WO1988000792A1

WO1988000792A1 - Rotary tyne assembly

Info

Publication number: WO1988000792A1
Application number: PCT/AU1987/000238
Authority: WO
Inventors: Michael Patrick Mcdonnell
Original assignee: RAMBURT NOMINEES Pty Ltd
Current assignee: RAMBURT NOMINEES Pty Ltd
Priority date: 1986-07-29
Filing date: 1987-07-29
Publication date: 1988-02-11
Anticipated expiration: 1989-01-29

Abstract

A tyne assembly (16) is rotatable about an axis (15) and comprises multiple sets (28) of tyne elements (22). The tyne elements are carried by support means (18) which are angularly spaced about and extend generally parallel to the axis. The support means may be in the form of multiple rods, bars or pins. Each tyne element comprises a pair of elongate projecting tynes (24, 25) with sharp tips (23) and bridged by a curved or bent centre portion (26). The tyne elements are retained by the support means in one or more of the co-planar sets (28), each such set comprising two or more tyne elements which are arranged so that they do not overlap but have their centre portions angularly spaced about the axis so that the tynes project at variable angles with respect to the axis.

Description

ROTARY TYNE ASSEMBLY

This invention relates to a tyne assembly and more particularly but certainly not exclusively to a cultivator incorporating one or more of the tyne assemblies. In this specification, the term cultivator is generically employed to embrace not only agricultural implements which might normally be referred to as cultivators but also other soil or ground treatment implements such as harrows and scarifiers.

A recently described cultivator employs multiple offset units in which the tilling elements consist of double tyne elements, each integrally comprising a pair of elongate projecting tynes and a curved centre portion bridging the tynes. The curved portion of each tyne element embraces and is slidable along a mounting shaft and the set of tyne elements is locked against rotation on the shaft by multiple substantially rigid rods which extend parallel to the shaft and are equally angularly spaced about the shaft. The tyne elements overlap when viewed along the shaft and extend about angularly successive pairs of the rods so that an interlocking configuration results. The tyne elements are arranged in groups spaced along the mounting shaft.

While the utility of such an arrangement as a cultivator is recognized, it is not possible to employ relatively wide flat tyne elements without adversely affecting the spacing of the tyne element groups. The break-out strength of the tyne elements is also limited in view of the lack of rear support of the curved centre portion against direct loads along the shanks of the tynes.

It is accordingly an object of the invention to provide an improved tyne assembly, and a cultivator embodying the tyne assembly.

The-invention accordingly provides a tyne assembly, especially for a cultivator, comprising: plural support members which are angularly spaced about and extend generally parallel to a central axis; and plural double tyne elements each integrally comprising a pair of elongate projecting tynes and a curved or bent centre portion bridging the tynes; wherein the tyne elements are retained by said support members in one or more co-planar sets of two or more tyne elements, in each of which sets the tyne elements do not overlap but their centre portions are angularly spaced about said axis so that the tynes of the set project at variable angles with respect to said axis.

The support members may comprise bars of elongate rectangular cross-section, the major transverse dimension projecting radially from said axis. Alternatively, the support members may comprise multiple rods or bars which extend between the tyne elements of adjacent but axially offset sets of the tyne elements so as to interlock the two sets to the bars and prevent rotation of the tyne elements relative to the support members about said axis.

In a still further alternative, the support members comprise multiple pins which are securred to one or more tyne elements of each set and project therefrom parallel to said axis to engage a complementary slot in a tyne element of an adjacent set. The tyne assembly may then comprise multiple co-planar sets of three of said tyne elements, wherein there is an elongate said pin welded to each tyne element and wherein the pins welded to tyne elements of each intermediate set project parallel to said axis to engage respective complementary slots in the proximate tyne elements of the adjacent sets.

The tyne elements are preferably arranged spirally about said axis.

There may be a shaft coaxial with said axis if desired. The whole assembly is advantageously journalled in a sub-frame for rotation about said axis during use of the assembly.

The tyne elements are advantageously shaped flat bars of relatively thin rectangular cross-section.

The invention further provides a cultivator comprising a main frame and plural sub-frames mounting respective tyne assemblies as aforedescribed.

The invention will be further described, by way of example only, with reference to the accompanying drawings', in which: Figure 1 is a simple plan diagram of a tractor drawing a cultivator embodying three tyne assemblies according to the invention;

Figure 2 is a cross-section transverse to the axis of rotation of a tyne assembly according to a first embodiment of the invention, but depicting only a small proportion of the tyne elements which make up the assembly depicted in Figure 2;

Figure 3 is a cross-section on the line 3-3 in Figure 2; and

Figure 4 is a view similar to Figure 2 of a second embodiment of tyne assembly according to the invention;

- Figure 5 is a perspective view of one set of tyne elements of a third embodiment of tyne assembly according to the invention;

Figure 6 is a transverse cross-section of the tyne assembly of the third embodiment, taken between sets of tyne elements and showing only the two nearest sets of tyne elements; and

Figure 7 is a cross-section on -the line 7-7 in Figure 6.

