AU661780B2

AU661780B2 - Harrow frame for prickle chains

Info

Publication number: AU661780B2
Application number: AU42181/93A
Authority: AU
Inventors: Lyell James Woolford
Original assignee: Individual
Current assignee: Individual
Priority date: 1992-07-31
Filing date: 1993-07-26
Publication date: 1995-08-03
Anticipated expiration: 2013-07-26
Also published as: AU4218193A

Description

'.3 a 661780

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

,Regulation 3.2 t Vt

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Name of Applicant: Actual Inventor: Address for Service: Invention title: LYELL JAMES WOOLFORD LYELL JAMES WOOLFORD R K MADDERN ASSOCIATES, 345 King William Street, Adelaide, South Australia, Australia "HARROW FRAME FOR PRICKLE CHAINS"

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0o Details of Associated Provisional Aplication No: PL 3862 dated 31st July 1992 The following statement is a full description of this invention, including the best method of performing it known to me.

1 This invention relates to a harrow frame of the type which is useful for prickle chains.

In my Patent Application 60974/90, there was described and illustrated a harrow frame which was of general cruciform shape, wherein prickle chains were rotatable between the diagonal corners of the frame, one of the frame members being longitudinal and the other transverse. Such an arrangement proves particularly useful and has been widely used, but there are some difficulties which were encountered and which this invention seeks to overcome.

The main single difficulty which was encountered with the aforesaid harrow frame was the difficulty of transport.

Quite often frame members, when folded, would exceed metres width and 5.5 meters high, making folding of a harrow S frame for transport purposes extremely difficult. For road transport it was neces;ary to disassemble and reassemble the S frame, and even with all that extensive and time-consuming work, quite often the frame would exceed the allowable road width or length.

The ma.in object of this invention therefore is to provide a frame having a large cutting width, which is able to be more easily and readily folded into a transporting condition, and wherein the frame can be folded down to a much lower height, and to a narrower width than heretofore.

Another problem which is encountered with harrow frame of the prickle chain type is that it is desirable to be able to modify the angle of attack at which the prickle chains address the terrain to be cultivated, and another object of this invention is to provide means whereby this can be quickly and easily achieved.

According to this invention therefore, a folding harrow frame assembly for a prickle chain type harrow comprises a central towing frame having a towing hitch at its forward 2 mm m m lum mmmmmI ue amI n end, a main frame comprising four elongate main frame members which, when the frame is in its in-use mode, together form a substantially rectangular or diamond shaped frame, two of said frame members constituting leading frame members (with reference to the direction of forward travel of the frame), the other two frame members constituting trailing frame members, pivotal connection means pivotally connecting said leading frame members at their leading ends to said towing frame on opposite sides thereof, further pivotal connection means between the trailing ends of said leading frame members and the leading ends of their associated trailing frame members, releasable connection means between the adjacent trailing ends of said trailing frame members and which, when released, permit said trailing frame members to be separated 5 and thereafter each folded about its associated said further pivotal connection, to lie alongside but outboard of its fC t associated said leading frame member, said leading frame members, during the folding movement of the trailing frame S members, swinging inwardly towards one another, whereby the main frame can fold essentially horizontally to a reduced width for transport or storage purposes, and ground-engaging wheels supporting the main frame for movement across the ground to be harrowed.

Preferably, prickle chains are supported by and extend along said frame members so that when the frame is in use, the chains are drawn across the ground being tilled with each chain being disposed at an angle with respect to the direction of travel.

Preferably, a flexible cable extends between the leading corner of the frame and the diagonally opposite trailing corner, the cable including means for varying its effective length, for example a chain which can be advanced or retracted one link at a time. This provides means for adjusting the angle of the frame members with respect to one another and retains the frame members in their diamond shape when the frame is being pulled along.

