US1924572A - Road grading apparatus - Google Patents

Description

Aug. 29, 1933. H. H. SAMUEL 1,924,572

ROAD GRADINGl APPARATUS Filed Jan. 13, 1932 3 sheets-sheet 1 Aug. 29, 1933. H. H. SAMUEL ROAD GRADING APPARATUS Filed Jan. 13. 1932 3 Sheets-Sheet 2 IN VEN TOR /f/z/eZ,

wwf/fi @a ATTORNEY I Aug. 29, 1933. H, SAMUELl RoAn GRADING APPARATUS Filed Jan; 13. 1.932 3 Sheets-Sheet 3 INVENTOR f Bwa/x/ A52/Mael,

' ment, be Vmaintained throughout the gradingop-A `eration at the proper level to assure the 'exacty Patented VAug'.Y 2 9, 1933 This inventionrelates 'to improvements 1in road grading machinery;, 4and the invention has`r referencermore particularly,l `to a novel construe` y tion of machine especially adapted `for-the nal preparation .of the Asubgrad'el of -roadways pre.- paratory to laying concrete pavement thereon` This vinvention has :for its, principal objectto provide anovel road subgrader having selectively usable scarifying` means and scraping'j4 means,

both said'- means beingadjustable,fordepth of cut; and, furthermore; the subgrader is provided .witha novel construction ottiactionrmeans designed to run on the metal forms,v as laidtolreceive castconcrete slabs of pavement, in such manner `that both the scarifyingl vmeans ,f and scrapingmeans may, `when set `fora given adjustdepth of cut, whereby ajnniform evenjdepthof grade willbe established and thereby `anexact and correct thickness of concrete slab produced, when the concrete mixis cast upon the prepared subgrade and between theside forms.

This invention has for a further objectto p roi Videja a novel construction of subgrader of 'the f ylind and for the purposesl above mentioned,

- whichlmaylbe' operated by drawingthe same `with( aroadrcilingmachine, so that/'grading androll-A ingcan be accomplished-inoneoperation` v d single operator.

more particularly enumerated, will be understood ,from the following detaileddescriptionthereof.A

Anillustrative embodiment of thisinventon is shown in the accompanying drawings? inl Figiis a fronteievatin ff nie novi suba grader according to this vinventionas operatively mounted to run on concrete casting forms, and* f as arranged for the use and operation lofl the t scarifying means thereof Fig,\2 is asimilar irview, ,i

A Handvmounted, adjacentftofeither Ithe innr; orf'` oute'rsides of `said chassislbeams; according 4 tog showing `the subgrader as arranged for the `use and operation p of the scraping means thereof; Fig is avertical longitudinal section, taken on line 3- `-,f-3 `in Fig.` 2; and 'Figl A the subgrader apparatus;V

Fig. 5 is a detailviewi in part sectionlshowing one ofthe adjustable lateral guide rollers of the machine which cooperate with the concrete cast-` ing forms, and whi h V serve to hold the, machine,

L when;Y operated; vagainst lateral i shifting y cir:l

placement relative tosaidforms; and Fig.61sa y 'detailhorizontalgsection lo f'i he same, taken' 0n is a 4plan View` of .t

porting the machine from v job to jobgFigI 8 is a` deta'iljside elevationfxoffa detachable journal elementand transport wheel whichvfo'rm said detachable .traction means; and Figi. v9 is an exterior end elevation ofy said Ajournal element/ Similargcharacters-of!reference,,are employed X in .the above described views, te indivcatetcorref spending parts.

