US2094910A - Apparatus for compacting and surfacing plastic material - Google Patents

Description

Oct. 5, 1937. I R w .BAlLY 2,094,910

APPARATUS FOR lCOMPACTING AND SURFACING PLASTIC MATERIAL Filed Aug. 17, 1933 2 Sheets-Shea@ l x N ,L\ i n Q w' f' Q@ 2R @s 51: wf@

Oct. 5, 1937.

R. W. BAILY APPARATUS FOR COMPACTING AND SURFAGING PLASTIC MATERIAL Filed Aug. 17, 1955 2 sheets-'sheet Patented Oct. 5, 1937 UNITED STATES PATENT oFFlcE 'APPARATUS FOR COMPACTING SUB- FAUING PLASTIC MATERIAL l Robert William Bally, Philadelphia, Pal.-

Application August 17, 1933, Serial No. 685,590 4 claims. '(ol. sil-4s) A further object is t'o provide a sectional screed,

the parts of winch are individually adjustable for forming a composite screed, the adjustment providing for fitting the screed to various desired contours, such as the transverse contour of a pave-1 ment or the like, it being particularly applicable for roadways. although it can be used for oors and the like.

A further object is to provide a method for vibrating the concrete in a roadway or the like for causing it to become dense and homogeneous by ridding it of entrapped air and water, vibratingscreeds being usedfor this purpose which strike ofi the surface to the approximate contour desired, thevscreeds being controllable either to rectify the surface of the roadway into a true straight line or to make its surface conformto a predetermined convex or concave requirement, 26 the sections of the lscreeds havingeach a vibrator so that all the sections are vibrated and yet can be adjusted for a change in contour as desired. Still a further object is to provide a screed for forming a concave or convex surface which con- 30 sists of a plurality of screed sections, each having a straight or adjustably curved surface and each being adjustable with relation to a carrying frame and with relation to each other, so that in the case of the straight sections, a plurality of plane surfaces can be formed on the concrete atangles to each other to make approximately a curved surface. p Y

My invention also contemplates the combination of the screed sections mentioned with a re- 40 ciprocating planer following the screed sections to reduce the surface of the concrete to the desired trueness and smoothness without humps or depressions.

The method and apparatus for the use of and the design of the vibrating screeds are shown in my copending applications Serial Numbers 428,- 747 and 514,124. The apparatus for supporting the'screeds and determining their positions is .shown in my copending application Serial Number 576,727 issued as Patent Number 2,018,294,

on October 14, 1935. One form of the vibrators is shown in my Patent No.-1,a76,271.

My invention comprisesv a method and apparatus for vibrating thelconcrete of a roadway while itis in plastic condition and also striking.

off'the surface to approximate contour and then planing it to the exact desired contour, thus leaving the concrete dense and homogeneous, free from entrapped air and water and its surface true to the desired contour.

A further object is to provide the apparatus easily and quickly adjustable to desired changes in the contour and which further is capable of constructing single slabs that are too wide-for vibrating screeds heretofore known. l

Still a further object is to provide an apparatus in which a preliminary strike-off planer is followed by vibrating screeds and then by a finishing planer, whereby striking off the surplus concretefrom the surface of the freshly laid pavement is done by the strike-off planer rather than the vibrating screeds. j

With these and other objects in view, my invention consists in the ponstruetion, arrangement and combination of the various parts of my apparatus and in the practice of my method, whereby the objects contemplated are attained, as hereinafter more fully set forth, pointed out in my claims, and illustrated in the accompanying drawings, in which: l y

Figure 1 is a. rear elevation of a vibrating sectional screed embodying my invention.

Figure 1A is a view of the left end of Figure 1 showing a modified construction.

Figure 2 is a plan view of the same, a portion of the upper framework thereof, as indicated b i i Figure V6 is a rear elevation somewhat similar to the left end of Figure 1 showing a modifiedembodiment ofthe invention.

Figure 7 is a diagrammatic end elevation of a vibrating screed, such as shown in Figure 1,

followed by a planer; i

Figurer is al diagrammatic plan `view ofthe same. y l

Figure 9 is a rear elevationvof the planer showing it diagrammatically. n

Figure 10 is a.diagrammati'c plan view of a modified form in which theplaner is made in two sections. f l

Figure 11 is a rear elevation showing the planer of Figure l0 diagrammatically.

