US3604325A

US3604325A - Machine for finishing concrete surfaces

Info

Publication number: US3604325A
Application number: US782147A
Authority: US
Inventors: John A Borges
Original assignee: Individual
Current assignee: Individual
Priority date: 1968-12-09
Filing date: 1968-12-09
Publication date: 1971-09-14
Anticipated expiration: 1988-09-14

Abstract

A machine for smoothing the surface of newly poured concrete including a float which is moved across the concrete surface by a carriage traveling back and forth on an overhead frame spanning the surface. The float is vertically self-adjusting and reciprocates lengthwise as it moves across the concrete surface. The machine also includes a tilt adjustment, pressure adjustment and skew adjustment for the float and means for lifting and lowering the float to the concrete surface.

Description

United States Patent Inventor John A. Borges 601 Duane Avenue, Oregon City, Oreg. 97045 Appl. No 782,147

Filed Dec. 9, I968 Patented Sept. 14, I971 MACHINE FOR FINISHING CONCRETE SURFACES 14 Claims, I0 Drawing Figs.

[52] US. Cl.... 94/45 [5|] Int. Cl EOIc 19/22 {50] Field of Search 94/45 {56] References Cited UNITED STATES PATENTS 2,650,525 1/1953 Jones 94/45 2,957,396 10/1960 Bederman 94/45 $094,048 6/ I 963 Hudis 94/45 3,208,361 9/ I 965 Bidwell 94/45 3,368,466 2/1968 Rowe 94/45 3,452,654 7/1969 Kessel 94/45 Primary Examiner-Jacob L. Nackenoff A!t0rneyBuckh0rn, Blore, Klarquist and Sparkman ABSTRACT: A machine for smoothing the surface of newly poured concrete including a float which is moved across the concrete surface by a carriage traveling back and forth on an overhead frame spanning the surface. The float is vertically self-adjusting and reciprocates lengthwise as it moves across the concrete surface. The machine alsoincludes a tilt adjustment, pressure adjustment and skew adjustment for the float and means for lifting and lowering the float to the concrete surface.

PATENTEU SEP] 4 |97| SHEET 1 BF 3 JOHN A. BORGES INVENTOR BUB/(HORN, BLORE, KLAROU/ST a SPAR/(MAN ATTORNEYS PATENTEUSEPWBH 3.604.325

SHEET 3 OF 3 JOHN A. BORGES /N 1 5 N T 0/? B) BUCKHOHW, BLORE, KLAROU/S T 8 SPAR/(MAN ATTORNEYS MACHINE FOR FINISHING CONCRETE SURFACES BACKGROUND OF THE INVENTION I. Field of the Invention The present invention relates to a machine for smoothing and compacting the surface of concrete bridge decks, roadways and other slabs.

2. Description of the Prior Art The manual float method of smoothing the surface of newly poured concrete has been used for many years. Its purpose is to smooth and compact the concrete surface to prevent checking and to provide the slab with a smooth, even surface after shrinkage. The concrete surface is smoothed according to the float method after the slab has been rodded off to grade and contour and after the newly poured concrete has taken an initial set.

Heretofore the float method of smoothing concrete has been a hand operation using a straight wooden plank with plow handles attached to its opposite ends. According to this method, the slab must be spanned with two longitudinally spaced foot walks suspended above the slab and spaced or 12 feet apart. Two men, one on each foot walk and at each end of the plank, drag the plank across the slab, see-sawing the float plank as they move it across the slab. Additional help is often required to pull the heavy float plank with ropes across the slab.

The foregoing method gives good results only if the operation is performed by experienced, skilled persons at the proper time. Moreover, the time and effort required in moving the foot walks along the slab and in pulling the heavy, cumbersome float plank limits the use of the hand method to small pours of concrete. Nevertheless, highway bridge specifications of several states require that this type of float finish be used to attain small surface tolerances of, for example, one-eighth inch in 10 feet.

Machines have been suggested for smoothing the surface of concrete, but such prior machines have not been capable of duplicating or approaching the smooth and compact surface obtained using the above-described manual float finishing method.

