US2255345A - Apparatus for method for making concrete roadways - Google Patents

Description

R. W. BAILY Original Filed Feb.

APPARATUS AND METHOD FOR MAKING CONCRETE ROADWAYS Sept. 9,

Patented Sept. 9, 1941 APPARATUS AND CONCRETE METHOD FOR MAKING BOADWAYS Robert William Baily, Narberth, Pa.

Original application Feb Divided and 7, 1939, Serial No. 288,

7 Claims.

of this invention to provide a,

ruary 15, stzlgis application August 1930, Serial No.

practically fluid mass readily flowing to places of least resistance and causing the elimination of air and water entrapped in the concrete. Other objects are to provide an improved vibrating means, a novel face plate, bins and other elements.

A further object of my invention is to treat any material, the particles of which move relatively to each other when vibrated.

' This application is a division of my copending application, Serial No. 428,747, filed February 15, 1930.

Attention is called to my copending applications, Serial No. 514,124, filed February 7, 1931; Serial No. 256,249, filed February 13, 1939; Serial No. 74,114, filed April 13, 1936; Serial No. 166,822, filed September 7, 1937; Serial No. 114,877, filed December 8, 1936; Serial No. 228,625, filed September 6, 1938, and Serial No. 257,295, filed February 20,1939.

Referring to the accompanying drawing:

Figure 1 is a transverse vertical section of one form of my novel apparatus, the section being taken on the line 4-4 on Figure 2 and parts being broken away;

Figure 2 is a plan view of the apparatus;

Figure 3 is an elevation of one of the vibrators, the view. being at right angles to the view of thevibrator shown directly above it in Figure 1.

Referring to the drawing I designates a screed extending from one side of the roadway to the other and resting at its ends on the side forms 2.

The screed I has on its upper side any suitable vibrating mechanism. By way of example, I have shown the mechanism now to be described. The screed has attached to its upper face a suitable number of standards l6 supporting the rotary shaft l'l arranged transversely of the screed. The shaft may be driven by any suitable power, such as a gas engine, gasoline engine, electric motor or other prime mover which may be mounted on the screed or elsewhere. I show the pulley 18 on the shaft ll merely to indicate that weight 20 shall direction of movement of each power of some kind is to be applied to rotate the shaft. The shaft has at each standard a crank pin l9 slightly off center relative to the shaft H. A T-shaped weight 20 is connected by means of a leg 22 to the crank pin for imparting reciprocating motion thereto. Preferably the standards have two members 2| between which the cranks turn. The leg- 22 of each weight is connected to its respective crank while the ends of the cylindrical head of the weight is guided vertically by the slots 23 in the members 2|.

The important features of my invention are that the screed I always remains in contact with the concrete or any top finish thereon, as broken stone, and that the vibration produced by the have high frequency or impulses in excess of 900 per minute and preferably exceeding 2500 frequencies or impulses per minute. My invention does not tamp or pound the concrete, but imparts to it very rapid intensive vibration causing what might otherwise be a stiff harsh mass to become practically a fluid and hence to flow easily. The concrete is violently agitated by the weights or whatever vibratory means is used, causing the air entrapped'in the concrete to rise to the surface and escape, leaving a dense and homogeneous mass. I do away with the necessity for providing means for the escape of entrapped air, such .as grids, slots, small openings, transmitting platforms and the like, because the entrapped air escapes from the concrete before the face-plate 4, extending upward from the curved front end of screed l, and the member 32, passes beyond it.

The face-plate 4 receives considerable vibrationnot only operating vertically but also horizontally and impart to the concrete in front and below them the necessary vibration to cause it to flow to position and to be freed of entrapped air, so that the concrete beneath the screed is free from air and excess water.

The described apparatus may be moved backward or forward as desired by the handles 24 carried at the outer ends of the handle bars 25,

but any other suitable means may be used for moving the same.'

One portion of the leveling apparatus may be propelled at a different rate from the other end so that the lower face of the apparatus will move in a horizontal curved path. One end of the apparatus may be propelled in one direction while the other end is propelled in the opposite direction, so that the lower face of the apparatus will move in horizontal curved paths. Likewise the end may be sucbroken material into two strata, the top of cessively and simultaneously reversed so that the lower face will move in reversing horizontally curved paths.