Referring I low to' the drawings, thefreference' character 1'0 Yindicat'es the side chassistbeamstiof `the machine frame-work. t Secured to andgupon,l `and extending transversely between `said chassis 'beams 10 at theiro'nt end ofthe. machineiare a `pairoi longitudinally spacedbolster beams 11;

and arrangedinnige mannerfat the 4rearlend of n the machine is athird bolster beamf 12. Secured `-toaxid vupon the bolster ,beams 115,an d;12,'jand extendinglongitudinallyfrom-frontje, 'rearof l, -the Vmachine inafsubstantially centralposition is, aj;` bedgbeam 13, i- Similar' longitudinallubed" beams 14 are arranged invlaterally spaced rela Another object of this invention is to .provi'c'lkia-l novel construction .of subgrader `having selec-1." f tively usable and adjustable scarifying-and scrap- A ing means so arranged that the same may bercon?V trolled for bothj useand for `adjustment by` -a tion -ato y opposite sides of saidA f central' `bed beain Y transversely extending bridgeybearn I15. `l 'I he various beams f above described constitute the Y ylframe-'worlror carriage body. ofthefmachine,and'.v Other objects of-this invention,V not at this time Si, 13. Secured toand upon saidbed beams13=+1fi v adjacent to theA rear endjot the machine; isi-aA same i in assembled vrelationfby the processor vThe -cliassis bearnsfl'() arey respectively pro- J 17, VSaid traction wheels l'lmaybet arranged the conditionsvV governing the particular job, as will besubsequently again referredto. The tracvidedzadja'cent to their forward and,` rearward `V ends ',Wi.t11 bearing, members .1G--in Which-fer@ 1" :c

journaled'the axle portions fof tractiomwheels :100'

105L 'tici- 1 wheels areinitiallyfgauged or `transversely spaced apartY at distances tocorrespondto ,the

laterally spaced relationofv laid 'metallici concrete *1' s t, 091i' the ,connection therewith of,detachabletraction-1 t j means with Iwhich thel sameiinay be provided,a nd g Vwhich serve vas a convenientmeans yfor trans-` 90 4.saidbearns may be. suitably securedtogetherby .c

4any suitable form of `f astenir-igv means; although j I have Afound itzvveryfsatisfactory to fastenthe`v building operationspwhereby the vmachine carriage or frame-work may laterally straddle'said forms, Vwhile being supported by thetraction wheels 17 for longitudinal movement upon and ,along said forms. n

In order to prevent displacement of the framework'or carriage of the machine andthe traction wheels 1`7-thereof relative to the forms 18,

when Vmoved-"over and along the latter',V guidev means are mounted on the frame-work ,orcar- `riage to engage and cooperate` with the inner faces of therforms 18. One such guide -means is located adjacent to and inwardly of each trac-v tion wheel 17.l Each guide means comprises a `vertical shaft 19', whichis securely clamped to the ou'ter face of an adjacentbolster beam, 12'

or 13 as the case may be, by means of a U-clip '20, rwhich embraces'the shaft `19,-a'nd `the. legs of which pass through the body of thefbol'ster'beam,-

whereby the same be ysecured to thelatter by nuts 21v which screw upon thefree' ends of 'saidlegsf The lowerend of the shaft 19 ispro,

vided with a.diametricallyenlarged lateral annular ange v22 (see Fig. 5) to support the lower ends Oria-plurality of anti-friction rollers 23 disposed aroundthe llower end portion of the shaft.v YA guide roller 24 is mounted on the lower end portion'of the' shaft 19 to freely rotate there- 'on kand 'upon the.anti-friction rollers 23. `If

desired the lower open end ofthe guide roller 24 maybe closed by afbottomcover plate 25 suitably secured thereto, and which serves tofk'eep dirt and other'fcreigny matter from; gaining ace vcess to the interior of the'anti-friction `bearing elements-serving saidguide roller.A The flanges of the bolsterbeam, at the pointsrwhere a guideroller shaft A19 is connected "therewith, are-pro- 'vided with ,indented semi-circular seats 26, and

the shaftl is provided with reducedportions 2,7 eccentricto the axis thereof. Said eccentric por-` tions V27 are engaged respectivelyfin the seats 26.

