AU614979B2

AU614979B2 - Improved blade plough

Info

Publication number: AU614979B2
Application number: AU20104/88A
Authority: AU
Inventors: Barry Francis Homan
Original assignee: DAVEY GROUP Pty Ltd
Current assignee: DAVEY GROUP Pty Ltd
Priority date: 1987-07-30
Filing date: 1987-07-30
Publication date: 1991-09-19
Anticipated expiration: 2008-07-28
Also published as: AU2010488A; ZA885630B

Description

I'l liii; :i- 111 11 11111 11111 IL 11- I I a b: ii-- LII 61 4979 COMMONWEALTH OF AUSTRALIA The Patents Act 1952-1969 Name of Applicant: Address of Applicant: BARRY FRANCIS HOMAN Vanity Thackeray Streets, TOOWOOMBA, Queensland, 4350 _ik'

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ti 4 Actual Inventor: Address for Service: BARRY FRANCIS HOMAN G.R. CULLEN COMPANY, Patent Trade Mark Attorneys, Dalgety House, 79 Eagle Street, Brisbane, Qld. 4000, Australia.

COMPLETE SPECIFICATION FOR THE INVENTION ENTITLED: "IMPROVED BLADE PLOUGH" The following statement is a full description of the invention including the best method of performing it known to me: r

ANESE.

TO: The Commissioner of Patents, Commonwealth of Australia.

2 THIS INVENTION relates to an improved blade plough.

In particular, the invention is directed to a blade plough with a variable operating width.

In this specification, the term "blade plough" is used generally to describe an earth-working agricultural implement having a horizontal blade which, in use, cuts or slices through the earth at a predetermined depth below the surface with minimal disturbance to the surface itself.

Blade ploughs are commonly used to control the growth of unwanted woody vegetation in grazing areas by cutting through 04 *9 the woody root regrowth to thereby kill the unwanted .409. vegetation, yet leaving the fodder grasses on the surface of the ground relatively undamaged. In Australia, blade ploughs are particularly suitable for controlling the growth of the brigalow plant (acacia harpophylla).

A conventional blade plough typically comprises a *~09 wheeled frame to which one or more tynes or legs are 0*fastened. The blade is then fastened to the bottom end of each tine or leg. The frame includes a drawbar which extends forwardly of the plough for connection to a pulling vehicle, such as a tractor or crawler. The frame wheels are generally located intermediate of the blade and the drawbar

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connection to the tractor.

To withstand the high bending and torsional forces encountered during use, the plough blade is usually made from thick steel plate. In designing blade ploughs, the S

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4 4' 3 operating width is limited by several factors, including the power of the tractive vehicle, soil resistance, and the thickness of the blade. Once the appropriate operating width has been determined, the blade is manufactured and shaped to that width. Each wing of a conventional blade is of unitary construction and of fixed length, and hence the operating width is fixed.

It has been found that soil resistance may vary significantly with location. In light sandy soils, soil resistance is lower and a blade plough designed for use in r S' harder ground will therefore not operate at maximum efficiency since it could otherwise operate with a greater w. width for the same tractive power. Conversely, a plough having an operating width designed with reference to sandy S soils may not be able to operate at that width in hard soils.

It is an object of this invention to provide an improved blade plough having an operating width which can be till i varied relatively easily.

r, :In one broad form, the present invention provides a S 20 blade plough having a generally horizontal blade supported intermediate its ends, characterized in that the blade plough further comprises blade extension members detachably connected to the free ends of said blade for extending the operating width of said plough.

Typically, the blade extension members comprise blade attachments which are bolted onto the free ends of the 1_1 -t 1; a IWiii- 1.

4 plough blade. The blade attachments are preferably shaped to continue the plan profile of the blade.

The blade extension members may have individual cutting edges affixed thereto. Alternatively, a new cutting edge of unitary construction may be provided across the whole extended width of each wing of the blade.

