US2695552A - Apparatus for concrete finishing - Google Patents

Description

A. J. BALTES APPARATUS FOR CONCRETE FINISHING Nov. 30, 1954 5 sheets-sheet 1 Filed Aug. 5. 1950 INVENTOR.

LPH/VSE J. BALT-ES [SYM/g wmf/fad NOV. 30, 1954 A 1 BALTES 2,695,552

APPARATUS FOR CONCRETE FINISHING FiledrAug. 5, 1950 3 Sheets-Sheet 2 1N V EN TOR.

ALPHONSE J. BAL T E S NQV@ 3, E954 A J, BALTES 5959552 APPARATUS FOR CONCRETE FINISHING Filed Aug. 5, 1950 5 Sheets-Sheet 5 INVENTOR. ALPHONSE J. @AL TES United States Patent f) APPARATUS EOR CONCRETE FLNISHING Alphonse I. Baltes, Norwalk, Ohio Application August 5, 1950., Serial No. 177,315

2 Claims. (Cl. 24-.4S)

invention relates to. conc-rete working machinery in general, and relates. particularly tov roadwayy paving equipment for smoothing the roadway surface and 1rnproving the, physical constitution of a poured strip of concrete.

By way of background, in order that a full understanding may be had. of the.y place. this invention taires in concrete work, it .may besaid that this invention is a replacement of one prior type of operation; however, this invention goes beyond. the improvement of an old operation and providesV a new. function which has never been done heretofore, to. improve. concrete.

The, old. function which this machine improves. is the final surface finishing. Prior to this. invention, -paving of all types from sidewalks to roadways. was stricken olf with a straight edge, and then .finished by hand labor with` trowels. There. isl one machine available which attempts to reduce the hand finishing, but in reality is nothing more than a machine doing just what human labor previously performed. This machine has a small trowel'which is. oscillated in. .short strokes while being moved laterally from side to side between the forms.

Hand or machine work of this type has two main disadvantages, namely (1,) the. uneven surface produced, and (2) as well known to all concrete workers, troweling brings the moisture. and nes to the. surface, thereby makin-g a surface which will ake easily, and which is easily affected by salt.

The new feature. provided by this invention is the improvement of the physical constitution of the. concrete. This is accomplished to. a Satisfactory degree by weight alone, but the improvement is, heightened Eby the. addition of vibration to cause the concrete to pack closely to the forms and coarse bed. material.

Vibration applied to or near the. forms, and even to. isolated portions of the concrete body,y is well known. The forms are vibratedj to prevent honey-comb edges. Vibration of the concrete near the forms performs .the same function. Vibration rods are. extended into. random spots into the body .of the concrete in an attempt to :settle the ilowable concrete into. the. coarse bed mi): terial. The following objects of this invention, together with the description and claims of the. process and the preferred embodiment of the apparatus to carry out the process, explain the invention and 7the improved results obtained thereby.

An obiect of this invention is to improve the physical constitution of concrete paving by the uniform application of one moving weighted surface over a. large arca of the concrete.

Another obiect of this invention is to improve the physical constitution of the concrete paving by the uniform application of vibration force over a large surface area.

Another obiect of this invention is to obtain a superior physical constitution in a concrete strip by .the applica.- tion of a moving surface which is heavy enough .to cause concrete in its plastic condition to yield` as the surface is moved thereupon, and simultaneously vibrating the surface against the concrete as the surface is moved.

Yet another obiect of this invention is to smooth the surface of a concrete strip to close tolerances of surface variation, for example, to within one-eighth of an inch variation in ten feet measured in any direction.

A further obiect of this invention is the provision of an improved process of smoothing the surface of Va concrete strip, wherein the excess water and concrete 2,695,552 d Nov. 3o, 195,4

are actually squeezed, to;4 one side... rather. than blended into. rolling irregularities.

A. still turthc'ebiect of. this. invention.. iSl t0T Proyislc a machine for carrying alarse weighted 11921.13. with clins construction for. drcppug and picking up the toat, and for lifting the fi'oat on edge for cle.aningfy Other Objects. and. a fuller. understanding of the invention may be. had by referring; to the fcllowiua: de scription and claims, taken in. conjunction with the accompanying drawings.. which:

Figure l is a side-elevational viewY o f a machine. adapted to carry out thepriuciplcs. Qf this.. invention;

