AU715976B2 - A ground working apparatus - Google Patents

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT Name of Applicants: a a.

p *r a a. a a.

a a.

a..

LIMTHONO PTY. LTD.

002 208 826) PRIME GRAIN PTY. LTD.

001 264 799) Actual Inventor: Address for Service: Kevin SKERMAN CULLEN

CO.,

Patent Trade Mark Attorneys, 240 Queen Street, Brisbane, QId. 4000, Australia.

A GROUND WORKING APPARATUS Invention Title: Details of Associated Provisional Application: No. PO4490 filed on 8 January 1997 The following statement is a full description of this invention including the best method of performing it known to us: This invention relates to a ground working apparatus and particularly relates to a apparatus having a system for maintaining a desired balance of weight and depth control to the apparatus.

The invention will be described with reference to a ground working agricultural apparatus but it should be appreciated that the invention is also applicable to other soil or ground working apparatus such as road making machines.

Examples of agricultural tillage equipment include seeders, cultivators, scarifiers, chisel ploughs and ripping ploughs. The equipment includes a soil working device and in most cases a fairly large number of soil working devices are provided mounted as an array.

Thus, one type of tillage equipment has a fairly large number of :-:ground engaging tynes mounted to an implement frame. The frame is formed *ooo from steel sections and typically comprises an outer frame with a number of transverse cross bars to support the tynes or other implement).

.*.**These agricultural apparatus are usually supported by ground .wheels attached to the frame and are towed behind a tractor.

It is important to ensure that ground cultivation is carried out as uniformly as possible. For instance, even a small variation in furrow depth for seeding can cause irregular germination or reduced germination.

For this reason, it is important that the ground working devices for instance tynes) pass through the ground at a uniform depth.

While such uniformity of depth is possible on perfectly level fields, it is not so for undulating fields where the ground working devices will work the ground at different depths.

For non level fields, it is usual to attach the agricultural tillage equipment to a hitch frame, and attach the hitch frame to the tractor. The hitch frame is pivotally mounted to the equipment to provide at least some digging uniformity as the tractor and equipment moves over undulating ground.

However, it is found that the pivoting hitch does not sufficiently overcome the problem with uniform digging depth.

Instead it is found that an overturning moment is created due to the attachment of the hitch. The overturning moment is a force which applies a greater load onto the forward ground engaging devices (tynes) causing them to dig further in to the ground and applies a consequently lesser load on the rear tynes causing them to form shallower furrows. The moment can be reduced by attaching the hitch at or only slightly above the ground surface but such an attachment is not practical.

Even on level fields, a change in overturning moment may occur due to a change in soil condition.

,One attempt to reduce the overturning moment is to place the ground wheels well in front and behind the implement frame. However this arrangement results in loss of depth control as the apparatus does not track the ground very efficiently and will ride over small undulations.

To improve the ground tracking ability, it is necessary to place the **ground wheels close to the ground engaging implements and within the S* implement frame. This however creates the largest possible overturning moment which is also unsatisfactory.

Australian patent 592083 provides a mechanical linkage 20 arrangement to compensate for the overturning moment but has a limited range of effective operation, and provides no potential to control any part of the machine other than the centre section where the hitch mounts. Thus the linkage arrangement cannot compensate for hinged wing sections and for extra forces exerted on the implement frame by attachments such as presswheels mounted along the back.

An electronically controlled machine is known which uses complex electronic sensors and hydraulic control valves to counteract the overturning moment but as well as being expensive, is also unable to control wing sections.

The present invention is directed to a system which compensates for the overturning moment and which can provide the public with a useful or commercial choice.

In one form the invention resides in a ground working apparatus having a frame, ground engaging wheels, a hitch frame pivotally mounted to the apparatus and attachable to a tractor or other prime mover, at least one ground working implement, and an overturning moment reducing arrangement comprising a master pressure actuator operated upon movement of the tractor, and at least one slave pressure actuator to provide a overturning moment compensating force to a rear portion of the apparatus The pressure actuators provide a simple, reliable and inherently automated arrangement to compensate for the overturning moment.

Thus, the apparatus, be it agricultural equipment, road working equipment, or other equipment, can have its ground wheels close to the ground working implement(s) to provide a good ground tracking ability, and the hitch can :be significantly above the ground to allow it to conveniently hitch to the tractor, or other type of prime mover, and the apparatus.

15 It is preferred that the master pressure actuator is in a forward part of the hitch and that the actuator is connected to the tractor, such that forward pulling of the tractor actuates the pressure actuator.

The master and the slave pressure actuators can comprise fluid operated rams, such as hydraulic or pneumatic rams. Also, the actuators could comprise gas bags, or fluid bags. A mechanical pressure actuator is also envisaged which could comprise a spring defining the master actuator.

*The at least one slave pressure actuator may be positioned on the frame and adjacent and above the hitch point. For typical sized equipment, a number of slave actuators can be provided.

In one form, the slave actuator(s) functions to force the hitch to pivot relative to the frame. Thus if the soil condition changes, the pressure actuators compensate for the change in overturning moment by applying a force to the rear of the apparatus. The force can be a pressing down force or a lifting up force as the case may be.

