US 3110234 A
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Description (OCR text may contain errors)
Nov. 12, 1963 J. os'rER l 3,110,234
CONCRETE sCREEDINC MACHINES Filed July 15, 1960 4 sheets-sheet 2 INVENTCR. .fan/n r/Mw 05752 uM/Mw Arron/evs.
Nov. 12, 1963 J. @STER 3,110,234
CONCRETE SCREEDING MACHINES Filed July l5, 1960 4 Sheets-Sheet 3 INVENTOR. .fa/v4 rf/w asf-ER BY?t a irren/ys w Q m NGV. 12, 1963 J, @STER 3,110,234
CONCRETE SCREEDING MACHINES Filed July 15, 1960 4 Sheets-Sheet 4 -FIE .5
lllll Hl JNVENToR. 7o/va r//a/v sre BYCaW/ 5%241/ rrauwsvs United States Patent Oiiice anstatt Patented Nov. 12, 1963 3,ll(i,234 CNCRETE SCREEDING MACHNES Jonathan Oster, Litchfield, Meeker County, Minn. Filed .uiy 15, 1960, Ser. No. 43,062 1 Claim. (Cl. 94-45) This invention relates to screeding machines and more particularly to improvements therein relating to mounting of the track engaging means and of the screed supports such that a desired texture to the concrete is provided with only two passes of the machine over a roadway in either one of two directions.
Machines for screeding concrete roadways or decks on bridges are commonly supported at their opposite ends at the respective roadway sides on tracks suitably laid on the beams of the bridge. These machines move down the roadway and form the concrete to the desired shape and additionally attempt to provide a predetermined texture in the concrete surface. Most machines, to date, have not been able to provide a surface texture to the concrete which is suitable for the subsequent brooming or finishing operations. As a result thereof a crew of six to eight men have been required to work behind the screeding machine for providing the desired texture before the roadway is finished. This invention obviates the need for such a crew of men by providing a machine which produces the desired surface texture.
The present trend of highway construction is to provide bridges which have their respective ends angled with respect to the center line of the roadway other than at right angles thereto. As a result thereof when a screeding machine is entering onto or leaving from the bridge beams, one of the beams will be loaded by the machine while the other beam has no load at all. In fact, one of the beams may be loaded up to 75% of its maximum load as provided by the screeding machines before the other bridge beam receives any portion of the load. Bridge construction engineers have stated to the inventor that this is an undesirable occurrence on Ia newly constructed bridge. This invention provides improved ground engaging means which obviate the subject problem.
This invention further provides two reciprocating and oppositely movable sereeds on a single machine for eliminating the side thrust on the bridge beams caused by the screeds engaging the concrete. Further, improved screed mounting means are provided to impart a peculiar compound horizontal and vertical arcuate motion to the screeds resulting in what is termed puddling action which tends to recurrently and momentarily compress the concrete for bringing water and cement to the surface to provide a texture suitable for a brooming operation.
Accordingly, it is a prime object of the present invention to provide a screeding machine for use on a roadway which screeds at any selected angle with respect to the roadway center line.
it is another object of the present invention to provide a screeding machine for use on a roadway and the like which has no side thrust due to the screeding action.
It is a further object of the present invention to provide dual pivotal mounts for each screed for imparting a dual arcuate motion thereto to cause a puddling type of screeding action,
It is still another object of the present invention to provide an improved screeding machine which levels and provides a brooming operation texture to concrete in only two passes of the machine thereover in either one of two directions.
It is a still further object of the present invention to provide a screeding machine which completes any screeding operation with a minimum travel of the machine.
These and other more detailed and specific objects will be disclosed in the course of the following specification, reference being had to the accompanying drawings, in which- FIG. l is a side elevational view of a screeding machine embodying the teachings of the present invention as would be viewed on a bridge roadway as a machine approaches the observer.
FIG. 2 is a plan view of the FIG. l machine and showing the machine on an angled bridge roadway less the screed supporting and drag structures.
FIG. 3 is an enlarged and partial side elevational view of one end portion of the FIG. l machine and showing the Vertical arcuate motion of the screeds.
FIG. 4 is an enlarged vertical sectional view taken along the line 4 4 in the direction of the arrows in FIG. 3 and showing the horizontal arcuate motion of the screeds.