Known blade ploughs are normally provided with a cutting edge fastened to the leading edge of the blade of the plough in some su itable manner, typically by bolting. The cutting edge has a "wood chisel" profile as shown in FIG. 4.

That is, it has a sharpened edge pointing forwardly and downwardly to aid in penetrating the soil in much the same *t~s manner as the profile of a wood chisel assists in penetrating *a piece of wood being worked.

It has been found that after a period of use, the cutting edge of the blade plough is worn away by soil and rock such that an inverted chisel profile is formed, as shown *in FIG 5. The "land area", marked with the letter A in FIG :5:1 5, now resists the penetration of the soil by the cutting edge. Even though considerable forward force and downward pressure may be applied to the plough, it will not plough the 4 soil efficiently as the land area A will tend to skip over the surface of the soil rather than penetrate the soil.

Several modifications to the cutting edge have been 'proposed in order to overcome this problem but such modifications have met with little, if any, success. For V Li 0 example, in one known modification the thickness of the cutting edge was increased. However, such increased thickness only served to increase the soil resistance of the cutting edge with the inevitable result that the traction vehicle consumed more fuel or a traction vehicle of higher horsepower rating was required. Furthermore, even a thickened cutting edge would wear, giving rise to an even greater land area which resisted soil penetration. Another disadvantage of the thickened cutting edge was the increased cost of material required.

Another modification involved the hardening of the front and top faces of the cutting edge, or the coating of the front and top faces with a layer of harder wear-resistant S* material, as these faces are the leading faces. However, the cutting edge wore away gradually from the bottom up, and a land area was still formed to resist soil penetration.

Yet another modification involved the application of extra weight to the plough frame to increase downward force. However, this met with limited success as fuel efficiency was substantially reduced.

According to a preferred embodiment of this invention, the blade plough has an improved cutting edge I: which maintains a penetrative profile with use. In the improved cutting edge, a harder wear-resistant layer is provided on the underside, rather than on the leading top and front faces of the cutting edge member.

6 The harder layer suitably comprises a more wear resistant material than the cutting edge.

The harder layer can be a separate layer fixed to the underside of the cutting edge by any known suitable method, for example by welding, bolting or clamping.

Alternatively, the underside of the cutting edge can be hard surfaced to provide the harder layer, for example by fusing a hard surfacing alloy on the underside.

Since the hard layer is provided on the underside of the cutting edge, the top side of the cutting edge will *continue to wear away with use at a faster rate than the hard laminate underneath. This ensures that the penetrative "wood chisel" profile is maintained with use in the harder and more abrasive soils. Consequently, less horsepower is required to pull or push the earth working implement due to the improved slicing effect of the cutting edge. The, provision of the hard laminate on the underside of the cutting edge .*ra also extends the working life of the cutting edge considerably.

In order that the invention may be more fully understood and put into practice, a preferred embodiment S' thereof will now be described by way of example with reference to the accompanying drawings, in which: Fig. 1 is a side elevational view of a blade plough; Fig. 2 is a side elevational view of biasing means i1 -o ^,0 for use with the blade plough of Fig. 1; Fig. 3 is a perspective view of the blade of Fig.

I 1; Fig. 4 is a cross sectional view of a conventional cutting edge applied to the mouldboard of a blade plough; Fig. 5 is a cross sectional view of the worn profile of the conventional cutting edge of Fig. 4; Fig. 6 is a cross sectional view of the improved cutting edge of the preferred embodiment; 10 Fig. 7 is a cross sectional view of the worn eaeo profile of the improved cutting edge of Fig. 6; eFig. 8 is a plan view of the blade of the preferred embodiment; b0 00 Fig. 9 is a cross-sectional view along A-A of Fig.

8; Fig. 10 is an exploded perspective view of the attachment area of the blade plough of Fig. 8; and Fig. 11 is a plan view of the blade plough of Fig.

1.

