Soil cultivating machines

A soil cultivating implement has a row of tined soil working members that are driven to revolve about upwardly extending axes. The drive to the members includes meshed pinion gears and shafts of the members are mounted on every third pinion gear. The soil working members have tines, the inner ends of which are secured in recesses of plates near the axes of rotation of the working members. Each tine has an inner curved part and an elongated support portion to which downwardly, inclined soil working portions are integrally joined. The tines are free to deflect from their connections and neighboring soil working member tines work overlapping and/or adjoining strips of soil. The paths traced by the revolving tines spans a diameter that exceeds the width of two neighboring pinion gears.

According to the invention, there is provided a soil cultivating machine of 
the kind set forth, wherein driving means are provided for driving said 
soil working members about upwardly extending axes, said driving means 
having pinions on upwardly extending shafts whereby as seen in plan view 
the shafts of two neighbouring pinions are disposed inside the path 
described by a tine of a soil working member.

Referring to the accompanying drawings, the soil cultivating implement that 
is illustrated therein is in the form of a rotary harrow and comprises a 
hollow box-shaped frame portion 1 that extends substantially horizontally 
transverse, and usually substantially horizontally perpendicular, to the 
intended direction of operative travel of the implement that is indicated 
in FIGS. 1 to 3 of the drawings by an arrow A. The hollow frame portion 1 
rotatably supports a plurality of soil working or cultivating members 3 of 
which there are six in the embodiment that is being described, it being 
emphasised, however, that this number of the members 3 is by no means 
mandatory and that more, or less, of them could be provided if desired. 
Each member 3 is secured to the lowermost end of a corresponding 
substantially vertical, or at least upwardly extending, shaft 2, the six 
shafts 2 being rotatably mounted (see FIGS. 2 and 5) in upper and lower 
walls of the frame portion 1 in such positions that their longitudinal 
axes (axes of rotation) are spaced apart from one another at regular 
intervals of substantially 50 cms. The lowermost end of each shaft 2 
projects from beneath the bottom of the hollow frame portion 1 and is 
there externally splined to receive the internally splined hub 5 of a 
support 4 of the corresponding soil working or cultivating member 3. A 
retaining nut and co-operating washer (FIG. 2) co-operate with a short 
screwthreaded lower end portion of each shaft 2 in maintaining the 
corresponding hub 5 axially in position on the downwardly projecting 
splined portion of the shaft 2 concerned. An upper region of each support 
4 comprises a plate 6 whose center is integral with, or rigidly secured 
to, the corresponding hub 5, said plate 6 having a rectangular inverse 
polygonal configuration that can conveniently be considered as being 
triangular although reference to FIG. 3 of the drawings will show that it 
is by no means strictly triangular. The lower surface of each plate 6 has 
downward projections 7 which are arranged to define recesses 8 of 
substantially semi-circular cross-section, there being three recesses 8 
per plate 6 and those recesses being spaced apart from one another at 
regular 120.degree. intervals around the longitudinal axis of the 
corresponding hub 5. 
It can be seen in FIG. 3 of the drawings that each recess 8 comprises a 
portion that extends substantially tangentially with respect to a circle 
centered upon the longitudinal axis of the corresponding hub 5 and then a 
portion which defines a bend of substantially 90.degree., the center of 
curvature of said bend being coincident with, or quite close to, the 
longitudinal axis of said hub 5.The two portions of each recess 8 that 
have just been mentioned are considered as commencing from a corresponding 
radial plane which contains the front (with respect to the intended 
direction of rotation of the member 3 concerned) of the projections 7 that 
define each recess 8. The intended directions of operative rotation of the 
members 3 are indicated by arrows in FIGS. 1 and 3 of the drawings. The 
recesses 8 receive matchingly shaped fastening portions 9 of corresponding 
resilient tines 10, said tines 10 preferably, but not absolutely 
essentially, being formed from spring steel of circular cross-section. 
