US1627639A - Flashless cannon powder - Google Patents

Description

Patented May 10, 1927.

UNTED STATES,

Arl Es'r DRANGIS I. DU PON'I. AND ERNEST DU PtJNT, OF WILMINGTON, DELAWARE, ASSIGNORS TO U. S. F. POWDER COMPANY, OF WILMINGTON, DELAWARE, A COBPOBATION OF DELAWARE.

FLASHLESS cannon rowmm.

No Drawing.

This invention relates to flashless cannon powders; and'it comprises a smokeless and fiashless powder of the usual grain shapes employed in ordnance, each grain being composed of an integral body of colloided nitrocellulose containing distributed there through isolated particles of a mixture of charcoal with a nitrate, usually potassium nitrate, the proportion of charcoal and of nitrate frequently being about equal; all as more fully hereinafter 'set forth and as claimed.

Smokeless powder for cannons is made of eolloided' nitrocellulose. Sometimes nitro- 16 glycerin is present, as in the English eordite. The particular solvent used in colloiding is important as regards the character of the powder and 'its ballastie properties. Ether aleohol and acetone are solvents commonly used. For large guns the colloided powder is generally cut into sticks carrying longitudinal perforations. These perforations are to give a progressively increasing burning area.

.All smokeless ordnance powders have the defect of giving a muzzle flash; a flame of T secondary combustion beyond the muzzle as the hot explosion products meet the air.

For military purposes this flash is seriously detrimental. In various prior and copending applications we have described and claimed flashless smokeless propellant pow- I ders and methods of making the same. In

explosive units made according to these inventions an integral body of colloided powder contains uniformly distributed particles of what we have termed a flame propagating agent; the body of colloided nitrocellulose is a sort of honeycomb with the 40 agentin the cells. The ofiice of the agent is to provide new burning areas as combos-"- .tion reaches the cells. Another type of progressive increase of burningarea is superimposed upon that afforded by the usual perforations which are here also used. 'Asflame propagating agents we have disclosed a variety of materials including ammonium nitrate, barium nitrate, potassium bichromate, etc. In one of said applications. filed April 24, 1920, as Serial No. 376,267,.we

. have described and claimed a type offlashless powder -wherein flashlessness is secured v by a-thorough distribution of fine grained black powder through the granule; the- Applioatlon filed November 18, 1926. Serial 1E0. 148,318.

black powder existing as isolated grains ii the cells of what may be termed a honeycomb of colloided nitrocellulose. This black powder is of the usual composition; a relatively large amount of potassium nitratewith less amounts of sulfur and charcoal.

We have found that in some relations a proportion of nitrate to charcoal less than that existing in black powder is better; and that in some of these relations it is desirable that a mixture of charcoal and nitrate only be used; that sulfur shall be absent. Sulfur is always a component of black powder. The absence of sulfur is particularly desirable where the colloided body contains nitroglycerin. While various other proportions of'charcoal and potassium nitrate may be employed, we have found that in most instances a mixture of about equal parts is best. Instead of potassium nitrate we may use barium nitrate or even sodium or ammonium nitrate but we find potassium nitrate on the whole the best nitrate to use.

In a practical embodiment of the present invention, equal parts of potassium nitrate and charcoal may be worked together into a fine grain com osition in much the way used in making lack powder except that -no sulfur is added. The product is advantageously ofabout the same fineness as ordinary mealj powder. In making a typical flashless powder under the present invention about five parts of this product is placed in a standard black powder wheel mill with 100 parts of pulped nitrocellulose. The materials are incorporated together until an even distribution of the charcoal-nitrate composition is efiected. A blending liquid ma be used to aidin this incorporation. Th1s blendin liquid may be a non-solvent for nitrocellu ose, such as for instance oline,'as described in the copending app cation Serial No. 376,267 referred to above, or the .blending liquid may be one useful in colloiding, such as alcohol or ether or a mixture of the'two. After the incorporation is 7' complete-the mixture is colloided in any-of the usual ways sons to obtain an integral mass of nitrocellulose; this mass containing the charcoal-nitrate grains uniformly distributed therethrough. This colloided body may be formed into usual types ofgrainby the usualmethods andiwith the use-off the ordinary types oflapparatus Drdinarily it c jfinally: oes through gdie presses to, furnish v of: the varietiesof c making powder may 'bo :11ere' employed,

longitu a1, strin s or cords having the seven, longitudina perforations usiml in units or grains, for ordnance IEmrposes. I

arcoal used 111:

mCarb on' from other sources such as gas -b1a,ck,-may be used in lieu of charwa l I As a, flashless powder; cellulose containing distributed grams; of a I I 7 mixture composed of charcoal and potassium 7 "cellulose containingdistributed' grains; of a I mixturecomposed of charcoal and :1 nitrateand free of sulfur. c

i nitrate and free of sulfur.

-- 3.: As aiflashless powder, colloidefl ;nitro-' c cellulose containingdistributed grams ofai col loid edi ni troi 7 mix tuye I composed of charcoal 1 and a init 'rateii 1 the mtrato and the, charcoal being present in about equal amounts.

Asa, flashless powdegfoolloided; nit vo-j cellulose co'ntainmg nitroglycerin and also [containing distributed grams of mmixtm-e :25

composed of charcoal and a nitrate.

c 5. As a flashless powder, colloided nih'ocellulosecontain'ing nitroglycclrin colloiding 1 being fiect'ed with a solvent comprising ave I tone, said colloided nitrocellulose containing distributed" grains ofa mixture COITIPQSGT of charcoal and a flitrate;

"MERNESTDUPQNT.

In itestimony whereof, iwe hove h'erehhto i aifixed our 'slgnatures at 'Wilmington, D612 ware, this 12th dayof November, 1926.

I FRANCIS L'nupoim; i l