CA2149113A1

CA2149113A1 - Reversible plough

Info

Publication number: CA2149113A1
Application number: CA002149113A
Authority: CA
Inventors: Peter Douglas Temple Topham
Original assignee: Individual
Current assignee: Individual
Priority date: 1992-11-17
Filing date: 1993-08-19
Publication date: 1994-05-26
Also published as: AU4728493A; EP0725561A1; GB2272352A; WO1994010826A1; GB9224060D0

Abstract

A reversible plough is disclosed in which a plurality of plough bodies are pivotally supported from a beam (8) which itself is inclinable in opposite directions relative to the direction of movement of the plough, together with adjustment of the plough bodies, so as to permit the plough to produce right-hand or left-hand turning of the soil as required, to enable the plough to go back and forth producing similar furrows across a field. A particular linkage is provided in order, automatically, to adjust the direction of extent of the plough bodies, relative to the beam (8), the direction of extent of the plough bodies normally being at a slight angle to the direction of movement of the plough in order to compensate for the asymmetric pull of the tractor on the inclined beam (8). As disclosed, the plough bodies themselves comprise rotary-inversion-wheel-type ploughing discs, the inclination of the axis of rotation of the ploughing discs being inclined to opposite sides of the length of the plough body, depending on whether a left-hand or right-hand furrow is required.

Description

21~9113 ~ 1 --~E~ RSIB~E~ UGH"
This invention relates to an improved plough having rotary discs or inversion wheels as the ~eans for turning the soil and which is reversible.
With modern ploughing tachniques, there has been an increasing demand for a means o~ ploughing in which surface debris can be reliably ~uried during the ploughing operation. With the present invention~ this is achieved by having a se~uential ploughing operation in which a sliver is initially li~ted ~rom the soil surface and turned before the main ploughing action takes over and turns the sub surface ~oil over to bury the already skimmed surface layer.
- According tc the present inventiont there isiprovided a plough comprising:
a frame;
tilling apparatus supported by said frame and comprising a primary concave ploughing disc rotatable by reaction with the ground to be tilled and inclined in ~he direction of forw~rd movement o~ the plough to provide a ~ soil tilling and ploughing action and a sXimmer msunted I adjacent the primary Ploughing disc and more gr~atly l; inclined to the d7rection o~ ~orward movement than the primary ploughing disc, in ~rder to displace a sliver of soil together wi~h stubble and straw o~f the surface of the : . ground, the primary ploughing disc being operati~e in use : of the plough to roll the clean soil from the und~rside of the ~liYer over to cover the sliv~r of soil, s~ubble and straw initially displaced~
a point depending from the frame to penetrate the ground in front of the forward edge of the pri~:~ry ploughing disc, the skimmer al~o having a forward edge ~ substantially aligned~with ~he point;
: means for pivoting the primary ploughing di c ¦~ 35 rela~ive to the:frame ~etween positions in which it is oppositely inclined to the direction of forward ~ovement of .~'NL_':^..,_T
, 21~9113 - la - :
-~ the plough; and means for pivoting the skimmer, through an angle smaller than the angle of pivotal movement of the primary ploughing disc between positions in which it is oppositely inclined to the dire~tion of forward movement of the plough.
While the skimmer may itself comprise a secondary, smaller, ploughing disc, rota~abl~ abou~ its axis, within the concavity of th~ main ploughing disc, it has been found, e~pecially with heavier ploughi~g !: ' ! . I . l I

AMENDr~S~EET

2~ . PCr/G;B93/0~
1 1 ~ .

conditions, that the preferred skimmer is a fixed skimmer having a leading edge aligned with and behind a fixed point initially penetrating the ground and with the main ploughing disc b~ing behind the fixed skimmer, also with its leading edge s~stantially aligned ~ith the earth penetrating point. The skimmer may readily be adjusted in height to vary the depth of the initial sliver cut from the ground and ~or use in a reversible plough will be in the form of ~ lade ha~ring working edge 21t each end with different ones of the working edges being aligned initially to turn the ~;oil depending upon the direction of ploughing, ~n adjustable stop may be provided to vary the inclirlation of the skim~er blade, relative to the diraction of movement of the plough.
With a reversible plough where ~ beam from which : the various plouah bodies :depend is swingable about a headstock pivot be~ween oppositel y inclined positions depending upon wh~ther a l~ft-hand or a right-hand ~urrow is re~uired, there is a requirement to maintain th~
¦ ~ 20 various plough bodi~; parallel, ~ne wi~ the other, during beam reversal as it is swung fro~ one ploughing position ., to the other and there is a urther problem that the body angle of th~ plough bodies ~ould be so-controllable ~hat when the plough is in work, the angl e is such as to enable the plough tc c:ounteract ~he f2rce~ due to t:ha opposite ang~e of pull from the tractor to the ~lough~ .
The presen~ invention, in its later illustrated form, is directed at providing a reversible plough ha!ving a linkage capable of providing this control of plough body 3 0 dires::tion .
The illustrated form of the present inYentlon c:omprises a re~rersible plough comprising a headstoc:k fox atta;:hment at c~ne end to a ~tractor and provided with a substantially vertical a~is main pivot at its other end, a beam connec:ted by a riqid support to said main pivot whereby the beam is spaced ~rom sa d axis and is pivotable ~; ' ' .