`{By' reason of this arrangementadjustments of the guide roller 124 toward and-from the inner Yface of a vform 18 maybe easily :made by axially lturning-the shaft inonedirectin or the other to Iturn the eccentric portions`27 inthe seatsf26,

Y' A thereby moving thefguide roller 24 inwardly or use will bear against the inner faces lof the forms straight-upon the" tops ofV the' forms, and the `machine properly centered over the' road surface 'betweenvtheformskwhich is to begraded. The,

guide rollers 24 may bearrangedtobearr on the form faces at any desired point/intermediate the I top-and 'bottomfportions of the-1atter.If arranged to'bear'lowI down on the form faces, that l The kind and structural character of the forms themselves will readily indicate the *best point to'be'- engagedby the guide rollers 24.

rI he scarifying means of the machinefisflooated 'at the forwardend of the same, and lcomprises the following arrangement. Securedto' the bolr*sterbeauns 11', paralle'l to `andspaced inwardly from the1sidesA ofthe outer bed beams 14 are angleirons 28, which together'with the bed beams 14 and the spaced bolsterfbea'msA llprovidel ver tical guideways in which are ydisposed vertically movable carrier'members" 29. IIt is preferabler *tofcutaway the :body of the Vcentral bed beam l' `carrier members.

13 to provide a guideway for aV similarly 'arranged vertically movable central carrier member 29. Suitably'secured to the lower ends of said carrier members 29, so as to extend transversely of the machine, isa V-shaped holder compris-v ing the upwardlyand rearwardly inclined backplate 30 and the upwardly andforwardly inclined front-plate 31. Mounted upony the lupper outer surface of the latter, are a plurality of laterally spacedscarifying teeth 32, having chamfered chisel-likeends- These teeth are 'reversible" end for end, and'can be removed from the holder, reversed -and reinserted therein when first vfused ends become too worn. Thek teeth are l rigidly held in secured'relation to the holder by means of a clamp-strap 33 adapted tooverlie the'upper end portions of,v the teeth, said clamp-'I housing 36 fixed on the central bedbeam 13', is afshaft l37.1 Fixed'o'n'saidshaft 37 within the housing 36 isaY segmental vor quadrant gear 38;l

Journaled in bearings 39 fixed 'on thewtop of said housing 36 isa longitudinal power shaft 40, the same extendingfrearwardly through a 'plate 3010i said holder. Journaled in and exbed beams 14, and extending through a central bearing 'standard 4l mounted on the vbridge 'beam` v15 so that its rearwardend is located adjacent to Fixed von "the thel rear end' of the machine. Y rearwardend of said power shaft 40' isa hand .wheel 42`for manuallyapplying powerv thereto- Fixed on said'powershaft 4l) is a worm 40 Iwhich engages-said segmental-or Quadrant gear V33, whereby power applied to shaft 40` in either direction is transmitted to shaft 37. 'Secured to said shaft 37 respectively adjacentto the outer carrier members 29 are leverv arms 43, thefree n ends ofrwhich are connected by linl s44 .to said threaded into the angle irons 28 so as to lie Adjustable stop-screws 45 are in the path of downward swinging movement of .12,0

said lever arms 45.A By adjusting the height' of -said Astop-screws 45Itl1e'downward' movement of theecarrier members 29 Vandthe scarifying :means to be made by said scarifying means whenrlowered'w n to operative position.A v 13 so as to keep-thetractioniwheels"17 running Thescrap'ing means of the machine is' located fat the rearward end ofthe same,'and comprises lthe following arrangement. Pivotally-connected Ybysuitable hinge knuckles 45 to the rearward bolster beam 11 are laterally spaced apart reari wardly extending carrierV arms .47 having down- .wardlycurved free ends. Suitablymounted onl the forward faces of the curved free endsof.

said carrier `arms 47 to extend transverselyY of the machineis a concavo-convexfscraper plate 48, with its concave face forwardlypresented.

