Soil working device with cleaner

The presence of rank vegetation or loose crop residue on the soil surface (straw, maize stalks etc.) is always troublesome to ploughs, cultivators, seed drills and other agricultural implements required to slice vertically through and penetrate the soil. In the illustrated embodiment of the invention (FIG. 1), the leading edge area of the knife coulter 10 of a seed drill 14 is continually cleared of trash by resilient disc-mounted cleaning members 16-18. The cleaning members comprise springs which have an outwardly positioned elongated section designed to be engaged by the ground or an abutment on the disc support structure to flex each member as the disc on which they are mounted is rotated. On losing contact with the ground or the abutment, each member will, in turn, spring back from a flexed position (member 16) to a relaxed position (member 17). During this spring back movement, the elongated section moves past or along the leading edge of the knife coulter and strikes trash therefrom.

The invention relates to soil-working assemblies. 
The presence of rank vegetation or loose crop residue on the soil surface 
(straw, maize stalks etc.) is always troublesome to ploughs, cultivators, 
seed drills and other agricultural implements required to slice vertically 
and penetrate the soil. 
Soil slicing is often performed by a mainly vertical sharp-edged member on 
the implement e.g. a knife coulter, plough shin plate, or cultivator tine 
etc. Sometimes this is complemented by having the initial surface 
penetration made by a ground driven rotating disc cutter working in front 
of and in line with the main slicing member. 
The problem which arises is the wrapping of material on and on either side 
of the cutting edge of the soil-slicing member. This can build up to the 
extent that the edge is forced upwards out of contact with the ground and 
the machine has to be stopped and cleared. 
It is an object of the present invention to provide a self-cleaning 
soil-working assembly which in operation will discourage or prevent a 
build up of material on the cutting edge above referred to thereby to 
prevent a wad of material from forming there. 
According to the present invention, a self-cleaning soil-working assembly 
comprises a soil-working element and a resilient cleaning member adapted 
to spring back from a flexed position to, or towards, a relaxed position, 
the motion of the resilient member as it moves to, or towards, its relaxed 
position being used to strike from the soil-working element trash or other 
matter adhering thereto. 
Self-cleaning arrangements for soil-working elements have been disclosed 
prior to the present invention which involve the use of cleaning members 
moving at a steady speed past the element to be cleaned. There is a 
tendency in such cases for material removed from the soil-working element 
to become attached to the cleaning members instead with correspondingly 
reduced effectiveness of the latter. This apart, without the inconvenience 
of having to provide a high-speed drive for the cleaning members, there is 
always the risk that because of their relatively slow speed, the cleaning 
members will redeposit significant amounts of the removed material back in 
the path of the oncoming soil-working element. The cleaning members 
present in asemblies according to the present invention, on the other 
hand, avoid both these drawbacks by the flicking action implicit in their 
"flex and release" mode of operation, the impulsive forces exerted on the 
offending material being effective to propel it well away from the 
soil-working element with minimal risk of this material being transferred 
to the cleaning members instead. 
Conveniently, in the assembly of the present invention, the cleaning member 
is adapted to move in a closed path and during a first part of the closed 
path, the resilient member is flexed to an ever greater extent as it is 
forced against an abutment surface following an initial contact therewith, 
and during a second part of the closed path the resilient member loses 
contact with the abutment surface and springs back to, or towards, its 
relaxed position. 
Conveniently in this case, the base section of the resilient member is 
adapted to move bodily in a circular path about a substantially horizontal 
axis spaced from the abutment surface by an amount significantly less than 
the projection of the resilient member from said axis when in its fully 
relaxed position. 
Conveniently, the resilient member comprises a base-mounted spring member 
having a coiled base section leading into an elongate section for engaging 
the abutment surface. 
Conveniently, the resilient member is mounted so as to use the top-surface 
of the ground over which the assembly moves in operation as the abutment 
surface. 
Conveniently, the abutment surface is provided instead on or by a support 
structure for the cleaning member. 
Conveniently, there is a plurality of said resilient members equispaced 
along the closed path referred to above. 
The soil-working element may, for example, be a knife coulter, plough shin 
plate, cultivation tine, or like non-rotating element, or a rotary plough 
element, rotary cultivator element, rotary harrow element, or like 
rotating element. 
The invention also includes a plough, cultivator, seed drill or like 
agricultural implement incorporating a soil-working assembly according to 
the present invention.