-Y`VO 94~10826 21 ~ 9 1 I 3 PCl/GB93/01764 thereabout in a substantially horizontal plane so as to ~e inclinable to either side of the direction of movement of the plough, a plurality of plough bodies pivotally supported by said be~m for pivoted movem~nt about S substantially vertical axe~ whereby the plough bodies can pivot upon pivotal move~ent o~ the beam t~ maintain their kr~iling position su~stantially parallel with the direction of movement of the plouqh during pivotal move~ent of the bea~, a parallelogram linkage havi~g arms 10 ~ixed to ~:aid plough bodies and to a lin}c extending parallel to the beam, and a ~;econdary pivot co~ecting said link and the headstock, the secondary pivot being spas~ed f rom the main piYot towards the 4ront of the headstoclc and the length of the parallelogram linkage arms . 15 being such that in all pivotal positions of the beam, the line of the link bet~reen the points of connection to ~he arms is located b~3tween the main pivot axis and the beam, whereby as the beam is pivoted relati~re to ~h~ head~tock, the plough bodies ar~ controlledl~r pivoted relative to the 2 0 b~am .
. Preferably, the secondary pivot is ~o-located or locatable that the p~ough bodies ar~ inclined to the c:entre line o~ the headstock in a position to counteract the t~ndency o~ the beam to swing due to th resultant ~5 line of pull from the plough bodies being offset rom the cerltre line of the h~adstockO ~hus, means may be provided for controllably ~rarying the distance between the secondaxy pivo~: and the line of ~he link connecting the ends of the arms while the see:ondary pivot itsel f ~ay be 3 0 positionabl~ relatiY~ to the h~adstock O Such positioning may be along a locu~ e~tending along the length or at an ~ngle to the length of the headstodc or, in another embodiment, may. be along an arc centred on a fixed axis of the headstoc:k.
3~ ~n a pr~ferrQd, si~;:ple, con~tnlcti~n, the link s in the form of an isosceles triangle frame with the ~9 ~3 W0~4~10826 PCT/GB93/01 ends of its bas~ being pivotally connected to the arms and its apex beinq connect~d to the headstock at said secondary pivot.
Preferab~y, th~ plough has rotary inversion wheels as the soil turning m ~ ers, with these members comprising a ~lat ! or substantially ~lat, central disc, provided with a frustoconic~l working flange at its periphery, In the illustrated e~bodiment, thi~ flange is provided by a number of ~e~th, indi~idually d~tachably s~cured to the periphery of the central disc.
; . The i~vention will be further described, by way of example, with re~erence to th~ accompanying drawings, in which:-Figur2 1 is a plan view of a reversible plough;
:1 15 Fi~ure 2 is a diagrammatic view illustrating the , ~ construction for contro11ing the direction of operation of ~1l ploughing bodies:
: Fi~ure 3 is a diagram~further illustrating the operation of the plough;
2Q Figure 4 is a view similar to Fi ~ re 3 but . ~ illustrating a modified construction;
., Figure S is a plan Yi~W of th~ beam of the plough of Figura l;
~! Fi~ure 6 is a plan view of the headstock of th~
; 25 plaugh;
: Figure 7 i an elevational view of the eads ock;
Fiyure 8 is an end view nf the headstock;~ j I ! Figure 9 is a part fragmentary view illustrating :~ ~ 30 a plough body:provided with ~ rotary dis~ from ~he front with the rotary d:isc arranged in a:non-ploughing conditi~n at right-angles to the direction of extent of the plough : ~ body;
igu~ 10 is a side elevational view of the plough body of Figure 9;:
: Figure ll is~a sectional view illustrating ~he WO 94~10826 PCIi/GB93/0l764 2l~9ll3 mnunti~g f or the r~tary disc;
Figure 12 is a top view of the plough body with the rotary diec re~oved;
Fi~re 13 is a diagrammatiz ~Iriew illustrating an S alternativ~ form of link for U52 in the plough; and Figure 14 is a diagrammatic view explaining the theoretical basis ~or th2 control linkage used in the plough .
Figure 15 i8 a diagrammatio plan ~iew showing the relative positions o~ skilDmer and plough inversion wheel for ploughing in one direction.
Figure 16 is a Yiew similar to Figure 15 but showing the in~ersion wheel aTld skimmer arran~ed for ploughing in the opposite direction.
Figure 17 is an end view of a skimmer blade.
Figure 1~ i~ a front view of the blade of Figure Figure 19 is a front ~riew of an alternati~Je embodiment of ~kimmer blade, and Figure 20 is a top ~i@W of the blade of Figure 19 ~
Pc~erring to the drawings, Figure ~ ustrates a plough whic:h comprises a headstoc:k 2 pro~rided w~ th outw~rdly e2rtendin~ retaining brackets 4 which are engageable with brac:k~ts 6 on a beam 8 for retair~ing the beam in either of two limiting positions inclirled to the centre line of th@ headstock. ~h~le, in this embodiment, two working positions only are showrl ~ by aE~propriate redesigning o~ the brackets 4 and 6 more than orle working position may be pro~rided on eac:h side of the centre line, the plough bodies ~ being correctly aligTI~d by the linkage to be des ::ribed regardless of the degree of inclination of th~ beam adopted..: The b am lt . elf compri es a rigid supp~rt 9 comprising a bearing 11 for mounting to a 3 5 vertical axis ma~n pivot P at the rear end of the headstock 2. Wheels 10 are provided fQr supporting the WO 94/10826 ; ; 2 f 4 9113 PC~/GB93/01~

