USRE6570E - Improvement in pavements - Google Patents

Description

SUSa U ED FOR wnesmfi our?! BEST AVAILABLE COPY PATENT OFFICE.

ANDREW B. DEAN, OF LOUISVILLE, KENTUCKY.

lMPROV-EMENT IN PAVEMENTS.

Specification forming part of Letters Patent No. 161,0l3, dated March 23, 1875; reissue No. 6,570, dated August 3, 1875; application filed July 3, 1875.

To all whom it may concern:

Be it known that I, ANDREW B. DEAN,.of Louisville, in. the county of Jefferson and State of Kentucky, have invented a new and valuable Improvement in Asphalt Compounds; and I do hereby declare that the following is a full, clear, and exact description of the same.

This invention has relation to asphalt compounds for paving carriage-ways, sidewalks, and for other purposes; and it consists in utilizing a substance known as candle-gum, by mixing this substance with asphaltum in such proportions as will give to it stronger cohesive properties and a good tough body, that will be impenetrable by water, unaffected by moist- .ure or frost, and which will be nearly imperishable under ordinary uses.-

The candle-gum is known'by those acquainted with its peculiarities to possess great cohesive, durable, and preservative properties; and when it is properlyincorporated with hard mineral substances it will make a substantial pavement without the addition of asphalt; but, as water-lime, when properly combined with sand, will, under the efiects of moisture, form a. more durable cement than either material would make when used alone, so it is with candle-gum when mixed with asphalt by melting them together. The candle-gum supplies a most perfect and durable body and life not contained in the asphalt, and when the candle-gum is thoroughly infused into the as phalt, and properly, mixed with mineral substances, and firmly compressed, the compound will set and form a "body possessing all the qualities above stated.

To make a good pavement, a solid foundation is a most important feature, and the following description will enable others to carry my invention intoefi'eot.

First, prepare a foundation of broken stone or coarse gravel, and fill all the lower interstices with sand or flue gravel, leavingthe surface irregular and rugged, to afford a better hold and a. stronger connection with the surface-paving. I then take theoandle-gum and meltit until'it is in a liquid state, and apply a thin coating of it to the surface of the foundation. .This application is'made toafi'ord a more perfect bondof union between the sur- I face-paving and the foundation. [then put into a suitable vessel asphaltum and candlegum in such proportions as the climateand character of thework require, and heat these substances to a liquid state and thoroughly mix with them any hard mineral substance, such as coarse gravel, broken stone, &c., with a. quantity of sand. This compound is evenly spread over the substratum or foundation, and firmly pressed, so as to fill every space in the rugged surface thereof. This will hold the foundation in 'an unbroken body. Over this layer I spread a surface-coating of coarse sand and fine gravel or finely-broken stone, mixed with hot candle-gum and asphaltum, and treated in the same manner as the intermediate coating. This final coating should be compressedwhile it is hot. The compression is best performed by means of a roller, the surface of which should be kept moistened while in use.

My improved pavement may be made by using the candle-gum and asphalt for thebinder, properly intermixed with mineral substances, either with or without the addition of another material intermixed with the candle-gum and asphalt.

The substance which I have h'ereinabove denominated candle-gum is a sulphureted hydrocarbon, and, as usually prepared, is composed of hydrocarbon, sulphur, and traces of iron, copper, oxygen, and nitrogen. Candlegum, or, as it is sometimes called,candle'-tar,

is a residuum left after the distillation of fatty bodies used in the manufacture of candlessuch, for instance, as tallow-grease from porkhouses, stearine, and palm-oil, andotlier animal and vegetable: oils. The fats or oils are treated with sulphuric acid at a high temperature, which blachens the fat. This black substance is then treated with steam in boiling water; then heated in a 7 copper still to about 400 Fahrenheit, after which superheated steam is allowed td" escape into the fat, which distills the fat over in to a worm or condenser, out of which the product flows ofl'as in ordinary distillation, and is made white by the application to it of hydrostatic pressure. The residue in the copper still is then removed to an iron still, where the heat is increased to about 500 Fahrenheit. The steam-distillation is continued, as before, until no more fatty Search Room 2. A pavement the binder of which is candlegum and asphalt mixed together and incorporated with sand, gravel, broken stone, or other hard mineral substance, as set forth.

In testimony that I claim the above I have hereunto subscribed my name in thepreseuce of two witnesses.

ANDREW B. DEAN.

Attest:

W. SHORT, J. W. SGHEURER, Jr.