US3126969A

US3126969A - Moldboard plows

Info

Publication number: US3126969A
Authority: US
Publication date: 1964-03-31
Anticipated expiration: 1981-03-31

Description

March 31, 1964 w. w. SEWELL MOLDBOARD FLOWS Filed Sept. 25, 1961 Wall. TER W. til-W54 1.

IN V EN TOR.

United States Patent 3,126,969 MOLDBOARD PLGWEi Walter W. Seweil, Washington, Mich, assignor to Ford Motor Company, Dearhorn, Mich, a corporation of Deiaware Filed Sept. 25, 1961, Ser. No. 14%),396 3 Claims. (Cl. 1727i9) This invention relates to moldboard plows, and more particularly to such plows having an improved construction facilitating passage of the soil across the moldboard surface of the plow and turning of a furrow with minimum draft on the plow.

The invention is incorporated in a moldboard plow of more or less conventional design and contour. According to the present invention, a thin steel sheet, which previously has been given a thin, tightly adherent coating of polytetrafluoroethylene (Teflon) and then formed to moldboard contour, is applied to the moldboard to provide a smooth surface of Teflon having a very low coefficient of friction in order to promote scouring.

One feature of the present construction is that the layer of Teflon is thin and tightly adherent to its metal backing. While the Tefion layer may tend to wear rapidly in areas of higher soil pressure of the moldboard, it will wear slowly in areas of low soil pressure, which are the primary areas in which soil scouring is a problem. Accordingly, a plow according to the present invention will continue to scour satisfactorily in so-called problem soils" of high moisture content, even though an appreciable portion of the Teflon surface layer has been worn away, exposing the surface of the sheet to which the Teflon is bonded.

The invention is equally applicable to the soil-contacting surface of plow jointers, which are mounted immediately above moldboards to facilitate turning the furrow and improve trash covering.

Among the objects of the present invention are to provide an improved moldboard plow construction which is economical to manufacture, which will function well in poor scouring soils, which has a relatively long life, and in which the worn parts may readily be replaced when worn beyond use; and generally to improve such plows.

Other objects, and objects relating to details of construction, will be apparent from the detailed description to follow.

My invention is clearly defined in the appended claims. In the claims, as well as in the description, parts may at times be identified by specific names for clarity and con venience, but such nomenclature is to be understood as having the broadest meaning consistent with the context and with the concept of my invention as distinguished from the pertinent prior art. The best form in which I have contemplated applying my invention is illustrated in the accompanying drawings forming part of this specification, in which:

FIGURE 1 is an elevation of the moldboard surface of a plow, including a jointer, embodying the present invention.

FiGURE 2 is a plan view of the Teflon coated sheets for covering the moldboard and jointer surfaces of the plow of FIGURE 1.

FIGURE 3 is an enlarged fragmentary section, taken on the line 33 of FIGURE 1.

FIGURE 4 is an enlarged fragmentary section of the moldboard and covering sheet, taken on the line 4-4 of FIGURE 1.

FIGURE 5 is an enlarged section of one of the Tefloncovered sheets.

The plow of FIGURE 1 is more or less conventional in shape, having a compound curved moldboard surface, and includes a rigid steel moldboard 10, a share 11 and a shin 12, the share and shin lying in a continuation of the curved surface of the moldboard. The moldboard 1%, share 11 and shin 12 are bolted to a frog or frame 14, to which the plow beam (not shown), attaches. The construction of the plow of the present invention is in most respects conventional, the frog or frame being generally similar to that shown in Altgelt United States Patent 2,622,502.

The moldboard share and shin are mounted on a por tion of the frame 14 by a scrim of bolts 15. If desired, a plow jointer 16 may be located above the shin 12 and moldboard 10, the forward portion of the jointer lying generally in an upward extension of the surface of the shin and moldboard, and the rear portion of the jointer curving outwardly beyond the moldboard surface to aid in turning the furrow cut by the plow. The jointer, likewise, is supported from the plow frame by bolts 15.

According to the present invention, the plow moldboard 10 is covered by a relatively thin, mild steel sheet 17 conforming generally with the outline of the moldboard and having a thin, tightly adherent layer of tetrafluoroethylene, commonly known by the trademark Teflon. It has been found desirable to utilize steel sheet of a thickness between 15 and 24 gauge, preferably about 20 gauge, having a tightly adherent sheet of Teflon cemented thereto, having a thickness between .010" and .045", preferably about .030".

The Teflon covered sheet 17 preferably is blanked to the form shown in FIGURE 2 and then coated in a well known manner with Teflon before being formed to the warped contour of the moldboard. It has been found that a thin Teflon coating cemented on a thin steel sheet can withstand the forming operation without destroying the bond between the sheets and the Teflon or otherwise adversely affecting the Teflon.

The Teflon covered sheet 17 may be formed to the general contour of the moldboard 10 in the same forming dies which are used to form the moldboard itself. After forming, the sheet 17 is secured to the moldboard 10 by two spaced fasteners or bolts 20 which may also serve to secure the moldboard to the plow frame 14. Preferably, the bolts 20 are spaced a substantial distance a part, one bolt being toward the forward end of the sheet and the other bolt towards the rear.

In addition, a series of bendable tabs 21 are formed along the lower and rear edge of the sheet 17 and are adapted to be bent over the lower trailing edge and rear edge of the moldboard (FIG. 2), to prevent entrance and packing of dirt between the sheet and the moldboard, which would tend to force the sheet away from the surface of the moldboard.

