US361953A - Malcolm - Google Patents

Description

. UNITED STATES PATENT OFFICE.

MALCOLM MACLEOD, or MANCHESTER, COUNTY OF LANCASTER, ENGLAND.

FS'FHALT PAVEM EN'T.v

SPECIPICATIOR forming part of Letters Patent No. 361,953 dated April 26, 1887. Application filed September-'3, 1886. Serial-No. 212,625. (No specimens.) Patented in England anuiiry 12, 1885, 30.406.

To all whom, it may concern} Be it known that I, MALCOLM .MACLEOD, a

subject of the Queuof Great Britain, and a, fesident of 66 Deansgate, Manchester, in the countyof LancastenEngland, have invented an Improvement in Asphalt Pavements, (Eng-' lishLetters Patent for which were issued to I me January 12, 1885, No. 406;) and I do hereby I from the following specification and claims.

declare the following to be a full ,clear, and exact description of the same.

Thenature of my invention will fully appear I am-enabled by my device to lay a bed of asphalt of a low melting temperature beneath a bed or'surface of higher melting temperatu re, the intermediate layer of limestone, granite, grave], or other similarmateriai prevent- 7 ing the high temperature of the upper and harder asphalt from melting, andso mixing itself with the lower or softer asphalt.

I have several methods of carrying out my invention, but prefer the followingas the best: I vprepare a sufficient quantity of, say, British asphalt, composed of pitch and oil, in the usual way. This varnish, when sulficient-ly prepared, I pour over broken limest'one, (by preference, but can ,use any hard material.)

Thisi I spread'over the surface it is intended to cover with asphalt, and compress it by roll- 3- ing or ramming. Over this surface I spread a layer of limestone, granite, gravel, or other suitable material of about, say, an inch in diameter. This'I ram into the rolled surface and pass over all a heavy roller 'until thei limestone, granite, gravel, or other suitable material is forced into thefoundation to about half its thickness, and the whole is thoroughly compressed. I then remo've any loose limestone or other material. Upon the foundation thus prepared I lay a bed or surface of rock or other hard-asphalt prepared in the usual.

way. The layer of limestone or other mate:

rial nowprevents the floating oils or other substances of the .softeror lower asphalt fromrising into the rock or other hard asphalt, and absorbs them partly into itself. The hot rock or other hard asphalt readily adheres to the limestone, granite, orjother intermediate ma teriahyand the whole forms a homogeneous mass, the intermediate layer of limestone or described.

other suitable material acting as a key to connect thetwo asphalts.

In the case of roadways, where a safer hold forhorses isdesired, I lay the foundation in .the way described for pavements, but prefer to put'down the hard asphalt in two layers, viz: After the basic layer of limestone or other material is. laid I'cover'it with a layer of hot rock asphalt, and upon it spreadevenly'pie'ces of stone or other similar materialand compress theminto the hard asphalt while it is hotfso that theiruppersurfaces are level with the completed heightof the roadway. 'I then fill in the spaces between the stones with hot gravel-stones, broken stone of all kinds, and,

generally, all hard refuse material.

What I claim as new is 1. Apavement, roofing, or flooring composed of two layers of asphalt, said layers being of different melting temperatures, and

unitedto one another without mixing by means of anintermediate keying of limestone, ranite, or other suitable material projecting mm the lower through the upper layer, of asphalt,-substantiallyas described.

2. A composite pavement consisting of a lower layer of asphaltum or cement, a superincumbent layer of asphaltum or cement, and .an intermediate layer of stony particles "projecting into the lower layer or stratum "andthrough the upper stratum of asphaltum or cement, substantially as and for the purposes MALCOLM MAOLEOD.

Witnessesr ARTHUR O. HALL, ALBERT E. HALL,

9 Maruth, Manchester, England.