plough baam in its ploughing p~sition with these wheels being mounted on struts rotatable about pivots 18 at the end of the beam, these pivots also ~upporting outermost plough bodies 12 which a~e rot:atable wit;h the wheel 5 supports about the pivot axis l8. Rotatiorl of the beam 8 about the pivot P is controlled by a hydraulic c:ylinder 2 0 . ha~ing a piston connected at 22 to an arm projecting to th~ side of the rigid ~;uppo~ 9.
The c:ons~ructiQn of th~ individual plough bodies 10 12 will be described later, with refarence to Figures 9, lO, ll and 12.
With the plough as illustrated in Figure 1, in the position shown, upon forward movement of the plough, the rotary plough discs or inversion wheels will turn soil lS to the left to form the requi~ed furrowsO However, due to the fact that the resultant fs:~rce required to pull the .~ plough l~odies is displaced to one side of the centre line i o~ the main pivot P, ther~ would b~ a tendency, where the ¦ plough bodies are parallel with ~he line o~ ~xten~ of the ~0 ploughing ~or them to pull sideways bn the tractor with resultant ~raction difficulties., In ~rder to osrercome this probl~m, th~ plough bodies as sh~wn in th~ e~odiment of Figure 1 are inclined slightly to the longitudinal ~ centra line o~ the head~tock a~d the direction of:
: : 25~ ploughing so~as to apply a:sideways force which : coun~eracts the eff~ct of their b~ing ~o one side of the :~ ; centre line. ~hen the beam is r~tated so as to be oppositely inclined to ~th~ direc~ion of pIou~hing, th~
plough ~odies are arranged ko b~ inclined them ~lves 30 ~appropriat~1y to provide the:oppo~ correcting force :~ with the oppositely inclined b~amO
: ~ A~c~rdingly, with the illustrated plo~gh, ther has been d~signed a l~inkage to maintain the plou~h bodies : parallel~t~ one another during beam~rPversal and to have 35 the body arlgle variable~ when the plough is in work. The variable angle; is ~o counterac~ the forces due to the .

: - ~

yvo94/lo826 21~9113 PCI/GB93/01764 of :Eset angle of pull from trac:tor to plough . In the particular case of ~e plough l :hown, designed to run out of t:h~ furrow, th~ bodies must be biased to pull away from the centre line of the tractor to maintain fitability.
Figure 2 diagrammatically illustrate a linkage arrangament for c:ontrolling the angle Q~ plough b4dies resporlsive to p~ Yotal move~Rent of the beam., Thus, refarring to this Figure, ~e b~am 8 casl be ~een a~
pivoting about ~he point P on th~ ~eadstock with EB and FC
being two arms c~ntrolling the angle of the plough bodies with the lens~h of EB being equal to FC. The~;e arms are shows~ in Figure 1 by ref rence numeral ~ 5 0 EB and FC are constrained to remain parallel one with the other by the link ESC which is the a;ame length as EF. In the form illustrated BDC is the base of a rigid triangular link frame ABC with the trian~lar link being an isosceles l;riangle so f o~ed that AD equals PG, where G
is the mid-point of EF, and D i5 the mid-point of BC with AB eS~ual to A~C and BD equal tcs 13CQ With th~ e constra~ ts, AP must equal BE and CF, and AP, BE and CF
will remain parallel when the beam rotate~ a}:~out pivot point P.
~his system can be considered as r~presenting a paix of parallelogram lin};ages APFC and APEB lir~ed by a third parallelogra~a lin Icage BCFE and allows the parallelogram linkage APFG to go ov~r-ce~tre when the beam is ro~:ated anticloc:kwise while the linkage parallelogram APEB mairltairls control.
This linkage can be considered mathematic:ally by visualising a pha~tom link connected between the mid-point of EF (which by def initiQn is G) and point D on the triangular li~age. l)G is- the ame length a~ BE and CF
and always remains parallel with them. A~ so, instead of using the triangular lirlk, the lîne A~ may be c:onsider~d 3 5 instead as being perpendicular tv the original connecting link BC, and also the line EFq Thus although for WO 94/10826 214 9113 PCI/GB93J017 ~