There are, of course, three tines 10 per member 3 and it will be seen from 
FIG. 3 of the drawings that the innermost extremities of the fastening 
portions 9 of those three tines 10 are located quite close to the 
outermost surface of the corresponding shaft 2. Naturally, each tine 
fastening portion 9 also comprises a short initial inner part that extends 
substantially tangentially with respect to a circle centered upon the 
longitudinal axis of the corresponding hub 5 and a following bend of 
substantially 90.degree. in magnitude whose center of curvature is 
substantially coincident with, or is located quite close to, the 
longitudinal axis of said hub 5. The fastening portions 9 of the three 
tines 10 of each soil working or cultivating member 3 are secured in their 
appointed positions by three bolts 11 and an underlying clamping plate 12 
which, when the bolts 11 are tightened, is disposed very close to the 
lowermost surfaces of the projections 7 (see FIG. 4). The three bolts 11 
of each member 3 extend substantially parallel to the longitudinal axis of 
the corresponding hub 5 and, as can be seen in FIG. 3 of the drawings, lie 
at the three corners of the approximately triangular plate 6 and the 
similarly shaped clamping plate 12. 
Where the fastening portions 9 of the tines 10 become free of confinement 
by the projections 7 of the corresponding plates 6, they become supports 
13 of the corresponding tines 10, said supports 13 being inclined 
obliquely outwardly and rearwardly away from the fastening portions 9 with 
respect to the intended directions of operative rotation of the 
corresponding members 3. The longitudinal axis of each support 13 is 
substantially horizontally disposed when the axis of rotation of the 
corresponding shaft 2 is substantially vertically disposed and is coplanar 
with the center line of the corresponding fastening portion 9, the plane 
in question being substantially perpendicular to the longitudinal axis 
(axis of rotation) of the hub 5 concerned. The outermost end of each 
support is connected by way of an integral bend of substantially 
90.degree. to the upper end of a soil working portion 14 of the 
corresponding tine. The longitudinal axis of each soil working portion 14 
can be considered as being substantially parallel to the longitudinal axis 
of the corresponding hub 5 although it is evident from the drawings that 
it is not truly parallel thereto. In fact, it is of rectilinear 
configuration and extends downwardly from the corresponding support 13 
towards the ground surface in trailing relationship (by a few degrees) 
from top to bottom with respect to the intended direction of operative 
rotation of the corresponding member 3. 
When operatively rotated, each soil working or cultivating member 3 has an 
effective working width of substantially 50 cms. and, since the 
longitudinal axes of immediately neighbouring shafts 2 are spaced apart 
from one another by substantially the same distance, the resilient tines 
10 of immediately neighbouring members 3 will work at least adjoining, and 
usually slightly overlapping, strips of soil so that the whole implement 
will cultivate a single broad strip of land which, in the case of the 
example illustrated in the accompanying drawings, will have a width of 
substantially 3 ms. Each shaft 2 is provided inside the hollow frame 
portion 1 with a corresponding straight- or spur-toothed pinion 15, each 
pinion having an effective diameter of substantially 165 mms. The two 
pinions 15 that correspond to each pair of immediately neighbouring 
members 3 are drivingly interconnected with one another by way of two 
similar intervening pinions 16 that are mounted on two rotary shafts 17 
whose upper and lower ends are carried by ball bearings mounted in the 
upper and lower walls of the frame portion 1. In the example which is 
being described, there are six of the shafts 2 and ten of the shafts 17 
and their longitudinal axes (the axes of rotation of all sixteen of those 
shafts) are contained in a single substantially vertical plane that is 
substantially perpendicular to the direction A. One of the two shafts 2 
that is closest to the center of the implement has an upward extension 
through the top of the hollow frame portion 1 into a lower portion of a 
gear box 18 (see particularly FIG. 2). The shaft extension is splined and 
co-operates, inside said lower portion of the gear box 18, with the hub of 
a straight- and spur- toothed pinion 19 whose teeth are in driven mesh 
with those of a smaller pinion 20. The pinion 19 has a larger effective 
diameter than the similar pinions 15 and 16 and substantially twice the 
effective diameter of the pinion 20. The pinion 20 is fast in rotation 
with a substantially vertical shaft 21 upon which it is mounted, said 
shaft 21 extending upwardly above the pinion 20 into an upper portion of 