As shown in Fig. 1, a blade plough 10 comprises a frame 13 mounted on a pair of wheels 12 which rotate about a C common axis E. Typically, the frame 13 comprises a thick C CC steel plate. The frame 13 has a central tine or leg 14 depending downwardly therefrom at the rear end of the plough.

Attached to the bottom end of the tine or leg 14 is a Vshaped horizontal blade 20. Aerating fins 35 may be provided iNTr 8 in the topside of each wing of the blade to assist in killing the cut roots of the vegetation to be eradicated, e.g.

brigalow plants. The frame 13 also includes an extension extending forwardly thereof and provided with a gooseneck fitting 16.

The wheels 12 are mounted on wheel arms 17 which are pivotally connected to frame 13 at one or more pivot points along a transverse axis F. The angle of wheel arms 17 and hence the position of wheels 12 can be adjusted by hydraulic cylinder(s) 18.

A sub-frame comprising a drawbar 11 is pivotally connected to the underside of frame 13 at one or more points S along a transverse axis D which is located behind the wheel axis E and forward of the blade 20. An attachment point H is S 15 provided at the forward end of the drawbar 11 for attachment to a tractor, crawler or similar tractive vehicle.

During normal operation along level ground G, the C horizontal blade 20 will cut or slice through the soil at a cr predetermined distance below the surface of the soil. When the blade plough encounters an undulation the frame 13 will pivot relative to the drawbar sub-frame 11 to allow the blade to continue ploughing substantially at the predetermined pitch even though the attachment point H of the drawbar 11 has traversed the undulation G' That is, since the frame 13 may pivot independently of the attachment point H, the blade will continue ploughing at substantially the i- 9 same pitch and depth on the uphill plane while the tractor is on the downhill plane. Correct ploughing depth provides for effective eradication of woody re-growth.

Bias means are provided at pitch control point I to compensate for varying soil forces on the blade 20. In the preferred embodiment, illustrated in Fig. 2, a shaft 21 is provided through a sleeve in the gooseneck fitting 16 at the end of the extension 15, i.e. at the pitch control point I.

The fitting 16 is free to slide up and down shaft 21. The shaft 21 is pivotally connected to a flange 19 on the drawbar sub-frame. Springs 22A and 22B are provided above and below t the gooseneck fitting 16, respectively, to bias the pitch .control point I in its correct position. The springs 22A and 22B may be tensioned by varying the position of respective threaded end plates 23A, 23B, e.g. to suit the general characteristics of the soil to be ploughed. This biasing system provides such downward force as is required to balance the varying upward force acting on the pitch control point I.

t In other words, a floating pitch system is retained, but with the frame biased towards a desired operative attitude.

Other bias means can suitably be used. For l example, a single spring may be mounted between flanges It connected to the end plate 23 and gooseneck fitting 16.

Alternatively, the springs 22A, 22B may be replaced by hydraulic cylinder(s) or other resilient biasing means.

The blade plough of the preferred embodiment also /a X I ^N-vk :1 comprises a utting edge 25 fastened to the mouldboard 26 of the blade plough, typically by bolts 27 as shown in Fig. 4, or other suitable fasteners. The cutting edge 25 is orientated at an angle to the soil to facilitate penetration.

In this respect, the cutting edge is analogous to the.profile of a wood chisel.

After a period of use, conventional cutting edges will be worn away by the harder and more abrasive soils to a profile as illustrated in Fig. 5. The wear pattern 24 caused by soil flowing over the conventional' cutting edge in the direction results in a land area being formed on the underside of the cutting edge. This land area resists penetration of the soil by the cutting edge.

0*46 In the preferred embodiment, a harder or more wear- 0* resistant layer 28 is provided along the underside of the cutting edge 25 as shown in Fig. 6. The hard layer 28 extends rearwardly from the leading edge of the cutting edge.