SUMMARY OF THE INVENTION The present invention provides a machine for applying a smooth float finish to the surface of concrete of a quality formerly obtained only by persons highly skilled in using manually operated wooden floats. The machine powers a long wooden float across a concrete surface to be finished while simultaneously reciprocating the float in a direction lengthwise of the float and while the float adjusts itself automatically to the contour and grade of the surface. The machine itself is powered for movement along the slab to be finished. Float tilting means are provided for changing the angle of attack of the float with respect to the concrete surface, and additional means are provided for skewing the float with respect to its direction of travel. A single operator controls the finishing operation, including the tilt of the float, and raising and lowering of the float with respect to the surface of the concrete, and the float travel from an operator's platform on an overhead carriage from which the float is suspended. The machine enables the smoothing operation to be carried out by one person, in a minimum time and with minumum effort, making practical the application of the float finishing method to large surface areas which heretofore could not be float finished practically by hand.

BRIEF DESCRIPTION OF THE DRAWING The foregoing features and advantages of the present invention will become more apparent from the following detailed description which proceeds with reference to the accompanying drawings wherein:

FIG. 1 is a foreshortened side elevation of an apparatus in accordance with the present invention;

FIG. 2 is an end elevation of the apparatus of FIG. I taken along the line 2-2 of FIG. I, on an enlarged scalc and foreshortened in width;

FIG. 3 is a vertical sectional view taken approximately along the line 33 of FIG. I on a scale slightly reduced from that of FIG. 2;

FIG. 4 is a vertical sectional view taken approximately along the line 4-4 of FIG. 3 on thesame scale as FIG. 3;

FIG. 5 is a vertical sectional view taken along the line 55 of FIG. 4 on the same scale as FIG. 4;

FIG. 6 is a vertical sectional view taken along the line 66 of FIG. 4 on a scale enlarged from that of FIG. 4;

FIG. 7 is an enlarged elevational view, partly in section, of the lower float assembly portion of the apparatus shown in FIG. 3;

FIG. 8 is a vertical sectional view taken along the line 8-8 of FIG. 7 on the same scale as FIG. 7;

FIG. 9 is a horizontal sectional view taken along the line 9- I DETAILED DESCRIPTION General Assembly With reference to the drawings, FIG. 1 discloses the apparatus of the invention including a generally rectangular overhead frame structure 10 which spans the width of a section of newly poured concrete, bridge deck, highway pavement, or other slab 12, the surface of which is to be finished. The frame structure includes a pair of longitudinal side frame members 14 and end frame members 16 (FIG. 2) supported at each of its four corners by legs 17 on grooved wheels 18 which travel on a pair of tubular tracks 20 laid alongside the opposite sides of the slab. As shown best in FIGS. 2 and 3, side frame members 14 have inverted angle members affixed to their upper surfaces to define a pair of tracks 22 on which wheels 24 of a carriage 26 are guided as the carriage travels back and forth along the frame over the slab to be finished.

A long, straight, rectangular float member 28 rests of its own weight on the surface of the slab l2 and is dragged across the slab surface during movement of carriage 26 back and forth on overhead frame 10 to compact and smooth such surface. The float member is mounted for self-adjusting vertical movement and for see-sawing movement lengthwise of the float as it moves across the slab surface by a float mounting means 30 suspended by a pair of vertical hangers 32 from the carnage.

Float Assembly and Mounting Referring particularly to FIGS. 3, 7 and 8, the float member includes a long, straight wooden plank 34 having one of its flat broad surfaces in contact with and normally resting upon the surface of the slab 12 to be finished. The plank may extend for a length of 10 feet or more and has an upright metal channel member 36 bolted to the upper surface of the plank along its longitudinal centerline. The channel itself is capable of receiving metal weights whereby a variable pressure can be applied to the concrete surface by the float. The float mounting means 30 includes vertical slide means which permits the float plank to adjust itself vertically to the surface grade and contour of the concrete as it rides over the surface. Such slide means includes a pair of vertical slide rods 38 connected at their lower ends at 39 to the opposite ends of float channel 36 and a pair of vertical sleeves 40 carried by the mounting means 30 for slidably receiving slide rods 38. From FIG. 8 it will be evident that with this arrangement float mount 30 can travel in a straight horizontal path as induced by the carriage while the float follows an independent path determined by the grade and contour of the slab surface.

