Untitled record

ΡΒ.Ττ:

ΖτνζΤζ/ζΤ¹.

<img file="US61580A_D0001.tif" />

Γϊό.2 ζ>

<img file="US61580A_D0002.tif" />

<img file="US61580A_D0003.tif" />

THE GRAPHIC CO.PHOTO-LITH.39&amp;41 PARK PLACE.N.Y.

JOHN B. TARR, OF CHICAGO, ILLINOIS.

Letters Patent No. 61,580, dated January 29,1867.

IMPROVED METALLIC PAVEMENT.

®lje S^chulc rtfeuto to in these fetters Intent into nraktog jnrt of φ same.

TO ALL WHOM IT MAY CONCERN:

Be it known that I, John B. Tarr, of Chicago, in the county of Cook, and State of Illinois, have invented a new and improved Metallic Pavement; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, making a part of this specification, in which—

Figure 1 is a- perspective view of two slabs of the metallic pavement, put together.

Figure 2 is a top.view showing several slabs put together.

Figure 3 is an edge view of one.of the slabs.

Figure 4 is a view showing a'pavemeut applied over an archway.

Similar letters of reference'indrcate corresponding parts in the several figures.

This invention relates to an improvement in the construction of metallic pavements for streets, sidewalks, halls, vaults, and for other purposes, where pavements are required. The object of my invention is to construct a metallic pavement of sections or slabs in such manner that when laid down one section or slab will support, as well as firmly hold down in place, those slabs which are adjacent to it without the use of bolts, rivets, or other-fastenings than are afforded by the slabs themselves, as will be hereinafter described.

To enable others skilled in the art to understand my invention, I will describe its construction and operation.

In the accompanying drawings, fig. 1 is a perspective view of a portion .of a pavement, the surfaces of, the slabs composing which are smooth;. In figs. 2 and 3 I have shown a pavement which is more particularly designed for streets, it. having the surfaces of its slabs scored diagonally, so as to present projections for the purpose of affording’foot-hold for horses. These projections may be of the form represented, or of any other suitable form. Each slab A is constructed of a rectangular form, either oblong or square, with rectangular lips a projecting from its corners, and also with intermediate steps or depressions b in two of its edges; which latter are made so as to receive, each, two of the corner projections a in laying'down the pavement, as shown in fig. 2. The depressions b b, which are'in the middle of the lengtli of each slab A, receive the .projections·of four slabs. . The depth of the depressions b b is equal to the thickness of tho projections a a, so that when the slabs are put together their upper'surfaces will bo flush'with each other and perfectly level.' It will be seen by reference to figs. 1 and 2 that the slabs are put together so as to break joints with each other, and also so that the projecting corners of each slab fit snugly into the intermediate depressions of two slabs, thus the slabs are not only held down in place without the use of separate fastenings. By thus forming the slabs they will be prevented from sinking, should the earth beneath them settle-and cease to afford them support. I prefer to produce these slabs A of cast steel by casting this metal in metallic moulds, and, while the metal is in a melted state, to subject it to great pressure for the purpose of expelling the air from it, and rendering it tougher and more dense, so that the slabs will not be liable to break easily. By casting the slabs in this way they can all be made of a uniform size, and fitted together strongly ; and it will be found that the knobs or projections on their surfaces will be chilled and hardened so as to be durable. I do not confine my invention to cast-steel slabs constructed as above described, as the slabs can be made of cast iron, or even of wrought iron. I contemplate employing the self-locking slabs for vault covers, and casting them with openings for receiving plates of glass for allowing light to pass through them.