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I Preferably, the other two diagonal corners of the frame are each provided with an outstanding frame member portion at the forward end of the trailing frame member defining therewith an shape, and vertical pivot means joining the outer end of the outstanding frame member portion to the trailing end of the leading frame member so that upon release of the diagonal cable, the trailing frame members can be separated and folded to lie alongside but outboard of the leading frame members and parallel therewith.

n I1t r L I -i jp ,7 F Another difficulty which is encountered with the cruciform type of harrow frame which has been used previously is that when folding the frame for transport purposes, the chains loop so as to drag on the ground and are difficult to lift upwardly clear of the ground. In another embodiment of this invention, there are four separate lengths of prickle chain each connected through bearing means at its ends to a respective one of the four frame members, so that each frame member independently has its own prickle chain, and each of the prickle chains can be readily l.ifted to be supported by the relevant frame members. Still further, use is made in another embodiment of an over-centre type lift arrangement whereby the prickle chains are quickly and readily lifted from the ground to be supported intermediate their eniF via the respective frame members which carry them.

:j In order to ensure proper tracking of the folded frame 0 in transport, it is not feasible to utilise castors on all the wheels at the respective corners of the frame, and in another embodiment of the invention there are provided two diagonally opposite bogies (one to each side Of the central longitudinal axis of the frame) secured to respective said leading frame members, each having two wheels each carried on a sub-frame and provision is made for the wheel sub-frames to be rotated about a vertical axis with respect to the bogies so that the wheels align with the direction of travel when the frame is in its transport position, but can also be repositioned to align with the direction of travel when the frame is in its in-use position.

It is desirable if not essential that the prickle chains should be retained under tension, and heretofore tension has been achieved by means of springs at the forward ends of the prickle chains which provide the required tension. However when positioned at the forward ends of the prickle chains, not only must the springs tension the chains but must also provide the required resistance against the load which is encountered by the chains as they traverse the terrain which i -I ~3~f~ is being cultivated. In a further embodiment of this invention, tension spring adjusters are utilised to tension the prickle chains but are located at the rearward ends thereof, the adjusters being effective to decrease or increase the effective lengths of the chains.

In order to further explain the present invention, an embodiment of the invention is described hereunder in some further detail with reference to and as illustrated in the accompanying drawings in which:- Fig. 1 is a plan view of a harrow frame for prickle chains which is illustrated in its in-use position; 0*0#VE 15 Fig. la is a fragmentary plan view of the rear corner of the frame shown in Fig. 1; Fig. 2 is a plan view illustrating the harrow frame when folded to its transporting or storage position; 0 Fig. 3 is a perspective view to a larger scale which illustrates the manner in which the bogie wheels can be adjusted for position to track in either the transport or in- 00 use modes; Fig. 4 is a perspective view illustrating the hitch S arrangement in further detail; Fig. 5 is a perspective view which illustrates the overcentre lift arrangement for raising the prickle chains from the ground when they are not required for cultivating; and Fig. 6 is a fragmentary perspective view showing a corner connection between a leading and a trailing frame member.

In this embodiment a harrow frame 10 is rectangularly or diamond shaped and comprises four elongate frame members 11, 12, 13, 14, of which the members 11, 12 are leading frame il members and the frame members 13, 14 are trailing frame members when the frame is in its in-use mode as illustri-ted in Fig. 1. Each frame member is provided with a dependin pivotal bracket 15 carrying a bearing 16 to which the forward end of a prickle chain 17 is coupled, the rear end of the prickle chain 17 being coupled to respective trailing bearings 18, the trailing beariigs 18 being carried on swivel arms 19 spring-loaded by springs 20 which are found to be much more effective at the trailing ends of the chains 17 than at the forward ends.

As shown in Fig. i, the chains 17 are arranged so that S their lengthwise axes intersect to ensure that the ground over which the harrow is drawn is completely cultivated.

o o o At the forward corner of the frame 10 there is provided Oo a towbar 24, the rear end of which terminates in a crossbar 25 to which the forward ends of the leading frame members 11, 12 are hinged for pivotal movement about vertical axes.

20 Secondary links 26 are pivoted at their rear ends to the leading frame members 11 and 12, and at their forward ends to the towbar 24 at vertical pivots 27. This arrangement overcomes a serious difficulty previously encountered in that without the use of secondary links the frame can swivel 25 uncontrollably from side to side when being towed.

5*~ A cable 30 extends from the leading corner of the frame to the diagonally opposite trailing corner, the cable comprising a short length of chain 31 which is secured at its forward end to an anchorage fixed to the underside of towbar hm .24, whilst its rear end can be coupled link by link to an i anchor 32 adjacent the pivot connection 33 between the trailing frame members 13 and 14 at the trailing corner of the frame 10. This provides means to adjust the angle of the frame members with respect to one another and thereby with respect to the direction of travel. The cable 30 also ensures that the frame members do not collapse or fold inwardly when the frame is being pulled along.

