AU2018202048A1 - Improved disc assembly for ground opening - Google Patents

Abstract

Abstract A disc assembly which includes: a drawbar; a series of spaced discs supported from the drawbar, each disc being rotatable; force applying means connected between the drawbar and the discs, the force applying means being adapted to alter the force applied by each of said discs on an underlying surface. 1/5 c

Description

IMPROVED DISC ASSEMBLY FOR GROUND OPENING

Technical Field

The present invention relates to an assembly of dises which is designed to be moved across an area of land to open cuts or slots in the land as part of a process of cultivating the land e.g. to allow seeds and/or fertiliser to be drilled into the slots

Background Art

It is well known to use dises, in a variety of arrangements, to open ground ahead of other equipment, such as seed drills. Generally, the dises are arranged in one or more rows, with each row mounted on a supporting shaft through the centre of the disc. Each of the dises can rotate freely relative to the supporting shaft, and as the dises are dragged across the ground to be cultivated, the forward movement rotates the dises. The dises are torced into the ground by a combination of the forward action plus the weight of the equipment (e.g. drill), and each disc cuts a slot in the ground.

The above described design has the acknowledged disadvantage that the depth to which each disc cuts into the ground can be highly variable, depending upon the weight of the equipment associated with the dises, the condition of soil, and the amount of vegetation in or on the soil that has to be cut through by the dises in order to reach the underlying ground. It is possible to increase the pressure applied by each disc using a spring tensioner, but this still does not give very reliable results.

Disclosure of Invention

An object of the present invention is the provisión of a disc assembly which overcomes, or at least reduces, the above described disadvantages.

The present invention provides a disc assembly which includes: • a drawbar; • a series of spaced dises supported from said drawbar, each disc being rotatable; • forcé applying means connected between the drawbar and the dises, the forcé applying means being adapted to alter the forcé applied by each of said dises on an underlying surface.

Preferably, the assembly includes drive means for driving each of the dises to rotate. Typically, this drive means includes a drive such as a power take off drive or a hydraulic motor.

Preferably, said forcé applying means consists of a hydraulic ram. In one preferred embodiment, the hydraulic ram is pivotably connected between the drawbar and a tie bar which extends substantially perpendicular to the drawbar; the tie bar is supported parallel to a cross-bar which is rigidly secured substantially perpendicular to the drawbar, such that the tie bar is pivotable relative to the drawbar and the crossbar by extending or contracting the hydraulic ram.

Preferably also, the crossbar supports a series of spaced brackets, each of which has a hanger pivoted thereto; the tie bar extends through an aperture in each of the hangers; the spaced brackets support a driveshaft, which is driveably connected to one or more disc shafts to which each disc is mounted for rotation therewith.

Preferably also, a spring over ride device is mounted between each hanger and a support supporting the disc, such that the dises are able to rotate away from ground contact against the forcé exerted by the spring over ride device if the dises encounter obstacles.

Preferably, said dises are secured to said drawbar at a position approximately midway along the length of said drawbar, where the length of the drawbar as measured from the attachment point to a towing vehicle to the attachment point at the rear of the towbar.

Preferably, each of the dises is a split disc formed in two or more portions which are releasably securable to a central annulus. Most preferably, each disc is formed in two portions and the dividing line between said portions is a curved line.

Brief Description of Drawings

By way of example only, a preferred embodiment of the present invention is described in detail, with reference to the accompanying drawings in which:-Figure 1 is an isometric view of a drill assembly in accordance with the present invention, with the drive chains between the component parts omitted for clarity;

Figure 2 is a sectional side view of the drill assembly of Figure 1, along lines 2 - 2 of Figure 1;

Figure 3 is a plan view of the drill assembly of Figure 1;

Figure 4 is an isometric view of a sprung override device;

Figure 4 a is a longitudinal section through the device of Figure 4; and

Figure 5 is a side view of a single disc on a larger scale.

Best Mode for Carrying out the Invention

In the preferred embodiment described with reference to the drawings, the dises in the disc assembly are driven.

Referring to the drawings, a disc assembly 10 includes a drawbar 11, a cross bar 12, a tie bar 13, a support frame 15 rigidly secured to the cross bar 12 and a series of sets 16 of spaced dises 17.

The drawbar 11 is an elongated rectangular cross-section tube which is provided at one end with a connector 18 for securing the assembly to a towing vehicle (typically a tractor); the other end of the drawbar 11 is rigidly secured to a crossmember 19 of the support frame 15. The support frame 15 consists of a pairof parallel side portions 15a, which are spaced apart by the length of the crossmember 19 and which are co-planar with, and parallel to, the drawbar 11. Adjacent the crossmember 19, each side portion 15a is rigidly secured to one end of a downwardly angled extensión 15b, to the free end of which a further implement, such as a drill, may be secured.