In order to keep the concrete between the form 2, the end plates 35 of the apparatus have the wings 26 which are inclined inwardly and rearwardly.

The intensity of the described vibration may be varied by the substitution of weights of different mass, using cranks of difierent throws, or changing the number of revolutions of the cranks per minute.

27 designates the concrete in front Of'the member 32 while 28 denotes the dense concrete roadway slab after it has been vibrated into a dense homogeneous mass Without air or excess water.

if desired, with colored mortar or concrete so that the road surface will not have the usual white or glaring surface. The face-plate or between the bins may be adjusted vertically by removing the bolts 33, raising or lowering the face-plate 32 and its lower portion 36 and replacing the bolts. It may be necessary particularly when the concrete is hard or dry to have 'the'lower portion 36 of the face-plate 32 extend down, as shown in face finish. The stones for the top stone layer 3| may be fed to the surface of the concrete by any suitable means, my invention being then used to vibrate the stone surface layer and the concrete below. In case the concrete mass is soft and plastic it may be necessary to raise the faceplate or gage 32 so that its lower edge is above the desired finish of the roadway.

When broken stone is not used for the top of the roadway, the bin 29 may be used for a top layer of colored concrete or for applying fresh concrete to the subgrade. The bin 30 may be removed if desired if the bin 29 is suificiently wide to feed concrete fast'enough. My apparatus is composition are to be used. crete may be fed by the bin 30 while top stone or other finish may be fed by the bin 29, as shown in Figure 4.

In case the weight of concrete in the bin 30 is bin and running on the side forms 2.

As the screed is supported on the side forms 2, it line and Figure 1 to a predetermined grade line. In Figure 1 the screed strikes off the concrete and the upper stratum being the wearing suri'ace at the finished grade line.

partition 32 strikes off the concrete to the finished grade It is obvious that my method may be used with Portland cement concrete, bituminous concrete, or any other material to which it is adapted.

I claim:

1. In apparatus of the kind described for depositing material in superposed strata, an elongated hopper arranged for propulsion at a predetermined elevation over a supporting medium, and having an orifice in the bottom, a vertically adjustable dividing member rigidly attached at the ends of the hopper, for dividing the hopper into compartments, said member projecting downwardly through said orifice, and serving to strike off material passing from the first compartment, the rearward wall of said hopper having a curved portion extending downwardly and rearwardly into a rearward extension for aifording a strike off and surface vibrating vibrating said extension and the hopper and said dividing member, for vibrating the material as it is deposited.

2. A slab laying apparatus adapted to be propelled at a predetermined elevation over a supporting medium, said apparatus including a pair of elongated hoppers having a common transverse dividing wall rigidly attached to the ends of said hoppers and arranged for adjust ment to determine the elevation of the lower edge of said common wall, said wall forming one side of a bottom orifice of each hopper, and serving as a strike-on member, the lower portion of the rearward wall of said second hopper extending through a curved surface into a rearwardiy projecting extension to serve as a strike-0fi and surface vibrating means, a revolving out-of-baL means mounted upon the screed surplus Water expelled from the concrete during vibration.

V 5. An apparatus for treating a material for densifying and for at least partially leveling same, comprising a substantially horizontal vibrating member adapted to be propelled against the material and to sever that portion lying above a predetermined level of elevation from the material below said elevation, said member having a front rounded surface, means for propelling said member along the material, means for imparting to the member and therethrough to the material vibrations, a vibrating member approximately parallel to said first-named member in front thereof and coacting therewith for vibrating the material in front of the first member.

6. The method of forming a pavement slab having a wear-resistant surface, comprising striking off as a stratum, a Portland cement concrete mixture at a predetermined level, depositing upon adjustable rear said stratum while still plastic, closely disposed large pieces of wear-resisting material, and applying surface vibrations to unify and compact the slab thus formed and to'unite the Wear resisting pieces to the supporting concrete stratum.

'7. A hopper member provided with a vertically wall for striking off a stratum of road material to a predetermined elevation, a second hopper immediately following the first hopper and adapted to deposit a second stratum of road material on said first stratum, the rear wall of said second hopper having a curved portion extending downwardly and rearwardly into a rearward extension for affording a strike-off and surface vibrating means, vibrating means mounted upon and vibrating said extension and said second h'opper for vibrating the said road Inaterial.

ROBERT WILLIAM BAIL-Y.

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