US2881540A

US2881540A - Land leveling machine

Info

Publication number: US2881540A
Application number: US366148A
Authority: US
Inventors: Frank N Sprague
Original assignee: Individual
Current assignee: Individual
Priority date: 1950-07-21
Filing date: 1953-07-06
Publication date: 1959-04-14
Anticipated expiration: 1976-04-14

Description

April 14, 1959 F. N. SPRAGUE 2,831,540

LAND LEVELING MACHINE Original Filed July 21, 1950 3 Sheets-Sheet l r M E G. e N t .M 8 m R P w w 2 2 w. .S M. v Q S Q B T on N .8 5 v 8 Q I o: 10: 1 o o o F; H 0 vmbwnvo u wm fiwmmmfi mm 0 0% a K mm. R wmm m o m N 8 $0 0 M v ON On F V? 9 mm q a R 8 m M April '14, 1959 I F N. SPRAGLIE 2,831,540

' LAND LEVELINQJ MACHINE z nalF Ju y 21, 1950 s Sheets-She et 2 Inventor FRANK N. SPRAGUE I WHITEHEAD a VOGL PER 6M Gttomegs April 14, 1959 FJQTSPRAGUE I LAND LEVELING MACHINE Original Filed July 21, 1950 3 sheets-sheet :s I

Snoentor WHITEHEAD 8 VOGL J attorneys United States Patent LAND LEVELlNG MACHINE Frank N. Sprague, Payette, Idaho Original application July 21, 1950, Serial No. 175,131, now Patent No. 2,723,129, dated November 8, 1955. Divided and this application July 6, 1953, Serial No. 366,148

3 Claims. (Cl. 37-153) This invention relates to earth-moving devices of the class particularly adapted for land-leveling operations and is a divisional application of an application filed by applicant July 21, 1950, Serial No. 175,131, now Patent No. 2,723,129, claiming subject matter disclosed but not claimed in said former application.

The purpose of this invention is to provide a landleveling apparatus which is especially adapted to condition a field subsequent to plowing wherein it is desirable to have the ground perfectly level and smooth.

An object of this invention is to provide a new and improved wheel-mounted land-leveling apparatus having a plurality of leveling elements which are associated with the wheels of the apparatus in such a manner as to hold the elements in their altitudinal operative positions as the apparatus moves over uneven earth and the wheels rise over ridges or drop into depressions.

Other objects of this invention are to provide in such a land-leveling apparatus, (a) for its attachment to the lift bars of a tractor and be thereby held in operative position with the tractor lift bars lowered, but adapted to be lifted oil? the ground with all leveling elements above the ground whenever the tractor lift bars are raised, with the unit then resting on its rear wheels and adapted to be easily transported; (b) a connective link which is universally free to yield to all movement differentials between the tractor and the land leveler as the tractor drags the leveler over uneven ground; (0) an apparatus more efficient, but lighter than devices commonly used for such purpose; and (d) a device which is extremely simple in construction, and with its elements arranged to I in the accompanying drawing in which:

Figure 1 is a side elevation of the land-leveling apparatus as connected to a tractor and positioned as'for operation.

Figure 2 is a side elevation similar to Fig. 1, but illustrating the forward part of the land-leveling apparatus lifted from the earth and the apparatus positioned as for transportation.

Figure 3 is a plan of the apparatus.

Figure 4 is a front elevation as viewed from the indicated line 4-4 at Fig. 3.

Figure 5 is a fragmentary portion, on an enlarged scale, as taken on the indicated line 5-5 at Fig. 3.

Figure 6 is-a fragmentary portion, on an enlarged scale, astaken on the indicated line 6-6 at Fig. 3.

' Figure 7 is a fragmentary section, on an enlarged 'scale, as taken on the indicated line 7-7 at Fig. l.

Figure 8 is a fragmentary longitudinal central sectlon, on an enlarged scale, as taken substantially at the 2,881,540 Patented Apr. 14, 1959 indicated line 8-8 at Fig. 3, but with the portions of elements broken to conserve space.

Figure 9 is a fragmentary detail, on a further enlarged scale, of elements as viewed from the indicated arrow 9 at Fig. 1.

Figure 10 is a section as taken substantially on the indicated line 10-10 at Fig. 9.

Figure 11 is a fragmentary section on an enlarged scale as taken on the indicated line 11-11 at Fig. 3.

Figure 12 is a line diagram of a portion of the apparatus illustrating a linkage between the wheels of the apparatus and the leveling members and with broken lines illustrating alternative positions thereof.