Sheet metal 2

shaped strips

22 and 24 overlie the edges of the sheet 17 adjacent the shin 12 and share 11 to prevent entrance of dirt under the forward portion of sheet 17. Inasmuch as the direction of soil flow across the moldboard is upwardly and to the left, as viewed in FIG. 1, the

strips

22 and 24 and the tabs 21 along the lower trailing edge of the moldboard effectively prevent the entrance of dirt behind the sheet. The tabs 21 at the rear of the sheet 17 serve to prevent entrance of dirt behind the sheet 17 when the plow is pushed rearwardly, as may occur from time to time.

The plow according to present invention has a substantially reduced draft and improved scouring, so that it may be used in wet, sticky soils that tend to adhere to a conventional moldboard plow rather than flowing free ly from the moldboard. The thin coating 19' of Teflon on the sheet 17 overlying the moldboard tends to wear away rat-her rapidly in the areas of higher soil pressure adjacent the shin 12 and share 11, so that after relatively short usage the Teflon will be worn away entirely in these areas. Difliculty in scouring, however, occurs in the areas of lesser soil pressure on the moldboard, and in these areas the Teflon wears much more slowly. By utilizing a thin sheet of Teflon which is tightly adherent to the steel sheet, there is no tendency of the Teflon to be peeled (from the sheet, and the Teflon is Worn away gradually by abrasion of the soil, commencing in the areas of highest pressure. As -a result, the plow according to the present invention will continue to scour satisfactorily in problem soils and turn a clean furrow, even after the Teflon has been worn completely away from one-third or more of the area of the moldboard, the draft of the plow being only slightly increased.

After the Teflon 19 has been completely worn away from more than one-half of the area of sheet 17, the sheet 17 may easily be replaced by removing the bolts 20 and bending the tabs 21 out of engagement about the edge of the moldboard. A replacement Teflon coated sheet 17 may then be inserted under the

strips

22 and 24 and bolted into place in a similar manner, the tabs 21 being bent around the lower trailing and rear edge of the moldboard.

If desired, a similar Teflon coated sheet 25 may be applied to the soil contacting surface of the jointer 16. The sheet 25 preferably is of mild steel, corresponds in thickness to the sheet 17 and has a similar coating of Teflon similarly applied. The sheet 25, which corresponds generally to the outline of the jointer 16, may be preformed to the curved contour of the jointer, or may be flat before application and clamped against the face of the jointer while the tabs 26 along the margin of the sheet are bent about the edges of the jointer. It has been found unnecessary to use any means of securing the sheet 25 to the soil contacting surface of the jointer 16 other than by the tabs 26.

Application of a thin Teflon coated steel sheet to the jointer improves the soil turning and trash covering functions of the jointer substantially in all types of soils. Inasmuch as the soil pressure against the jointer is much less than against the moldboard, the Teflon covered jointer may be used to advantage with plows having a conventional steel moldboard without a Teflon covering and in abrasive soils which would wear away a coating of Teflon from the moldboard surface relatively rapidly.

I claim:

1. A moldboard plow having a moldboard surface formed of a moldboard, a shin and a share, the shin and share being mounted generally flush with the moldboard, a thin metal sheet conforming in general to the outline of and overlying the moldboard, the metal sheet having a thin, tightly adherent coating of polytetrafluoroethylene on its exposed face, and metal strips lying between the confronting edges of the moldboard, shin and share and having narrow flanges overlying the adjacent edges of the polytetrafluoroethylene-coated sheet.

2. A plow having a moldboard, and a thin metal sheet conforming in general to the outline of and overlying the moldboard, the metal sheet having a thin, tightly adherent coating of polytetrafluoroethylene on its exposed face, the thickness of the metal sheet being between approximately 15 and 24 gauge and the thickness of the polytet-rafluoroethylene coating being between approximately .010 and .045 of an inch.

3. A plow having a moldboard, a thin metal sheet conforming in general to the outline of and overlying one face of the moldboard and having one face thereof exposed, the metal sheet having a thin, tightly adherent coating of polytetrafluoroethylene on its exposed face, at least one bolt extending through the metal sheet and moldboard, and tab means on at least one of the marginal edges of said metal sheet overlying the corresponding edge of said moldboard to aid in holding said metal sheet on said moldboard.

References Cited in the file of this patent UNITED STATES PATENTS 72,305 Leach Dec. 17, 1867 1,903,723 Palmer Apr. 11, 1933 2,672,805 Longenbach Mar. 23, 1954 2,727,845 Bishop Dec. 20, 1955 2,913,060 Owen et a1 Nov. 17, 1959

Claims

1. A MOLDBOARD PLOW HAVING A MOLDBOARD SURFACE FORMED OF A MOLDBOARD, A SHIN AND A SHARE, THE SHIN AND SHARE BEING MOUNTED GENERALLY FLUSH WITH THE MOLDBOARD, A THIN METAL SHEET CONFORMING IN GENERAL TO THE OUTLINE OF AND OVERLYING THE MOLDBOARD, THE METAL SHEET HAVING A THIN, TIGHTLY ADHERENT COATING OF POLYTETRAFLUOROETHYLENE ON ITS EXPOSED FACE, AND METAL STREIPS LYING BETWEEN THE CONFRONTING EDGES OF THE MOLDBOARD, SHIN AND SHARE AND HAVING NARROW FLANGES OVERLYING THE ADJACENT EDGES OF THE POLYTETRAFLUOROETHYLENE-COATED SHEET.