GB2172783A

GB2172783A - Cultivator

Info

Publication number: GB2172783A
Application number: GB08607516A
Authority: GB
Original assignee: National Research Development Corp UK; National Research Development Corp of India
Current assignee: National Research Development Corp UK; National Research Development Corp of India
Priority date: 1985-03-27
Filing date: 1986-03-26
Publication date: 1986-10-01
Also published as: DE3610470A1; GB2172783B; FR2579403A1; GB8508006D0; GB8607616D0

Abstract

A cultivator including a number of earth working assemblies 10, 11, 12. Each assembly comprises an optional cutting disc 16 followed by a coulter 17 followed by a helically-bladed rotor 18 rotating in the direction shown. As the cultivator moves forward, the rotors 18 will operate to transfer the furrow slice cut by the associated disc and coulter sidewardly into the void left by the previously furrow. During this transfer, a mixing, inversion and cultivating action will also take place. <IMAGE>

Description

SPECIFICATION Cultivator The present invention relates to cultivators and in particular, but not exclusively, to cultivators for straw incorporation.

Because of the possibility of a ban on straw burning, quantities of chopped straw or stubble may have to be dealt with. Ploughing in is possible but in unaerobic conditions the ploughed in layers of straw persist for some time. A surface cultivate of the top 15 cm to intimately mix the chopped straw with this depth of soil would be desirable but efficient machinery to do this is not yet available.

An object of the present invention is to provide such machinery.

According to the present invention, a cultivator comprises a plurality of soil-working assemblies each comprising a coulter followed by a helicallybladed rotor, the rotors of the different assemblies being staggered across the width of the cultivator so as in operation to invert and transfer the furrow slice cut by each assembly into the void left behind by the adjacent preceding assembly.

Conveniently, the cultivator includes a cutting disc or share preceding the coulter.

The helically bladed rotors are preferably rotated about approximately horizontal axes inclined to the forward direction of the cultivator over the soil e.g.

at between 10 and 20 thereto, a value of about 14" currently being preferred.

Conveniently, the rotors taper towards their leading ends and in a preferred embodiment the rotors have frusto-conical hubs with an included angle of about 30 .

Conveniently, the coulter is a so-called A-blade coulter.

In one embodiment of the invention, the rotor blades are made up of a series of suitably disposed and dimensioned rods extending radially outwards from the hub portions of the rotors.

Conveniently, in this case, the inner ends of the rods are mounted on a stock of hub-embracing collars each rotatable on the hub between two limits determined by two sets of appropriately positioned stops on the hub, the rods being disposed in a helix of one hand when the hubs engage a first set of the stops and being disposed in a helix of the opposite hand when the hubs engage the second set of stops.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is a diagrammatic plan view (not to scale) of a cultivator according to the present invention; Figure 2 is an end view of one of the rotors looking along the rotation axis of the rotor from the front end; and Figure 3 is a perspective view of one of the Ablade coulters.

Thus referring now to the drawings, Figure 1 indicates the relative positions of three earthworking assemblies 10, 11, 12 staggered across the width of the cultivator 14.

Each assembly comprises an optional ploughtype ground-driven cutting disc 16 followed by an A-blade coulter 17 followed by an externally-driven helically-bladed rotor 18.

As will be seen from the drawings, the rotors 18 each have a frusto-conical hub portion carrying three helical blades and both the hub and the blades taper forwardly, the included angle of the hub being about 30 : The span of the blades at the rear end of each rotor is typically about 90 cms and this compares with a disc-to-disc separation of the order of 56 cm.

The axes of rotation of the rotors are approximately horizontal and at about 14" to the direction of travel A of the cultivator although inclinations of from, say, 10 to 20 will probably be acceptable.

In a variation (not shown) of the illustrated embodiment, each rotor hub only carries two helical blades.

In operation of the cultivator, e.g. in a field of stubble, the discs 16 will penetrate the soil, cutting through the trash, and the A-blade coulters 17 will work below the soil at furrow depth to shear the soil horizontally. The rotors 18 will be driven from the tractor shaft in an anti-clockwise direction viewed from the rear at speeds within the range 60--100 rpm and will operate to transfer the furrow slice cut by the associated disc and coulter sidewardly into the void left by the previous furrow as indicated by arrows B. During this transfer, a mixing, inversion and cultivating action will also take place.

The illustrated embodiments of the machine are also suitable for deeper work akin to ploughing and hence the term "cultivator" should be broadly interpreted in the claims and throughout the remainder of the specification.

If reversible ploughing is required, however, then the helical blades could be replaced by an array of suitably disposed and dimensioned rods extending radially outwards from the hub portions of the rotors. The inner ends of the rods are mounted on a stack of hub-embracing collars each rotatable on the hub between limits determined by two sets of appropriately positioned stops on the hub.

To reverse.the plough, the section of the frame carrying the rotors 18 is swing through 180" so that they now impart an oppositely handed movement to the furrow slice. Simultaneously to complete the switch to oppositely handed ploughing, the drive shaft to the rotors reverses their direction of rotation and the forces now exerted by the ground on the tips of the rotor rods cause the helical disposition of the rods to reverse pitch as the collars are rotated from engagement with their first set of stops into engagement with their second set of stops. This system of pitch-reversal is especially suited to the optional two-bladed rotors referred to earlier in the specification.