Figure 13 is a fragmentary section, illustrating an alternate construction of a dragbar.

A multitude of instances arise wherein it is expedient to provide field leveling operations of a character which require a final grading and preparing of a field, such as after an earth-moving operation, or to fill in small washes or rows, or to break up clods left by deep plowing, or to condition a field to a uniformity and flatness not attainable by conventional harrowing operations. A common apparatus for this purpose is a float, adapted to be pulled by a tractor or any other conventional means. A conventionally-built float will comprise one or a plurality of dragbars positioned transversely to the direction of movement, which by their weight break down small high spots or hummocks over which they pass and then slide the displaced earth transversely along the dragbars toward lower spots. These conventional floats are heavy and still unsatisfactorily limited in their earthmoving capacity. Excessive weight of a given float will cause the float to dig too deeply into the earth and dig a trench instead of performing a leveling operation, but a float not excessively weighted cannot effectively cut down a ridge of earth which lies transverse to its direction of movement, as the dragbars of such float will ride over such ridge. A conventional float is necessarily a clumsy heavy piece of equipment which is not only dilficult to drag in the fields, but is also not adapted for transportation to and from the field.

While the present invention is a leveling apparatus of the same general class as leveling bars or floats, its principle of operation is a radical departure from that of such conventional apparatus. It'comprises, in essence, a wheel mounted float having comparatively narrow, lightweight dragbars suspended from a frame and coactively associated with the front wheels of the apparatus as hereinafter described. In operation, there is small resistance to the drag bars wherever the earth surface is comparatively level, but considerable force is exerted whenever a drag bar encounters a hillock or ridge, whereby the drag bar will tend to cut through and remove the obstruction rather than ride over it. The coaction of the front wheels and drag bars permits automatic adjustment of the position of the drag bars with respect to the frame whenever a wheel drops into a depression or passes over a hump whereby the actual level of the drag bars is not appreciably changed by such dropping or rising of the wheels. The advantages of such functioning in landleveling apparatus are obvious, and these and other desirable features will become apparent in the following detailed description of a preferred embodiment of my invention.

In this embodiment, a plurality of drag bars 16 depend from a Wheel-mounted frame 17, as hereinafter described said frame having a pair of rear wheels 18 and a pair of front wheels 19 to provide a stable four-point support of the apparatus. A tongue 20 is pivotally attached to the frame, and extends forwardly of the apparatus and is adapted for connection to a crossbar 21 mounted between the lift bars 22 of a conventional tractor 23, it being 2,ss1,54- I" -tally disposed side angle bars 24, each having one leg upstanding and the other leg inwardly turned. These side bars 24 are interconnected at their front ends by a front angle bar 25, welded thereto, and interconnected near their rear ends by a transverse shaft 26 secured as by bolts 26 to the upstanding legs of said side bars. These side bars 24 are suitably reinforced by trussing with rods 2?, welded thereto, to form the upper cord truss members, and connected to the bars 24 by a plurality of evenly spaced uprights 28. To hold the frame 17 square, diagonal braces 29 are welded to the side barsv24 and to the front bar 25. It follows that these braces, in conjunction with the trussed construction of the side bars, provides a rigid frame except that it is not adapted to resist a warping action about the longitudinal axis, for it is contemplated that neither the stiffness of the front bar 25 nor the tightness of the connection of the shaft 26 to the side bars 24 is sufficient to prevent such longitudinal warping as might occur with one corner of the frame lowered slightly. As hereinafter pointed out, such warping action of the frame is desirable and necessary for the proper functioning of the apparatus.

The tongue comprises a T-shaped unit having its central leg 30 extending forwardly of the frame 17 and its transverse cross leg 31 adjacent the front bar and pivotally attached thereto by clip angles 32 at each end which forwardly outstand the front bar 25. It follows that the leg may be rotated upwardly from its operative position in alignment with the apparatus longitudinal axis, as by raising the tractor lift bars 22. The purpose of this upward rotative movement is to lower the rear wheels 18 by means hereafter described, and thereby raise the apparatus.