FIG. 5 is an enlarged horizontal sectional View as taken in the direction of the arrows along the line S--S in FIG. 3 and showing the ground engaging means of the present invention as well as the compound arcuate motion of the screeds.
Referring more particularly now to the appended drawing like numerals denote like parts and structural features in the various views.V The machine comprises an elongated and trussed frame it) which in the operating position extends transversely across the roadway generally designated 12. A pair of track engaging wheel assemblies l4 are attached to the respective ends of the frame i6 and are movable on the frame for permitting the frame it? to assume a selected angle of operation with respect to the roadway 12 center line. The assemblies 14 movably engage the provided tracks 16 which are suitably mounted on the bridge beams 18 for supporting the screeding machine. A hydraulic pressure system 20 having an internal combustion engine is suitably mounted on the frame ld upper side and is operatively connected to a hydraulic reservoir 22 for operating the machine as will be subsequently described.
A pair of reciprocating rams or motors 24 are pivotably mounted on the frame lower side and are pivotably and respectively connected to the two screeds 26 for causing same to oppositely reciprocate or oscillate along the length of the frame 19 for performing the later described screeding operation. The frame 10 is formed of separable sections 28 for permitting the machine to accommodate various roadway Widths. As shown two sections 28 are bolted together as Iat 29. It is understood, of course, that the respective screeds 26 will also have different lengths in consonance with the frame 10 length.
The exemplary track engaging means 14- providing for the variable angled operation lof the illustrated screeding machine such `as shown in FIG. 2 will now be described with more particular reference to FIGS. 3, 4 and 5. The frame 10 consists of two longitudinally-extending and parallel upright-trussed sections 30 tied together by the truss ties 32 and 32 which are suitably bolted to the sections as shown. The lower truss chord members 34 are formed of H beams which rest on the drive assembly frame generally designated 36. As best seen in FIG. 5 the frame 36 comprises a pair of side support 'frame members 38 having their respective ends joined by the two end cross brackets 4i). The iianged rollers or wheels 42 are rotatably secured between the frame members 38, as by the depending support means 44 (FIG. 4). The wheels 42 shafts 45 have the Vdrive sprockets 48 non-rotatably secured thereto and which are drivingly connected to the motor sprockets Sti as by the drive chains 52. A hydraulic motor 54 is suitably mounted on the frame 36 and has its drive shaft connected to the motor sprockets 3 Si? (FIG. 4) through the exibie coupling 56 as rotatably supported by the bearing members 58.
The just described drive assembly is actuated by the valve control mean 6i) (FIG. 1) which selectively permits and controls the lrate of hydraulic Huid ow through the lines 62 from the system 2t) for actuating and controlling the rotation rate of the motor 54. It is understood that the valve means 661 returns hydraulic fluid to the reservoir or accumulator 22. The operation of the hydraulic system is not important to a complete understanding of the present invention and will not, therefore, be further described.
Upper side' frame members 64 are welded to the upper side of the members 38 at their respective end portions j and upon which the lower chord members 34 are respectively movably disposed. The upper flanges 66 of the members 64 are suitably apertured as at 68 for respectively receiving the bolts 70 which operatively engage the connecting clips 72 .for non-movably securing the chord members 34 to the upper members 64. 'I'he 'apertures 68 are spaced apart along the :length of the upper member 64 a distance greater than the respective widths of the flanges 74 of the lower chord members 34. As best seen in FIG. 5, when the bolts 76 are loosened for permitting the clips 72 to freely move, the trussed frame `10 can be disposed on the support frame 36 at various angles. The method for so adjusting the frame will be later fully described.
