US3256788A - Concrete screeder - Google Patents

Description

June 21, 1966 J. L. scHwElHoFER ETAL. 3,256,788

CONCRETE SCREEDER Filed oct. 17, 1962 @7 "Ef/Mimi! INVENTOR)` ATTORNEY basements, slabs and the like.

United States Patent() 3,256,788 CONCRETE SCREEDER James L. Schweihofer, 6887 Marsh Road, China Township, St. 'Clair County, Mich., and'David C. Schweihofer, 5869 St. Clair Highway, Cotterville Township, St. Clair County, Mich.

Filed Det. 17, 1962, Ser. No. 231,217

Claims. (Cl.9445) This invention relates to concrete surfacing devices in general and more particularly to devices Ifor leveling and surfacing freshly poured concrete.

For many years, concrete floors, driveways, sidewalks and the like have been leveled and surfaced by the simple expedient of drawing a two-by-four back and `forth between marginal dening forms. The marginal form-s or guides are set to the desired level of the surface to be provided, the concrete is poured between the. forms in a suitable abundance to provide some excess, and the twoby-four is worked as a 'screed back and forth while it is moved Iforward. The screed serves to ystrike off the excess concrete, move it `forward into any voids, and to work the cement and fine aggregate in the concrete to the surface to provide a reasonably level and rough finish surface which may be later Worked with a suitable finishing machine.

Large roadways are more expeditiously prepared by the use of large and heavy road machines which travel on side rails suicient to ysupport their weight. machines are exceptionally large and expensive and are ordinarily suited only for road building purposes.

As will be appreciated, there is a need for concrete sur facing equipment which is power operated, compact, sufciently lightweight to be reasonably portable, and such as may be set up and manipulated in close quarters .for Such equipment must be versatile enough to also handle driveways and sidewalks of different widths and those including offsets and curvatures. It must vibrate, agitate or otherwise serve to pack the concrete to a reasonably level and smooth uished surface, accommodate a range of widths an dbe capable of operation by unskilled laborers in a proficient and expeditious manner.

It yis with these objects in mind that the following machine has been provided and is here offered for consideration.

The concrete finishing machine of this invention includes a backbone frame member which is supported and carried on a pair of parallel spaced and relatively reciprocal screeds. The screeds are operated by vdrive means provided on the frame member and are reciprocal under the frame member which they support.

In the description which yfollows it will be appreciated that the weight of the frame member is balanced on the screeds to ikeep them in working contact with the concrete as excess concrete is carried forward and the surface is Worked to |bring the cement and small aggregate 4up to provide a better surface finish.

The screeds are reciprocated back and forth and each, rather than just one thereof, is moved axially of the frame as the machine is moved across the work surface. Such relative reciprocal motion is imparted to the screeds by a balanced eccentric drive provided on the backbone frame and operatively connected to each of the screeds.

The structural arrangement of a preferred embodiment of this invention will be best understood and better appreciated, as will the numerous objects and advantages obtained thereby, upon a reading of the following specification having reference to the accompanying drawing.

In the drawing: v

FIGURE 1 is a top plan view of a concrete finishing machine embodying the principles of this invention.

ice

FIGURE 2 is a fragmentary and enlarged perspective view of the iinishing machine shown by FIGURE 1.

FIGURES 3 and 4 are enlarged and fragmentary crosssectional views of different details as seen in the plane of the respective sectional lines shown in FIGURE 1.

FIGURE 5 is an enlarged cross-section of the handle mechanism as seen in the plane of 5-5 of FIGURE 1.

FIGUR-ES 6 and 7 are enlarged cross-sectional details of certain structural features of the machine shown by FIGURE il as seen in the respective planes of the section lines provided thereon.

FIGURE 8 is a perspective view of a modification to the backbone member.

The concrete finishing machine 10 shown by the drawing includes a frame member 12 which is supported upon a pair of parallel spaced screeds 14 and 16. Drive means 18 are provided on the frame member 12 to operate the -screeds 14 and 16 as the machine vv10 is pulled by the handle 24 transversely over the marginal guides 20 and l22.

As will be appreciated, the marginal guides 20 and -22 are spaced to define an area between which is poured the concrete material to be worked by the machine 10. In most instances a sufiicient amount -of freshly deposited concrete is provided between the marginal guide-s 20 and 22 to provide some excess which is carried and worked forwards as the machine is advanced to till in any Ivoids and depressions. vAs the machine is manually advanced, the drive means i18 serve-s to operate the screeds 14 and 16 back and forth. This agitates the concrete and provides a level surface while working the cement and iine aggregate towards the work surface -as necessary to provide a more finished and smooth exterior surface.

