US2201493A - Apparatus for road building - Google Patents

Description

May 21, 1940. E. B. JoRGENsEN APPARATUS FOR ROAD BUILDING sheets-sheet 1 Filed Sept. 4, 1937 Kia 3.1.2 exi...

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E/vocH fRG dancin/65N INVENTOR n M m T A May 21, 1940- E. B. JoRGENsEN 2,201,493

APPARATUS FOR ROAD BUILDING Filed Sept. 4, 1937 Sheets-Sheet 2 s SQ Hyg/wm@ A T TORNE Y Patented. May 21, 1940 UNITED STATES PATENT OFFICE signor, by mesne assignments, to Vlber Company, Los Angeles, Calif., a corporation of California Application September 4, 1937, Serial No. 162,511

9Claims.

This invention relates to a machine and a method for road building and in particular to a machine and a method for stabilizing sub-grade or base-forming materials and for laying a stabilized subgrade stratum as a base for a surfacing stratum.

It is now recognized that the durability of surfaced roadways depends to a large extent upon the original provision and continued maintenance of a high weight-bearing capacity of the sub-grade base for the road under all conditions of weathering and use. It is also well known that the condition of the subgrade base, particularly for Portland cement concrete surfacing, both as to the load-bearing capacity and as to the moisture content at the time the concrete mass is laid, is an important factor eecting the quality and durability of the concrete slab. The treatment of the indigenous soil or other materials which are available for the construction of the sub-grade stratum for surfaced roads has come to be called stabilization or sub-grade stabilization, and the terms generally refer not only to the control of the moisture content at the time of compaction but also to the improvement of the load-bearing capacity of the indigenous materials by the addition thereto of admixture materials. 'I'hese admixture materials which are commonly used are finely divided bonding soil, clay, powdered and granular rock, cement, sand, chemicals such as calcium chloride or sodium chloride, organic and bituminous binding materials, and Water.

lll'he indigenous materials in a given location are usually examined and suitably tested to determine what available admixture materials will best serve the purpose of suiciently stabilizing, both from a physical as well as economical point of view. Depending upon the local conditions, admixture materials are then prescribed which will give the desired load-bearing capacity. 'I'he moisture content of the materials forming the sub-base is important because in placing the material on the roadbed, and compacting it, there is an optimum moisture conditionneither too wet nor too drywhich facilitates the handling of the material. In subbases for concrete surfacing, it is particularly important not only that the sub-grade base material be stabilized as to the assortment of particle sizes and their binding or holding together, (both of which effect the load-bearing capacity) but also that the sub-grade base, in its finished forni, ready for the laying thereon of the concrete mix, must be neither too wet nor too dry because these conditions eiiect the warping and expansion of the surface stratum during its setting.

The treatment or preparation of the material for the sub-grade base, the distribution of it again on the roadbed, and its consolidation after placement, are usually carried out by hand labor,

or hand labor assisted by shovels, plows, harrows,

rakes, drags, and the like, by which the material is manipulated over and over or back and forth. in piles or rows on the roadbed, until the admixture is mixed in, and the water content equably adjusted, usually by sprinkling and further mixing on the road. lSuch methods are costly, and do not usually give uniform results, and the moisture content of the materials in particular is subject to the vagaries of the weather, because of the long manipulating time required with these simpler tools and machines to eil'ect the uniform mixing in of the required water. l l

'I'he general object of this invention is therefore to provide an improved apparatus and method for continuously treating the materials to be used for the sub-grade base for a surfaced roadway or pavement to stabilize the same and simultaneously continuously forming a sub-grade stratum. A further object is to provide an lmproved apparatus and method for forming the sub-grade base for a. pavement or a roadway in which the moisture content of the material to be used for said sub-grade will be maintained during forming of the sub-base. i Another object is to provide an improved vapparatus and method by which the indigenous materials may be continuously mixed with admixture materials for stabilizing the same. Still another object is to provide a machine and a method by which a treated sub-grade soil mixture may be continuously distributed and compacted in place on the roadbed. Further objects of the invention will appear hereinafter.

The invention consists in the method described hereinafter, and resides also in the combination of parts all of which contribute to produce an emcient sub-base treating and placing machine.