Figure. 2 is. a rear elevation. cf the.: machine; aud

Figure 3. is a; top plan view of; the. machine- The principles of this. invention may bc incorporated. into. various types of actual machines, andl carried out. with variations in operating techlliq'll,v but. llld.' mentally the machine. comprises a Heat .1.0 having. a finishing surface lying a; plane. The surface must be. substantially as. wide. as.. the width cf. thev strip of. ceucrete to be finished. and. Of Slllfllient mass to compress concrete which has taken an initial set,l or isY in a non llowiug plastic condition.. The float 10, in. the embodi-v meut of the. invention. Illustrated5 is fabricated from shccf metal plate. 1 1 to. provide. the inishing surface forA contacting the surface. 0f a concrete strip., In a road-builgd ina machine. for highway Constr.ustioni,v thc float lll Should. preferably be fully as wide as the distance between the forms. Therefore. the sheet metal plate Surface 1l. will probably need to be fabricated from. several pieces in most instances. The ends of the sheet metal 1.1 are turned up as illustrated by the reference character 12. The turned, ends prevent the plate from digging into the concrete, and materially aid in pushing excess concrete along before the float.

The oat 10 is strengthened by a plurality of lateral l beam ribs,v 13. to provide strength and weight. It has. been found to be desirable to make the float 1,0 with the plane of the finishing surface in various curvatures in order to provide a crest in the roadway under construction. ln orderto make one lloat serve. in all requirements, the sheet metal plate 11 has been connected with the lateral I beam ribs 13 by means of adjustment bol-ts. 16 in order to warp or flex the sheet metal plate 11 into.. the desired surface plane and to hold it in that selected condition. Saddle strips 14 are secured tov the, upper side of the I ribs 13 and a plurality of longitudinal angle brackets 15 are secured to the. top surface of the sheet metal plate 11. The bolts 1,6 are attached to the angle brackets 15 by means of the ears 18., and the bol-ts also pass through the saddle straps 14. Therefore, the bol-ts 16 may be caused to dra-w up on the sheet metal plate 1 1 in selected spots, and to hold the sheet metal plate fixed in other spots to thereby produce any desired surface contour upon the sheet metal plate .11. The ends 12 are split by a plurality of cuts `1,9 in order to permit exing along the curved ends.

The float 10, as thus described, is a complete working unit, in and of itself for improving the physical conf stitution of a concrete strip and smoothing the surface thereof, and this float may be moved along a concrete strip by any suitable mechanism. The very size of such a oat has proven to produce results beyond expectation, but it has now been `found that those results may be improved, and further new .results obtained by consideration of the weight of lthe float. Bythe application of evenly distributed weight over the entire surface area of the oat, it has been found that the physical constitution of the concrete has been greatly improved. The top Portion of the strip is considerably stronger and more dense. This .desirable weight will normally come about in the usual construction of a float made to carry out the invention. Good engineer-ing practice will require sheet meta-l 11 to be thick enough to withstand handling in the field Without extra care. This weight, in addition to the weight of the l beams 13., will lresult in a float which will have a .constant weight per unit of Contact considerably greater than applied by a workman using a hand trowel. This. weight for the float is feasible because of the. .SZC @.f the nishin-g Surface. .Gencreteis notabletoescauearO-uud. edges.;

Patente as in the case of a small trowel, to relieve the pressure. The normal resistance of the concrete to ow would produce this high pressure, even if it were not for the coniining forms along the edges of the oat.

So size and weight appear to be two important factors in the process and apparatus of this invention, although weight becomes secondary to size, and smoothing can be accomplished without the optimum Weight. Weight is of considerable importance in producing the best physical constitution in the concrete.

The condition of the concrete is helpful in producing the best results. If the concrete is poured between forms and stricken off to almost exactly the correct height, then it appears that a very light float could be employed to smooth the surface of the concrete strip in one continuous stroke. Concrete, when poured between forms for making a pavement, such as a sidewalk, driveway or highway roadbed, is quite fluid but quickly begins to set. The concrete takes on a non-owing plastic state which is characterized by retaining an impression without filling in. For example, a mans hand extended into freshly poured paving concrete will oe filled in, but after the concrete becomes plastic because of taking on an initial set, the impression will remain, In some instances, concrete having an extremely high slump is used and is therefore in substantially a nonflowing plastic condition initially. However, contrary to expectations, a light float will not do a good smoothing job, even in quite flowable fresh concrete as normally poured for paving walks and roadways. Those acquainted with concrete work know that concrete which will not support a mans foot directly, will quite readily support a length of board with the man standing thereon. Thus, if a light oat were used, it would tend to ride over mounds of excess concrete.

The correct amount of weight is not predictable exactly, and accordingly any float for carrying out this process should be provided with means for producing a variable weight per unit of Contact, in order that the Weight may be fashioned to suit the particular concrete being worked. Usually it is desirable to wait until the concrete has taken at least a slight set, but in many cases it will be best to follow the original smoothing quite closely with the process of this invention.

