US1716797A - Method of producing colored smoke clouds - Google Patents

Description

eirsaoz OR STATES PATENT OFFICE.

JOHN CLIFFORD SAVAGE, OF NEW YORK, N. Y.

METHOD OF PRODUCING No Drawing. Application filed April 3,

This invention relates to the formation of colored smoke for signalling, advertising, smoke screen or other work, and has particular but not exclusive reference to the forn ing of clouds or trails of colored smoke from aircraft.

My invention comprises a new method of producing colored smoke, and in one phase thereof provides a smoke producing mixture or mixtures which may be non-inflammable or non-toxic.

Heretofore, mixtures for the production of colored smoke have depended for their ability to function on the inclusion in their composition of certain chemicals which react with sufficient heat to insure vaporization of the coloring medium, and usually there is actual combustion of one or more of the ingredients for the generation of heat.

In my method the heat necessary to vaporize the compound is provided from external and not from internal sources and the compound employed by me does not necessarily include among its constituents material or materials, such as lactose and potassium chlorate, which are expressly included in the usual compound to provide a heat producing reaction.

I have discovered that all systems of colored smoke production depending upon combustion of one or more ingredients lose in efficiency, for the reason that in every case a certain proportion of the coloring medium is burnt, with consequently a very considerable loss in color value.

The aim of my invention is to prevent any part of the coloring medium being combusted and I therefore employ a mixture, the

pgnstituentsoi which danot react in the COLORED SMOKE cLoU ns.

1924. Serial No. 704,081.

ample of my colored smoke producing mixture is as follows Orange oil soluble aniline dye 10 pounds.

Light mineral lubricating oil 1 gallon. Tetrachlorethane or carbon tetrachloride 1 pint.

This mixture, when introduced into the exhaust of a gasoline engine, is vaporized and, when ejected into the air, condenses to form a red smoke. In practice I have run a pipe from the exhaust manifold of an aeroplane to the rear of the fuselage and have fed the smoke producing mixture into said pipe at a point approximately four feet from the manifold. The coloring agent is the aniline dye, and the mineral oil acts as a vehicle and a base smoke, which base smoke is colored by the exceedingly fine particles of the condensed coloring material.

WVhile my invention finds its most ready application in connection with the exhaust of an internal combustion engine, its method of operation is not limited to this. I may for example, employ a stream of steam, superheated if necessary, and directly or indirectly into contact with my compound, to provide sufficient heat to effect the necessary vaporization thereof or any other method, the essential factor being that no (or a negligible amount of) combustion shall take place and that the hot gases or vapors shall be sufficient temperature to effect the requisite vaporization.

Although one phase of my invention aims at the prevention of wastage of coloring ma terial by completely avoiding combustion, I am aware that in cases where my type of mixture is introduced into the exhaust gases of a gasoline motor, and in cases where such motor is running on an imperfectly carbureted mixture, there may be some free oxygen, carbon monoxide or other combustion supportlng material present in the exhaust gases and consequently some degree of c0mbustion, but such accidental occurrences do not upset the principle of my invention.

To produce a green smoke I employ a mixture of orange oil soluble aniline dye and synthetic indigo blended in suitable proportions to secure the requisite shade of green, the other ingredients remaining the same. Black or dark-grey smokes can be secured by the inclusion of anthracene in the mixture in place of the aniline, or purple smokes by the inclusion of iodine.

In the attached claims by primary/secondary coloration medium I mean a coloration medium producing one of the primary colors of the spectrum, or a shade, to wit a secondary color, as for example purple.

Having described my invention what I claim and desire to secure by Letters Patent is as follows':-

1. The method of producing colored smoke clouds or trails, which consists in vaporizing a primary/secondary coloration medium in the absence of combustion and producing a base smoke neutral thereto, and ejecting the two in conjunction into the atmosphere.

. 2. The method of producing colored smoke clouds or trails, which consists in vaporizing a material which, when condensed, forms a white smoke, and coloring the base smoke by mixing the same wlth a primary/secondary coloration medium in the absence of combustion. V

3. The method of producing primary/ secondary colored smoke clouds or trails, which consists in vaporizing a material which, when condensed, forms a white smoke, vaporizing a primary/secondary coloration medium in the absence of combustion and coloring the base smoke by condensation of the coloration medium vapor.

4. The method of producing primary/secondary colored smoke clouds or trails which consists in subjecting oil and a vaporizable coloration medium to heat whereby the said substances are conjointly vaporized, and ejecting the vapors thus formed into the atmosphere.

5. The method of producing primary/secondary colored smoke clouds or trails which consists in mixing oil and a vaporizable coloration medium to form a body which will flow, flowing said body into a chamber subjected to heat wherein the body is vaporized, and ejecting the vapor into the atmosphere.

6. The method of producing primary/ secondary colored smoke clouds or trails, which consists in vaporizing an oil by sub- "jecting the same to heat, vaporizing a primary/secondary coloration medium, and simultaneously ejecting the said vapors into the atmosphere.

In testimony whereof, I have signed my name to this specification.

JOHN C. SAVAGE