Referring to FIGS. 8 and 9, each guide sleeve 40 is fixed, as by welding, to an enlarged end 41 of a threaded bolt 42 which extends through a horizontal pipe section 43 and is secured at its opposite end by a nut 44 which abuts an enlarged end 45 of pipe 43 to apply an adjustable tension to the bolt. In this manner guide sleeve 40 and thus the float structure can be provided with a certain lengthwise flexibility during reciprocation of the float to prevent damage to the float mounting and drive means. Each horizontal pipe section 43 is fixed to one of a pair of rectangular horizontally slidable members 47 mounted for sliding movement along an elongated guideway 48 of rectangular cross section.

Stub shafts 50 projecting from the opposite ends of guideway 48 extend through opposite end channel members 52, which, together with a pair of side channel members 54, define a rectangular box frame portion of the mounting means. Guideway 48 is secured to end members 52 of the box frame by nuts 56 threaded onto stub shafts 50. Stub shafts 50 also project through openings in the lower ends of the hanger members 32 and are limited in their longitudinal sliding movement by collars 58, 59 secured to stub shafts 50 on opposite sides of each hanger 32. This enables the entire mounting assembly 30, including the box frame and its supported guideway, slides, float guide means and float, to pivot together about the axes of stub shafts 50 from hangers 32.

The box frame of the mounting assembly 30 also supports a pair of

angle members

61, 62 as shown in FIGS. 7 and 8, which together serve as a base to which a speed reduction unit 64 of an electric motor 66 is fastened to support both the speed reducer and the motor. Motor 66 drives a crank wheel 68 through the speed reduction unit, and the crank in turn is connected by a connecting rod 70 to one of sleeves 47 to translate rotary motion of the crank disc to reciprocating movement of the connected slide 47 along guideway 48. The driven slide 47 is in turn connnected by a tie rod 72 to the other slide 47 whereby both slides reciprocate in unison thereby inducing a see-sawing motion on the float as it is moved across the slab by the carriage.

Float Tilt and Lift Means As previously indicated, the entire mounting assembly 30 is mounted for pivotal movement on stub shafts 50 relative to hangers 32 to enable tilting of the float plank 34 horizontally in a fore-and-aft direction to change the angle of attack of the float plank with respect to the surface of slab 12. The means provided for tilting the mounting assembly includes a long vertical rod 76 shown most clearly in FIGS. 1, 3 and fixed at its lower end to one of side channels 54 of the box frame. Stub shafts 50 are offset on one side of the longitudinal centerline of the box frame, as clearly shown in FIG. 8, and rod 76 is offset on the opposite side of such centerline, thereby increasing the leverage effect of rod 76 and thus the ease of tilting the float assembly about the pivot axis of the assembly.

Rod 76 extends upwardly to an upper terminus above carriage 26. A horizontally disposed handlebar 78 is pivoted nearer one end than the other to the upper end of rod 76. The other end of the handlebar is connected by a tie rod 82 to the outer end of a horizontally extending bar 80 pivoted to rod 76 below the handlebar. Bar 80 is notched at intervals along its lower edge for selective locking engagement with an upwardly extending licking member 84 fixed to one of hangers 32 on the carriage. When notched bar 80 is lifted by handlebar 78 out of locking engagement with bar 84, the upper end of rod 76 can be moved easily horizontally, which in turn effects a pivoting movement of the float mounting assembly about the pivot axes of stub shafts 50 to change the angle of tilt of the float with respect to the concrete surface. When the desired tilt is achieved, the notched bar 80 is dropped onto locking bar 84 by pivoting the long end of handle 78 downwardly, thereby locking rod 76 and thus the float plank in their adjusted positions.

Means are also provided for lifting and lowering the float plank into contact with the surface of the concrete slab, as shown in FIG. 3.. Such means includes an upstanding frame structure 86 on a platform portion 88 of carriage assembly 26 and a hand-operated winch 90 mounted at operator height at the upper end of frame 86. A cable 92 on the winch drum (not shown) extends downwardly through the carriage assembly to a connection 93 with a pair of

branch cables

94, 95, which diverge downwardly from connection 93 to

connections

96, 97 with channel portion 36 of float member 28. By passing out or taking in cable 92 with winch 90, float plank 34 can be lowered to or lifted from contact with the slab surface. A spring 99 extends between main cable 92 and an arm on the frame to take up slack in the cables when the float is resting on the slab.