By using the correct amount of weight, another result is obtained which was unexpected when this invention was contemplated, namely, a surface which is not only smooth, but is also quite nonvariant. It seems at iirst consideration that smoothness and nonvariance are one and the same, but such is not the case. In prior practice, regardless of whether hand or machine smoothed, a small bead of excess concrete is left here and there. Some workers ignore these small beads, but unfortunately the tire and wheel of a fast moving vehicle do not. Every small imperfection sets up vertical vibration in the wheel which then exerts itself at a spot further down the strip. Countless repetitions of this vibration cause failure.

Those workers who attempt to produce a good quality road surface will smooth out each bead. A good road finisher can spread the material of the bead out until it cannot be seen. But again, the material is still on the surface, and the vehicle tire will react to it. The only way to correct this situation is to have no variations. Some states now require a maximum variation of one-eighth of one inch in any ten feet of roadbed.

By the proper selection of weight for the iioat 10, it has been found that the excess of water and concrete is squeezed to the sides of the oat and will escape there. A light float will not force even quite fluid concrete to flow in this manner. By providing sufficient weight, all of the surface is supported by the concrete, and the excess will be squeezed down into the bed material, or off to the sides. No slight rises remain.

lt has been found that in addition to the packing by the very weight of the oat l0, the smoothing of the entire pavement surface in one pass will produce a uniform smooth surface and does not draw the fine materials and moisture to the surface of the strip. Those who have worked with concrete will readily appreciate the fact that hand troweling of a concrete surface to finish that surface will tend to draw the moisture and tine material up to the surface of the concrete where it floats in pools of water. Upon drying and hardening, this fine material forms the top surface of the pavement. Such line material and excess of cement is an inferior top surface and will succumb 4 quickly to the action of weather and chemical de-icingI agents.A It has been found that after passing this heavy oat over the surface of a concrete roadbed, a smooth surface resulted as expected, but in addition it was found that the surface was of a normal mixture of concrete ingredients, rather than a concentration of iines and cement. This surface is far superior to surfaces heretofore produced in roadways which have been made by ther prior method pavement are familiar well upon the bed material.

of hand troweling.

Upon investigation it was found that the entire crosssection of the roadbed produced by this improved process and machine was far more dense and more closely associated with the bed material than had even been produced before the conventional methods. Therefore, the weight for the float lil is preferably such that non-flowing plastic concrete will yield under and before the oat as the float is dragged along the surface of the concrete strip.

Those acquainted with the construction of concrete with the practice of vibrating the forms 17 to reduce the honeycombing tendency of the concrete along the forms. Furthermore, long vibration rods are probed into the body of the freshly poured concrete in random spots in an attempt to settle the concrete Upon the addition of a vibrator 36 connected to the top surface of the sheet metal by means of a rod 37, the entire surface of the oat vibrated upon the surface of the concrete strip and not only settled the concrete firmly against the form 17, but ma- 'l terially improved the settling of the entire mass of concrete completely uniform and solid in all areas. Vibration methods previously used in random spots never 'carry the oat 10. The carriage into the bed structure. Therefore, upon the addition of vibrator 36 to this improved float, it was possible to produce a dense pavement cross-sectional structure which was The hand have acquired the uniformity of cross-sectional density that has been produced by the combination of this heavy float with vibration.

A carriage 20 has been constructed to conveniently has wheels 21 which are adapted to ride upon forms 17. The wheels are laterally adjustable, and even reversible, in order to accommodate the carriage 20 to any width of pavement or to place the anges on either side of the forms, as required. Towv brackets 22 are provided at both ends of the carriage 20 and are provided to draw a chain 23 which is suitably attached to the tloat 10. Thus, the iioat 10 is equipped with tow chains at both ends, and therefore, regardless of which direction the carriage 20 may travel, the iioat l@ is dragged l along by the chains 23. Obviously, the chains 23 will not carry the weight of the iioat 10, but only provide forwardI towing force. v

A sling construction 24 is provided to lift the -oat 10 being moved into or away from its place of work. The sling 24 includes eccentric brackets 25 mounted upon the carriage and tie rods 26 extending from the brackets to the iioat 10. In the drawings the tie rods 26fare suitably attached to the tops of two of the I ribs 13. A crank arm 28 and a hydraulic cylinder V29 are provided to rotate the links 25 and cause lifting or lowering of the iioat 10. The brackets 25 are carried on the four ends of two suitable rods 40. One rod 40 is directly driven by the crank arm 28, and the other rod 4t) is caused to rotate at the same time by connecting two or more of the brackets 25 together by means of links 27. By means of the sling construction thus described the float 10 may be lraised above the surface which supports the wheels 21, or may be released to rest upon that surface. Of course, if there were no surface to stop the downward movement of the float 10, the float would still be supported upon the sling 24, but normally the iioat is not lowereduntil it is above the surface to be smoothed, and therefore -will be supA ported upon the concrete strip rather than upon the sling.