-Extending along ythe back Aof saidscraper plate is a reenforcingrib 49, which may bemade of angle iron welded or otherwise secured to the body'of said scraper plate. Suitably ser'z'uredt'oV the lower marginal portion of'saidscraper plate is ajj toe-plate 50 -of `hardened steel vand having J its lower free working edge suitably sharpened. Secured to ,and uponthe bridge beam"15 are laterally disposed'housings 51 respectively outwardly .olf-set in opposite directions from the longitudinal center of the machine. Each ,housling 51'is provided at itsupper end with spaced bearings 52 in which' is journaled a power shaft 53, having ahand wheel 54 on its inward end for manually applying power thereto. 'Mounted onpivoting shafts orn journals 55 extending trans# versely through said housings 51 are segmental o r quadrant gears (not shown) which are similar to the quadrant gear '38' of the above described scarifying means. These gears have outwardly projecting lever arms 55 4connected to move therewith. Fixed on each power shaft 53 is a worm 5'?V to engage and transmit to said quadrant gears the ,power applied to said shafts 53.- vThe pivoted` scraper plate structure is connected at its opposite end portions by links 58 with the free ends of the respective lever 'arms 56. Connectedrefl spectively with opposite Vend portions' of :the

scraper plate structure are' upwardly projecting stop-rods`59, the "free ends of which slidably pass tion, and consequently the exact level of ther finished subgradesurface relative tothe tops of the forms may be assured, so that no waste occurs by casting any excessof concrete when laying pavement slabs thereof. Itvlill be observed that each end of the scraping means is individually controlled by its own raising and lowering means and itsY corresponding stop means, and.l consequently` the scraping Vmeans may be nicely adjustedl to produce subgrades havinglateralpitch or declination for producing crowned pavement.`

'Securedto the' bolster beam 12 by 4brackets 62 is a platform 63 upon whichy the operator of the machine may stand in order to! manipulate the hand wheels for selectively bringing `the scarify` ing and scraping means into'and out of service, as may be required during the operation ofthe machiner Y l The machine is adapted to be drawn during operation thereof by anysuitabledraft means, Preferably, however, the machineis `connected with a power 'graderoller as a 4trailer thereto, j whereby grading and rolling may be accomplished 4 in one operation. A novel self-compensating coupling means ,isprovided which so functions .that ya true straight pull upon the grading machinis assured regardless of any given path of travel taken by the hauling roller. This novel coupling means comprises a V-shaped draftyoke64, the respective arms of which are pivotally connected,

as at 65to the forward bolster beam 11. 'Pivotal-J ly coupled, to turn in horizontal plane, withthe forward apex end of said draft yoke "64, -is a draft'- `linlr 66. `Mounted in connection with the forward end of saiddraft-link are a pair of vgrooved "rolll ers 67-68 which respectively `engage Vopposite sides of'a transverse draft bar ewhich is con,-`

nectedwith the rear end of a roller, tractor-or other hauling means by suitable off-setting `brackets or frame supports 70.

In the use of the machine for preparing a subgrade upon which is to be cast afirst'courser of concrete slabs, the forms" 18 are set to correct grade along each 'side of the course.` The forms 18 being set, the" grading machine is mounted thereon so that the traction wheels v"17 thereof ride on the tops of said forms, with the guide rollers 24 adjusted to bearagainst. the inner faces'of the forms so `as to hold the machine against lateral displacementand so that the saine runs true along the forms. The grading roller or other hauling. means is-now coupled through thefde-I' 'scribed draft appliances'with the machine; and

' the operator takes his'station ontheplatform 63 ready to control the operations of the machine;V