Carriage Assembly Carriage 26 includes an open rectangular base 98 formed of four channel members as shown in FIGS. 4 and 5. The base mounts axle members 100 which rotatably mount carriage wheels 24. The upper side of base 98 supports an annular turntable 102 having a channel-shaped cross section. Circular platform 88 is positioned within annular turntable 102 and is mounted in a manner whereby the platform remains stationary while the turntable may be rotated within limits. To this end turntable 102 includes a series of four brace bars 104 which radiate from the center of the space within the turntable to the inner periphery thereof where they are secured to annular channel 102. The brace bars are held together at the center of the turntable by an upper bearing plate 106. Brace bars 104 lie just beneath platform 88 and restrain the platform against any appreciable tilting movement.

A lower bearing plate 108 in face-to-face engagement with upper plate 106 is fixed to a pair of parallel and horizontally spaced angle members 110, 111 which extend the width of base 98 and are secured at their opposite ends to the side channels of the base. Thus the platform is-supported through the bearing plates and angle members by base 98. A stop bar 112 extends downwardly from the underside of platform 88 between angle members 110, 111 of the base to prevent movement of the platform 88 when turntable 102 is rotated. A kingpin 114 extends downwardly through an opening in platform 88, between brace bars 104, through bearing

plates

106, 108, and between angle members 110, 111. The kingpin has a nut 116 threaded on its lower end which tensions the pin when screwed against washers 1 18 and a large abutment plate 120 fixed to the two angle members 110, 111. The nut has a pair of handle rods as shown in FIG. 4 to facilitate its loosening and tightening by hand.

When the kingpin is placed in tension by tightening nut 116, turntable 102 cannot be rotated. When the nut is loosened, the turntable can be rotated about the kingpin, while at the same time stop 112 prevents rotation of platform 88. As shown in FIG. 5, the upper ends of float hangers 32 are fixed to the rotatable turntable 102. Thus, by rotating the turntable slightly the entire float mounting assembly and the float can be oriented on a skew with respect to the direction of travel of the float and carriage across slab 12.

Platform 88 mounts not only frame 86 for the float lifting winch 90 but also a reversible electric motor 122 for powering the carriage back and forth on frame 10 across the slab. Electric motor 122 may be automatically reversed via limit switches (not shown), or its reversing action may be manually controlled by a control 124 mounted on winch stand 86. The carriage motor includes a pulley wheel 126 about which one wrap of a horizontally extending cable 128 is trained. As shown in FIG. 1, cable 128 is anchored at one end of frame 10 on a post 130, and is wound on the drum of a post-mounted hand winch 132 at the oppositeend of the frame to enable adjustment of the tension in the cable. Upon rotation of pulley 126 the carriage is pulled along cable 128.

Electric power for operating float motor 66 and carriage motor 122 is supplied from an external source such as, for example, a gasoline-powered generator near the machine, and is conducted to the carriage through a conductor cable 134 suspended from a support wire 136. Wire 136 is supported by high posts at the opposite ends of frame as shown in FIG. 1. A cantilever beam 138 on winch stand 86 suspends a spring support 140 from its outer end, and the support in turn supports a portion of support wire 136. Beam 138 also serves as a retainer and support for conductor cable 134 which may be wrapped about the beam as shown in FIG. 3 as it extends to control 124 and then to the motors.

Frame Adjustments Frame 10 itself contains several adjustments which increase the versatility of the machine. First, with reference to FIG. 2, it will be noted that each leg 17 is telescoping and includes an internal jack operated by a crank handle 142 at the top of the leg whereby the height of the overhead frame above the slab can be varied. Furthermore each leg 17 is rigidly affixed to one of the two box-shaped longitudinal side frame members 14 by a U-bracket 144. Bracket 144 is held in a preselected position along a side frame member by clamp bolts 145. By loosening the bolts, each leg may be slid along its frame member to any desired position to vary the effective length of the machine to accommodate any width of slab up to the maximum length of the longitudinal frame members. This same feature together with telescoping lower leg braces 146 at opposite ends of the frame enable the longitudinal frame members l4 and thus the carriage and float to be oriented on a skew with respect to the side edges of slab 12 while at the same time frame 10 is capable of travel lengthwise parallel to the slab. Setscrews 147 on the leg braces hold the leg braces at any desired length. The need for operating the frame on a skew is encountered in certain types of construction, such as on bridge approaches which intersect the bridge deck at an angle.