6 The towbar 24 of the frame 10 is conventionally coupled to a tractor (not shown). A pair of bogie frames 34 and secured by clamps to the frame members 11, 12 respectively, are each supported by a pair of wheels 36, each wheel 36 being carried by an adjustable sub-frame bracket 37 (Fig. 3), the adjustable bracket 37 having an arcuate slot 38 by which the wheel attitude may be changed to track with the frame alternatively in the transport or in the in-use modes. A clamp device 39 retains the wheel sub-frames in their adjusted positions.

The trailing end of each of the trailing frame members 13, 14 is also provided with a sub-frame bracket 41 which, in the in-use mode, is directed inwardly and terminates in the castor pin 42 of a castor wheel 43.

The leading end of each harrow frame member 13, 14 is provided with an outstanding arm 46 so that as seen in Fig.

1, the trailing frame members are L-shaped at their leading ends, and each outstanding arm 46 is hinged at 47 to its associated le kding frame -'.ber 11, 12, the hinge point 47 being offset to one side of the frame member.

ii The pivotal connection between the trailing frame members 13, 14 comprises pivot pin 33 at the location of the anchor 32 and which is withdrawn when it is desired to fold the frame 10. At that stage, the cable 30 will have been released from its anchor 32, and the frame 10 drawn forwardly so that the Lrame members 11, 12 lie almost parallel as shown in Fig. 2. With the pin 33 withdrawn, the frame members 13, 14 can be swivelled around to lie outside but parallel to the respective frame members 11, 12 as shown in Fig. 2. In order to retain the pairs of france members 11, 14 and 12, 13 with the members of each pair together in approximate parallel relationship, use is made of rigid cross clamps or bridging members 48 (refer Fig. 2) whilst in order to retain the frame members 11, 12 in a fixed, spaced apart relationshAp, there is provided a pair of co-operable clamp members 49, 49' 7

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(refer Fig. 1) bridging the frame members 11, 12 and which releasably retain them together.

Before the folding of the frame members can be achieved it is necessary for the prickle chains 17 to be lifted from the ground, and this is achieved by a number of over-centre pivotal levers 50 carried on the frame members and spaced therealong and which are hooked onto the prickle chain 17 by hooks 51 coupled to their levers 50 by short length chains 52 (refer Fig. tI 1~ t

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When released from its anchor 32, the cable 30 is run along one of the leading frame members and threaded between the upstanding levers 50 to hold it in place.

Referring to Fig. 6, to ensure that the chains 17 do not sag excessively over the ground which is to be harrowed, the chains 17 are tensioned by means of tension springs 20 each of which is associated with a tensioning device which is coupled to a chain 17 via the pivoting arms 19. The tensioning device comprises a pivoted plate 54 pivoted about a pin 55, and the moving end of spring 20 is coupled to a latch bar 56 which releasably engages in the plate 54, and when the plate is swung over to the position shown in Fig. 6, the spring 20 is tensioned, a removable pin 57 being used to lock the plate 54 and latch bar 56 together. The other spring end is anchored to its associated frame member 11, 12.

It will be seen that this invention provides a simple and effective means to reduce both height and width for transport purposes without the need to separately disassemble and reassemble the frame as is the case with known prior art.

It will also be seen tnat use of the longitudinal cable provides means to vary the angle of the frame members relative to one another, and thereby the attack angle of the prickle chains when the frame is in its in-use mode. Since each beam carries its own chain and the tension does not change, it is a simple matter to lift the prickle chains as shown in Fig. 5. The bogie wheels in being repositionable 8 i

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-<1 between the two modes, provide stable wheel conditions for towing purposes, and this is achieved without the use of expensive hydraulics which are otherwise deemed necessary.

These and other advantages will readily be discerned from the above description and the accompanying drawings.