The screeds 26 and a novel mounting means therefore will now be described with particular reference to FIGS. 1, 3 and 4. The plurality of the upper truss ties 32' are spaced apart along the frame 1t) length and each has two screed arm support assemblies 76, one for each screed.I Each of the screeds 26 is provided with a plurality of hanger plates 78 suitably bolted to the screed members 26 and are respectively and pivotably associated with the respective pivot 'hangers 8% by the pivot pins 82. Cotter keys or the equivalents are inserted lthro-ugh apertures in Vthe pins 82 for respectively retaining same in the illustrated positions. Each of the hangers 80 is welded to a vertical rock-er arm S4 which is :loosely slidably disposed through the rocker arm sleeve S5 (FIG. 4) and held thereon by the stop-nut 86 which is threadingly engaged to the arm S4 upper end portion. The screeds 26 are liftablegfrom the illustrated operating position by the lifting cylinder 88 attached to one of the ties 32 and is hydraulically associated with the valve means 6i). A pair of lifting straps 90 connect both the screeds 26 to the ram arm 92. Because of later described screeding drag assemblies 94 the screeds 26 will pivot toward one another as the ram 88 is actuated to lift same. Accordingly, the sleeve 85 has greater inner diameter than the outer diameter of the arm 84 upper end portion. It should be apparent that the nuts 86 provide an adjustable operating height for the -screeds 26.
The sleeves 85 are welded tol the inner ends of the respective horizontal rocker arms 92 which are rotatably supported about a horizontal axis in the two rocker arm bearing assemblies 94. A pair of Cotter keys are disposed through each arm 92 adjacent one of the bearing assemblies 94 for retaining same in the illustrated operating position.
Referring .to FIG. 3 it should be apparent that as the reciprocating motors 24 (FIG. l) are actuated by the valve means 60 the screeds 26 will move in an arcuate manner with respect to the several horizontal rocker arms 92 in much the same manner as a glider, such as shown by the two-way arrows 96. As the screeds transverse the arc the vertical relationshipl to the roadway or deck 12 changes to provide somewhat of a slapping action which acts to recurrently and momentarily compress the freshly poured concrete forming the roadway or `deck 12. In this manner, the water and cement are drawn to the surface for providing the before mentioned textured surface. Further, it should be apparent that as the screeds i 26 are synchnonistically moved in opposing directions the movements of each will compensate for the forces developed from the others movement. In this manner there is no side thrust imparted through the frame 1i) to the roller or wheel assemblies 14 resulting in no side strains induced in the bridge beams 18.
The screed drag assembly 94- is best understood by referring to FIGS. 3, 4 and 5 wherein a plurality of drag rods 9a are shown in spacedeapa-rt relation on both sides of the frame 1t] and respectively attached to the screeds 26. The upper and outer end of each rod 9S is connected to the screed drag support bars 166i by a universal pivot connection 162 which permits both vertical and horizontal pivoting of the rod 9S. The support members 169 are respectively welded and braced to the lower truss ties 32 and support the planking 164 to provide a walking surface for the operator. The rods 9S respective lower and inner ends are connected to the respective screeds 26 by the universal pivot connections 166. The rods 9S each consist of a sleeve member 109 (FIG. 4) in which a shaft 119 is axially slidably disposed and has a plurality of apertures for receiving the bolt 112 to provide an adjustable length to the rod.
As best seen in FIG. 4 the rods 98 are pivotally attached to the screed hanger plates 78 and as such cannot keep the screeds vertical. For this purpose a plurality of turnbuckle assemblies l114 are provided on every other rod 9S on each side of t'ne frame :10 and extend from the support channel -116 upwardly to the outer part of the sleeve 169. -Each assembly 114 has one pivotable connection, as at 117. By adjusting the turnbuckle assemblies 114 it should be apparent that the screeds vertical attitudes can be readily adjusted.
In viewing FIG. 5 it is seen that both screeds 26 will move slightly forwardly and rearwardly in an arcuate manner with yrespect to the forward travel of the screed machine ias the motors 24 (FlG. 1) cause same to reciprocate transversely to the line of travel. This last described motion in combination with the vertical arcuate motion of the screeds has been found to provide the desired texture in a newly poured concrete roadway or bridge deck by causing the machine to travel only twice thereover. It is understood, however, that the screed horizontal arcuate motion by itself does provide improved screeding action over straight line reciprocating screeds.
Each of the screeds 26 consist of large wooden planks 11S which are suitably bolted to both the hanger plates 78 and the lower support channel 116, and having a smaller cross-sectioned board 119, such as a 2 x 4, suitably attached to the planking lowering edge for providing :the screeding surface. It is to be understood that any form of screed construction may be successfully utilized with the present invention.