One wheel 18 at each end of the frame is powered by a chain and sprocket drive 149 from an electric motor 150 mounted on a platform 152 at the base of a leg 17. An appropriate control panel (not shown) may be mounted on one end of the frame for controlling the operation of the frame wheel motors 150 whenever it is desired to move the frame along the slab.

Operation In operation pipe tracks 20 are laid parallel and close to the opposite side edges of a slab 12 to be finished, such as a bridge deck or roadway. The frame is then set up for movement along the track intermittently by operation of wheel motors 150. The width of a section of slab that may be smoothed at one time is determined, of course, by the length of the float plank itself. The surface of the slab is not smoothed until after the slab has been poured, the fresh concrete has been rodded off to grade and contour either by hand or by any one of a number of finishing machines for this purpose, and after the freshly poured concrete has taken its initial set. When this has occurred, the float is lowered into contact with a section of the slab surface to be finished, using hand winch 90, and the float is allowed to rest on the surface under its full weight, which may be varied by securing weights to the float channel 36.

The carriage motor 122 and float reciprocating motor 66 are energized by the operator standing on platform 88. Carriage 26 moves back and forth on frame 10, moving float 28 with it across the surface of the concrete in a see-sawing motion. However, the control of the carriage and float motors is such that either motor can be operated independently of the other so that the float can be moved across the slab without a see-sawing motion if desired, or so that the float can be reciprocated lengthwise at one spot on the concrete while the carriage remains stationary. The pin and sleeve mount of the float enables it to conform to the general contour and grade of the concrete surface as it travels across the surface with its see-sawing motion.

The carriage travels back and forth across the same section of slab as many times as may be necessary to lay down and remove all high places and fill all low spots in the surface.

When the desired surface finish of one section of the slab has been obtained, the float is lifted from the surface using cable winch 90, the carriage and float motors are stopped, and the frame is moved longitudinally of the slab approximately'onehalf the length of the float. Thus, for example, if the float will smooth a 10-foot swath in one position ofthe frame, the frame is moved longitudinally at 5-foot intervals. When the frame has been moved, the entire operation is repeated, and then the frame is moved at subsequent intervals until the entire surface of the slab has been smoothed.

A single man can handle the entire operation with ease while riding the platform of the carriage. From the carriage, the operator has complete control of the operation of the carriage and float motors, float tilt and float lift.

Having illustrated and described apreferred form of the invention, it should be apparent to those having skill in the art that the same permits of modification in arrangement and detail. I claim as my invention all such modifications as come within the true spirit and scope of the following claims.

1. ln an apparatus for finishing a concrete surface including an overhead frame structure spanning the width of said surface and movable lengthwise thereof, and a carriage movable on said frame structure across said surface,

a float structure for smoothing the concrete surface comprising:

a float member adapted to engage the concrete surface,

float-mounting means positioned above said float member and mounting said float member so as to be self-supporting on said surface, said mounting means including vertical slide means interconnecting said mounting means and said float member so as to permit self-adjusting vertical movement of said float member as determined by the contour and grade of said surface while controlling horizontal movements of said member, said vertical slide means including vertically extending slide rod means and guide sleeve means slidingly receiving said rod means, one of said sleeve and rod means being connected to said float member and the other being connected to said mounting means, said mounting means including horizontally slidable means mounting said vertical slide means for horizontal reciprocation in a direction lengthwise of said float member,

float-reciprocating means carried by said mounting means for reciprocating said horizontally slidable means and thus said vertical slide means and said float member generally horizontally,

and means suspending said mounting means from said carriage whereby travel of said carriage on said frame moves said float member across the concrete surface during reciprocating and self-adjusting vertical movement of said float member.