3io. Y,

Ifgit is desired to'scarify the surface between the forms which'isgto 'be graded,the operator manip# ulatestherhand'wheel42 'to lower the scarifying -means to operative position, whereby the teeth 3`2are broughtlinto-"operative 'relation to the earth. If the Vscarifying operation is to be separately performed, the-scraping means is raised to inactive position;vr Itisfrequentlypossible to perform both"` the scarifying operation and the scraping operation at the same time, in which case the scraping meansis lowered'to a selected adjusted position'acc'ording tothe depth of sub-j` grade desired. As the grading roller or `other hauling meansV is moved'v forward, the trailing grading machine follows thereafter and is pulled v:straight and true through the described ldraft coupling devices, any lateral deviation or off-set path of travel ofthe grading roller orwhauling 1 means being automatically compensated for by corresponding "movement of the draft bar 69 between the rollers? 67--68 of the draft linl; 66, so

that a constant straight pull withoutv Iateraldeviation "is transmitted to the gradingvmachine, and consequentlyl n o over turning pressure is exerted' by the guide rollers 24 on the forms 18. lThe scarier teeth 32 will, as they are advanced, dig into the subsurface so as to'eiiiciently loosen irc the'soil and breakdown high spots therein.' A*The downwardly and `rearwardly inclined front plates 31 of the holder of 'the scarifierteeth will operate toi downwardly deflect loosened soil so that the same,` is passed rearwardlybetween theteeth and behind the'scarifying means tov lie in front of the :scraping means; at the same time any larger stones dislodged from the soil, and not capable of fisc passing between the teeth 32, willfbe rolled ahead -along 'the surface.' The operator can readily Y`manipulate the scarifying means to raise and .lower the samelasconditions'may require while *the machine is being advanced. Since thescr'apingfme'ans is rearward of the scarifying means, the soil loosened by the latter lies inthe path of f the former, so that the toe-plate50 will scrape and spread the same evenly atlthe true subgrade level, any excess soil being tumbled ahead'by the concave surface ofthe scraper plate `48, until -the j accumulation `thereof becomes suiiicient to be released, whereupon the'operator may actuatethe hand wheels -54 to raise the scraper plate, and *thus deposit the excess accumulated soil Tin one.'

place ready yfor removal; again lowering the` scraper plate `for continued `operation as thev machine proceeds. From the above it will be ap- `parent .that scarifying, scrapingandrolling of 'the subgrade may be performed in one operation, thereby saving lconsiderable time and labor.

If conditions warrantyhowever, either the scari-l fying or scraping means may be alone employed atany-stage ofthe work.

In operating the machine preparatory to laying -a secondcouijse of concrete to abut or laterally adjoin a first laid courseythe forms `1S Aat theV innerfside of Ytheifi'rstlaid course are removed,

andan outer run of forms are jerected-paralle'ling crete well .within or back. of itsedge, so as to avoid rislr of chipping such edgeQther journals of the traction wheels 17 are'reversible'in their bearings 16 so that the same may be located on the exterior side of the chassis beam instead of the inner side as shown in the drawings. When so reversed the ftractionwheels 1'7 will bear on the top surface of the vfinished*concrete well ba'ckvfrom its edge,.

while the adjacent guiderollers 24 will neverthef less bear on the exposed side face of vthe laid conf described,

crete. slabs. The scarifying and scraping operations Vare thereupon carried on inthe same manner as already described as the thus mounted grading machine is advanced along the work.