Figure 12 is a rear elevation showing a means a screed section of adjustable cur- Figure 15 is a diagrammatic plan view showing staggered screeds rather than alined screeds; and

Figure 1 6 is-'adiagrammatic plan view showing' a strike-oif planer, vibrating screeds and a finishing planer successively arranged.

In Figure 1, concrete I0 is illustrated between side'forms I2 and the concrete isf-being coni-f pacted by screed sections I 4,- I4a., and I'4b. "The screed sections are board or plank-like devices and they may or may not be flexibly connected together, as by hinges I6. They'are preferably' provided along their forward edges with up,

standing flanges I8 which prevent concrete from surgingup over their forward edges and onto'-V fThe sections -I4, I4a, and-I4b are preferably mounted so'thatthey-can be adjusted, although they may be permanently mounted in a position forforming arpredetermined contour of 4roadway if desired.: `Ihhave illustrated them as being mounted lay-means' of brackets 20, yokes 22, con-Y nectingelements 24, such as shown in my Patent -"Number 2,018,294?,` andposts 26. The' posts 26 are'carriedbya-cross lbar 28 of a carriage which has end framefmembers 30 and wheels 32. wheels`32 travel-'on theside formsIZ. Figure 1A showsr a means for adjusting the frame vertically with respect tothe carriage.

The elements 24 are* elastic belts of considerable width, as shown at the left Vend of Figure 2, and encircling pins 34 and 36 of the brackets 20 and lyokes 22- respectively. T he""posts 26 are l ythreaded rods 'providediwith lock nuts 38 for" vertically" adjusting the posts relative to the 4 4crossfbar f28 f and retaining such adjustment.

shafts `42'ftherein.7 The shafts have oflcenter weights 44 within the casings 4|! for imparting vibrations tothe screed sections I4, Ma, and I4b upon rotation of the shafts. The shafts are con-4' nectedtoge'ther'by -flexible couplers 46 so that `lhaving. to provide a=separ`ate power means for each one, although separate power means could be provided if desired. The couplersV 46 permit the-screed4sections I4, I 4a, and I 4b to be bowed upor downfas desired.

I have shown as am'eans'for rotating'theshafts 42 ,-an engine 48 mounted on a bracket 50. The bracket 60 in turn is mounted on a bracket 52 on the .cross bar. 28,fflexible belts 54 and pins 56 being provided for mountingthe brackets relative to each other. v 'l By means of iiexible couplers 58, the engine 48 is connected with shafts '60. One of the shafts 60 is belted `by a belt 62f'to the shaft-42 onA the screed section\|4.- f f- Y? W From the foregoing construction, it is obvious Athatfthe screed comprising-the screed sections and the engine 46 are elastically mounted so that the transmission of vibrations thereof `to the carriage frame isminimized. f Various -means fmay be provided for propelling the carriage. frame'and consequently-the screed along the concrete I0. Il have shown winding' drums 84 in Figures 1, 2, and 3 having cables 66 The shafts 61 with relation to each other and which are controlled by clutch levers 69. 'I'he stakes 18 can be driven a considerable distance apart and changed from time to time as the machine progresses along the pavement.

In Figure 5, I'have shown another arrangement wherein the wheels 32 are operatively connected together by a chain or belt 12 and connected with a counter-shaft 14 by a chain or belt 16, the counter-shaft to be driven at a suitabley low speed by means of gearing or the like from the engine 48.

Means is provided for moving the screed sections I4, I4a and I4b forwardly without depending on the posts 26 for vthis purpose. This means .consists of a cross bar 18 and exible elements,

such as chains connected therewithand with the screed sections. vPlows or defiectors 82 may be mounted on the forward edges of ythe screed sections' Ila and I4b to'force VsurpIuscoricrete away from the side forms I2 and toward the center of the roadway,

1n Figure 7, 1 have shown' in 'addition to 'the screed sections, a. planer A following the screed.

Thecarriage frame is a little different in shape,v

vbut operates the same Vas in the previous figures and consequently it, as well as other parts cor--l responding to those in they previous gures, will,A be given the same reference numerals. 4The planl.

er consists of a blade 84 havingafront plate or flange 88 to carry' ahead surplus concrete that may accumulate in front of the planer.