The operation of the illustrated screeding machine will now be briey described. The machine is first transported to the Work site and generally aligned with the roadway adjacent one end of a bridge which is to have its deck screeded. As shown in FIG. 2 the illustrated machine has been placed Kadjacent and aligned parallel to the bridge edge 120 with the wheel assemblies 14 having been moved such as to be parallel with the roadway centerline 122 and to operatively engage the tracks 16. 1t is assumed, of course, that the bolts 7@ of the wheel assemblies 174 were loosened for pemmitting the wheels to be accurately placed on the tracks 16. of the -bolts '70 the engine Ztl is started for building up pressure in the hydraulic system. The screeds 26 are in a raised or non-operative position by having caused the cylinder 88 (FG. 4) to bring its ram 92 upwardly. The valve control means 6tlis then actuated for providing iiuid to the drive motors 54. As soon as the screeds 26 are aligned with the bridge end 120, they are dropped down into the illustrated operating position and simultaneously therewith themotors 24 are actuated for caus-V After tightening all ing the screeds 26 to Ireciprocate as aforedescribed. During the iirst pass over the bridge, the machine travels at a relatively high rate, for example, 8 feet per minute, to form thet concrete which has been previously poured on the bridge into the ydesired shape for fthe bridge deck or roadway. Upon reaching the bridge other end, the valve means 60 are again actuated to reverse the motors S4 for causing the screeding machine to travel back across the bridge. At the same time the rate of travel is greatly reduced permitting the screeds to have a relative speed up in their oscillation `or reciprocation with respect to the travel of the machine. During this latter pass over the bridge, the screeds provide a texture to the concrete surface which is suitable for brooming operations.
It is readily apparent from inspecting the FIG. 2, that by parallel aligning the screeds 26 with the edge 120 of the bridge that the entire deck 12 will be screeded permitting a minimum travel of the machine and thereby reducing operation time. In machines, not having the Variably angled track engaging means 14, the screeds must remain perpendicular to the roadway center line and in bridges angled with respect to the roadway center line the screeding operation is started and finished at the line 124 01T the bridge rather than at the bridge end 120.
It is understood that suitable modifications may be made in the structure as disclosed, provided such modiiications come within the spirit and scope of the appended claim. Having now therefore fully illust-rated and described my invention, what I cla'nn to be new and desire to protect by Letters Patent is:
In a screeding machine having an elongated frame consisting of two longitudinally extending and spacedapart trussed sections tied together by a plurality of spaced-apart upper and lower ties, two screeds disposed under the frame and between the sections with the screeds being associated with the respective sections, a plurality of horizontal rocker arms rotatably disposed on the respective upper ties along the respective sections, a sleeve member non-rotatably secured to each rocker arm and being disposed above the respective screeds, a vertical rocker arm loosely slidably disposed through each of the sleeves and extending downwardly toward the respective screeds, means pivotably coupling each of therocker arms along the respective sections to the respective screeds, adjustable stop means on each of the vertical rocker arms for upwardly supporting the screeds, a plurality of horizontal drag support members extending outwardly from the respective lower ties, a plurality of drag rods respectively associated by said drag supports, a universal joint connecting each of the drag rods to the respective drag supports, a second universal joint pivotably connecting each drag rod to the respective screeds at points spaced along their lengths, means on some of the rods which operatively and adjustably engage the respective screeds for maintaining the vertical attitude thereof and including a universal joint at the screed, hydraulic means on the frame and being operatively connected to both screeds for lifting same, each sleeve having an inner diameter greater than the vertical rocker arm outer diameter for permitting the rocker arms to slide therein as the hydraulic means lifts same, and screed actuating means on the frame and operatively associated with the screeds for imparting oscillating movements thereto along the frame length in mutually opposite directions.
References Cited in the tile of this patent UNITED STATES PATENTS 1,619,083 Maxon Mar. 1, 1927 1,987,398 Gardiner Jan. 8, 1935 2,054,263 McCrery Sept. 15, 1936 2,134,082 Goodrich Oct. 25, 1938 2,796,811 Barber et al June 25, 1957 2,866,394 Smith Dec. 30, 1958 2,957,396 Bederman Oct. 25, 1960 2,969,720 Burnham lan. 3l, 1961