In the drawings:

Fig. 1 shows a longitudinal sectional view of my machine, representing the samle in the act of simultaneously picking up road material. mixing it with admixture, and redepositing-it in compacted form in place as the sub-grade stratum of a roadway;

F'ig. 2 shows a plan view lof my machine with parts broken away to show ldetail;

3 3 of Fig. 1i

Fig. 4 shows a portion of the longitudinal sectional view, representing an alternative structure for compacting the stabilized mixture on.

the roadbed.

Fig. 5 is an isometric view showing in more detail a portion of the grid structures.

In the preferred embodiment of my invention as illustrated in Figs. i, 2, and 3 the main or caniage frame Il is constructed of side members l2, end members Il. and intermediary crossmembers I4. and is supported for movement along the roadway on pre-laid track members il, by front ilanged wheels Il and driven rear `iianged wheels i1. Scraper means il attached to the frame in front of the front wheels Il serve to sweep debris oil.' the track in advance of the machine.

Mounted on the main frame is an internal combustion engine il associated with a clutch and clutch lever 25 and power transmission mechanism 2l including a gear-shift lever 2|. Mounted for actuation by a counter shaft 24 from said transmission 2l is an electrical generator 22 to provide electrical energy for operating the high speed motor Il which operates the vibrating element 32. 'Ihe counter drive v shaft 24 also drives the conveyors and mixer. in

synchronism with the forward movement of the machine when it is in position to operate, through the bevel gear Il.

'I'he machine is propelled through the rear wheels I1 on the rear axle 21 by means of a geared drive 23 operatively connected through theclutch 25 and the transmission 2l to the engine I5. Supported below the main frame Ii is a secondary frame 33 which extends across the roadway or strip of roadway and is adapted to be raised and lowered relative to the main frame by jacks 3| represented as located at the corners of the secondary frame, the jacks being adapted to position the secondary frame up and down by operation of the hand wheels 32 connected with the threaded shafts 33 in the brackets 28. Mounted on the secondary frame 3l is a scooping or picking-up mechanism having nearly horizontal cutting blades 34 at the forward edge of each member of a gang of parallel inclined channels or troughs 35. Moving upwardly in these troughs 35 are cross-wise vanes or propelling members 36 attached to an endless conveyor chain 31 operating over sprocket-wheels 33 on the shaft 41 above the lower end of the incline and driven sprocket-wheels 39 above the upper end of the incline. The sprockets 35 are driven through the pulley 46 on the shaft 45 by means of a belt 40 and pulley 4I on the cross drive shaft 24, an adjustable idler pulley 44 attached to the main frame being provided for belt length adjustment when raising and lowering the cutting blades 34. 'I'he scooping mechanism is preferably made in lengthwise sections, each having a separate cutting blade 34 and a separate inclined channel member 35 with side partitions 42 and propelling members 36 extending across the full width of the roadway and being notched as shown at 43 to pass the partitions 42. The upper ends of the troughs 35 are pivotally supported on the shaft 45,

and the lower ends of the troughs, near the cutting blades 34, are held together as a scooping unit by the cross member 33, which is adjustably positioned from the secondary frame 30 by the screw jacks 48 and the yoke members 49. At the upper end of the flight conveyor is a cross-screw conveyorconsistingofaspiral mountedonashaftll inan This cross-screw conveyor is dimosed distance awayfromthedischargeofthe conveyor and its housing I2 forms, with instable valving member Il, a throat conveyor is open on the side adjacent the dischargeendofthefiightconveyorandservesto carryawayanysurphlsmsteriaiwhlchdoesnot passthroughthethrcatbetweentheadiustable valvlng member 53 and the screw conveyor housing I2. The member Il is pivotaily supported at one end to the shaft 4I on the under side of the discharge or upper end of the flight conveyor andisadaptedtobeadlustedbythethreaded shaft I4 and the hand wheel Il. The screw conveyor discharges the overnow material, which does not pass through the throat. to the downwardly inclined discharge spout Il which mills the surplus material at the side of the roadway. Beneath the throat opening is a hopper I8 extending across the roadway and supported by the secondary frame 3l. The bottom of the hopper 5I consists of a reciprocable grid 5IA made up of bars 51 and the hopper including the grid bars is reciprocated at right angles to the linear position of the bars by a crank shaft motion shown in detail in Fig. 3. Beneath the hopper Il is a stationary grid member 5l having enclosing walls 5| and supported on the secondary frame. Beneath this stationary grid member is a second reciprocable grid member l2 with enclosing walls lla and beneath it is a second stationary grid member I3 with enclosing walls lib. The enclosing wall members Il, Ila, and lib are arranged to enclose the grid mbers but allow relative motion of the separate parts, and a dis charge chute l2 across the full width of the roadway, direots the discharged and treated material.