The frame member 1.2 includes a backbone frame member 26 having cros's frame members 28 and 30 provided in the plane and transversely across the ends thereof. The cross frame members 28 and 30 provided in the plane and transversely across the ends thereof. The cross frame members 28 and 30 are notched on the underside thereof, as shown by FIGURES 3 and 4 at 32, to receive the screeds 14 and 16. Depending lguides 34 are welded to the end of the Cros-s members 28 and -30 to provide a saddle over the screed members. Trunnion supports 36 are provided on the ends of the cross members 28 and 30 for rollers 38 which ride on the top edge of the screeds and support the frame in rolling engagement therewith.

The screeds 14 and 16 may be standard straight-edged two-by-fours but are -preferably hollow-rectangular aluminum members. Such metal screeds have a longer serviceable life, are less subject to wear and are lighter in weight for easier handling and responsive operation as will subsequently be appreciated. In the discussion which follows it will also be appreciated that different sets of screeds may be used to service work areas of different widths. That is, the screed operating framework 12 may be used with longer screeds than those shown, or shorter ones, to accommodate driveways in one instance and perhaps sidewalks in another.

The drive means 18 provided on the frame 12 includes,l

in this instance, an electric motor 40 mounted on the backbone member 26 on a supporting pla-te 42. The

4motor 40 is connected to a right angle drive gear box 46 which is mounted in a cradle 44 provided within the backbone frame member 26. The motor is connected to the input shaft of the gear box 46 by a drive belt and pulley arrangement 48. Although not shown, multiple pulleys may fbe employed to obtain variable speed drive.

The output or drive lshaft 50 of the gear box 46 extends on opposite sides of the backbone vmember 26 and has crank arms 52 and 54 provided on the ends thereof.

The crank arms are connected to operator arms 56 and 58 which are in turn engaged -to the screeds 14 and 16. This is accomplished by means of a saddle mount 60 received on the screeds and including a transversely disposed pin 62 to which the operator arms are engaged. The saddle mounts 60 are removably secured to the screeds by retainer pins or bolts 64.

The cradle support 44 for the gear box 46 disposes the output shaft 50 relatively lower on the frame 12 to avoid any lifting of the screeds 14 and 16 as the crank arms 52 and 54 are rotated. As will be appreciated, the youtput or drive shaft 50 is disposed so that the arc through which the crank arms 52 and 54 -travel does not cross the lower edge of the screeds 14 and 16.

The handle 24 is provided on the machine 10 to enable pulling the machine manually over the work area. The handle brackets include U-shaped |cross member 66 provided on the backbone frame member 26 and include strengthening braces 68. A rod 70 is secured between the upturned ends of the handle support 66 and the handle is connected to a simple carriage device that travels between the ends of the rod. In the present instance this includes a sleeve 72 on the rod 70 with side walls 74- between which the end of the handle is pivotally connected and which also accommodate limit stops 76 which hold the handle at an elevated position out of the concrete when it is not in use.

Suitable operating controls 78- are provided on the handle member 24 and are connected by leads 80 to the drive motor 40. This enables the motor to be operated by the laborer vwho is pulling the machine over the work surface.

From the preceding description it will be appreciated that the frame member 12 is supported on the screeds 14 and 16 in a manner providing relative rolling engagement of the screeds thereunder. The weight of the frame 12, and drive means 18 is normally suiiicient to held the screeds 14 and 16 on the marginal guides 18 while the machine is moved across the work surface. Although the drive means 18 are shown as provided near one end of the backbone frame member 26, it will be appreciated that the drive means might be provided centrally with the operator arms 56 and 58 connected to the screeds 14 and 16 near the ends thereof. This would provide for better weight distribution in certain instances but it has been lfound in practice that operational engagement of the screeds more centrally between the marginal guides 26 and 22 provides for better operational control.

In those instances in which weight distribution is likely to be a problem, as in covering longer spans, additional weight may be provided on the other end of the frame (not shown) or lift stops 82 may be secured to the tops of the screeds 14 and 16 and disposed to overlie'the guide rollers 38, as best shown Iby FIGURE 7.

Another modification which needs very little comment, includes the possibility of having the backbone frame member 26 include telescopic parts 84 and 86, as shown by FIGURE 8, whereby the length thereof may be shortened. In those instances in which the telescoping connection is provided between the handle brackets 66 it is obvious that the connecting handle parts should also be telescopic.

The assembly and operation of the subject device is as follows:

The marginal guides fand 22 are disposed to frame the area which is to have the concrete poured therebetween. They are set at the level of the floor or surface to be provided.

The screeds 14 and 16 are disposed in parallel spaced relation transversely across and between the marginal guides 20 and 22. The frame member 12 is then set on the screeds 14 and 16 with the cross frame members 28 and 30 extending therebetween and the rollers 38 on the ends of the cross members engaged with the top edges of the screeds. The operator arms 56 and 58 are engaged with the pins 62 on the screed connecting saddle brackets 60 and the brackets are positioned on the screeds and secured thereto.v

As will be appreciated, the screeds vand the backbone member are moved relatively in assembly as necessary to orient the saddle bracket 60 with the amperture through the sides of the screeds 14 and 16 through which the bracket fastener pin or bolt 64 is received.