structural reasons we have shown the 1 ink as being triangular, it can be of any con~enient f orm, provided tllat it defines the locations of the pointg B, C and A.
With the above explanation, one obtains the 5 geometric diagram il~u~;trated in Figur~ 3. Where AP~;D
becomes a new parallel linkage, it i. clear t:hat because of the rigid nature of the triangular link, the proj ection of ~D onto the line EGF will always be p~rpendicular since by c:orlstruc:tion th~ beam assembly PG is perperldicular to 10 the line EF.
While, in the abo~re explanation, the point ~ has been considered as being a f ixed pi~rot point on the centre line of the frame, position ~ could be ~risualised as being able to slide along ~he line AP, i. e. that t~ere is no 15 fixed link between ~ arld P. The point A would ski}l, however, remain in a fixed position relatiYe to P because DG is a fixed length and AD and PG must relaain parallel to each other, as defined as the visuali~ed li ~age was described. Having adopted t~e possibility of haYing a slide a~ A the~ the poss~bility exists to alter ~he dimensions of the link AD, . ill ~aintaining AD parallel to PG. Lengthening or shortenin~ ~he leng~h AD will rotate DG so that it is not parallel to~AP.
This idea can be taken one stage ~urther in that the point A need not necessarily slide along the lîne AP.
~hus, as shown in Figure 4~, the con~ept is introduced of point A being allowed to slide along a loaus J~. The positio~ of A and length AD do not neces~arily constrain ~G paral1el to ~PH a~d ~he variation from parallel will be a function of the po~ition~of point ~ along the locus AK
: and the r~lative lengths of AD, DG and PG and tha angle HH
~ubtended by the be~m. The constraint that AD is parallel to PG still exi~ts, The plough illustrated in Fi~ure 1 utilises a fixed triangular~linkage with the secondary piYot A being received within ~ slipper pad h2ving a variable degree of - ~WO 94/10826 21 ~ 91 1 3 P~/GB93/01764 angular movement. However, as will be discussed later, either wi~ this arrangement or with a ~;lipper f ixed to the centre 1 ine o~ the plc: ugh h adstock advarltages can be appreciated by having what is ef f ectivel~ a triangular 5 link with a ~ariable geometry. Such a triangular linlc could be made as showrl in Fisure 13 where the triangular link is shown as comprising a base 26 connecting the pi~ots B and C, two sides 27 and 28 welded to an outer 3:ox section 30 and an inner bo~ section 32 ~li dable within the 10 outer box s~ction 34 along the centre line of the triangular link. The position of the inner box ~ec:tion along the length o~ the outer box sectioIl is ::ontrollable by a threaded member 3 4 . The bax section 3 2 carries a bearing 36 for engagement with the pivot A. It will be 15 appreciated that in Figllre 13 the beam is shown in its mid-position, between its normal ploughing positions extending transv~rsely of the direction of ploughing.
We will explain later, in connection with Figure 14, the mathe~atiaal bat:Jcground to the ~mbodimenks 20 illustrated.
R~vertiIlg to the parti~ular construction of the plough shown in Figure 1, the headstock is illustrated in Figures 6, 7 and 8. The headstock c:omprises a trian~lar base f raIae having the pivot P at its r~arward end and 25 provided with lower c:onnecting members 40 at its forward end. An upper pivot conn~cti on 44 is connected by a central sloping member 46 and two ïateral sloping mem~ers 42 to the base frame. Forward of the pivot point P there is provided a mounting for the apex of the triangular ~ ink 3 Q which comprises a platf orm 52 ha~ring an upstanding mem}~er 50 defining a re~rwardly openirlg rece ~ with diverging sides. A hole 54 is pro~ided in this mounting plat:e 52 to provide a f ixed vertical axis ~or receiving a 3:)olt 54 ' wh.ich pi~otally retains a pivot supporting member 56 which 35 carries the se ::ondary pi~ot P~O The pivot supporting member 56 i~ ~hus pivotal between limiting positions in WO 94/10826 ~,, 49~3 PCl/GB93/0l '!