The sling does not normally provide any downward force upon the carriage and is adapted to drive through a transmission 31, and also to drive a pump 32 for delivering hydraulic pressure to the cylinder 29 for operation of the sling 24. The operator of this machine may therefore vry easily lift and lower the iioat without manual e ort.

Two cable drums 33 are mounted at opposite sides of the carriage and are driven through the transmission 31. ln the embodiment of the invention illustrated, it has been chosen to drive the carriage 29 by means of cables 39 rather than to attempt to drive the wheels 21. The iioat 10 has considerable friction upon the surface of the concrete, and also will be held by air pressure differential. This phenomena is well understood by those familiar with concrete work. Accordingly, considerable force, and variable force, is required to drag the iioat It). For this reason cables 39 wound upon the drums 33 are employed for pulling the carriage Ztl. The cables are extended a considerable distance ahead of the carriage and secured in suitable pins. Thereafter, the operator winds the cable upon the drums 33 to move the carriage and drag the oat 10.

A beam 35 is mounted upon the carriage 2i? for aid in cleaning the finishing surface on the bottoni of the float it). In the end of its use, when the float is not to be used for a period of time, the carriage Ztl is moved beyond the end of the poured concrete and the float l() uncoupled from the sling 24. The carriage is then backed up and the cables 39 attached to the float. Thereafter, the drums 33 are rotated to pull the cables and lift the lioat into a position substantially as illustrated in dotted outline in the Figure 1. With the float l() standing on edge as thus illustrated in Figure 1, the bottom thereof is quite easily cleaned to preserve the smooth finishing surface.

No dimensions have been specified, because it has been found that the principles of this invention are applicable to substantially all paving widths. In small roadway paving projects, for example, large concrete mixing machines are not practical. Therefore, a small job will best be constructed of single width strips of about ten feet. The wheels of my machine are then set to ride the forms, and a single fioat 10 employed.

However, on large jobs, a double lane can be poured at one time. In that event the sheet metal il is divided by a knife edge 41. A cutter or colter 42, carried upon a bracket 43, precedes the iioat l0 and cleaves the concrete, thereby settling large fill material and generally preparing the concrete for the later finishing by the oat and knife ed e.

gThe cut thus made does not go through the entire bed of concrete, but forms a plane of weakness which will protect the divided portions against lateral cracking. The cut is filled with yieldable filler material in the conventional manner.

Although the invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and the scope of the invention as hereinafter clamped.

What is claimed is:

1. A road machine comprising a carriage supported upon wheels to ride on spaced road forms for a concrete roadway, an elongated float beneath said carriage extending from the forward portion to the rear portion of said carriage and connected to said forward and rear portions by means of tow means, said float including spaced beams and a flexible substantially rectangular plate with adjustable means connecting said plate to said beams whereby said plate can be flexed relative thereto, said plate being of less width than the distance between said wheels to rest and be supported directly on the concrete poured between said forms, supporting means connecting the front and rear ends of said fioat with said carriage, and controlled power means on said carriage for raising and lowering said supporting means simultaneously to a predetermined height to accurately control the height of said plate relative to said road forms.

2. A road machine comprising a carriage supported upon wheels to ride on spaced road forms for a concrete roadway, an elongated float beneath said carriage extending from the forward portion to the rear portion of said carriage and connected to said forward and rear portions by means of tow means, said float including spaced beams and a iiexible substantially rectangular plate with adjustable means connecting said plate to said beams whereby said plate can be iiexed relative thereto, said plate being of less width than the distance between said wheels to rest and be supported directly on the concrete poured between said forms, supporting means connecting the front and rear ends of said iioat with said carriage, controlled power means on said carriage for raising and lowering said supporting means simultaneously to a predetermined height to accurately control the height of said plate relative to said road forms, said power and supporting means including a piston operated sling linkage the piston of which may be deactivatable to relieve said float of support by said linkage and thereby impose the weight of said frame and plate upon said concrete.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,388,690 Baker Aug. 23, 1921 1,586,325 Older May 25, 1926 1,939,341 Edge Dec. 12, 1933 2,312,968 Heltzel Mar. 2, 1943 FOREIGN PATENTS Number Country Date 831,023 France of 1938

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