the gear box 18 and being provided, at its uppermost end, with a crown 
wheel or bevel pinion 22. The teeth of the crown wheel or bevel pinion 22 
are in driven mesh with those of a smaller bevel pinion 23 mounted on a 
substantially horizontal shaft 24 that is in substantially parallel 
relationship with the direction A. The shaft 24 is driven from an 
overlying and parallel rotary input shaft 26 of the gear box 18 by way of 
a change-speed gear 25 that it is not necessary to describe in detail for 
the purposes of the present invention. However, briefly and as will be 
evident from the top right-hand corner of FIG. 2 of the drawings, the 
change-speed gear 25 comprises pairs of interchangeable and/or 
exchangeable pinions whose splined hubs will co-operate with the 
matchingly splined rearmost ends of the shafts 24 and 26 that project from 
the back of the upper portion of the gear box 18 into a quickly 
releasable, but sealed, cover of the change-speed gear 25. It will be 
evident that the particular pair of pinions that is chosen for use in the 
change-speed gear 25 and their arrangement relative to the shafts 24 and 
26 will govern the transmission ratio from the shaft 26 to the shaft 24 
and thus the speed at which the members 3 will revolve during operation of 
the implement in response to a more or less fixed speed of rotation 
applied to the forwardly projecting leading end of the input shaft 26 from 
the power take-off shaft of an agricultural tractor or other operating 
vehicle through the intermediary of a telescopic transmission shaft (not 
shown) which is of a construction that is known per se having universal 
joints at its opposite ends. 
The opposite sides or ends of the hollow frame portion 1 are closed by 
substantially vertical side plates 27 that are in parallel relationship 
with one another and substantially parallel relationship with the 
direction A, it being noted from FIG. 1 of the drawings that said side 
plates 27 project rearwardly from behind the hollow frame portion 1 with 
respect to the remainder of that portion. Substantially horizontally 
aligned stub shafts 28 are provided at the tops and fronts of the two side 
plates 27 and arms 29 are turnable upwardly and downwardly about the 
corresponding stub shafts alongside the outer surfaces of the two plates 
27. The arms 29 extend rearwardly from the stub shafts 28 and their 
angular positions about the axis defined by those two stub shafts can be 
set, in each case, by entering a bolt 30 through one of two holes in the 
arm 29 concerned and through one hole 30A (FIG. 2) in two curved rows of 
those holes 30A, the holes in each row being at the same distance from the 
axis defined by the stub shafts 28 which distance is, of course, the same 
as the distance from that axis of one of the two holes in the 
corresponding arm 29. The rearmost ends of the two arms 29 with respect to 
the direction A have a rotatable supporting member in the form of a ground 
roller 31 mounted between them with the aid of substantially horizontally 
aligned bearings in such a way that said roller 31 extends throughout 
substantially the whole working width of the six soil working or 
cultivating members 3. The substantially horizontal axis of rotation of 
the roller 31 is coincident with the longitudinal axis of a central 
tubular support 32 of that roller. Five support plates 33 of circular or 
substantially circular configuration are secured to the central tubular 
support 32 of the roller 31 in parallel relationship with one another and 
substantially parallel relationship with the direction A at regular 
intervals along the length of the roller, there being two of the support 
plates 33 located at the opposite ends of the tubular support 32. Each 
support plate 33 is formed close to its periphery with a plurality of 
regularly spaced apart holes and elongate elements 34 of tubular or 
rod-shaped formation are entered through the holes in the successive 
plates 33 so as to extend helically around the axis of rotation of the 
roller 31 in the manner that is illustrated in FIG. 1 of the drawings. 
The front of the hollow frame portion 1 with respect to the direction A is 
provided with a coupling member or trestle 35 that is of substantially 
triangular configuration when seen in front or rear elevation, the 
coupling member or trestle 35 being constructed and arranged for 
co-operation with the three-point lifting device or hitch of an 
agricultural tractor or other operating vehicle. Locations close to the 
apex of the coupling member or trestle 35 are connected, for strengthening 
purposes, to the top and rear of the hollow frame portion 1 by two tie 
beams 36 that are inclined obliquely downwardly and rearwardly, with 
respect to the direction A, from the coupling member or trestle 35 to the 
hollow frame portion 1 in rearwardly divergent relationship. 