2. Apparatus according to claim 1 wherein said float member comprises an elongate flat straight member having leading and trailing edges as determined by the direction of travel of said carriage,

said reciprocating means reciprocates said member lengthwise,

said means suspending said mounting means including means mounting said mounting means for pivoting movement about a horizontal axis of said mounting means extending lengthwise of said float member,

and vertically movable means on said carriage and pivotally connected to said mounting means at a position offset from said horizontal axis for tilting said mounting means and thus said float member about said axis so as to change the height relationship between said leading and trailing edges.

3. Apparatus according to claim 1 including winch on said carriage means for raising said float member from the concrete surface and for lowering said float member into contact with said surface.

4. Apparatus according to claim 1 including vertically movable means on said carriage and connected to said mounting means for tilting said mounting means and said float member about an axis extending generally parallel to a leading edge of said float member and winch means on said carriage for lifting said float member from the surface of said concrete.

5. Apparatus according to claim 1 including skewing means forvarying the angular orientation of said float member with respect to said concrete surface in a generally horizontal plane whereby said float member can be moved across said surface while skewed with respect to the direction of travel of said carriage, said skewing means including turntable means on said carriage shiftable about a vertical axis, said means suspending said mounting means being connected to said turntable means whereby shifting of said turntable effects a skewing of said mounting means and thus said float member.

6. Apparatus according to claim 1 wherein said carriage included an operator's platform, motor means carried by said platform, pulley wheel means driven by said motor means, and pulley cable means for moving said carriage along said frame, and control means mounted on said platform for controlling the operation of said motor means and thus said carriage.

7. Apparatus according to claim 6 wherein said float member includes an elongate, straight member having a broad flat bottom surface, lifting means on said carriage and connected to said float member for lifting said float member from the concrete surface, tilt means on said carriage and connected to said mounting means for varying the angular relationship of the bottom surface of said float member to the concrete surface to be finished, and tilt and lift control means accessible from said platform for controlling said lifting means and said tilting means.

8. An apparatus for smoothing a concrete surface comprising:

an overhead frame structure for spanning the width of the concrete surface to be smoothed and supported on wheeled legs at its opposite ends for travel lengthwise of said surface,

a carriage movable on said overhead frame structure across said surface,

an elongate float member for smoothing the concrete surface,

and float-mounting means depending from said carriage mounting said float member for self-adjusting vertical movement as determined by variations in grade and contour of said surface and for horizontal reciprocating movement lengthwise of said float member,

said float-mounting means including a horizontally reciprocative member slidable lengthwise of said float member, vertical guide sleeve means carried by said reciprocative member, and slide rod means extending vertically from said float member and slidable within said guide sleeve means.

9. Apparatus according to claim 8 wherein said legs supporting said frame structure are extensible for adjusting the height of said frame structure above the surface to be smoothed.

10. Apparatus according to claim 8 including power means drivingly connected to at least one of said wheeled legs for driving said frame structure lengthwise of said surface.

11. Apparatus according to claim 8 including means for adjusting the position of said legs along the length of said frame structure for varying the effective length of said frame structure to accommodate varying widths of concrete surfaces and to enable the skewing of said overhead frame structure with respect to the direction of travel of said structure.

12. Apparatus according to claim 1 wherein said slide means permitting vertical self-adjustment of said float member includes an upright sleeve member carried by a horizontally reciprocative portion of said mounting means and an upright slide member extending upwardly from said float member and slidable within said sleeve member.

13. Apparatus according to claim I wherein said means for reciprocating said float member included a horizontal guide member, said horizontally slidable means being mounted for slidin movement along said guide member,

sai horizontally slidable means pivotally mounting said guide sleeve means,

said slide rod means being pivotally connected to said float member and slidable within said vertical guide sleeve means,

motor means carried by said mounting means,

and float drive means drivingly connected to said horizontally slidable means and said motor means for reciprocating said horizontally slidable means back and forth on said guide member.

14. Apparatus according to claim 8 wherein said carriage comprises:

a wheeled base movable on said frame structure,

a turntable supported on said base for turning movement about a vertical central axis relative to said base,

and an operator platform supported by said base and restrained against turning movement relative to said base,

and hanger means extending downwardly from said turntable supporting said float-mounting means.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,604,325 Dated September 14 1971 Inventofls) JOHN BORGES It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 3, line 61, "licking" should be -locking; Column 5, line 29, "Setscrews" should be --Set screws--; Column 6, lines 70-71, claim 3, "including winch on said carriage means" should be -including winch means on said carriage; Column 7, line 16, claim 6, "included" should be --includes-; Column 8, line 25, claim 13, "included" should be --includes--.