Referring first to FIG. 1, this shows the knife coulter 10 and rotating 
crinkle-edged cutter disc 12 of a direct-seeding drill 14. One such drill 
is described for example in UK Patent Application No. 3,6978/77. 
As the drill is moved forwards (in the direction indicated by arrow A), the 
cutter disc 12 will make the initial penetration in the soil surface to 
provide in the soil a vertical slit which will be opened and enlarged by 
the following coulter 10. 
Mounted on the disc 12 are three resilient spring-form members 16, 17, 18 
each having a coiled base section (e.g. 18a) secured to the disc 12 and 
leading into an elongate section (e.g. 18b) for engaging the ground (e.g. 
when in the illustrated position of member 16). 
As will be observed from the drawing, the base sections (18a etc.) of 
members 16, 17, 18 are equispaced about the rotation axis B-B of disc 12 
and this axis is spaced from the abutment surface provided, in the 
illustrated embodiment, by the top surface of the ground, by an amount 
significantly less then the projection of these members from axis B-B when 
they are in their fully relaxed positions (e.g. members 17 and 18 in the 
situation shown). 
The crinkle-edged disc 12 has good trash-cutting properties and it also has 
the advantage of making positive contact with the soil for slip-free 
rotation of the disc. 
In operation of the assembly above described, forward motion of the drill 
(in direction A) will result in a ground-driven rotation of disc 12 in the 
clockwise sense (as viewed in the drawing) so that the base sections 18a 
etc. of the members 16-18 will be moved bodily around axis B-B in a closed 
circular path. 
During a first part of this path (being traversed by member 16 in the 
situation shown), each member is flexed to an ever greater extent as the 
rotating disc forces the base section of the member closer and closer to 
the ground surface. However, as the disc continues to rotate, the point 
will be reached at which the member will lose ground contact and will 
spring back to its relaxed position. During its motion to, or towards, 
this position the elongate section of the member will strike from the 
leading (cutting) edge (20) of the coulter 10 any trash or other material 
gathered there, the separation of this edge from disc axis B-B being such 
as to allow this to happen with cleaner members of the particular 
dimensions and configurations chosen for the assembly. 
It will be appreciated, that as the disc 12 continues to rotate, the three 
members 16, 17, 18 will perform in sequence so as to produce continual 
cleaning of coulter edge 20. 
Although in the embodiment illustrated in FIG. 1, the abutment surface for 
flexing members 16-18 is provided by the top surface of the ground over 
which the drill 14 moves, it is envisaged that in other embodiments of the 
invention or in modifications of the illustrated embodiment, the cleaning 
members (whether mounted on a pre-cutting disc or, for example, on some 
other suitably rotating support) can be arranged to engage with an 
abutment surface provided not by the ground but by some other part of the 
soil-working assembly. In such cases, movement of the cleaning members 
along the abutment part would once again flex them to an ever greater 
extent until, as with the embodiment of FIG. 1, they would eventually 
reach a second part of their closed-path motion in which they would lose 
contact with the abutment surface to strike away trash or other adhering 
matter as above described. FIG. 2 shows one such alternative in which the 
abutment surface is provided by a stud 22 projecting inwardly towards disc 
12 from a support structure 24 for the disc. 
With the embodiments so far described and illustrated, resilient 
spring-form members 16-18 have been used to allow disc penetration into 
the ground as the members are flexed. In variations (not shown) of these 
embodiments, this resilience may be achieved by any other suitable type of 
spring mountings for the ground-engaging or abutment-engaging members. 
In variations of the illustrated embodiments and of the various 
modifications and alternatives above referred to, the cleaning members are 
carried in their closed-path motion by a positively-powered support rather 
than by one relying on ground-engagement as with the illustrated 
embodiments. 
As already indicated, the self-cleaning soil-working assembly of the 
present invention can be used in a variety of contexts and the invention 
is therefore not to be interpreted as being limited to those specific 
examples discussed in the application.