US1755330A - Priming mixture - Google Patents

Description

Patented Apr. 22, 1930 UNIT-ED STATES PATENT OFFICE JOSE PH ID. MCN'UT'I, OF NEW HAVEN, CONNECTICUT, ASSIGNOR, BY MI'SNE ASSIGN- MENTS, TO WINCHESTER REPEATING ARMS 00., OF

" A CORPORATION OF DELAWARE NEW HAVEN,- connncrrcu'r,

PRIMING MIXTURE No Drawing.

My invention relates to an improvement in priming mixtures, the object being to produce a priming mixture of such a character that it will leave no corrosive residuum to act on the material of the barrel of the firearm in which it is used, and which will not deteriorate in storage.

I With these ends in view, my invention consists in a priming mixture comprising a metallic nitrate, a metallic thiocyanate, a metallic fulminate, and a chemically-basic stabilizing agent.

. In carrying out my invention, I employ the above-named ingredients in substantially the following proportions, dependent upon the specific use to be made of the mixture:

485 parts of mercury fulminate, carrying 16% of water;

209 parts of barium nitrate;

7 6 parts of lead thiocyanate;

230 parts of ground lass, and

From to 2 parts 0 diphenylamin.

In proceeding to make the mixture, the 'diphenylamin or other chemically-basic stabilizer and the barium nitrate are treated with a suflicient quantity of alcohol to effect their intimate mixture, which is then evaporated to dryness. The barium nitrate and the stabilizing agent are thus brought into the most intimate relations. The required quantity of barium nitrate and stabilizer so mixed, is then weighed out, together with the required quantities of lead thiocyanate and ground glass, and these are mixed in any convenient manner. A small amount of a solution of gum in water is now incorporated with the mixture; the required quantity of mercury fulminate is added thereto; and the whole is thoroughly mixed together. The resultant mixture is then ready for immediate use in the manufacture of primers or of primed rimfire cartridge shells. Y

Most priming compositions of the prior art depend upon some salt of chloric acid, such as potassium chlorate, in combination with a fuel mixture containing unoxidized sulphur or carbon. Such priming mixtures, although otherwise excellent,- have the serious defect of leaving a residue containing metallic chlorides deposited in the bore of the arm in which Application filed March 23, 1927. Serial No. 177,842.

they are used. Such salts, when moist, have a highly corrosive action on most ferrous alloys and being strongly hygroscopic, attract moisture from the air and exert a ruinous effect upon the gun barrel in which they have been deposited, which it is very diflicult to obviate or counteract.

Many attempts have been made in the past to use priming mixtures dependent upon the properties of ,mercury fulminate, together with derivatives of nitric acid, but have failed of complete success, owing to either the extreme brisance of this compound, or to its instability. Upon standing the metallic salts of fulminic acid, in the presence of certain nitrates, decompose, very gradually at first. But owing to the acid nature of the decomposition products this is a self-accelerating unless the said products be nullified as fast as formed.

I have discovered that a variety of substances may be used to destroy or render harmless these decomposition products, such substances being decidedly basic in character, typical examples being carbonates of strongly basic radicals, such as ammonia, the alkali metals or the alkaline earth metals. Such substances are defined in the claims as chemically-basic stabilizing ingredients. I prefer, however, to use basic organic compounds, as these are less likely to leave any solid residues after the explosion of the mixture. In particular, I find the substituted ammonia compounds to accomplish the desired results. I have described the use of diphenylamirn'as this compound has physical characteristics rendering it peculiarly advantageous. I do not, however, limit myself to this compound alone for the purpose of stabilizing the mixture.

In order to mask or cushion the extreme brisance ofthe fulminate, I combine with it an oxidizing compound and a fuel, thus lessening the amount of fulminate required, by

increasingthe amount of flame, the burning stantially 209 specific example given, I use barium nitrate as an oxidizing agent and lead thiocyanate as a fuel. The ground glass is merely a regu later of the sensitivity of the mixture to mechanical shock, and may be omitted entirely, or increased in quantity to meet varying requirements.

I claim:

1. A priming mixture, comprising a metallic fulminate, an oxidizing agent having a non-corrosive residue, a fuel having a non-corrosive residue and diphenylamin.

2. A priming mixture, comprising a heavy metal fulminate, an alkaline earth metal nitrate, a heavy metal thiocyanate and di phenylamin.

3. A, priming mixture, comprising mercury fulminate, barium nitrate, lead thiocyanate and diphenylamin.

4. A priming mixture, comprising substantially 485 parts of mercury fulminate, subparts of barium nitrate, substantially 76 parts of lead thiocyanate, and up to two parts of diphenylamin.

5. Apriming mixture, comprising s ubstan- 7 parts of mercury fulminate, sub

tially 485 stantially 209 parts of barium nitrate, substantially 76 parts of lead thiocyanate, substantially 230 parts of groundglass and up to two parts of diphenylamin.

6. A priming mixture, comprising substantially 485 parts of mercury fulminate, substantially 209 parts of barium nitrate, substantially 76 parts of lead thiocyanate, substantially 230 parts of ground glass, up to two parts of diphenylamin, and substantially 8 parts of gum.

In testimony specification.

whereof, have signed this JOSEPH D. MoNUTT.