romY the above description it willwbeV obvious that the level of the moving grading machine is determined by the set forms 18, and consequently is constant relative to the forms. It therefore follows that if the scraping blade isset to given depthV below the form tops, the produced subgrade will be accurately produced and iixed at such depth without variation therefrom. Not only will thel produced subgrade be uniformly run,A but the same'may be .predetermined by the setting of the scraping plate to the exact point desired. This is of great importance since it eliminates the waste consequent upon casting concrete slabs of thicknesses inv excess-of contract specifications which lresults from excessive cutting down of subgrade levels, and which frequently occurs when subgrades are prepared by hand or b y machines running on ground surface. It has been estimated Vthat'inlmost concrete roadkworkvthe nishedjslabs average over an eighth of an inch in excess of required specified thicknesses, for whichr excess the contractor receives no compensation although 'being penalized for deficient thicknesses. An excess of an eighth of an inch in Va twenty foot road would consume about 4l cubic yards of concrete per mile, whichrat an average cost ofv approximately six dollars per yard would involve a loss of nearly $250.00, per mile f The vsaving of this lossalone illustrates the advantages vto 'be gained byy accurate subgrading as 4it can b e accomplished by the novel construction of gradingmachine according to this invention as above As a further part ofthe instant invention meansA are provided for facilitating vthe transportation of the novel grading machineV from place to Vplace where its use isv required. To` this end there provided'a pair of detachable journal brackets adapted to be affixed to and intermediate the ends of the exterior bolster beams 11-12,

` upon which may be rotatably mounted transport tractionwheels 7l for movablysupporting the machine so that it can be towed'from place. to place. Each such journal bracket comprises a clip-plate 72 :having annndeicut rib 73 at onev side. rlrhis clipplate is disposed under a bolster Abeam with said rib 7.3 hooked over. the bottom flange` at the inner side of the beam. Integral with said clip-plate '72 is boss 74'from which-proa jects a journal'portio'n '75 to receive the hub of the tractionY wheelV '71. Bolts '76? are Vpassed through said clipeplate and boss with their heads overlapping thebottom flange of the bolsterbearn at the Outer Sidr thereof Integral with, and" eX- ingsshall be interpreted as illustrative and not in a limiting sense.

I claim :--v

' l. Ina machine for subgrading between preparatory to 'casting concrete pavingslabs, a

frame-work having traction means to vride'on f said forms, a scarifying means vertically movable' in connectionwith said frame-work to ac-I tive or inactive positions, pivoted lever arms lfor Alowering and raising said scarifying1me`ans,

means for actuating said lever arms, and verticallyadjustable stop screws mounted on said frame-'work to lie in the path of said lever arms and adapted .to Vvstoppdownwardmovement there-A ofY to thereby selectively limit the active position level of said scarifyingmeans. 2. A machine for subgrading between forms preparatory to casting concrete Vpaving slabs,

comprising a frame-werk having tractionwheels' toother edge of said scarifyingmeans for operar tion at a predetermined depth below the tops of said forms, a manipulatable scraping member adjacent to the rearward end of said machine-tol extend transversely substantially throughouttheA space between said forms, and adjustable means to selectively.position the effective scraping edge of said scraping memberffor operation at apredetermined depth below the tops of said forms.` H3. A machine for subgrading between forms preparatory to casting concrete pavingV .slabs,'

'comprising a frame-work having tractionwheels to .ride on the tops of said forms, guide rollersmountedy in connection with said frame-work Vto bear laterally aainst side Vfaces of vsaid forms, 1

a manipulatable toothed scarifying means adjacent to theforward end of saidframe-Work-to extend transversely between said forms,.adjustk.able means to selectively position the effective toothed edge of said scarifying meansfor opera.e

able means to selectively position the effective'k s.

scraping edge of said scraping member for operation at a predetermined depth* belowthe tops of said forms, and means Vaccessiblevat the rear .end of said frame-work for selectively manipulat- .ing said scarifying means and said scraping membsratwill?. j v 4, In a machine for subgrading between forms preparatory to casting concrete paving slabs, a

frame-Work having traction wheels to ride on the l tops of said forms, guide rollers mounted in connection with said frame-work to bear lateral- 1y against Side.; faces @mais forms and.

lll-5 to adjust said faces. i. `5. In a `machine for subgrading between forms preparatory to casting` concrete pavingslabs, a

Vfname- Work having traction wheels to ride on the 4tops of said forms, said frame-work having rotatively adjustable dependent shafts', guide i* rollers at the lower portions of said shafts, said shafts having means to laterally shiftjthe same when -rotatively adjusted to dispose said guide rollers toeengage side faces ofsaid formaandI means to fix said shafts in given` laterally adv'- justed positions. w l