Referring particularly to Pig. 3, the grid members 5l and l2 are reciprocated by the crank shaft 54 and the arms l5 to the connecting members Il. 'Ihe crank shaft 54 is driven through the worm gear 51 by the worm Il on the shaft 1l. The helical gear Il on a straight shaft extension of the crankshaft 34 drives the helical gear Il attached to the shaft 5I for the spiral conveyor. 'Ihe shaft 1l is operatively connected with the cross-drive shaft 24 through the bevel gears I5 and Il and shaft I1 which is slip-keyed to the pinion bevel gear Il driven by the bevel gear 5l at one end of the cross-drive shaft 24. The slip-keying of the shaft I1 in the pinion bevel gear 53 allows for the driving of the mixer grid bars and the cross conveyor when the secondary frame 3l is at any elevation relative to the main frame Il.

Attached by the bracket member I3 to the secondary frame 30 beneath the inclined trough is a means for generating high frequency vibration consisting of a high speed motor Il, a flexible shaft and flexible housing 5|, and a rotary vibratory mechanism at the end of the flexible shaft in a tubular casing l2, the whole being mounted in such a position that the vibratory tube I2 is submerged in the discharged material from the grids. The rotary vibratory mechanism may be made in accordance with my Patent No. 2,061,943, or of other construction to sive high frequency vibration of the order of 10,000 per minute. 'I'he electrical power for actuating the high speed motors is received by electrical consos'ewlnanhsrllA open l2 nectors Il which are in turn .connected to the electrical generator 22. As many vibratory units as are required to properly compact the material,l

are disposed across the width of the roadway.

Attached rearwardly of the'end of the tubular vibratory casing I! andof the position of discharge of treated'material from the mixer is a screed member ll pivotally attached at .Il to the discharge chute l2. The screed member Il is adjustably positioned by the worm 94 operating in the segment of a spiral gear I9, by the turning of the hand wheel I having a shaft Il and a spring balanced attachment means 91 to the secondary frame 30. Supported on the secondary frame 30 is a hopper Ill having a discharge spout |02 or a series of discharge spouts extending across the full width of the roadway, and a control valve I03 in the spout for regulating the delivery of material into the mixer hopper l0.

Referring specifically to Fig. 4, an alternative means of compacting the deposited material is indicated in the form of a weighted roller lili having a shaft vI Il and a journal mounting Il! adjustably supported on the secondary frame 30 through spring balanced bars IIB in a sleeved bracket III. The roller is positioned rearwardly of the discharge chute 92 from the mixer.

My method of road building as particularly related to the preparation-of the sub-base consists generally of the steps of cutting the roadbed to a desired -lower level, picking up the loose material lying on the roadway above this predetermined lower level, dividing out a usable portion of this loose material and discarding the remainder, mixing the usable portion with a suitable admixture for stabilizing it, evenly distributing the mixture on the prepared lower level of the roadbed and then compacting the mixture to form a stabilized sub-grade base. The manner of operating the particular embodiment of my invention as described above is as follows:

Preliminary to the use of my apparatus, side forms for the desired roadway including track members are placed along the roadway, after the usual cutting, lling and initial grading of the roadway has been completed. The material between the side forms which may be indigenous soil or imported material, is then loosened, if necessary, by any convenient means such as by hand picks and shovels or by machine operated plows or harrows, and a suitable amount of moisture is added by sprinkling. Admixture material, other than water, may also be added at this stage ofthe operation providing itis reasonably well distributed over the road surface although I prefer to use the means as hereinafter described which operates simultaneously with the other parts of my stabilizing machine. With the roadway ahead of my machine previously prepared as above described, the cutting blades attached to the lower edge of the inclined conveyor means are lowered to a position so that they will scoop up the loose soil or road materials to a predetermined lower level, by adjustment of the elevation of the secondary frame by means of the jacks and also bythe adjusting means which regulate the position of the .cutting edge. As the carriage is advanced, the loose soil is scooped up by the cutting blades onto the conveyor trough along which it is propelled by the ight conveyor blades to the throat. The ight conveyor is actuated in synchronism with the forward movement of the carriage by the motor through the driving means as described in detail above. The throat adjusting member at the upper end of the iiight conveyor is regulated so that the desired proportion of soil drops into the mixer hopper and the excess overflows intothe housing for the cross-screw conveyor and is discarded at the side of the roadway. The acceptedportionis stabilized by mixing it with thel proper amount of a suitable admixture material which is added to the hopper of the mixer through, the spout from the admixture hopper. In the' mixer the ingredients are thoroughly mixed and any lumps are disintegrated by the action ofthe reciprocating grid bars.

