITY OF SHOCKWAVE PROPAGATION. THE CORE PORTION OF A STRIPPED END OF A MILD DETONATING CORD, PROTRUDING FROM THE END OF A FERRULE, IS EMBEDDED IN A HIGH EXPLOSIVE FILLER WITHIN A BOOSTER SHELL CUP THAT IS SECURED TO THE FERRULE.

Description

Patented Mar. 23, 1971 3,572,246 DETONATING FUZE SYSTEM George F. Hare, Feasterville, and Bruce W. Travor, Holland, Pa., assignors to the United States of America as represented by the Secretary of the Army Filed Oct. 23, 1968, Ser. No. 770,029

Int. Cl. F4211 3/10 U.S. Cl. 1102-27 2 Claims ABSTRACT OF THE DISCLOSURE A mild detonating fuze system having an assured continuity of shockwave propagation. The core portion of a stripped end of a mild detonating cord, protruding from the end of a ferrule, is embedded in a high explosive ller within a booster shell cup that is secured to the ferrule.

The invention described herein may be manufactured, used, and licensed by or for the Government for governmental purposes without the payment to us of any royalty thereon.

This invention relates to a mild detonating fuze system and, more particularly, to one having a booster end transfer arrangement.

In mild detonating fuze systems, lhereinafter referred to as MDP` systems, a problem has existed in the discontinuity of shockwave propagation caused by air gaps adjacent a booster end transfer arrangement. When an air gap is present the shockwave decays rapidly in the propagation train, which results in no propagation or a lower order shockwave which decays entirely within a few inches of travel in the MDF core. An old method for solving this problem was to increase the grains/foot of the basic Pentaerythrite Tetranitrate, hereinafter referred to as PETN, core. This method was unsatisfactory since it increased the weight of the MDF system and caused problems of retaining the core in the r,fittings due to the greater shock force.

One of the objects of the invention 'therefor is to provide a detonating fuze system in which the .foregoing disadvantage is eliminated.

Another object of the invention is to provide such a system which has maximum reliability and is minimally light in hardware weight.

These and other objects, advantages and features will become more apparent from the following description and accompanying drawing which is a longitudinal sectional view of a detonating fuze system embodying the principles of the invention.

In actual use of the invention, both ends of the explosive core of a detonating cord are directly embedded in a high explosive contained in the respective booster and transfer assembly at each end of the cord, and thus while the drawing shows only one end of a detonating cord, it is understood that a duplicate arrangement exists at the other symmetrical end of the cord.

The mild detonating cord is a multi-braided type having a lead sheathed explosive core 12 surrounded by multiple layers of suitable materials such as polyethylene, fiber glass and polytetratiuoroethylene, commonly known as Teon, which protect the core from breaking while permitting flexibility in the cord. Each end of cord 10 is stripped in successive stages thereby exposing

layers

14, 16, 18 and the end portion 20 of core 12. A centrally apertured ferrule 22 is itted over the end of cord 10 and secured thereto by suitable epoxy. Ferrule 22 has at its forward end a protruding head portion 24 and an external annular groove 26 for purposes hereinafter described. Core end portion 20 protrudes from the forward end of ferrule 22 and is embedded in a high explosive ller 28 such as PETN which is contained within cup 30 of the respective booster and transfer assembly 32. Cup 30 also has contained therein an annular ring 34 having at its forward end a conical inner surface 36 tapering inwardly and at its rearward end an annular ange 38 which forms a central recess 40 at said rearward end. Booster and transfer assembly 32 is connected to ferrule 22 by sliding cup 30l over the forward end of ferrule 22, with core end portion 20 extending through ring 34 and into ller 28, until head portion 24 of ferrule 22 seats in recess 40 of ring 34. Cup 30 is secured to the forward end of ferrule 22 by suitable epoxy and by crimping the end of cup 30 into groove 26 as at 42. A retaining sleeve 44, preferably of a lightweight metal such as aluminum, isI secured to cord 10 by suitably epoxy material and serves to hold assembly 32 to ferrule 22 and also to protect the stripped end of cord 16 from being broken or otherwise damaged. The forward end portion of sleeve 44 has annular internal flange 46, which, when sleeve 44 is fitted over cord 10, holds cup 30 securely against ferrule 22. When cup 30` is properly positioned with respect to ferrule 22 as shown in the drawing, the conical inner surface 36 provides a space around the core end portion 20 projecting beyond the body of ring 34 and into tiller 28. This space also contains the high explosive iller 28 so that with the end of the explosive being surrounded by high explosive iller, there is no air gap present between the explosive core and the explosive filler sufficient to prevent propagation of high order detonation of the diller so that reliable continuity of shockwave propagation is obtained.

Various modioations, changes or alterations may be resorted to without departing from the scope of the invention as defined in the appended claims.

We claim:

1. A mild detonating fuze system including:

a mild detonating cord containing an explosive core,

an end of said cord being stripped to expose a portion of said core,

a centrally apertured ferrule secured to said cord with a portion of said core portion protruding from said ferrule, and

a booster end transfer arrangement secured to said ferrule,

said booster end transfer arrangement comprising a booster shell cup and a high explosive `filler in said cup, said iiller having a rearwardly protruding conical portion thereof surrounding said protruding core portion,

said booster shell cup containing an annular ring having a central passage and at its rearward end a central recess, said ferrule having a protruding head portion at its forward end which seats in said recess when said booster end transfer arrangement is secured to said ferrule,

said annular ring having a conical inner surface tapering inwardly from its forward end to said central 3 4 passage, said ring conical surface surrounding said References Cited uef com@ pomo?, UNITED STATES PATENTS whereby no a1r gap 1s present between sald core and said filler to prevent propagation of high order Quin d to t'o of sad ll I YY a e nal n l er 5 3,326,127 6/1967 sehimmel 102-47 2. The device of claim 1 including a retaining sleeve secured to said cord and holding said booster end trans- VERLIN R, PENDEGRASSD Primary Examiner fer arrangement to said ferrule.