In those instances in which lift stops 82 are provided on the screeds 14 and 16, the cross member 30 of the frame 12 should be disposed thereunder before the operator arms are connected to the screeds.

From the foregoing it will be appreciated thatV the assembly of the subject device is exceptionally simple and quick to accomplish at the site of use. Similarly, the

Vequipment may be disassembled and readily moved to another location for use whenever desired.

It is preferably to have the marginal guides 2t) and 22 extend slightly beyond the area to be Worked by the concrete finishing machine 10. This enables the forwardly disposed screed 14 to come first into contact with the excess concrete and to carry it forward into any voids or depressions. The rearwardly disposed screen 16 will serve a like purpose for any concrete excess between the screeds but if most of the excess has been handled by the forwardly disposed screed 14 the rearwardly disposed screen affords a secondary working of the concrete and assures a smoother and more professionally finished surface. Also, it is preferable to avoid any accumulation of concrete between the screeds which might build up on the lead edge of the rearwardly disposed screed 16 and interfere with the operation of the operator arm connected thereto. n

As the operator pulls the finishing machine 10 across the work area, by means of the handle 24, he is able to operate the motor 40 by means of the controls 78 provided on the handle. Accordingly, the forward motion of the machine is such as the experienced operator appreciates will best work the concrete surface to the desired` extent. It may be found expeditions to work the area rough in one direction and to travel the machine back over the rough surface for a more thorough finishing job.

Although a preferred embodiment has been shown and described, it will be appreciated that certain modifications and improvements are foreseeable and readily within the scope of the invention set forth. Such of these irnprovernents and modifications as are not specifically excluded by the wording of the hereinafter appended claims are to be considered as inclusive thereunder.

' We claim:

1. A concrete surfacing device, comprising: a pair of screeds disposed in parallel spaced relation and having a frame member received and slidably supported thereon and therebetween, said screeds being each reciprocal relative to each other and to said frame member, .and common operative means provided on said frame member and connected to each of said screeds for relatively opposite and simultaneously reciprocation of said screeds with respect to said frame member.

2. A concrete surfacing device, comprising: a pair of screeds disposed in -parallel spaced relation, a drive motor supporting frame provided between said screeds and including a backbone frame having :cross frame members received and slidably supported on said screeds, and drive means provided transversely on said backbone frame and connected at opposite ends to different of said screeds for simultaneous reciprocating activation of said screeds and said drive means including balanced eccentric throws connected to said screeds.

4. The concrete surfacing device of claim 2: said drive means including a motor axially mounted on said backbone frame, and a right angle gear drive means mounted on said backbone frame and operatively connected to said drive motor, and said right angle gear means including balanced eccentric throw arm connections engaging said screeds.

5. A concrete surfacing device, comprising: a frame member adapted to be received between and to be slidably supported on a pair of straight-edged parallel spaced screeds, said frame member including a backbone member adapted to be disposed in parallel spaced relation between said screeds, cross rails provided at the ends of said backbone member and adapted for frame supporting engagement with said screeds, guide and roller means provided on the ends of said cross rails for maintaining said frame member in engagement with said screeds dur ing transverse and relative reciprocal movement of said screeds, drive means provided on said backbone member and including an output shaft extending transversely of said backbone member and having separate crank throw arms engaged to opposite ends thereof, said crank throw arms being adapted for engagement with said screeds for reciprocation of said screeds relative to each other and to said frame member, and a handle provided on said frame for transverse movement of said frame and screeds used therewith together and having operational controls provided thereon and connected to said drive means for operation thereof.

Reerencv'es Cited bythe Examiner UNITED STATES PATENTS 2,098,870 11/ 1937 Heltzel 94-45 2,248,247 7/ 1941 Nichols 94-45 2,372,163 3/ 1945 Whiteman 94--45 2,386,662 10/ 1945 Crock 94-45 2,400,321 5/1946 TroXell 94-45 JACOB L. NACKENOFF, Primary Examiner.

CHARLES E. OCONNELL, Examiner.

N. C. BYERS, Assistant Examiner.

Claims (1)

1. A CONCRETE SURFACE DEVICE, COMPRISIG A PAIR OF SCREEDS DISPOSED IN PARALLEL SPACED RELATION AND HAVING A FRAME MEMBER RECEIVED AND SLIDABLY SUPPORTED THEREON AND THEREBETWEEN, SAID SCREEDS BEING EACH RECIPROCAL RELATIVE TO EACH THER AND TO SAID FRME MEMBER, AND COMMON OPERATIVE MEANS PROVIDED ON AID FRAME MEMBER AND CONNECTED TO EACH OF SAID SCREEDS FOR RELATIVELY OPPOSITE AND SIMULTANEOUSLY RECIPROCATION OF SAID SCREEDS WITH RESPECT TO SAID FRAME MEMBER.

Images