A cultivator 10 embodying tyne assemblies 16 according to the invention is shown diagrammatically in Figure 1. Cultivator 10 is being drawn by a tractor 8 and includes a main frame 11 supporting three sub-frames 12 for respective offset tyne assemblies 16. Each tyne assembly rotates about a central axis 15 inclined at less than 90° to the direction of travel and comprises multiple sets 28 of tyne elements 22. A first embodiment of tyne assembly 16 is illustrated in Figures 2 and 3 and includes three elongate rectangular-section support bars 18 which are equi-angularly spaced about and extend parallel to central axis 15 , a pair of spaced mounting plates 20 fixed, e.g. by welding to opposite ends of support bars 18 so as to locate the bars at equiangularly spaced positions about axis 15, and multiple double tyne elements 22 secured to bars 18. Typically, mounting plates 20 would carry stub-shafts journalled in suitable bearings in a respective sub-frame 12 of cultivator 10.

Tyne elements 22 are arranged in multiple, co-planar sets 28 of three, spaced apart along axis 15 and bars,18. A representative such set is depicted in Figure 2. It will be observed that each tyne element comprises a pair of elongate projecting tynes 24, 25 with sharp tips 23 bridged by a curved centre portion 26 so that the tynes have an included angle of about 60°. These tyήe elements may be thick wire or thin rod bent to the desired shape but, in accordance with a preferred aspect of the invention, are advantageously shaped flat bars. This is the form illustrated in Figures 2 and 3, and bes • seen in Figure 3. An exemplary cross-section is 10 X 40mm. The center-to-centre separation of sets 28 may be, e.g., 100mm and the overall axial length of assembly 16 about 2 metres.

The support bars 18 each exhibit a somewhat elongate rectangular section so that they are most appropriately described as flat bar. The major transverse dimension of each bar extends radially with reference' to axis 15, i.e. the median plane between the major faces of each bar contains axis 15. The tyne elements of each set are disposed in the 120° spaces between the support bars with the centre portion of each tyne element in abutment -with two bars. The tyne elements are then secured to the support bars in pairs by respective fasteners such as bolts 30. Bolts are suitable if the tyne elements are relatively flat and broad, as in this case, but a U-clamp or other device would be necessary were they more in the form of thick wire or thin rod.

Double tyne elements 22 would not typically be formed in a material properly described as spring steel, but rather by bending to the desired shape a steel bar, rod or wire chosen so that the tyne element has a degree of flexibility and ductility sufficient to permit the tynes 24, 25 to flex and appropriately respond to ground obstructions without breaking off.

It will be noted -that no shaft is provided on axis 15. Nevertheless, if ^"desired for enhanced rigidity and strength, such a shaft could be provided and the bars 18 arranged to abut or even be secured to the shaft.

It will be appreciated that because the tyne elements^" of each set 28 do not overlap, it is feasible for particular applications to employ tyne elements of substantial width without encountering difficulties in maintaining spacing between the sets of tyne elements. This is in contrast to the aforedescribed prior arrangement in which the tyne elements necessarily overlap and there was accordingly a definite limitation on the possible width of tyne element which could be employed. It will also be appreciated, from Figure 3 in particular, that the tyne elements are strongly supported behind their centre portions - by abutting two of the support bars 18 - and can therefore withstand very substantial longitudinal loads along the tynes 24, 25 of each element.

Figure 4 shows a slightly more complex embodiment in which six support bars 18' are provided. These bars 18 ' are formed into two groups of three bars similar to the three bars 18 of the first embodiment and the tyne element sets 28' are successively mounted to the alternate groups of support bars. In this configuration, the alternate sets are angularly offset with respect to each other by 60°. Typically, double tyne element groups comprising six tyne elements in two co-planar sets, arranged as shown in Figure 4, would be spaced at suitable intervals along axis 15 ' . With this arrangement, the interaction between adjacent tyne elements and adjacent bars in, for example, the region "A" in Figure 4, ensures the relative locations of the components and it would be sufficient to mount one group of three support bars only to one mounting plate 20 ' and the other group to the other mounting plate.

In a further embodiment (not separately illustrated) support bars 18 ' are replaced by elongate rods (broken lines 40 in Figure 4) which are dimensioned to closely locate in the closed spaces defined by overlapping tyne elements of adjacent sets angularly offset by 60°. In this case, the rods and tyne elements form a positively interlocked assembly and separate fastening devices are not required. Rods 40 would of course be secured to mounting plates similar to the mounting plates 20, 20' of the other two embodiments.