(The harder layer 28 may be of any known suitable material, for example wear-resistant alloy steels such as tungsten '20 steels or the like. The wear-resistant laminate 28 may be fixed to the underside of the cutting edge 25 by any suitable Q"v4" method, for example welding or bolting. Alternatively, the 8> v hard laminate 28 can be formed by hard surfacing the underside of the cutting edge with a wear-resistant alloy.

Although the improved cutting edge of the invention will wear with use, the worn profile 29 as shown in Fig. 7 is still a "chisel" profile and the penetrative properties are Sretained to a large degree. The chisel profile is retained since the cutting edge is of softer material than the hard laminate. Hence, the hard laminate 28 will always remain as the leading edge of the cutting edge. Although a land area A' will be formed on the hard layer 28, the land area A' of the improved cutting edge of this invention is'typically onethird or less than the land area A of the conventional cutting edge of Fig. 5. The end result is that the improved cutting edge is able to maintain penetration with use, thereby maintaining fuel efficiency and not increasing the power required of the tractor implement. Although the S* improved cutting edge has been described with particular reference to a blade plough, it can also be used with other earth-working implements.

A particularly advant7geous feature of the blade plough of this invention is the use of blade extension members to allow for variation of operating width. In the illustrated embodiment, the blade extension members are in the form of blade attachments 30A, 30B which are bolted to the free ends of the mouldboard of the blade wings 20A, respectively. The connection between blade attachment and blade wing 20A is shown in more detail in Figs. 9 and S the connection between blade attachment 30B and blade wing 20B being of similar construction. (The fins 35 have been omitted from Figs. 9 and 10 for clarity).

;1 i 12 The blade wing 20A has a rebated or undercut portion at its outer (free) end which overlaps with a tongue 34 formed by a rebated portion of blade attachment member A plurality of bolt holes 38, 37 are provided in the blade wing 20A and tongue 34 so that bolts 36 may be inserted in the registered holes to fasten the blade attachment to the end of the blade wing 20A. Flange 39 on the attachment 39A can be bolted to the fin 35 at the end of blade wing Preferably the top and bottom surfaces of blade wing 20A and attachment 30A are flush when the tongue 34 is received under the undercut portion of the blade wing 20A as shown in Fig. 9. (Bars 40 may be welded to the wing 20A to protect the nuts on bolts 36 from abrasion). Similarly, the mouldboards 26, 32 are aligned when the attachment 30A is connected with blade wing Other methods of detachably fastening the extension member 30A to the blade wing 20A, may be used. For example, e the extension member 30A may be provided with a number of pins extending laterally therefrom for engagement in corresponding sockets located in the abutting end of blade wing If the extension member 30A is connected to the end of blade wing 20A to increase the operating width of the blade plough, the original cutting edge is replaced by an extended cutting edge 25' which is fastened to both 1 111 I A i 13 mouldboards 32, 26. In an alternative embodiment, the extension member 30A is provided with its own cutting edge *fastened to mouldboard 32 so that the extension member provides not only a continuation of the blade wing 20A, but also a continuation of the cutting edge.

The blade extension members allow the operating width of the plough to be varied easily. For example, the plough can be operated in normal conditions with the extension members attached, but should the plough be required to operate in harder ground, the extension members are simply removed. This permits the plough to be pulled by the same tractor as soil resistance is reduced, thereby obviating the -need and expense of a higher--powered tractor.

S4'"4* The foregoing describes only some embodiments of the invention, and modifications which are obvious to those skilled in the art may be made thereto without departing from the scope of the invention as claimed in the following claims.

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Claims

1. A blade plough comprising a generally horizontal blade supported between its ends, and a pair of blade extension members each of which is detachably connected to a respective end of the blade for extending the operating width of the plough, wherein the blade comprises a mouldboard member and the blade extension members are connected to respective free ends of the mouldboard member, further comprising at least one cutting edge member connected across a leading ,rprtion of the mouldboard member and at least one of the blade extension members. S2. A blade plough as claimed in claim 1 wherein each of the blade and its respective blade extension member have overlapping rebated portions bolted together. A blade plough as claimed in any preceding claim .qKerein each blade extension member has an upstanding flange It* hwXich in use is bolted to an upstanding portion on a respective end of the blade.