The crossbar 12 is made in two equal sections. The inner end 12a, 12b of each section is rigidly secured (e.g. by welding) to the adjacent side of the drawbar and 11. The crossbar 12 supports a series of spaced brackets 20, each of which provides a U cross-section cutout 21 in which the crossbar 12 is received. Each bracket 20 has a hanger 22 pivoted thereto at a pivot 23, and also supports a bearing 24 in which a rotatable drive shaft 25 is journalled.

Each hanger 22 is formed with an aperture through which the tie bar 13 extends, so that the tie bar 13 assists in spacing and stabilising the hangers 22. The lower end of each hanger 22 has a pair of side plates 29, 30 pivoted at a pivot 31; the side plates 29, 30 are arranged one on each side of the hanger 22, and form the sides of a spring override device described in detail below with reference to figure 4. The ends of the side plates 29, 30 opposite to the pivot 31 are pivoted by a pivot 32 one on each side of a píate 33.

Each píate 33 is pivotably mounted on the drive shaft 25 at its upper end, and at its lower end supports one of a series of disc shafts 35 which extends parallel to the crossbar 12, through a series of bearings (not shown) mounted on the plates 33. Each disc shaft 35 is supported by two spaced plates 33, and carries a set 16 of six spaced dises 17.

It will be appreciated that the number of dises 17 in a sets 16, and the spacing between the dises in each set, may be adjusted as required to suit the conditions.

Each disc 17 is rigidly secured to the corresponding shaft 35 for rotation with the shaft. Details of the disc construction are given below with reference to figure 5. The shaft 35 is depicted as having a circular cross-section, but may have a rectangular crosssection.

The drive shaft 25 extends along the full length of the assembly, and is driven by a chain and sprocket drive (not shown) from a power takeoff drive 40 which is mounted on the part of the drawbar 11 above the drive shaft 25. The power takeoff drive 40 has a connection 41 which in use is connected to the power takeoff of the towing vehicle; the drive 40 also is provided with a pair of drive sprockets (not shown), mounted one on each side of the drive 40 at the end of each of the stub shafts 40a. A drive chain (not shown) connects each drive sprocket with a corresponding drive sprocket 42 mounted on the drive shaft 25, to rotate the drive shaft 25. It will be appreciated that the power takeoff drive 40 could be replaced by any suitable type of drive e.g. a hydraulic motor.

The drive shaft 25 carries a series of spaced sprockets 43, one opposite each set of dises 16. Corresponding sprockets 44 are located on each shaft 35 for each set of dises; a drive chain (not shown) extends between each sprocket 43 and the corresponding sprocket 34, so that if the drive shaft 25 is driven from the power takeoff drive 40, the sepárate shafts 35 also are driven, to rotate the dises. The shaft 35 rotates anticlockwise so that each of the dises 17 is rotated in the direction of Arrow A (Figure 2) i.e. in the direction of forward motion ofthe disc assembly.

It will be appreciated that altemative means of driving the shafts 35 could be used, but any drive arrangement should be such that movement of the disc assemblies in the direction of Arrow B is permitted:- to allow disc assemblies to move upwards if the dises encounter large obstacles (e.g. rocks) in use, or to allow each of the sets 16 of dises to be moved a short distance upwards by a hydraulic ram 50, as described below, to allow the disc assembly to be moved out of ground contact when the equipment is towed along a road.

It will be noted that the set 16 of dises are mounted in a negative castor position i.e. to the rear of the mounting in the direction of movement of the equipment in use - this gives a dragging effect on the dises relative to the ground (whether the dises are driven or not) and improves the stability of the dises in the ground.

The hydraulic ram 50 is mounted between the underside of the drawbar 11 by a pivot mounting 51; the opposite end of the ram 50 is pivoted at pivot 52 just above the lower end of the píate 22. The ram 50 may be fitted with limiter blocks (in known manner) to limit the movement of the ram.

Retracting the ram 50 (i.e. moving in the direction of Arrow C) pivots the píate 22 on pivot 23 and thus swings the tie bar 13 and all of the plates 33 (which are connected to the tie bar 13 by the sets of plates 29/30) and the associated dises 17, clockwise (i.e. in the reverse direction to Arrow A), in greater contact with the ground. Extending the ram 50 pivots the plates 33 and dises 17 in the opposite direction, to raise the dises out of ground contact.