engagement with the diverging walls of the meInber 50, the secondary pivot ~ being displaceable about a radius centred on the axi~ o the hole 54.
W~th thi5 arrangement, as shown in Figure 1, ths 5 pivot point A is offset to one ~ide of` the cen~r~ of the headstock 46 with the result that with the beam in its inclined ploughing position shown in this Figure, the plough bodies will be in~::lined to the centre line of the headstock to th~ required ~xt~, to provide the corrected 10 bias. When the direction of th~ plough is rev~rsed so that the beam is swung round to the other side of the headstock, the pivotable member 55 will it~;elf rock to engage the opposite side of the rece s provided }:~y the member 50 with the pivot point A t~en being on the 15 opposite side of the centre line of the headstock with the result that the appropriate alignment of the plough ~3odies is achieved.
Figure~ 9 to 12 illu~:trate the constructio~ of the plou~h bodi~ the~selves. As shot~m in these ~iç~res, 20 the rotary disc: is not shown in its operative po-~ition but i~ shown arranged to extend with its plan~ perpendicular to the line of extent of the plough body.
The plough body is illustrated detached from the remainder of the plough and comprises an upper L~shaped 25 fram~ member 60 haviT~g a lower extension 62 weld~d ~ereto with the exterlsion ~2 being connec:ted by bolts 63 to a downward~y dep~nding leg 64 provided at its fr~nt edge with a soil penetrating or cutting member ~6S Asl ~3hown, the member 66 is bolted into position and is reversible so 30 that as ~he point 67 wear~;, it can simply be adjusted down using a plurality of bolt hole~ proYided on the leg 64 to permit adjusting of the positioT~ sf the soil pen~trati~g alement 66 to take up for shortening of the member in use.
Once the limit of adjustment has been rPached, the meDIber 3 5 6 6 can s imply be removed and reversed to use the other point 67.

-~094/10826 æ~ ~3I13 PCr/GB93tOI764 Extending rearwardly from the leg 64 is a landslide 6B whic:h extends beneath a rotary ~oil inversion wheel 90. R~arwardly of the ~oil in~rPrsion wh~el 90 a post 70 is upstanding from the landslide and secured by bolt 73 to a member 72 which has a~ upper flange providing a suppor~ 74 for the lower end l~f a shaft 76.
The frame memb~r 60 i~ adapted to be secllred to bodies piYotally mount~d on t:he p~vots E,F and 18 by members 80 and 81 (Figure 1) extending rearwardly from the ~0 bodies mc~unted on the pivots. Carried by the rearwardly extending portion of th~ frame 60 i5 a body B2 which carxies at its rearward end a support 8~ for the upper end of the sha~t 76. The shaft 76 rotatably mounts a sleeve 84 proYided with grease nipples 85. P~lso carried by the 15 frame mensber 8~ are a pair of adjustable stops 88 which limit rotakion o~ the sleeve 84 by c:ooperatirlg with a stop 92 rc~tatable with the sleeve ~4. Secured ts:s the sleeve 84 i~ a plate 9~ which extends ~orwardly and has a laterally projecting portion to which is secured a pivot 96 for 2 O attachment to the end o~ a piston coc~perable with a hydraulîc cylindQr 97. At the low~r end of the slee~e, there is provided a bearing 100 ~or mounting a rotatabl~
hub 98. Secured 1:o the forward end o~ th~ hub 98 is an in~rersion whee} mountis~g plate 102 to which i~ secured by 25 bolts 103 the central planar plate ~04 of i~version wheel 90. The working por1;ion of the irlversion wheel ~0 can be considered as being c:onstituted ~y an annular frustocorllc:al flange ~;e ::ured to th~ periphery s:~ the central disc portion }04 by bolts 105. In the embodiment 30 shown, the worl~ing flar~ge is constitu~ed by a plurality o~
separate teeth 10 6 bolted to the periph~ry of the central disc portio~ although other forms of flang~ ~re possible, for exa~nple a continuous flange which may have a smc)oth edge, a toothed edge ~ an undulating edge or any other edge 3 5 f ormation as conside;red desirable; depending upon the environment in which the plough is to be usPd.