Signed and sealed this 21st day of March 1972.

(SEAL) Atte'st:

EDWARD M.FLETCHER, JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents M 90-1050 (10-69) UsCOMM-DC aoa'rs-pn

Claims

1. In an apparatus for finishing a concrete surface including an overhead frame structure spanning the width of said surface and movable lengthwise thereof, and a carriage movable on said frame structure across said surface, a float structure for smoothing the concrete surface comprising: a float member adapted to engage the concrete surface, float-mounting means positioned above said float member and mounting said float member so as to be self-supporting on said surface, said mounting means including vertical slide means interconnecting said mounting means and said float member so as to permit self-adjusting vertical movement of said float member as determined by the contour and grade of said surface while controlling horizontal movements of said member, said vertical slide means including vertically extending slide rod means and guide sleeve means slidingly receiving said rod means, one of said sleeve and rod means being connected to said float member and the other being connected to said mounting means, said mounting means including horizontally slidable means mounting said vertical slide means for horizontal reciprocation in a direction lengthwise of said float member, float-reciprocating means carried by said mounting means for reciprocating said horizontally slidable means and thus said vertical slide means and said float member generally horizontally, and means suspending said mounting means from said carriage whereby travel of said carriage on said frame moves said float member across the concrete surface during reciprocating and self-adjusting vertical movement of said float member.

2. Apparatus according to claim 1 wherein said float member comprises an elongate flat straight member having leading and trailing edges as determined by the direction of travel of said carriage, said reciprocating means reciprocates said member lengthwIse, said means suspending said mounting means including means mounting said mounting means for pivoting movement about a horizontal axis of said mounting means extending lengthwise of said float member, and vertically movable means on said carriage and pivotally connected to said mounting means at a position offset from said horizontal axis for tilting said mounting means and thus said float member about said axis so as to change the height relationship between said leading and trailing edges.

5. Apparatus according to claim 1 including skewing means for varying the angular orientation of said float member with respect to said concrete surface in a generally horizontal plane whereby said float member can be moved across said surface while skewed with respect to the direction of travel of said carriage, said skewing means including turntable means on said carriage shiftable about a vertical axis, said means suspending said mounting means being connected to said turntable means whereby shifting of said turntable effects a skewing of said mounting means and thus said float member.

6. Apparatus according to claim 1 wherein said carriage included an operator''s platform, motor means carried by said platform, pulley wheel means driven by said motor means, and pulley cable means for moving said carriage along said frame, and control means mounted on said platform for controlling the operation of said motor means and thus said carriage.

8. An apparatus for smoothing a concrete surface comprising: an overhead frame structure for spanning the width of the concrete surface to be smoothed and supported on wheeled legs at its opposite ends for travel lengthwise of said surface, a carriage movable on said overhead frame structure across said surface, an elongate float member for smoothing the concrete surface, and float-mounting means depending from said carriage mounting said float member for self-adjusting vertical movement as determined by variations in grade and contour of said surface and for horizontal reciprocating movement lengthwise of said float member, said float-mounting means including a horizontally reciprocative member slidable lengthwise of said float member, vertical guide sleeve means carried by said reciprocative member, and slide rod means extending vertically from said float member and slidable within said guide sleeve means.

13. Apparatus according to claim 1 wherein said means for reciprocating said float member included a horizontal guide member, said horizontally slidable means being mounted for sliding movement along said guide member, said horizontally slidable means pivotally mounting said guide sleeve means, said slide rod means being pivotally connected to said float member and slidable within said vertical guide sleeve means, motor means carried by said mounting means, and float drive means drivingly connected to said horizontally slidable means and said motor means for reciprocating said horizontally slidable means back and forth on said guide member.

14. Apparatus according to claim 8 wherein said carriage comprises: a wheeled base movable on said frame structure, a turntable supported on said base for turning movement about a vertical central axis relative to said base, and an operator platform supported by said base and restrained against turning movement relative to said base, and hanger means extending downwardly from said turntable supporting said float-mounting means.