US2726943A - Pyrotechinc composition - Google Patents

Description

Dec. 13, 1955 R. H. HEISKELL PYROTECHNIC COMPOSITION Filed June 9, 1955 BURNING RATES OF ANTIMONY PENTOXIDE AND MANGANESE MIXTURES IOggOlOO O O O O O 6 5 4 3 2 BURNING TIME(SEO0NDS)(GOLUMN I"LONG X3/8"D!A.)

SURVEILLANCE TESTS ON LOOSE POWDER INVENTOOR R. H. HEISKELL lAl/ HOURS EXPOSED TO ATMOSPHERE I40F AND95%R.H.

Amnzoouw. m2; ozimnm ATTORNE 5 United States Patent PYROTECHNIC COMPOSITION Raymond Heiskell; San Bruno, Calif.

Application June 9,1955; SerialNo. 514,496.

6 Claims. (Cl; 522) (Granted underTitiez 3 5,. Us S; Code: (1952), sec. 266).

The. invention described herein may be manufactured and used by or. forv the Government of the United. States of America for governmental purposes without the. payment of any royalties thereon or therefor.

This invention relates to an igniter mixture and, more particularly it concerns a dark burning nonrflash igniter composition adapted to ignite the tracer composition arranged within a projjectfle.

Heretofore tracer ammunitionused by our armed. forces proved unsatisfactory especially when used in night encounters in that, under conditions, of darkness, the ignition of the igniter composition which ignites the main tracer charge produced a blinding flash and too much light streak at the muzzle of the gun, thus illuminating and disclosing the position of the gun to the enemy and confusing and misleading the gunner or fire director when aiming of the gun. was. accomplished by observa tion of the tracer streak.

Various attempts have been made to produce an igniter for a tracer composition which burns without a visible flame. These prior art compositions were sufficiently luminous to cause the trajectory of the projectile to be visible,- especially at night, lacked stability under adverse conditions of humidity and temperature, and generally proved unsatisfactory as the burning rate thereof was too rapid for the purpose intended and the ignition sensitivity characteristics not uniform.

The compositions of the present invention, which are disclosed in Serial Numbers 130,578130,581 inclusive and 130,585, filed December 1, 1949, by the present inventor, all abandoned, this application being a continuation in part thereof, are adapted to eliminate the above mentioned disadvantages of the prior art compositions.

Accordingly, it is an object of the present invention to provide dark burning non-flash igniter compositions which may serve to ignite the tracer mixture of a projectile. It is a further object of the invention to provide a delayed ignition projectile tracer comprising a dark burning non-flash ignition pellet for igniting the projectile tracer, wherein the ignition pellet comprises a composition of the invention.

It is still a further object of the invention to provide dark burning non-flash igniter compositions having desirable burning rates, uniform ignition sensitivity characteristics, and that are stable under adverse temperature and humidity conditions.

Still other objects and the attendant advantages of the invention will be readily appreciated as the same becomes better understood by reference to the following detailed description, and the drawing wherein:

Fig. l of the drawing graphically illustrates the burning rate of compositions of the invention and more particularly the burning rate of manganese and antimony pentoxide mixtures;

Fig. 2 graphically illustrates the stability of compositions of the present invention and more particularly the 2,726,943 Patented Dec... 13, 19.5.5

'ice

stacllaility of. antimony pentoxide and, manganese mixtures; an

Fig. 3 is a sectional view of a projectile, with a portion thereof cut, away, illustrating the novel. dark burning non-flash delayed. ignition tracer of the invention.

In. an igniter composition. of the type herein disclosed, there are three characteristics which are essential. to. its proper functioning. These characteristics. are:

1. Burning without visible flame and with a, flame hot enough to. ignite. the tracer composition,

2. Burning at the proper rate of, speed to give. the required time delay between, the firing of the, projectile and the ignition of the tracer composition, and I 3. Stability under adverse conditions to thereby ass re that the. igniter will function under any condition of humidity or temperature which may be encountered: in combat areas.

The composition of the present invention having the foregoing characteristics. comprises a m xture, of an oxygen bearing: compound selected from the group v consisting of barium peroxide, antimony pentoXidc, cupric oxide, lead dioxide, and lead chromate as the oxidizing agent, and manganese. A, small quantity of a; binder or lubricant i preferably added to. th m xt r the lubricant being one adapted to. make the loading operation easier and to, eliminate the possibility of ignition during loading, and the binder being employed to. per.- mit the formation of. he P wder into. p let form- Graphite is an excellent lubricantv While some substances such, for example, as. stearic acid perform the. function of both; lubricant and binder.