WO 94/lû8t6 Z 1 ~ 9 1~3 PCrlGB93/0 To the forward end of the pla~e 94 there is provîded a do~nwardly extending sc:raper 108 which is cooperable with the inversion wheel durin~ use of the E~lough .
To the top of the body 82, there is provided a pivot shaft 110 for receipt within a bore at the end of a ::olmecting bar 112. A.s can be seen in Figure 1, the connecting bar 112 extends between the rod~ llO extending upwardly from two neighbouring plough bodies in order to ensure that the plough bodies remain parallel one with the other .
Also shown in Figure lQ is a support 150 for use in detacha:bly mounting a secondary ploughing disc operative as disclosed in my earlier GB-A-2 254 232 or for mounting a f ixed skimmer blade as later de~c:ribed ~, 5upport 150 depends from a plate 154 which is rotatable about the shaft 86 independently of the sleeve 84. A pair of stops 152, which may be adjustable, projact upward ~rom the plate 94 E;O that ~?on operatio~s o~ the hydraulic cylinder ~7 to reverse the angle of in~lination of the .
in~ersion wheel 90, the plate 94 will r6:tate until such time as a stop 152 engages the plate 154 to displace the plat~3 154 throu~h the remainder o~ 3 rotational movement o~ the plate 94 with th~ result that the plate 154 is swung through a smaller angle than the angle through which the plate 94 is turned. Conversely, upon return movement of the lplate 9~, stop 1~2 is only engageable with the plate 154 for th~ latter part of the mo~emen- of the plate 94 withl the result that th~ required smaller degree of pivoting movement of thQ p~.ate 154 i required.
A}ternatively, the plate 154 may be pivoted ~Eor swinging movem~nt about an axis f ormed of the axis of the swinging movement of the main ploughing disc a~ will be described with reference to Fig~res 15 anà 16.
3 5 Although not ~;hown in Figure 10, the box 150 serves as a ~apport for a detachable secondary ploughing Y,VO 94~ 1 0826 2 1 ~ 9 11 3 P~r/GB93~01 764 disc which will be molmted in front of the main ploughing disc or inver~;ion wheel 90 w~th its leading edge substantially aligne~ with the leg 64. With the secondary ploughing disc in position with its E;uppor~ mounted 5 depending from the box a;ection 150, the tilling apparatu~
can be seen to comprise the primary concave ploughillg disc 90 rotatable by reactioll with the grourld to be tilled and in::lined to th~ direction of forward move~e~at to pro~ride a soil tilling and ploughing action arld the secondary, smaller, ploughin~ disc mounted within the concavity of the primary ploughing disr~ and more greatly inclined to the dire~tion of f orward movement in order to displace a s}iver of soil, toge'cher with stubble and ~traw off the surf ace of th~ ground, the primary ploughing disc: being operati~e in use o~ the plough to roll the clean soil from th~ underside of the sliYer over to cover the sliYer of soil, stubble and str~w initially displaced, the secondary ploughing disc: being rotatable about its axis. The ~orward edge~ o~E both the ~;econdary and the primary ploughing discs ar~ substantially aligned with the point 66 and 1 eg 64 . The g:ec:ondary ploughing disc may be a soil inversion wheel cons~r~ction with a flat central disc as for the main ploughing disc althou~ in some circumstaIlces a simple concave disc: may be utilised. A ~mall scraper may be pro~icled Zl ~ociated with the secondary ploughin disc to operate in a manner similar to that in which th~
sc~rap~r 108 operates with the main ~;oil in~ersion wheel 90. Alternat:ively, instead of t~Le ~;ec:ondlary ploughing disc, a non-rotatable skimmer blad~3 may be used as later described with reference to Figures 15 tc~ 20.
In use of the plough t it can be seen that in one norma} working position for producing left-hand furrows, the plo~lgh will be in the position as æhowrl in Figure 1 with the beam having been incl ined about the main pivot P
until the left-hand retainers 4 and 6 have engaged. In that positiorl, the linkage comprising the main triangular WO 94~10826 PC~/GB93/01- j ~49113 link 26, 27, 28 s::ontrols the position of the two innermostplough bodies so that they are slightly out of parallel with the direction o~ movement of the plough, in order to provide a correcting bia~, assisting straight traction by 5 the tractor. The outarmost plough bodies are maintainPd parallel with the two inner controlled plough bodies by the cormecting bars 112.
When it is desired to reverse the direction of the plough, t~e ::yl i nder 25 can be actuated to rotate the 10 beam 8 about khe main pivot P until the right-hand retainers 4 and 6 are engaged. During this rotatlon, the p- ough bodies will automatically be, them~elves, rotated relative to the beam so as to reach th~ desired orientation, slightly non-para3 lel, in the opposite sense, 15 with the direction of motion of the plouyh. P.t the same timel the inversion wheels are, themselves, moved from the worlcing position shn~m in Figure 1 i:o an oppositely inclined working position relative to the plough body by , operation of thQ cylind~rs 97.... The limitin~ rotating positions of the inversion whee~ relative to the plough body are controlled by t~e adjustable stops ~8.
As ~urther explanation j there will now be described in connectio~ with Figure 14, the mathematical ~xplana~ion ~f the linkage used ~or cc)ntrolling the angular position of the plough ~odies. This ~an be expressed as having a problem to ~how the body steering angle GG in terms e: f the ~;lider aslgle JJ, th2 beam angl .
HH and the link l~nqth AD. The lengths PG (beam o~fset~, iPG (leYer arm) ~ JP ~slider pivot position~, can be 3 0 considered as the required data sinee, due to th~
collstraints imposed in the practical linkage, Al:) must always be parallel to PG. In ~igure 14 ~ JA and G~? have }~en produced to meet at R and GL lhas been drawn parallel to JA to meet I~D produced at M8 The method that i5 applied is to use the parallelogram AXGM ~o de~erminP the length of DM and by -~O 94~10826 214 9113 PC~/GB93~01764 - 15 ~
applying thè sine rule to triangle DGM to f ind the angle DG.
.

~ ~ .

WO 94/l08~6 214 9 1il 3 PCI/GB93/~

First, f ind KP by applyin~ the sine rule to triangle J~P.

