US1952508A - Pavement - Google Patents

Description

March 27, 1934. E, McCONNAUGHAY 1,952,508

PAVEMENT Filed April 17, 1931 c vAVAVA A A A A A :v vA A A KENNETH E. HCQNIYHWHHZ.

Patented Mar. 27, 1934 UNITED STATES PATENT OFFICE PAVEMENT Application April 17, 1931, Serial No. 530,826

6 Claims.

In the laying of bituminous pavements, it is the usual practice to employ forms which shape the pavement at its edges. These forms customarily are of wood or metal and remain in place at the sides of the pavement until the pavement is rolled, when they are removed and set up in advanced position to be employed in a continuation of the pavement. The removal of such a form disturbs the paving material as well as the 10 earth with which the form is usually backed, creates a space between the paving material and' the earth, results in intermixing of the paving material and the earth, and in general provides an unsatisfactory edge for the pavement. Further, because of the expense and bulk of such forms, the length of form which can be set up in advance of paving is practically limited, thus limiting the length of pavement which can be laid at one operation. It is the object of my invention, considered broadly, to provide a form for the edges of pavements, which form will not possess the disadvantages present in forms which previously have been used. More specifically, it is my object to provide a form which can be made and set with little expense, which need not be removed, and which will provide a permanent support for the edges of the pavement. I

In carrying out my invention, I make the form of a strip of textile material impregnated with bitumen. At intervals, this strip is arranged to receive a supporting stake by which the strip is held in place. After the form is set, it is backed with earth, and a bituminous paving material is spread on the road. The stakes which originally supported the form are then removed, and the road is compacted, as by rolling.

The accompanying drawing illustrates my invention: Fig. 1 is an elevation, in partial section,

' showing a motor truck equipped with apparatus for making my improved form; Fig. 2 is a perspective view illustrating the form in place; and Fig. 3 is a perspective view of the form itself.

There are a number of ways in which a form embodying my invention can be manufactured. I prefer, however, to make it with the device illustrated in Fig. 1, the form being coated before it is set up. In that device, there is mounted on an automobiletruck 10 a rotatable spool 11 upon which there is wound the material forthe form. This material is in the form of a strip or ribbon of a width substantially corresponding 'to the depth of the pavement at its edges. Preferably, before the strip is wound on the spool, it is provided with means for receiving the stakes which will support it in place.

In rear of the spool 11 there is mounted on the truck 10 a vat or tank 12 containing a supply of liquid bituminous material within which there is mounted a plurality of rollers or guides 13 which serve to guide the strip through the bitumen as it is fed rearwardly.

Preferably, although not necessarily, the strip, after it emerges from the bitumen bath, is treated on one side with chips of stone. Thisis conveniently accomplished by causing the strip to pass beneath the open bottom of a hopper 15 which contains a supply of stone chips, the strip entering below the hopper 15 beneath a guide roller 16 and emerging from the hopper beneath a vertically adjustable gate 17 which regulates the quantity of stone chips carried away from the hopper by the strip. After passing beneath the hopper 15, the strip passes between rolls 18 which compress it and embed the stone chips.

As the strip emerges from the rollers 18, it falls to the ground where it may be set in the manner hereinafter described.

For the purpose of feeding the strip from the spool 11 and through the vat 12, I provide two pairs of feed rolls 20, one pair of which is located at the forward end of the vat 12 and the other pair of which is located at the rear of the vat. These feed rolls, as well as the feed rolls 18, may be driven from the automobile engine through any convenient type of power take-off 21.

Preferably the guide rolls 13 in the vat 12 are arranged to fiex the strip in opposite directions as it passes through the bitumen. This is conveniently accomplished by placing two or more rolls in staggered relation and comparatively close together. The opposite flexing of the strip which occurs as it passes over such rolls opens its pores and facilitatesits impregnation with the bitumen.

The strip may be made of a variety of materials, such as felt, burlap, canvas, heavy cotton cloth, woven fiat rope, or similar material. I have also found heavy paper to be satisfactory, although a textile material is more satisfactory.

I prefer to make the strip of burlap and to form it as indicated in Fig. 3. That is, a strip of burlap having a width approximately four times the depth of the pavement to be laid is folded upon 1% itself to providea strip having four thicknesses of material. At spaced intervals, the strip'is provided with two transverse rows of stitching 25, and between such stitching-rows, the material of the strip is slit at the top and bottom to provide 0 for the entering of a supporting stake or pin. The rows of stitching 25 prevent the slits from extending along the strip and also serve to hold the folds of the strip-material together. The strip in the condition just described is wound upon the spool 11 to be used as necessary.

The bitumen contained in the tank 12 may be liquefied in any convenient manner, I but I prefer to use an emulsified bitumen of the general type in which the bitumen is dispersed in water.

In laying pavement withmy form produced as above described, the fundation of the road is first graded, and the truck 10 is then run along each side of the road, the form feeding from it and laying along the road. The form is set to grade by means of stakes 26 which are passed through the slits in the form and between adjacent rows of stitching 25. The form is then backed with earth, as indicated at A. Following this, the paving material is placed inthe roadway and evenly distributed between the forms at both sides of the road to the desired grade and cross-section. The stakes 26 are then removed, and the paving material is compacted as by rolling.

While I prefer to make the form as above described, other methods of making it may be employed. For example, the strip of textile material in uncoated condition may be set to grade with the aid of stakes and the bitumen may be sprayed upon it.

A form such as I have described may be manufactured at a low cost, and its removal and re-use is therefore not necessary. During the operation of compacting the paving material, the form becomes thoroughly bonded to the bitumen in the paving material and prevents breaking off of the edge of the pavement under trafiic. Further, the form separates the paving material from the earth and prevents the earth from becoming incorporated in the pavement.

The thickness of the form will vary with the rigidity desired. If a comparatively rigid form is desired, four or even more thicknesses of textile material may be used, while a lesser number may be used if rigidity is not essential. The use of the stone chips has a tendency to increase the rigidity of the form, and the stone chips may be eliminated if rigidity is not desired.

I claim as my invention:

1. A form for pavement, comprising a strip formed of a plurality of layers of textile material provided at intervals with pairs of spaced transverse rows of stitching and impregnated with bitumen.

2. In a bituminous pavement, an edge-supporting strip comprising a plurality of layers of textile material impregnated with bitumen bonded to the bitumen of the pavement.

3. A process of paving, which comprises.im-

pregnating a flexible strip of textile material with bitumen, setting one of such strips to define an edge of the pavement, distributing a bituminous paving material against one side of said strip,

and rolling such paving material to compact it and bond it to said strip.

. 4. Aprocess of producing and setting a form for pavements, comprising laying along one edge of the surface to be paved a continuous length of flexible textile material and during laying impregnating such textile material with liquefied bitumen, and then supporting the impregnated strip of textile material in position to define a pavement-edge.

5. A process of paving, which comprises setting a strip of textile material impregnated with bitumen to define an edge of the pavement, backing said strip on the side opposite the pavement with earth, distributing a bituminous paving material against the other side of said strip, and rolling such paving material to compact it and bond it to said strip.

6. A process of producing and setting a form for pavements, comprising laying along one edge of the surface to be paved a continuous length of flexible textile material and during laying impregnating such textile material with liquefied bitumen and imbedding aggregate particles on at least one face of the t xtile material, and then supporting the impregnated strip of textile material in position to define a pavement-edge.

KENNETH E. MCCONNAUGHAY.

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