Thus, the pressure of the dises 17 on the ground can be increased or decreased as necessary, and this movement can be carried out while the equipment is in use.

The pressure exerted on the ground by each of the dises 17 is governed partly by the setting of the ram 50, and partly by the weight of the equipment i.e. the weight exerted on the drawbar 11 by the disc assembly, by the tractor or other towing vehicle, and by the equipment attached to the disc assembly e.g. a drill. The dises 17 need to be able to exert a sufficient pressure on the underlying ground to cut through any crop residues, roots or trash in or on the ground.

The pressure of the dises 17 on the ground tends to exert a lifting forcé on the towbar 11 and any equipment attached to that towbar. Most towing vehicles, such as tractors, are very heavy and are unlikely to be adversely affected by the lifting forcé from the disc assembly. However, equipment such as a drill is proportionately lighter, and can be moved out of ground contact if too much upwards pressure is exerted by the disc assembly. In the apparatus of the present invention, the position at which the disc assembly is secured to the drawbar 11 (i.e. the position at which the crossbar 12 is secured to the drawbar) is approximately halfway along the overall length of the drawbar 11 plus the angled extensions 15 b. Referring in particular to Figure 2, the distance X is approximately half of distance Y. This means that the disc assembly of the present invention is spaced substantially further in front of a drill than is conventional practice.

Obviously, the depth of cut of each of the dises as a result of the weight of the equipment, as described above, is a constant factor; any variations required in the depth of cut are obtained by adjusting the extensión or retraction of the hydraulic ram 50. It is envisaged that the equipment of the present invention will be able to control the depth of cut plus or minus 1 cm.

When the equipment is in use, one or more of the sets 16 of dises may encounter obstacles such as rocks in the ground, which cannot be cut through. If this occurs, it is important that the dises can move over any such obstacle without damage to the disc; the inclusión of the spring override devices is designed to allow any set of dises which encounter an obstacle to swing upwards, and pass over the obstacle without damage.

Figures 4 and 4 a show a spring override device 70, which is connected between each set of plates 22/33. The device includes side plates 29, 30, which are connected together at one end by a top píate 71 to form a U cross-section housing. The other end of each side píate 29, 30 is formed with a connecting eye 72, 73 for connecting the side plates to the pivot 31.

The housing formed by the plates 29, 30, 71 proteets a rod 74, one end of which extends through the centre of píate 71, secured by a screw threaded nut 75. The opposite end of the rod 74 also is screw threaded to receive an adjusting nut 76. A coil spring 77 is mounted on the rod 74, with the ends of the spring retained by the top píate 71 and a washer 78 adjacent the adjusting nut 76. A second pair of connecting eyes 79, 80 is rigidly secured to the nut 75, to secure the device to the píate 33 at pivot 32, as described above.

If any of the dises 17 in a particular set of dises 16 encounters an obstacle and needs to move out of the way of that obstacle, the spring 77 provides sufficient resilience in the connection between the plates 22 and 33 to allow that movement to occur, and allow that set of dises to pivot in the direction of Arrow B. Once the set of dises is over the obstacle, the set moves back to the position of Figure 2, i.e. in the direction of Arrow B’.

The pressure on the set of dises required before this movement occurs is governed by the stiffness and degree of compression of the coil spring 77; this can be adjusted in known manner by moving the nut 76 along the supporting rod 74 to compress or extend the coil spring.

If the equipment of the present invention is to be used on ground which is likely to be free of any large obstacles, then the spring override devices may be omitted, and replaced by non-sprung connecting plates. Or the springs may be “locked” by moving the adjusting nut 76 along the rod 74 until the spring 77 is fully compressed and thus provides a substantially rigid connection.

Each of the dises 17 may be a plain, fluted, or turbo disc and may be mounted with the plañe of the disc parallel to the direction of movement of the equipment, or at an angle to the direction of movement of the equipment, as required by the conditions. Each disc 17 may be of known type i.e. a solid undivided disc. Preferably however each disc 17 is a split disc as shown in figure 5.

As shown in Figure 5, each disc 17 consists of two irregularly shaped disc portions 60, 61 mounted upon a central annulus 62. The disc portions are mounted on the annulus by means of a series of spaced removable studs 63.

The central annulus 62 in use is rigidly mounted on the corresponding shaft 35 which extends through the central aperture 64, and the annulus is secured in position using any of a range of known methods.

The disc portions 60, 61 join together to form a complete disc, which may be of any of a range of types (fluted, turbo, and so on), but the dividing line between the portions is not a straight line - the mating edges of the portions are curved as shown in Figure 5. Curving the dividing line 65 in this way means that the two disc portions are positively meshed together along the dividing line.