KP JP
S inJJ 5 ~ / Z +~ D

Therefore KP = JP Sin ~J
C;: s (HH~JJ) clearly D~ = KP + PG - AD 2 f rom 1 and 2 J~ S in JJ + p~; AD
C~s (HH JJ~
now, applying the sine nlle to triangle DMG
DM = DG
Sin (JJ-G~) si~ /2~ ~~~l~il~

hence Sin (JJ-GG) G ~ Cos (~ D) DG

and GG a JJ ~ Sin 1 [ ~ Cos(~ D~ ] 4 , D~;
and el iminating DM f rom 3 and 4 GG - JJ ~ Sin~1 [ JPsin JJ ~ ( ~ cos~H~~JJ) ¦ 5 DG ~X;
E~ua i:ion 5 is the general expres~ion relating angle GG . in terms of angles JJ and GG and length AD with giverl len~ths JP, DG, PG and AD.
If ~z more particular case wh~re the slider angle ig always~ zero, as is~ the embodim~nt of Fi~re 13, and GG is controlled by ~aryin~ AD, then equation 5 reduces to GG = -Sin 1 [ ( AD) Cos ~HH-JJ) ] 5a D~

-~1~ 94/10826 . ; 1 ~9i 13 PCr~G;B93/0l764 Figures 15 and 16 diagrammatically illustrate a constructiorl using a non rotatable ~kimmer blade 204, dependins~ from a pivotal arm 154 which, instead of being swingable about the axis 2 00 abou~ which the arm 98 5 carrying the inversion wheel 90 is swingable, is swingable relative to the plcugh body about a vertic:al axis 202 forward of the axis 200. The skimmer blade 204 will, in use of the plough, be the sama side of l:he landslide 68 as the main tilling inversion wheel or disc ~ ~0 with the 10 fc~rward c:utting edge ~ of the blade 204 beLng substantially aligned behind the point 67 as is the forward edge of the i~er~ion wheel 90.
q~he! mounting o~ the~ blade 204 is shown in greater detail in Figures 17 and 18 where a tube 2 06 15 depends from the arm~l54. The s~ppor~: rod 208 is telesc:opica}ly receivable in the tube 206 so as to permit vertical adjustment of the height of the cki~mer blade 204 i relati~re to the plough body. The skim~er blade 20.
; ~ ::omprises a c:urved main portion with a bottom wear blade 20 2~0 detachably secured to: the bottom ~of ~e blade, for ~: ~ example by means of bolts, :not shown.~ Both ends of the blade 204 have working edg~s which;will be alternati~ely :1 aligned with ~he point 67 depending:upon ~he direction of ploughing and whether left- or ri~ht-hand ploughing is:
: as being carried vut. An alternative shape of skimmer blade 212 is shown~in Figure 19 and 20. ~: ~
In each case, the skimmer will serve to turn a .sliver of the!~:top~urface and deb~iq~from th$ gr~und ~eing ploughed before the main full depth ploughing is achie~ed : 30 using the inversion:wheel` which~uries~the materiaI turned by~the~:fixed~skimmer blade~with ea:rth~turned up ~rom below.
djustable stops can be:provi~ed to limit th~
swinging:movement of the~arm 154, pre~erably both tha height o~ the:~skimmer blade~and of the in~ersion wheel 90 :is adjustable. ~he incl~ination of the skimmer, wheth2r a , WO 94J10826 214 9113 PCr/GB93/01-blade or a rotary discI preiferably also is adjustable relative ~o the ground. The inc~ination to the horizontal c:an ba adjusted by inc:lining the axis about which the arm carrying the ikimmer is pi~,rc~table or by adju~ting the 5 inclination of the skiDer relative to the arm t 154 ~ by which it is carried.

, ~

Claims

1. A plough comprising:
a frame;
tilling apparatus supported by said frame and comprising a primary concave ploughing disc rotatable by reaction with the ground to be tilled and inclined in the direction of forward movement of the plough to provide a soil tilling and ploughing action and a skimmer mounted adjacent the primary ploughing disc and more greatly inclined to the direction of forward movement than the primary ploughing disc, in order to displace a sliver of soil together with stubble and straw off the surface of the ground, the primary ploughing disc being operative in use of the plough to roll the clean soil from the underside of the sliver over to cover the sliver of soil, stubble and straw initially displaced;
a point depending from the frame to penetrate the ground in front of the forward edge of the primary ploughing disc, the skimmer also having a forward edge substantially aligned with the point;
means for pivoting the primary ploughing disc relative to the frame between positions in which it is oppositely inclined to the direction of forward movement of the plough; and means for pivoting the skimmer, through an angle smaller than the angle of pivotal movement of the primary ploughing disc, between positions in which it is oppositely inclined to the direction of forward movement of the plough.

2. A plough according to claim 1, wherein the skimmer is detachably mounted to the tilling apparatus.

3. A plough according to claim 1 or 2, wherein the skimmer is adjustable in respect of the inclination to the horizontal.