In the use of the soil cultivating implement that has been described, its 
coupling member or trestle is connected to the three-point lifting device 
or hitch of an agricultural tractor or other operating vehicle and the 
rotary input shaft 26 of the gear box 18 is placed in driven connection 
with the power take-off shaft of the same agricultural tractor or other 
operating vehicle by way of the aforementioned known telescopic 
transmission shaft that is not illustrated in the drawings. The speed at 
which the members 3 should rotate in response to a more or less fixed 
speed of rotation applied to the rotary input shaft 26 will depend upon 
the nature and condition of the soil and upon the degree of fineness 
thereof that is required at the end of the cultivation. Bearing these 
factors in mind, the change-speed gear 25 is appropriately adjusted before 
work commences. Substantially the same factors dictate the maximum depth 
of penetration of the soil working portions 14 of the tines 10 into the 
soil which is desirable and this maximum depth of penetration is adjusted, 
before work commences, by setting the axis of rotation of the ground 
roller 31 at an appropriate level relative to the remainder of the 
implement. It will be realised that this is accomplished by entering the 
bolts 30 through appropriate holes 30A. As the implement moves in the 
direction A over a field whose soil is to be cultivated, the described 
transmission that extends between the rotary input shaft 26 and the shafts 
2 will cause the members 3 to revolve in the directions that are indicated 
by the arrows in FIG. 1 of the drawings, it being noted that each member 3 
revolves in the opposite direction to its neighbour, or to both of its 
neighbours, in the single row of six such members. The six members 3 work 
strips of land having widths of substantially 50 cms. and, as mentioned 
above, those strips of land will at least adjoin one another and will 
usually overlap one another to a small extent so that, in either case, a 
single broad strip of land having a width of substantially 3 ms. will be 
cultivated by the implement. In addition to performing its supporting 
function, the ground roller 31 that immediately follows the members 3 over 
the soil has a gentle compressing effect upon the crumbled soil and will 
act to crush any unbroken lumps of earth that may be left upon the soil 
surface by the immediately foregoing members 3. The ground roller 31 also 
acts to ensure that the worked soil is distributed substantially uniformly 
throughout the width of the implement and will entirely suppress, or very 
greatly reduce, any ridges of worked soil that might otherwise be formed 
in substantially parallel relationship with the direction A. 
In view of the resilient formation of the tines 10, their soil working 
portions 14 are capable of deflecting to avoid damage upon meeting any 
stones or other firmly embedded obstacles. In particular, each support 13 
is fixedly mounted by the corresponding fastening portion 9 only at the 
end thereof which is close to the corresponding shaft 2 and is torsionally 
deformable to an extent which gives the soil working portion 14 that is 
integral therewith considerable angular deflectability. The speed of 
rotation of the soil working members 3 may be low as compared with the 
soil working or cultivating members of some other rotary harrows or like 
implements because the soil working portions 14 of the tines 10 of each 
member 3 are spaced apart from the axis of rotation of that member by 
distances of substantially 25 cms. and this ensures that their speed of 
movement through the soil is entirely adequate despite the lower speed of 
revolution of the shafts 2. In this connection, it will be noted that the 
transmission in the gear box 18 is arranged for speed reduction, rather 
than increase, between the bevel pinion 23 and the straight- or 
spur-toothed pinion 19. 
The torsionally deformable supports 13 by which the soil working portions 
14 of the tines 10 are mounted enables those portions 14 to move through 
the soil in a more or less vibratory manner and this is advantageous 
inasmuch as the soil then tends to become crumbled along natural lines of 
fracture. Any tine 10 that should be damaged or broken or that becomes 
worn to an extent that reduces its effectiveness below an acceptable level 
can readily be replaced, as an individual, by an operation that merely 
entails loosening and retightening the three bolts 11 of the corresponding 
soil working or cultivating member 3. 
Although certain features of the soil cultivating implement that have been 
described and/or that are illustrated in the accompanying drawings will be 
set forth in the following claims as inventive features, it is emphasised 
that the invention is not necessarily limited to those features and that 
it includes within its scope each of the parts of the soil cultivating 
implement that has been described, and/or that is illustrated in the 
accompanying drawings, both individually and in various combinations.