'I'he stabilized mixture is then discharged through the chute onto the roadbed in a layer which gives, upon compacting, the desired thickness of the sub-grade base. The compacting of this layer is made in the preferred form of my apparatus shown 'in Figs. 1 and 2 by the action of a high frequencyinsertible vibrator mechanism encased in a tube which is driven by means of the high speed motor which receives its electrical energy from the generator on the main frame driven by the engine of my machine. Instead of an electric generator and electric motor combination, an air compressor and a compressed' air motor to drive the vibrator mechanism may be used. The Amixture is packed by the vibrations to its maximum density, particularly when the vibrational energy is applied between the bot# tom of the roadbed and a forming member such as the' screed which serves to confine the vibrating. materials around the vibrator to form the desired stratum, with the vibrator tube continuously advancing with the machine.

When it is desired to transport the carriage without operating the various units of the combination, the secondary frame is raised relative to the main frame, pulling all ofthe parts up so that they will not interfere with the movement of the machine.

Instead of the vibration to compact the stabilized mixture as it falls upon the road, `a

weightedv roller may be substituted asindicated in Fig. 4, the other operations being substantially as described for the preferred embodiment.

While I have described my method of making a stabilized sub-base for a roadway by reference to a preferred apparatus ofgmy invention, I do not wish to limit myself to this particular apparatus since it is possible to perform the method by other well known apparatus or by hand operations, and while I have shown a preferred embodiment of my apparatus invention, I do not wish to be restricted to the particular form shown, but limit my invention only insofar as is necessitated by the prior art and the appended claims.

I claim:

l. In a sub-grade base stabilizing machine for road building, in combination, a carriage, scooping means attached thereto for picking up loose road materials above a selected lower base levelon theroa'dbed, a conveyor on said carriage for elevating the scooped-up road material, means for continuously dividing the road material discharged from the said conveyor into a usable portion and a surplus portion, means for conveyingthe surplus portion away from the machine, means for feeding into the usable portion of the road material to be treated a predetermined proportion of a stabilizing agent, means mounted on said carriage for mixing the usable road material-v and the stabilizing agent, means for continuously discharging the mixture from said mixing means onto the roadbed, means oper'- able withthe carriage for leveling off the discharged mixture to a desired road level, and vibratory mechanisms attached to said carriage adapted to be dragged throughsaid discharged mixture and below the top surface to compact it on the roadbed. l,

2. In a sub-grade base stabilizing machine for road building, in combination, a wheeled'main frame adapted to travel along a prepared roadway, a secondary frame adjustably supported below and by said main frame, scooping means attached to said secondary frame adapted for picking up loose road materials above a selected lower base level on the roadbed and having substantially horizontal cutting blades on its forward edge, conveyor means on Asaid secondary frame for elevating the scooped-up road material', adjustable throat means for continuously dividing the road material discharged from the said conveyor into a usable portion and a rejected portion, a cross conveyorfor receiving and discharging the rejected portion away from the path of the machine, .mixing means mounted on said secondary frame for receiving the usable road material, valved-spout means for feeding into the mixer a selected proportion of a stabilizing agent, a hopper on the secondary frame for holding the stabilizing agent, spout means for continuously discharging v'the mixture from said mixing means onto therroadbed beneath the machine, means operable with the wheeled main frame for leveling oil.' the discharged mixture, and vibratory mechanisms attached to said secondary frame adapted to be dragged through said discharged mixture to compact it on the roadbed.