The connection between the tongue 20 and the tractor 23 is of the nature of a universal joint, the cross bar 21 being pivotally connected to the lift bars 22 to provide rotative movements about a horizontal axis transverse to the longitudinal tractor axis. The end of the tongue 20 carries a clevis 33 connected to the cross bar 21 by a pin 34 to provide rotative movements about a normally vertical axis, the clevis 33 being abutted against the end of the tongue 20 and held thereto by a headed bolt 35 to provide rotative movements about the longitudinal axis of the tongue. It follows that dipping movements, as in a change of grade between the tractor and the leveling apparatus rotate the cross bar 21 at its attachment to lift i bars 22, while turning movements, as on a horizontal curve, rotate the clevis 33 about the pins 34, and longitudinal twisting as by sidewise swaying rotates the clevis 33 about the bolt 35. Suitable bearing washers 36 are provided at the pin 34 and bolt head 35. The bolt 35 is held in the tongue in any conventional manner, as by being threaded therein and locked in position by a cotter key 37.

The rear wheels 18 are preferably a balloon tire type to provide a large resilient bearing surface to hold the weight 'of the unit without impressing their marks too deeply into the earth. Each wheel is mounted in a yoke 38, fixedly attached to the shaft 26 adjacent a side bar 24 whereby rotation of the shaft 26 simultaneously alters the altitudinal position of the wheels 18 with respect to the frame 17. In operation of the apparatus it is contemplated that the yokes 38 approximate a horizontal position forwardly of the shaft 26, and from such position the wheels may be rotated downwardly with respect to the frame to ac 4 tually lift the rear portion of the frame 17 and the drag bars 16 attached thereto.

Rotation of the shaft 26 is accomplished through the lifting of the tongue 28 as hereinbefore stated through the following structure. A strut 39 fixedly upstands the tongue 20 near the pivotal point and is thus adapted to move rearwardly as the tongue 29 is rotated upwardly. A pivotal link 48* connects the outer end of this strut 39 with the end of a rocker arm 41 which is'mcnnted upon a standard 42 rigidly upstanding between the braces 29 at the forward end of the frame, the point of connection with the rocker arm 41 being downward and forwardly of the standard 42 with the tongue 28 in its lowered position, whereby rearward movement of the link 40, through raising of the tongue 20, causes a forward movement of the upwardly disposed opposite end of the rocker arm 41. This upward end of the rocker arm 41 is connected to the outer end of a strut 43 centrally and substantially upstandingly attached to the shaft 26 through a pull-rod 44. This rod is provided with suitable clevises 45 at each end for pivotal connection with the rocker arm 41 and strut 43, and is further provided with a turnbuckle 46 for adjusting the position of the wheels 18 with re spect to the alignment of the tongue 28.

The normal operative position of the apparatus is assumed with the tongue 20 lowered to approximate alignment with the apparatus longitudinal axis. Therefore, by raising the tractor lift bars 22 and rotating the tongue 20 upwardly, the frame 17 Will be lifted above the rear wheels. This motion is extended through a definite portion of the raising movement of the lift bars 22, and a stop 47 outstanding from the side of the link 40 contacts the edge of the standard 42 to limit further movement of the linkage between the tongue 20 and the wheels 18 as the lift bars complete said portion of raising movement. Further raising of the lift bars 22 lifts the front portion of the leveling apparatus, and, in final position, the frame and drag bars 16 depending therefrom are well above the ground with the apparatus resting upon its rear wheels 18 and thereby positioned for easy transportation as clearly illustrated at Fig. 2.

A plurality of drag bars 16 may be positioned below the frame 17 in any suitable spacing arrangement, such as that illustrated in the drawing, and carried transversely of the side bars 24, at the ends of work arms 48 of hell crank levers, later described, which arms pivotally depend from each side bar. These drag bars may be of any desirable shape, angle bars being used in the hereindescribed embodiment, with one leg of the angles positioned across the bottoms of the arms 48 and with the other leg at the arm leading face, whereby the point of the angles will be downward when the arms 48 are sloped at about 45 degrees rearwardly from their pivotal connections with the side bars 24, as illustrated in the drawings. It is anticipated that the arms 48 will be thus sloped, for the drag bars will then tend to lift more easily over immovable obstructions and, more important, this positioning provides altitudinal movement of the drag bars through slight rotation of the arms 48 on their pivots, such movements being a basic feature of the operation of the apparatus as hereinafter described.

Arms 51 constitute the power arms of the bell crank levers which are pivoted as at 49 within sockets formed by centrally offset straps 50 attached to the upstanding legs of the bars 24. In the herein described embodiment four dragbars are used, three being placed between the front and rear wheels and one positioned rearwardly of the rear wheels. The three drag bars between the wheels are mutually linked by a connecting rod 52 above each side bar 24, rod 52 being pin connected to the lever arms 51. The trailing drag is independent of the others and is resiliently held in operative position by spring 53 connected to the lever arms 51 of the arms 48 and to suitable clip angle legs 54 upstanding the side bars 24.