4. A blade plough as claimed in any preceding claim, wherein the blade is generally V-shaped in plan and is supported centrally thereof by a single leg of the plough. A blade plough as claimed in any preceding claim, wherein the blade extension members have a plan profile which continues the plan profile of the blade.

6. A blade plough comprising a wheeled frame, at least one leg depending downwardly therefrom, and a generally horizontal blade connected between its ends to the bottom of the leg(s), the blade plough further comprising a pair of blade extens respective en the blade p member and respective f comprising at leading porti the blade ext

7. A ih'e cutting e r the unders Smember. A layer is a se o:,e tting edge .A 1 lidyer is form ,.edge member.

10. A described wit

11. A blade suppori blade plough members each end of the plough.

12. A 1 end of the 4 ~i -1>7 blade extension members each detachably connected to a respective end of the blade for extending the cutting width of I the blade vilough, wherein the blade comprises a mouldboard j member and the blade extension members are connected to respective free ends of the mouldboard member, further I comprising at least one cutting edge member connected across a leading portion of the mouldboard member and at least one of the blade extension members. j7. A blade plough as claimed in claim 1 or 6, wherein -4rh-e cutting edge member has a layer of wear resistant material I ,or; the underside thereof which is harder than the cutting edge *member. A blade plough as claimed in claim 7, wherein the laeri a separate laminate connected to the underside to the O'Ce4tting edge member. A blade plough as claimed in claim 7, wherein the ;.*.ldyer is formed by hard surfacing the underside of the cutting edge member. io. A blade plough substantially as hereinbefore .1described. with reference to the accompanying drawings. 11. A blade plough comprising a generally horizontal blade supported between its ends, characterised in that the blade plough further comprises a pair of blade extension members each of which is detachably connected to a respective edof the blade for extending the operating width of the 12. A '.'lade plough as claimed in claim 11 wherein earch end of the blade and its respective blade extension member U 16 have overlapping rebated portions bolted together.

13. A blade plough as claimed in claim 11 or 12 wherein the blade and each blade extension member have respective cutting edge members fastened to the leading portions thereof.

14. A blade plough as claimed in any one of claims 11 to 13 wherein the blade has a plurality of upright fin members thereon, and each blade extension member has an upright fin member thereon. A blade plough as claimed in any one of claims 11 to Lt1,4 wherein each blade extension member has an upstanding flange which in use is bolted to an upstanding portion on a 'rispective end of the blade. tc~r' .A blade plough as claimed in any one of claims 11 to 0 1 wherein the blade is generally V-shaped in plan and is se pported centrally thereof by a single leg of the plough. o 9*17.A blade plough as claimed in any one of claims 11 to wherein the blade extension members each have a plan ,,profile which continues the plan profile of the blade.

18. A blade plough comprising a wheeled frame, at least tone leg depending downwardly therefrom, and a generally horizontal blade connected between its ends to Lhe bottom of the leg(s), the blade plough further comprising a pair of blade extension members each being detachably connected to a respective end of the blade for extending the cutting width of the blade plough.

19. A blade plough as claimed in claim 11 or 18, wherein the blade has a cutting edge member connected to its leading edge, the cutting edge member b-aving a layer of wear 17 resistant material on the underside thereof which is harder than the cutting edge member. A blade plough as claimed in claim 19, wherein the layer is a separate laminate connected to the underside to the cutting edge member.

21. A blade plough as claimed in claim 19, wherein the layer is formed by hard surfacing the underside of the cutting edge member. DATED this ninth day of May 1991 r BARRY FRANCIS HOMAN by his patent attorneys S, CULLEN CO. ft t