'I'he planer may be' supported byexible elef on the side forms I2 following the wheelsy 32. The flexible elements 88 are preferably connected with some raising device, such as a bell crank lever 94 pivoted to a bracket 96 of the frame 98: On e'achscre'ed, I mount casings v4I! and Journal In Figure 7, the bell crank lever V94 is shown exments 88 such as chains which are connectedto f a subcarriageframe having wheels 92 to travel olution clockwise about its pivot to the bracket 96 which will elevate the planer A, the elements 88 passing overcenter with respect to the pivot of the lever 94, which will lock the planer in its elevated position. Any other vdevice may be used to accomplish this purpose.y

'I'he planer A may be propelled by flexible elements 98 extending to the carriage frame 30 or a suitable cross bar thereon, `such as indicated at IUI) inFigure 8.

Other suitable means can be used for supportn ing and propelling the planer A, as desired. In'Figure 12, I have shown diagrammatically how either one of the screed yelements I4 or the planer A can be adjusted ,to varyits `contour so that in the case ofthe screed sections, each may.

be warped to an arc of the desired radius to strike off a truly convex surface on the concrete 'I0 or to adjust the planer A to fit pavements of any `desired convexity or concavity. The ends .of the screed section or planer are rigidly connected ,with a frame member |02, while the central part vof the screed section or planer may rbe raised or lowered by a jack screw |04. The front ange 86 of the planer may be provided with deecting portions 81 to -prevent the .planer from pushing 'I 'he planer A is preferably longer than the 'the surplus concrete in front ofit over the side -forms I2.

45 tended rearwardly. It can be swunga half rev-L- r distance between the opposite side forms 'l2 so that it projects therebeyond as clearly shown in Figure 8. It may rest thereon whereby they act as a surfacing gauge for it, or may be hung in predetermined elevation with respect to the wheels 32 and 92 and supported thereby a predetermined distance above the side forms. 'Ihe planer may be of nonreciprocating type if desired, although it is preferably of the reciprocatory type which will now be described.

Reciprocations of the planer A are preferably in a transverse direction with respect to the forward movement of the planer whereby to saw olf or scrape the surface of the concrete l 0, thereby assisting in the finishing and polishing of the surface of the concrete by a trowelling action. To obtain this reciprocating action, the planer may be mechanically operated in several diierent ways. In Figure 9 for instance, I have shown an engine 48a driving a crank disk |06, to the crank pin of which, one end of a pitman |08 is connected. The other end of the pitman is pivoted tothe planer. The engine 48a may be provided especially for the planer, or the crank disk |06 may be operatively connected with the engine 48 vwhich operates the vibrators for the screed sections.

In Figure 10, I have shown a modified form of planer consisting of sections 84a and 84h provided with front anges 86a and 86h and deflector portions 81a and 81h. 'I'he sections 84a and 84h are telescopically associated with each other, for instance by means of hooked flanges H0 on one section engaging the edges of the blade and'front flange of the other section. The two sections are made to reciprocate in opposite directions, for instance by a crank shaft H2 journalled on one section and connected by a pitman Illlto the other section.

I'he crank shaft H2 is connected by suitable means, such as universal joints H6 and bevel gears H8, to the engine 48. Suitable clutches of course can be provided for the planers, but it has not been deemed necessary to illustrate these on the drawings'. b

In Figure 11, the overlapping planer sections 84a and 84h would apparently leave a consider-` able ridge at the right hand end of the section 84a. In practice however, thethickness of the section 84a with respect to the size of the roadway is considerably small and such a ridgewould be practically imperceptible, it being exaggerated on the drawings because of the scale necessary in order to properly show the invention.

By the reciprocating arrangement of two planer sections, as in Figure l0, and the sections alternately approaching and receding from each other, the effect of friction of the concrete on the planer, as in Figure 9, is neutralized so that there is not the marked tendency of the supporting frame 90 to shift transversely one way and then the other during the reciprocations of the planer.

In Figure 6, I show how a cross member 28a may be supported on the vibrating screeds Ila and Mb instead of on the wheels 32. In this construction it is unnecessary to have any supporting frame and the end screed sections lla and Mb may extend over the side forms l2 and rest thereon as illustrated.

When a planer is used with this type of screed, it can be drawn as in Figure 13 by its draft chains 98a connected directly with the screed.