The front wheels are castor wheels mounted in rotatable yokes 55 positioned at the outward sides of bars 24, each being supported by one of the transverse, horizontally disposed, rods 56 journaled upon the front frame member 25 with each front wheel being adapted to respond independently of the other, to altitudinal variations in the ground surface through rotation of its rod 56 in its journal. Aflixed to each rod 56 is a lever arm 57 between the yoke 55 and the side bar 24, which arm 57 is operatively linked to one arm of a bell crank lever 58 by a toggle 59. The bell crank 58 is pivotally connected to the side bar 24 and the upper arm is pivotally connected to the end of connecting rod 52. Through the linkage comprising the rod 56, the lever arm 57, the toggle 59, the bell crank 58, the connecting rod 52 and the lever arms 51, each front wheel 19 is operatively connected with the arms 48 between it and the rear wheels on its side of the apparatus, and through this linkage an altitudinal movement of a front wheel 19, with respect to the frame, results in an opposite altitudinal movement of ends of the drag bars on that side of the apparatus in the manner illustrated at Fig. 12.

To operate the land leveling apparatus, the tongue 20 is attached to the vertical actuated lift bars 22 of the tractor 23 which are lowered from the raised position illustrated at Fig. 2 to an operative position illustrated at Fig. 1, where the tongue 20 is substantially level and the frame 17 is held in a plane parallel with the surface of the earth. The drag bars 16 will then normally lie in a plane defined by the four points of wheel contact when the apparatus is on level ground.

In operation, when the apparatus is being pulled by the tractor, the lift bars 22 of the tractor remain in their lowered position but the front wheels 19 and the front portion of the frame of the leveler will lower and raise with respect to the position of the lift bars 22 as the tractor and the leveler pass over uneven portions of the earths surface. This is possible because the front end of the central leg 30 of the tongue is pivotally attached to the arms 22 by the cross bar 21 while the rear end of the leg 30 is pivotally attached to clip angles 32 on the leveling apparatus. While pivoting or tipping of the central leg 30 is necessary when the apparatus passes over uneven ground, there will be a small change in the position of the rear wheels 18 through the linkage connection of the rear wheel lifting arrangement with the tongue as hereinbefore described; however, such lifting of the rear wheels is not suflicient to elfect the operation of the unit. It follows that the pivotal attachments at each end of the central leg will thereby permit a limited vertical movement of the wheels and frame independently of the position of the arms 22. Such movement will assist the drag bars to level the ground surface and rear wheels 18 will remain substantially on the leveled surface and the frame and apparatus will rotate about an axis defined by these rear wheels responsive to dropping or raising movements of the front wheels.

The compensating linkages connecting the front wheels and the drag bars are adapted to hold the drag bars 16 substantially in the plane of the desired level ground surface. For example, whenever a front wheel drops, there will be a dropping of the frame connecting that front Wheel accompanied by a relative raising of the drag bars with respect to the frame. Thereby, the drag bars will remain substantially on a level surface and actually the vertical movement of the frame will be approximately one-half the vertical movement of the front wheels with a corresponding opposite compensating movement of the drag bars with respect to the frame. Although it is to be recognized that such proportional movements of the various drag bars is not completely precise in a manner which provides for perfect action, such operation keeps the drag bars on a substantially level surface.

In the operation of this apparatus it is anticipated that the frame will be held in a plane parallel with the surface of the earth, normally a horizontal plane, but that as the apparatus passes over uneven ground, each front wheel will lower or rise as it passes over uneven earth surface. Following the front wheels, the drag bars level the ground surface and the rear wheels will therefore hold substantially to a horizontal plane and the frame of the apparatus will rotate evenly about these rear Wheels when the front wheels rise or drop simultaneously, or warp or twist relative to the apparatus longitudinal axis when either front wheel rises or drops relative to the other. The movements of a front wheel 19 are not accompanied by a complete corresponding lowering or rising of the side bars because there will be a definite movement of the linkage connecting the front wheel and drag bars whereby a movement, such as a drop of the front wheel will cause a lift of the drag bars on that side of the apparatus, thereby holding the drag bars substantially at their-initial elevation.

When a front wheel drops, the ends of the drag bars at that side are swung rearwardly thereby giving them a diagonal position relative to the apparatus longitudinal axis resulting from the movement of the arms 48 with the result that earth being moved by the drag bars is shifted transversely toward the lowered spot wherein the wheel has dropped. Likewise, when a wheel is raised, that side of the drag bars shifts forwardly to move the earth in the other direction.