6. In a machine forsubgrading between forms preparatory to casting concrete paving slabs., a: `frame-work having traction wheels to ride on the tops of said forms, saidframe-work rotatively adjustable dependent Shaftag'uide-rollers having anti-friction bearings mounted on. the lower portionsof said shafts, said shaftshavingl eccentric portions, said frame-work having seats to receive said eccentric portions, and meansA to` Y, secure said shaftsv in given'rotatively adjusted positions whereby said guide `rollers -are 'dispos ed to engage side faces of said lforms.` Y

f7.. In a machine for subgrading betweenforrns preparatory to casting concrete paving s1abs, a frame-work having bearing portions on itsppposite longitudinal sides, and `traction wheels having `journal members mountedin said bearing portions, said traction wheels and vjournal mem? bers being reversibly relative to said bearing por- VVtions to selectively dispose said traction wheelsv at either the inner or outer ends of said bearing portions, said traction wheels being adapted to ride on the tops of said forms to movably'su'pport the machine in bridgingrelation across the same. Y Y

y 8. I n a machine for subgrading between forms preparatory to'casting concrete paving slabs, a

carriage to travel on the tops` of said forms in bridging relation thereto, means to retain saidv carriage against lateral `displacement relative toV said for1ns,"a` scarifyingmeans-mounted on saidr carriage to extend between saidforms, means to raise and lower saidscarifying means to inactive oractive position, and means to selectively position said scarifying means for operation at a predetermined depth belowtlietops of said forms, said scarifying meansv including a holder of Vf shaped cross-section, a Vplurality of downwardly v y and forwardly inclined laterally spaced scarifying teeth Aprojecting from said holder, and the upwardly andrforwardly inclined face of said A guide rollers relative tovsaidform ened soil relativelylarge stones and rubble. i

9. In a machine for subgrading `between formsA holder serving to defiect loosened soil rearwardly v a through spaces between said teethwhileoperatf, ing to roll forward and separate from 4said loos- 'f preparatory'` to casting concrete paving slabs,a``V

jcarriage to travel on the` tops o f said .forms Vbridging"relation thereto, means to retain said carriage against lateral displacementivrelative to v said forms, a scarifying means mounted o n said 7 carriage to extend between said forms, means-*tol raise and lower .saids'carifying means to inactive predetermined depth below the tops Vvof said 1 frames, said scarifying meansinclnding a holder of Vfshaped cross-section, apluralitygoflaterally preparatory tocasting concrete paving slabs,

' or active position, and means to selectivelyposi-` tion said scarifying means foroperation at av 100i carriage to' travel on' the tops of said forms inl,`

bridging relationthereto, means to retain said;V carriage against lateral `displacementrelative to Y said forms,` said'tcarriage having `a platform forV `st ationing an operator at its rearward end, a `sc'arier means at the forwardend portion of said carriage comprising a holder to extend bei,

tween vsaid` forms having a' plurality off downwardly andangularly directed laterally spaced scarirler teeth, means on Vsaid carriage to raise -and lower said scarier means including apower shaft and vhand-'wheel accessiblefromfsaid rear` A platform, adjustable stop means for predeterminf ki ing the working level of said scarifier means," a 15.

scrapingl means at the rearward endlportion of said carriage comprising a concave-convex scraper plate to rextendbetween, said forms hav-` ing al sharpened toefplate atfits lower margin,

i means `on said carriage to lraise Aand lower said scraperA plate including independentlymovablefv 'carrying' means connected respectively with'gop-z positev end portions of said` scraper j plate and power shafts for respectively 'actuating said' car` f rying means `eachfhaving a hand-'wheel' accessible from Asaid rear platform, and adjustable. stop means for predeterminingv the working level v of saidscraper plate.

so, i

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