US2489549A

US2489549A - Signal smoke compositions

Info

Publication number: US2489549A
Application number: US749360A
Authority: US
Inventors: Vinton John; Douglas M Macmillan
Original assignee: Individual
Current assignee: Individual
Priority date: 1947-05-20
Filing date: 1947-05-20
Publication date: 1949-11-29
Anticipated expiration: 1966-11-29

Description

Patented Nov. 29, 1949 SIGNAL SMOKE COMPOSITIONS John Vinton, San Francisco, and Douglas M.

MacMillan, Berkeley, Calif.

No Drawing. Application May 20, 1947,

" Serial No. 749,360

1 Claim.

This invention relates to signal -smoke composition.

It is the main object of our invention to disclose a composition suitable for providing a daylight visible redsmoke for use in cases where it is necessary to signal the location of a potential danger to a person at a considerable distance.

It is common practice in the operation of many if not all of the railroads in this country for a train making an unscheduled stop to provide a signal calculated to appraise a following engineer of the fact that the train ahead constitutes a potential hazard to him. At night, these signals take the form of the standard strontium nitrate fusee, red lights and lanterns of several varieties; there are conventions having to do with their manner of display, the distance behind the stopped train, etc.

In the case of daylight stoppages, however, it is preferable to use a smoke signal. In our experience, we have knowledge of several railroad accidents occurring in daylight due to the fact that the following engineer was unable to see the luminous signal which was displayed in an effort to stop There has been a real difliculty in securing smoke compositions which will dependably provide a smoke having the proper red danger color.

It is not feasible to employ lights or other illuminating devices of any color since the brightness necessary to render them distinct in daytime is excessive. We have determined that if a red smoke, visible in daytime, be utilized as a danger signal, it may be observed up to 25 times farther than may be the best standard daytime illuminating devices now in use.

The following constitutes the formula for our composition.

Dye No. 1-13 parts by weight Dye No. 2-1.8 parts by weight (Rhodamine B) Lactose-8.5 parts by weight Potassium chlorate-7 parts by weight.

In this composition, the lactose is the fuel and the potassium chlorate provides the oxygen for a controlled nameless combustion. The two dyes have the following compositions:

Dye No. 1

CH: CH

Dye No. 2 (Rhodamine B) O (I \Omcnm.

OOOH

In our experience it is not permissible to vary substantially from the above proportions except in the case of the Dye No. 2. Variation in the quantity of this ingredient between reasonable limits has only the effect of changing the shade of the red of the smoke produced. It is permissible to vary the portion of this dye between 1.0 and 3.0 parts by weight.

In the preparation of the material, we have found that we can produce a slow-burning composition having a high smoke density by mixing the various ingredients in sufficient water to constitute a heavy paste. This paste is dried or is allowed to dry by atmospheric exposure, then rubbed through a screen having such a mesh as to produce the desired particle size, a preferable screen having meshes to the inch. In addition to increasing the density of the smoke produced by the composition, the preparation as described eliminates the 'dust problem and is thus desirable from this additional consideration.

The composition may be used in any case where it is desired to produce a red smoke. We have particularly in mind, however, the employment 5 of this composition in a fusee such as that disclosed in Patent No. 3,412,018 issued December 3, 1946, to John Vinton, one of the present inventors.

We have found that the burning of this com- 10 position as described above produces a dense red smoke visible and recognizable as a danger signal for a long distance even in the brightest daylight. It is believed it could never fail to attract attention due to its intense red color or to be dis- 15 tinguishable from fires of other origins.

We claim:

The red smoke producing racompositiomeonsisting of a homogeneous mixture 'of 'the following ingredients in substantially the PIODOItiOl'lSggo CH3 0H HsCON=N and Dye No. 2 is COOH JOHN VINTON. DOUGLAS M. MACMIILAN.

REFERENCES CITED 2. The iollowing"referenceszare ofrecord in the fileribf lthisapatentz UNITED STATES PATENTS Number Name Date 1',319,'829 -'"Gowdy Oct. 21, 1919 -'r ,2,4 1,1,070 'i-VanyKarner Nov. 12, 1946 12311 383 Switzer Mar. 11, 1947 2,417,384 nSwitzer Mar. 11, 1947 ";,2,'.419';851 "0181111) Apr. 29, 1947 OTHER REFERENCES Color Index (RoweLgpage 190, No. 749. (Copy 30 in-,DivisionL-v43.)

Colored Signal Smokes-Chem; Eng.News;r-ivol.

Lat-Nature;tl9 io pa es 2405-244 :(241; pertinent).-.