1. A cultivator having a plurality of soil-working assemblies each comprising a coulter followed by a helically-bladed rotor, the rotors of the different

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Cultivator The present invention relates to cultivators and in particular, but not exclusively, to cultivators for straw incorporation. Because of the possibility of a ban on straw burning, quantities of chopped straw or stubble may have to be dealt with. Ploughing in is possible but in unaerobic conditions the ploughed in layers of straw persist for some time. A surface cultivate of the top 15 cm to intimately mix the chopped straw with this depth of soil would be desirable but efficient machinery to do this is not yet available. An object of the present invention is to provide such machinery. According to the present invention, a cultivator comprises a plurality of soil-working assemblies each comprising a coulter followed by a helicallybladed rotor, the rotors of the different assemblies being staggered across the width of the cultivator so as in operation to invert and transfer the furrow slice cut by each assembly into the void left behind by the adjacent preceding assembly. Conveniently, the cultivator includes a cutting disc or share preceding the coulter. The helically bladed rotors are preferably rotated about approximately horizontal axes inclined to the forward direction of the cultivator over the soil e.g. at between 10 and 20 thereto, a value of about 14" currently being preferred. Conveniently, the rotors taper towards their leading ends and in a preferred embodiment the rotors have frusto-conical hubs with an included angle of about 30 . Conveniently, the coulter is a so-called A-blade coulter. In one embodiment of the invention, the rotor blades are made up of a series of suitably disposed and dimensioned rods extending radially outwards from the hub portions of the rotors. Conveniently, in this case, the inner ends of the rods are mounted on a stock of hub-embracing collars each rotatable on the hub between two limits determined by two sets of appropriately positioned stops on the hub, the rods being disposed in a helix of one hand when the hubs engage a first set of the stops and being disposed in a helix of the opposite hand when the hubs engage the second set of stops. An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is a diagrammatic plan view (not to scale) of a cultivator according to the present invention; Figure 2 is an end view of one of the rotors looking along the rotation axis of the rotor from the front end; and Figure 3 is a perspective view of one of the Ablade coulters. Thus referring now to the drawings, Figure 1 indicates the relative positions of three earthworking assemblies 10, 11, 12 staggered across the width of the cultivator 14. Each assembly comprises an optional ploughtype ground-driven cutting disc 16 followed by an A-blade coulter 17 followed by an externally-driven helically-bladed rotor 18. As will be seen from the drawings, the rotors 18 each have a frusto-conical hub portion carrying three helical blades and both the hub and the blades taper forwardly, the included angle of the hub being about 30 : The span of the blades at the rear end of each rotor is typically about 90 cms and this compares with a disc-to-disc separation of the order of 56 cm. The axes of rotation of the rotors are approximately horizontal and at about 14" to the direction of travel A of the cultivator although inclinations of from, say, 10 to 20 will probably be acceptable. In a variation (not shown) of the illustrated embodiment, each rotor hub only carries two helical blades. In operation of the cultivator, e.g. in a field of stubble, the discs 16 will penetrate the soil, cutting through the trash, and the A-blade coulters 17 will work below the soil at furrow depth to shear the soil horizontally. The rotors 18 will be driven from the tractor shaft in an anti-clockwise direction viewed from the rear at speeds within the range 60--100 rpm and will operate to transfer the furrow slice cut by the associated disc and coulter sidewardly into the void left by the previous furrow as indicated by arrows B. During this transfer, a mixing, inversion and cultivating action will also take place. The illustrated embodiments of the machine are also suitable for deeper work akin to ploughing and hence the term "cultivator" should be broadly interpreted in the claims and throughout the remainder of the specification. If reversible ploughing is required, however, then the helical blades could be replaced by an array of suitably disposed and dimensioned rods extending radially outwards from the hub portions of the rotors. The inner ends of the rods are mounted on a stack of hub-embracing collars each rotatable on the hub between limits determined by two sets of appropriately positioned stops on the hub. To reverse.the plough, the section of the frame carrying the rotors 18 is swing through 180" so that they now impart an oppositely handed movement to the furrow slice. Simultaneously to complete the switch to oppositely handed ploughing, the drive shaft to the rotors reverses their direction of rotation and the forces now exerted by the ground on the tips of the rotor rods cause the helical disposition of the rods to reverse pitch as the collars are rotated from engagement with their first set of stops into engagement with their second set of stops. This system of pitch-reversal is especially suited to the optional two-bladed rotors referred to earlier in the specification. CLAIMS

1. A cultivator having a plurality of soil-working assemblies each comprising a coulter followed by a helically-bladed rotor, the rotors of the different assemblies being staggered across the width of the cultivator so as in operation to invert and transfer the furrow slice cut by each assembly into the void left behind by the adjacent preceding assembly.

2. A cultivator as claimed in Claim 1 including a cutting disc or share which precedes the coulter.

3. A cultivator as claimed in Claim 1 or Claim 2 which the helically-bladed rotors are rotated about approximately horizontal axes inclined to the forward direction of the cultivator over the soil.

4. A cultivator as claimed in Claim 1, Claim 2 or Claim 3 in which the rotors taper towards their leading ends.

5. A cultivator as claimed in any preceding claim in which the coulter is an A-blade coulter.

6. A cultivator as claimed in any preceding claim in which the rotor blades are made up of a series of suitably disposed and dimensioned rods extending radially outwards from the hub portions of the rotors.

7. A cultivator as claimed in Claim 6 in which the inner ends of the rods are mounted on a stack of hub-embracing collars each rotatable on the hub between two limits determined by two sets of appropriately positioned stops on the hub, the rods being disposed in a helix of one hand when the hubs engage a first set of the stops and being disposed in a helix of the opposite hand when the hubs engage the second set of stops.

8. A cultivator substantially as hereinbefore described with reference to and/or as illustrated in the accompanying drawings.