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Claims

2. A folding harrow frame assembly according to claim 1 wherein said leading frame members, when said frame is in a transport mode of use, are approxi::,ately parallel.
3. A folding harrow frame assembly according to either claim 1 or claim 2 further comprising a flexible cable extending between said one corner of the rectangular frame and the diagonally opposite trailing corner thereof, said cable including adjuster means for varying the effective ii ~1 rii I I length thereof, said cable being releasably anchored at its trailing end to an anchorage point at or near said diagonally opposite trailing corner.
4. A folding harrow frame assembly according to claim 3 wherein said adjuster means comprises a short length chain which can be advanced or retracted, link by link, relative to said anchorage point. A folding harrow frame assembly according to any one of the preceding claims wherein each of the trailing frame members is provided at its forward end with an outwardly projecting frame member portion which, when the frame is in its in-use mode, is in contiguous or near contiguous relation with a trailing end portion of a respective said leading frame member, each said further pivotal connection means comprising a vertical pivot pivotally connecting the outer end of said outwardly projecting frame member portion to the I' "0 trailing end of said leading frame member, the pivot axis of (I said vertical pivot being spaced to one side of said leading j frame member.
6. A folding harrow frame assembly according to any one of |Ii the preceding claims wherein said releasable connection means between the trailing frame members comprises a removable pivot pin or bolt located a short distance diagonally inwards from the rear trailing corner of the frame. t
7. A folding harrow frame assembly according to any one of the preceding claims further comprising two essentially diagonally opposite wheel bogies on opposite sides of the j- central longitudinal axis of the frame, each said wheel bogie being secured to a respective said leGding frame member near its trailing end, and each having two ground wheels each carried on a respective sub-frame, each said wheel sub-frame being rotatable about a vertical axis with respect to its bogie so that the wheels can align with the direction of travel when the frame is in its transport mode of use, but 1 I can also be repositioned to align with the direction of travel when the frame is in its in-use mode.
8. A folding harrow frame assembly according to claim 7 further comprising a pair of castor type ground wheels each supporting a trailing end of a respective said trailing frame member.
9. A folding harrow frame assembly according to any preceding claim further comprising four separate rotatable Sprickle chains each coupled through bearing means at its opposite ends to opposite ends of a respective one of said four frame members, whereby each main frame member independently has its own prickle chain extending along the length thereof, the chains being arranged so that when the frame is in-use, the chains are drawn across the ground being harrowed with each chain being disposed at an angle with I O.a respect to the direction of travel. A folding harrow frame assembly according to claim 9 wherein the rear or trailing end of each said prickle chain is coupled to a respective said bearing carried on a pivoted arm, and further comprising a spring and spring tensioning device co-acting between the pivoted arm and the associated said frame member.
11. A folding harrow frame assembly according to either claim 9 or claim 10 wherein each said frame member is I provided with a plurality of lifting devices spaced along the length thereof, releasably engageable with its associated said prickle chain for lifting same from the ground to be supported intermediate its opposite ends clear of the ground when the frame is in its transport mode of use.
12. A folding harrow frame assembly according to claim 11 wherein each said lifting device comprises an overcentre pivotal lever carried by said frame member and a hook operatively associated with the lev!Br for hookingly engaging the prickle chain. 12 K* W u hJ 1 v'y 1 I
13. A folding harrow frame assembly according to any one of the preceding claims wherein said frame members, when the frame is in its transport mode of use are held in transversely spaced apart fixed relationship by a first rigid bridging member which interconnects the leading frame members and by second and third bridging members interconnecting a said leading frame member and its associated said trailing frame member respectively.
14. A harrow frame substantially as hereinbefore described with reference to and illustrated in the accompanying drawings. Dated this 6th day of June 1995. LYELL JAMES WOOLFORD By his Patent Attorneys R K MADDERN ASSOCIATES Il e, ABSTRACT A folding harrow frame assembly for a prickle chain type harrow comprising a rectangular or diamond shaped frame comprised of two leading frame members (11, 12) and two trailing frame membeis (13, 14), connection means interconnecting adjacent ends of adjacent frame members and permitting the trailing frame members (13, 14) to be separated and folded to lie alongside but outboard of respective leading frame members (11, 12) and the leading frame members (11, 12) to fold inwards towards one another to lie approximately parallel to the direction of travel of the frame, a tow hitch arrangement (24) at the leading corner of the frame, and ground engaging wheels (36, 43) supporting the frame members (11, 12, 13, 14) for movement across the ground. t I i r Ct I i