The drag bars are preferably of equal length and extend symmetrically beyond the frame members to any desirable distance. In the course of leveling operations there will, therefore, be a sideward movement of some of the earth dragged by the drag bars which will tend to cause a small ridge beyond the ends of the drag bars. To break this ridge and further level it to a point of insignificance, a hooked arm 60 is connected at each end of the drag bar which extends outwardly beyond the ends of the bar. In preferred construction, these arms are pivotally mounted between the angle legs of the rear drag bar as by a pin 61, and are further held in outward position by latches 62, engageable in suitable orifices in the legs of the angle forming the drag bar, or may be folded back into the drag bar by release of the latch.

The weight 'of the drag bars is not a paramount feature of this leveling apparatus, for they are held substantially in a given altitudinal position regardless of the earths contours and will not be deviated by a small ridge which may be transverse of the leveling apparatus movement. Further, the drag bars being relatively narrow sections will tend to exert considerable force to cut a small hillock or uneven rise of earth.

In further modifications of this invention it is contemplated that certain of the forward drag bars may be formed with a knifed leading edge 63 to cut through or break down comparatively hard formations of earth with the trailing drag bars formed to conveniently spread the earth so cut or broken.

While I have illustrated and herein described many details of construction, alternatives and equivalents will be obvious to those skilled in the art, and I desire my protection to be limited not by the details illustrated and/or described but only by the spirit and scope of the appended claims.

I claim: 1. An earth leveling machine of the character described, comprising, in combination, a frame including a pair of longitudinal side bars pivotally mounted upon a transverse rear wheel shaft, a pair of rear wheels carried by said shaft, a front wheel carried at the front end of each side bar, means for altitudinally shifting the front wheels with respect to the side bar with each side bar being adapted to rotate about the rear wheel shaft responsive to the individual shifting of its front wheel above or below its normal position, a plurality of transverse drag bars underneath the frame between the front and rear wheels adapted to normally lie in a plane which is substantially that defined by the four points of wheelground contact with all wheels in a normal position as upon level ground, a like plurality of arms depending from each side bar to support the drag bars, means at each side bar adapted to shift said arms to raise and lower the drag bars with respect to the side bar and said altitudinal shifting means including an inverting linkage at each front wheel connected to the arm shifting means operable responsive to vertical movement of the wheel with respect to the side bar whereby to raise and lower the drag bars with respect to the side bar as the front wheel and side bar is lowered and raised, as by movement over uneven earth.

2. An earth leveling machine comprising a frame having longitudinal side members, a pair of rear wheels carried by a common transverse shaft attached to the side members, with each side member adapted to be independently raised or lowered by rotation about the rear wheel shaft, front wheels carried in yokes individually linked and pivotally connected to the front ends of the respective side members for altitudinal shifting of each front wheel with respect to its side bar by rotation of the pivoted yoke, a plurality of rocker arms pivotally depending from each side member, a plurality of transverse drag bars, each carried by two rocker arms, one depending from each side member and being adapted to lie substantially in a plane defined by the four points of wheel-ground contact with all wheels in a normal position as upon level ground, and an inverting linkage connecting each front wheel yoke with the rocker arms carried by its side member, which linkage is adapted to respectively lower or raise the drag bar ends with respect to the side member as the front wheel yoke on said side member rotates responsive to raising and lowering of the front wheel out of said normal plane and whereby the raising and lowering of the front wheel partially raises and lowers its side member and partially rotates the yoke to compensatingly lower and raise the drag bar ends and thereby hold the drag bar ends in the same plane with each front wheel and side member operating substantially independently of the other to hold the drag bars in a common plane independently of warping and twisting movements of the side bars and the unit which occur as the unit is being pulled over uneven ground.

3. In a machine as defined in claim 2, each linkage including a bell crank on such side member, a lever con necting said bell crank with the yoke and a rod connecting said bell crank with the rocker arms to said side member.

References Cited in the file of this patent UNITED STATES PATENTS 1,388,266 Kettenton Aug. 23, 1921 1,845,324 Nofisinger et al. Feb. 16, 1932 2,189,962 Rae et al. Feb. 13, 1940 2,254,414 Bowlin Sept. 2, 1941 2,283,744 Lethlean May 19, 1942 2,503,638 Shuey Apr. 11, 1950 2,722,067 Baron Nov. 1, 1955