A still further embodiment is depicted in Figures 5 to 7. In this case a central shaft 70 is provided co-axially with axis 15' ' and the tyne element sets 28" are interlocked by multiple elongate cylindrical pins 18 ^r ' extending parallel to the axis 15' * of shaft 70. Each set 28' ' of flat rectangular-section tyne elements 22' * has three such pins welded to the tyne elements by welds 72 in the included angle at the insides of the intersections of the tyne elements. As best seen in Figure 7, pins 18' ' project axially beyond the respective set of tyne elements and engage complementary slots 74-in the opposed side edges of the proximate tyne elements of the adjacent sets. These sets then carry further sets of^" pins 18a, 18b circumfere i lly offset from the first mentioned pin. The result is that the pins of a larger installation are arranged as a set laid either zig-zag fashion (as shown) or spirally about axis 15' * . The end pins may engage mounting plates or bearings at the ends of shaft 70. This embodiment has the advantage that the pins collectively set the location^'s and spacings of the sets of tyne elements. The spacings can thus be varied by substituting pins of different length and the relative locations of adjacent group of tynes may be varied by altering the circumferential locations of slots 74. By appropriate arrangement of the pins and slots , the tynes of the whole assembly may exhibit a preferred spiral configuration about axis 15' ' , each tyne element being angularly offset from its neighbours by a uniform preset angle.

The centre portions of each tyne element 22' * of each set 28'' also briefly abut in pairs as they curve into the tynes 24' * , 25'' and are fastened together by bolts 30' ^• .

It will also be noted from Figures 5 and 6 that the centre portion 26 ' ' of each tyne element 22' ' is concavedly conformed to and in firm abutment with shaft 70 so as to provide the necessary support behind the centre portions to withstand substantial longitudinal loads along the tynes 24 ' * , 25 ' ' .

In a preferred arrangement, pins 18 ' ' are of diameter, e.g. 12mm, greater than the thickness of the tyne elements, e.g., 8mm. As before, these tyne elements are advantageously 40 x 8mm flat bar.

Claims

1. A tyne assembly, especially for a cultivator, comprising: plural support members which are angularly spaced about and extend generally parallel to a central axis; and plural double tyne elements each integrally comprising a pair of elongate projecting tynes and a curved or bent centre portion bridging the tynes; wherein the tyne elements are retained by said support members in one or more co-planar sets of two or more tyne elements, in each of which sets the tyne elements do not overlap but their centre portions are angularly spaced about said axis so that the tynes of the set project at variable angles with respect to said axis.

2. A tyne assembly according to claim 1 wherein the support members comprise bars of elongate rectangular cross-section, the major transverse dimension projecting radially from said axis.

3. A tyne assembly according to claim 1 wherein the support members comprise multiple rods or bars which extend between the tyne elements of adjacent but axially offset sets of the tyne elements so as to interlock the two sets to the bars and prevent rotation of the tyne elements relative to the support members about said axis.

4. A tyne assembly according to claim 1 wherein said support members comprise multiple pins which are secured to one or more tyne elements of each set and project therefrom parallel to said axis to engage a complementary slot in a tyne element of an adjacent set.

5. A tyne assembly according to claim 4 comprising multiple co-planar sets of three of said tyne elements, wherein there is an elongate said pin welded to each tyne element and wherein the pins welded to tyne elements of each intermediate set project parallel to said axis to engage respective complementary slots in the proximate tyne elements of the adjacent sets.

6. A tyne assembly according to claim 4 or 5 wherein said pins are disposed in the respective included angles between the centre portions of adjacent tyne elements.

7. A tyne assembly according to claim 5 or 6 wherein, within each said set, each tyne of each tyne element abuts and is fastened to a tyne of an adjacent tyne element.

8. A tyne assembly according to any preceding- claim further comprising a shaft co-axial with said axis.

9. A tyne assembly according to claim 6 and 8 wherein said pins are disposed between said included angles and said shaft.

10. A tyne assembly according to any one of claims

4 to 7 further comprising a shaft co-axial with said axis wherein said centre portions of the tyne elements partially conform to and abut said shaft.

11. A tyne assembly according to any preceding claim in which the sets of tyne elements are arranged so that the tynes exhibit a spiral configuration about said axis.

12. A tyne assembly according to any preceding claim, journalled in a sub-frame for rotation about said axis during use of the assembly.

13. A tyne assembly according to claim 2 wherein said bars are equiangularly spaced about said axis and each tyne element is fastened to two of the bars by respective means also mounting one of the other tyne elements to that bar.

14. A tyne assembly according to any preceding claim wherein said tyne elements comprise shaped flat bars of relatively thin rectangular cross-section.

15. A cultivator comprising a main frame and plural sub-frames mounting respective tyne assemblies according to any preceding claim.