The ingredients of the composition. de cribe above may be varied within the following limits:

Example 1 (Preferred) Cuprie Oxide 65-30% 50% 50% Manganese 3570% 50% 49% Binder and Lubricant 010% 01% graphite Example II (Preferred) Barium peroxide 90-45% 60% Manganese 10-55% 30% 38% Binder and lubricant 010% 02% graphite Example III (Preferred) Antimony pentoxide 25% 50% 60% Fig. l of the drawing graphically illustrates the manner in which the burning speed of compositions of the invention vary as the percentage of manganese is varied. From an inspection of the graph it will be apparent that a composition of desired burning speed may be selected by varying the percentage composition of the ingredients. In a composition designed for use as a tracer igniter,

usually a relatively short burning is desirable. Thus the preferred percentage composition for use with a high velocity projectile will be characterized by a minimum burning time. Obviously mixtures having slower burning times may be used and in some instances such mixtures may be desirable when a longer time delay is necessary.

Fig. 2 graphically illustrates the high stability of the composition of the present invention under severe conditions of humidity and temperature. Curve A represents the curve developed by a composition compounded according to the present invention, whereas curves B and C represent curves developed by prior art compositions under similar conditions of high humidity and temperature. It can readily be seen that compositions of the invention possess great stability and show a marked improvement over prior compositions.

In preparing the ingredients comprising the dark burning mixture of the invention, it has been found that most satisfactory results are obtained when the oxygen bearing compound and manganese are of such a particle size as to pass through a U. S. standard sieve of mesh size 325/000. A small percentage of lubricant or binder may be added to the foregoing substances and the ingredients then thoroughly mixed in any suitable manner.

As shown in Fig. 3, the dark burning non-flash mixture 1 is preferably loaded in pellet 3 form into the tracer cavity 2 of the projectile 5, and then the pellet 3 is pressed into abutting engagement with the tracer mixture 4. In loading the igniter mixture into the tracer cavity of a projectile, it has been found that the best results are obtained when the mixture, preferably in pellet form, is pressed into the cavity at a pressure of 10,000 to 40,000 p. s. i. The mixture maybe readily pressed into pellets prior to the loading operation at a pressure suflicient to consolidate the mixture when a binder and lubricant is present as an ingredient of the composition in small percentage.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. A delayed ignition projectile tracer comprising a dark burning non-flash ignition pellet for igniting the projectile tracer, said pellet comprising at least 10% not to exceed 75% manganese and at least 25% not to exceed 90% of an oxygen bearing compound selected from the group consisting of cupric oxide, barium peroxide, antimony pentoxide, lead dioxide, and lead chromate, and up to 10% lubricant.

2. The projectile tracer of claim 1, wherein said pellet comprises -30% cupric oxide, 35-70% manganese, and up to 10% lubricant.

3. The projectile tracer of claim 1, wherein said pellet comprises 90-45% barium peroxide, 10-55% manganese, and up to 10% lubricant.

4. The projectile tracer of claim 1, wherein said pellet comprises 85-45% lead chromate, 15-55% manganese, and up to 10% lubricant.

5. The projectile tracer of claim 1, wherein said pellet comprises 85-45% lead dioxide, 15-55% manganese, and up to 10% lubricant.

6. The projectile tracer of claim 1, wherein said pellet comprises -25% antimony pentoxide, 25-75% manganese, and up to 10% lubricant.

No references cited

Claims (1)

1. A DELAYED IGNITION PROJECTILE TRACER COMPRISING A DARK BURNING NON-FLASH IGNITION PELLET FOR IGNITING THE PROJECTILE TRACER, SAID PELLET COMPRISING AT LEAST 10% NOT TO EXCEED 75% MANGANESE AND AT LEAST 25% NOT TO EXCEED 90% OF AN OXYGEN BEARING COMPOUND SELECTED FROM TE GROUP CONSISTING OF CUPRIC OXIDE, BARIUM PEROXIDE, ANTIMONY PENTOXIDE, LEAD DIOXIDE, BARIUM PERCHROMATE, AND UP TO 10% LUBRICANT.

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