As the apparatus is propelled over the concrete IU, one end of the screed may be advanced ahead of the other when there is any tendency for the concrete to be' high on one side of the roadway and low on 'the other. `This will serve to shift the concrete in the opposite directionto keep the quantity piled up in front of the screed evenly distributed transversely o f the roadway.

In Figure15, I have shown how the screed sections may be arranged in staggered relation andthe path of one'may overlap the path of the other so there will not be any unvibrated vstrip of concrete between the paths of the screed sections.

In Figure 16, I show a strike-off planer IIS ahead of the vibrating screed sections Il, Ila,. vand Mb. 'Ihis planer does the work of striking olf the majority of the surplus concrete above the finish line, making it easier for the screed to operate without'having to do this job andthe trueness of the finished pavement is thereby 1mproved.

Sometimes it is desirable to raise the screeds so that the machine can be run backwardly over the vibrated concrete and then lowered for a second vibrating application. This can be accomplished by elevating the frame member 28 relative to the carriage wheels 32. In Figure 1A, I show one way in which this can be done. An upright 30a extending from the wheels 32 is received in a socket member 30h secured to the frame member 28. A set screw 30e can be manipulated for raising the frame member 28 re1- ative tothe wheel 32 for thus bodily raising the screed above the surface of the concrete I0. The screw 30c,when rotated in an opposite direction, lowers the screed or planer, as the case may be, and its height with respect to the carriage frame can also be adjusted by the set screw.

The foregoing described apparatus is especially adapted for the method of compacting and surfacing plastic materials used for the construction of roadways. ,I have found that in such construction it is necessary to adjust the screed to conform to the crown of the roadway cross section. In some cases, these adjustments must be frequently made, due either to the transverse contour of the roadway changing from time to time as it does at intersections with other roadways, or because the screed itself or the carriage supporting the screed bends or deects due to changes in its Weight or the effective weight of the supported members, or due to variations in the resistance of the concrete to manipulation as the proportion of mixing water varies or as the harshness of the aggregates changes.

I have shown one way in which each 4end of each screed section may be vertically adjusted, although mechanical equivalent adjusting means of faster operating characteristics can be used as desired.

Because the vibrating screeds must be exceedingly stiff to prevent distortion induced by the violent action of the vibrators, it is dimcult if not impossible to arrange a long screed so that changes in its longitudinal vertical curvature passage of the vibrating screeds which formed such tangents or curves may be planed off or trowelled to the desired true curve or tangent with the minimum of labor and'skill.`

The labor and skill required tov produce the de- -sired true curve or tangent may be further reduced if a reciprocating planer having the true curvatre or tangent of the pavement, be made to follow immediately behind the Vibrating screeds to reduce the surface of the concrete to the desired curvature or tangency.

The `vibrating screed which I disclose reduces what are otherwise harsh and unworkable concrete mixtures to a plastic and owing substance, with the result that if any considerable amount of concrete collects and piles up in front of the vibrating screed, its hydrostatic pressure Will cause it to iiow under and beneath the screed and rise or surge up therebehind, resulting in the surface of the following concrete being considerably above the desired elevation. It then becomes necessary to plane the surface oi to the desired elevation. I have discovered that where the amount of concrete in front of the vibrating screed may appear to be sufcient, but where on the other hand, due to its porosityl and where, due to the elimination of the porosity by the effect of the vibrating screed, the surface of ,the concrete I claim as my invention: 1. In an apparatus of the character described, a carriage frame, a plurality of screed sections carried thereby andvextending. transversely relative to the direction of travel of the carriage frame, means for `individually adjusting the height of each end of each screedl section,.means for circularly vibrating each screed'section, a

planer following said screed sections and means for vibrating said planer, said planer being curved 'and the curvature thereof being adjustable.

2. In apparatus of the character described,.a-

3. vIn apparatus of the character described, a

transverse carriage, a plurality of screed sections, aresilient 4mounting for each section, means for adjustably connecting each of v.said mountingsy with said carriage to ,depend therefrom, vibrating means on each section and resilientlymounted power means carried by said carriage and operativelyconnected with each vibratingl means.

4. In apparatus of the character described, a.

transverse carriage, a plurality of screed sections,

a resilient mounting for each section, a vibrator and shaft journalled on each section, iiexible connections between said shafts, Vibrating means on each section operable by the shaft thereon and means for driving one and thereby all-of said shafts.

ROBERT WILLIAM BAILY.

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