The curve of the dividing line 65 is such that, in use, each part of the dividing line 65 is outwardly convex in the direction of travel (Arrow Z) of the disc assembly. It has been found that a curved dividing line which is outwardly convex in the direction of travel is significantly less likely to become clogged with stones or trash than either a straight dividing line or a dividing line which is concave in the direction of travel.

The advantage of the split disc shown in Figure 5 is that dises which break or become worn can easily be replaced on the corresponding shaft 35, without having to remove any of the other dises from that shaft:- the disc portions are simply removed from the corresponding annulus 62 and a fresh disc portions are secured to the annulus. Further, if only part of the disc is damaged, then only a single portion of the disc can be removed and replaced if appropriate.

The above described equipment is used as follows:- the connection píate 18 on the drawbar 11 is used to connect the assembly to a towing vehicle, and the following cultivation equipment (e.g. a drill) is connected to the extensions 15b. The power takeoff drive 40 is connected to the power takeoff of the towing vehicle in known manner, and the drive 40 is used as described above to rotate the drive shaft 25 and each of the shafts 35, thus rotating the dises 17 in the direction of Arrow A i.e. the direction of travel.

The hydraulic ram 50 is adjusted as necessary to obtain the required ground penetration of the dises and the towing vehicle moves all of the connected equipment forward in the direction of arrow E (Figure 2). The drive to the shafts 25/35 is adjusted as necessary to obtain the optimum speed of rotation:- this must be higher than the ground speed of the equipment.

In the above described preferred embodiment, the dises 17 have been shown arranged in a single line. However, it will be appreciated that the dises could be arranged as two or more lines, or in a staggered arrangement if preferred.

It has been found that the above described drill assembly shows greatly improved ground penetration due to: 1. The greater weight exerted on the ground by the assembly, because of the position at which the remainder of the assembly is mounted on the drawbar; 2. The forcé exerted on the dises by the hydraulic ram 50; 3. The fact that the dises are driven.

However, for some applications, good ground penetration may be achieved simply with the combination of features 1 and 2 above, and it may not be necessary to drive the dises. For such applications the driving equipment for the dises described above may be omitted, or simply not used.

Claims (11)

1. Claims:

   1. A disc assembly which includes: • a drawbar; • a series of spaced dises supported from the drawbar, each disc being rotatable; • forcé applying means connected between the drawbar and the dises, the forcé applying means being adapted to alter the forcé applied by each of said dises on an underlying surface.
2. 2. The assembly as claimed in claim 1, further including drive means for driving each of the dises to rotate.
3. 3. The assembly as claimed in claim 2, wherein each disc is mounted upon a rotatable shaft such that the disc is rotated with the shaft.
4. 4. The assembly as claimed in claim 3, wherein the rotatable shaft in use is driven from a drive shaft which is driveable from a drive selected from the following group: a power takeoff drive, a hydraulic motor.
5. 5. The assembly as claimed in claim 1 or claim 2, wherein the forcé applying means includes a hydraulic ram.
6. 6. The assembly as claimed in claim 5, wherein: - the hydraulic ram is pivotally connected between the drawbar and a tie bar which extends substantially perpendicular to the drawbar; - the tie bar is supported parallel to a crossbar which is rigidly secured substantially perpendicular to the drawbar, such that the tie bar is pivotable relative to the drawbar and the crossbar by extending or contracting the hydraulic ram.
7. 7. The assembly as claimed in claim 6, wherein: - the crossbar supports a series of spaced brackets, each of which has a hanger pivoted thereto; - the tie bar extends through an aperture in each of the hangers; - the spaced brackets support the drive shaft, which is drivably connected to the or each disc shaft to which each disc is mounted for rotation therewith.
8. 8. The assembly as claimed in claim 7, wherein a spring override device is mounted between each hanger and a support supporting the dises, such that the dises are able to rotate away from ground contact against the forcé exerted by the spring override device if the dises encounter obstacles.
9. 9. The assembly as claimed in any one of the preceding claims, wherein the dises are supported from the drawbar at a position approximately midway along the length of the drawbar, where the length of the drawbar is measured from an attachment point to a towing vehicle to an attachment point at the rear of the drawbar.
10. 10. The assembly as claimed in any one of the preceding claims, wherein each of the dises is a split disc formed in two or more portions each of which is releasably securable to a central annulus.
11. 11. The assembly as claimed in claim 10 wherein each disc is formed in two portions and the dividing line between said portions is a curved line.