4. A plough according to claim 1, 2 or 3, wherein a landslide extends rearwardly from the point below and to the rear of said primary ploughing disc.

5. A plough according to claim 1, 2, 3 or 4, wherein the primary ploughing disc comprises a substantially flat central member having a frustoconical ploughing flange extending from its periphery.

6. A plough according to claim 5, wherein the.
ploughing flange comprises a plurality of teeth preferably detachably secured to the periphery of the flat disc.

7. A plough according to any preceding claim, wherein the primary ploughing disc is pivotable about a substantially vertical axis.

8. A plough according to any preceding claim, wherein the means for pivoting the skimmer are operative in response to operation of the means for pivoting the primary ploughing disc.

9. A plough according to any preceding claim, wherein the skimmer is a secondary, smaller ploughing disc rotatable about its axis.

10. A plough according to any one of claims 1 to 8, wherein the skimmer comprises a rigid blade having a forward edge substantially aligned with the point.

11. A plough according to claim 10, wherein the rigid blade has a working edge at each end.

12. A plough according to claim 10 or 11, wherein a wear element is secured to the blade.

13. A plough according to any one of claims 10 to 13, wherein the blade is adjustable up and down relative to the plough frame.

14. A plough according to any one of claim. 10 to 13, wherein adjustable stops are provided for limiting pivotal movement of the blade to define positions for left and right hand ploughing.

15. A plough according to any preceding claim, comprising a headstock for attachment at one end to a tractor and provided with a substantially vertical axis main pivot at its other end, a beam connected as said frame by a rigid support to said main pivot whereby the beam is spaced from said axis and is pivotable thereabout in a substantially horizontal plane so as to be inclinable to either side of the direction of movement of the plough, a plurality of plough bodies comprising the tilling apparatus pivotally supported by said beam for pivotal movement about substantially vertical axes whereby the plough bodies can pivot upon pivotal movement of the beam to maintain their trailing position substantially parallel with the direction of movement of the plough during pivotal movement of the beam, a parallelogram linkage having arms fixed to said plough bodies and to a link extending parallel to the beam, and a secondary pivot connecting said link and the headstock, the secondary pivot being spaced from the main pivot towards the front of the headstock and the length of the parallelogram linkage arms being such that in all pivotal positions of the beam, the line of the link between the points of connection to the arms is located between the main pivot axis and the beam, whereby as the beam is pivoted relative to the headstock, the plough bodies are controlledly pivoted relative to the beam.

16. A plough according to claim 15, wherein the secondary pivot is so-located or locatable that the plough bodies are inclined to the centre line of the headstock in a position to counteract the tendency of the beam to swing due to the resultant line of pull from the plough bodies being offset from the centre line of the headstock.

17. A plough according to claim 15 or 16, wherein means are provided for controllable varying the distance between the secondary pivot and the line of the link connecting the ends of the arms.

18. A plough according to claim 17, wherein the link is in the form of an isosceles triangle frame with the ends of its base being pivotally connected to the arms and its apex being connected to the headstock at said secondary pivot.

19. A plough according to claim 18, wherein at the apex of the triangular frame, an adjustable connection is provided to said secondary pivot.

20. A plough according to claim 19, wherein the adjustable connection comprises a member controllably movable relative to the triangular frame in a direction perpendicular to said base, said member being pivoted to said secondary pivot.

21. A plough according to claim 20, wherein the member is comprised by an inner box section slidably movable within an outer box section fixed to the sides of said triangular frame and means for adjusting the position of the inner box section comprises a screw cooperating with both said box sections.

22. A plough according to any one of claims 15 to 21, wherein the secondary pivot is itself positionable relative to the headstock.

23. A plough according to claim 22, wherein the secondary pivot is itself positionable relative to the headstock along a locus extending at an angle to the length of the headstock.

24. A plough according to claim 23, wherein the angle of said locus is variable.

25. A plough according to claim 22, wherein the secondary pivot is displaceable about a radius centred on a fixed axis on said headstock.

26. A plough according to claim 25, wherein a pivot supporting member is mounted for movement about said fixed axis between limiting positions in which it is inclined to.
opposite sides of the headstock centre line, said secondary pivot being carried by said pivot supporting member.

27. A plough according to any one of claims 15 to 26, wherein said headstock is provided with means for holding said beam in required working positions inclined to the direction of movement of the plough.

28. A plough according to claim 27, wherein the means for holding the beam is adapted to hold the beam in either of two oppositely inclined limiting positions.

29. A plough according to any one of claims 15 to 28, wherein the link is secured to two plough bodies, said two plough bodies each being connected to at least one other plough body to ensure that the plough bodies are movable together and in parallelism one with the other.

30. A plough according to any one of claims 15 to 29, wherein each plough body comprises a point on a depending leg adapted to penetrate the soil in front of a rearwardly extending landslide which passes below and to the rear of a rotary ploughing disc.