3. In a sub-grade stabilizing machine for road building, in combination, a wheeled main frame adapted to be propelled along a prepared roadway, motor means mounted on said main frame for propelling said wheeled main frame, a secondary frame adjustably supported below and by said main trame, a channeled inclined scoop attached to said secondary frame adapted for picking up loose road materials above a selected lower base level on the roadbed, a flight conveyor of said secondary frame for propelling the picked-up road material up the channels of said scoop, an adjustible throat for continuously dividing the road material reaching the top of said inclined scoop into a usable portion and a rejected portion, means for conveying the rejected portion away from the machine, a mixer-hopper for receiving the usable portion, means for feeding into the mixer hopper a predetermined proportion of a stabilizing agent, mixing means mounted on said secondary frame for mixing the usable road material and the stabilizing agent, means for continuously discharging the mixture from said mixing mean onto the roadbed, means operable with the wheeled main frame for leveling oi! Ythe discharged mixture, and vibratory means depending from the secondary frame adapted to be dragged through said discharged mixture to compact it on the roadbed.

4. In a sub-grade base stabilizing machine for road building, in combination, a carriage, scooping means attached thereto for picking up loose road materials above a selected lower base level on the roadbed, a conveyor on said carriage for elevating the scooped-up road material, means for continuously dividing the road material discharged from the said conveyor into a usable portion and a surplus portion, means for conveying the surplus portion away from the machine, means for feeding into the usable portion oi' the road material to be treated a predetermined proportion of a stabilizing agent. means mounted on said carriage for mixing the usable road material and the stabilizing agent, means i'or continuously discharging the mixture from said mixing means' onto the roadbed, means operable with the carriage for leveling o!! the discharged mixture, and compactor means attached to said carriage adapted to consolidate the mixture on the roadbed.

5. In a sub-grade base stabilizing machine tor road building. in combination, a carriage,

vhopper means attached thereto for receiving loose road materials, adjustable throat means for continuously dividing the received road ma.- terial into a usable portion and a surplus portion, means for conveying the surplus portion away from the machine, means i'or feeding into the usable portion of the road material to be treated a predetermined proportion of a stabilizing agent, means mounted on said carriage for mixing the usable road material and the stabilizing agent, and means for continuously discharging the mixture from said mixing means onto the roadbed.

6. In a sub-grade base stabilizing machine for road building, in combination, a carriage, means attached thereto for picking up loose road material above a selected lower base level on the roadbed, elevating means on said carriage for the picked-up road material, means for continuously dividing the road material discharged from the said elevator into an accepted portion and a surplus portion, means for continuously conveying the surplus portion away from the machine, disintegrating and mixing means for the accepted portion of the road materials, spout means for continuously discharging the mixed materials from Vsaid disintegrating and mixing means onto the roadbed, means operable with the lcarriage for leveling on the discharging mixture, and vibratory mechanisms attached to said carriage adapted to be dragged through said discharged mixture between the leveling means and the bottom of the roadbed.

'7. In a sub-grade base stabilizing machine for road building, in combination, al carriage, scoopingmeans attached thereto for picking up loose road material above a selected lower base level on the roadbed, a conveyor on said carriage for elevating the scooped-up road material, adjustable throat means for continuously dividing the road material discharged from the said conveyor into a usable portion and a surplus portion, means for continuously conveying the surplus portion away from the machine, means for feeding into the usable portion ot the road material to be treated a predetermined proportion of a stabilizing agent, means mounted on said carriage for mixing the usable road material and the stabilizing agent. means for continuously discharging the mixture from said mixing means onto the roadbed, means on said carriage for evenly distributing said stabilized material on said roadbed and means for compacting the distributed material.

8. In a sub-grade base stabilizing machine for road building, in combination, a carriage, scooping means attached thereto for picking up loose road material above a selected lower base level on the roadbed, a conveyor on said carriage for elevating the scooped-up road material, adjustable throat means for continuously dividing the 75 road material discharged from the said conveyor into a usable portion and a surplus portion, means for continuously conveying thel surplus portion away from the machine, means for feeding into the usable portion of the road material to be treated a predetermined proportion of a stabilizing agent, means mounted on said carriage for mixing the usable road material and the stabilizing agent, means for continuously discharging the mixture from said mixing means onto the roadbed, and a Weighted roller means associated with said carriage for compacting material on the roadbed.

9. In a. machine for treating and distributing frame comprising alternately movable and stationary grid members extending transversely of the roadway and disposed one above the other, side walls for enclosing said grid members, a

receiving hopper ccm-extensive with the uppergrid member, a distributing spout co-extensive with the lower grid member and means for reciprocating the movable grid members.

ENOCH BERG JORGENSEN.

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