To increase the ground working area of the apparatus, the apparatus may have a main frame assembly, and at least one wing frame assembly. Typically, a central main frame assembly is provided with a wing frame assembly extending from each side edge of the main frame assembly. The wing frame assembly is preferably hingedly connected to the main frame assembly to allow it to track the ground independently of the main frame assembly. Each wing frame assembly may be provided with a said slave pressure actuator to compensate for the overturning moment. It should be appreciated that other combinations of main and wing frame assemblies could be made which fall within the scope of the present invention.

Embodiments of the invention will be described with reference to the following drawings, in which Figure 1 is a side view of a ground working apparatus according to an embodiment of the invention and which has a main frame assembly.

Figure 2 is a top view of Figure 1.

Figure 3 illustrates another embodiment of the invention which has 15 a main frame assembly and a pair of side wing frame assemblies.

Figure 4 illustrates, in close up, a hinge joint and a pressure actuator.

Referring to be Figures 1 and 2, there is illustrated a ground working apparatus 10. The apparatus 10 has an implement frame 11, ground 20 engaging wheels 12, a hitch frame 13 pivotally mounted to the apparatus 10 and attachable to a tractor or similar prime mover at a forward portion 14, and a number of ground working implements in the form of tynes Apparatus 10 also has an overturning moment reducing arrangement comprising a master pressure actuator 16 and two slave pressure actuators 17, 18.

Implement frame 11 can be of various designs, but in the embodiment, is formed from metal sections which are attached together by welding, bolting or other convenient means. The sections comprise a pair of longitudinal sections 19 and four transverse sections 20A to 20D. Transverse sections 20A-D support the tynes 15 which are attached to the transverse sections by conventional means. It can be seen that longitudinal sections 19 and the outermost transverse section 20 together form a surround frame.

Within surround frame are provided four wheels 12, the wheels being conventional in design and attached to the implement frame 11 in a conventional manner. In the embodiment, each of the four wheels are within the surround frame and close to tynes 15, this arrangement providing a good ground contour following (or ground tracking) ability. Thus, the front pair of wheels are positioned behind transverse section 20A, and the rear wheels are positioned ahead of rear transverse section 20E, with the wheel base centre distance front to back being approximately 2 metres. This allows the apparatus to support itself independently of the tractor and allows the apparatus to accurately follow ground contours. it should be appreciated that the wheel centre distance can vary.) io.: Tynes 15 are illustrated as examples of soil working implements.

Typically, an apparatus will have a number of tynes, the number being between 4 S. to 40 or more. Thus, it is important that each of the tynes dig into the soil at a So: 15 uniform depth. It is envisaged that an apparatus with only one, or a few ground working implements could be used eg, a heavy duty ripper), and the invention ~need not be limited to any number of tynes or other ground working implements.

Hitch frame 13 is formed from a pair of diverging arm members 21, 22 formed from steel section. The distal ends of arm members 21, 22 are pivotally mounted to transverse section 20A through pivot pins 23, 24.

The proximal ends of arm members 21, 22 converge to forward portion 14 and some form of coupling 25 is provided to allow hitch frame 13 to be coupled to the back of a tractor or other vehicle.

Referring to forward portion 14, it can be seen that master pressure actuator 16 is in this region. In the embodiment, the actuator comprises an hydraulic ram having a ram body 26 and a ram rod 27. Ram rod 27 is fitted with the connecting means 25. Ram body 26 is rigidly attached to hitch frame 13.

Thus, upon movement of the tractor, ram rod 27 is extended from ram body 26 or pushed into ram body 26 as the case may be.

Master pressure actuator 16 is connected to slave pressure actuators 17, 18 through suitable hydraulic conduit 28. Slave actuators 17, 18 also comprise hydraulic rams. The slave ram body 29 (see Figure 1) is attached relative to implement frame 11 while the slave ram rod 30 is attached relative to hitch frame 13. Thus, extension and retraction of slave ram rod 30 will cause or force pivoting between implement frame 11 and hitch frame 13.

Master pressure actuator 16 is pressurised depending on movement of the tractor. Thus, forward force from the tractor creates pressure in the hydraulic fluid which is proportional to the forward force which in turn is equal to the force being required to pull the tynes through the soil (this being called the draft force).

slave pressure actuators are connected to the working side of the master pressure actuator to form a closed hydraulic circuit. The pressure generated in this circuit by the master actuator therefore acts on the slave 15actuators creating an extending force.

15 As illustrated, particularly in Figure 1, the slave actuators are :mounted above the pivotal connection of the hitch frame to the implement frame S:in such a way that the extending force acts between the two frames.

The result of this system of actuators is that the slave compensates for the overturning movement generated in the implement frame by the height difference between the hitch pivot and the tyne working force in the soil.

Without the arrangement, the overturning moment would cause the implement frame to tip forward thereby putting more weight on the front wheels than the back.

The pressure actuators according to the invention constantly and automatically compensate for the overturning moment and the correct balance is maintained regardless of the terrain.

A pressure guage (not illustrated) is connected in the circuit and is visible from the tractor, to show a measure of the draft force being applied by the tractor.

In the embodiment, the apparatus has a shut-off valve 31 which is kept in the closed position while working but which can be open to the tractor for 8 the purpose of charging the system.

While not illustrated in the drawings, the agricultural implement can include hinged or flexible wing sections on each side of the centre section frame.

Figure 3 illustrates a further embodiment of the invention where two wing frames 50,51 are hingedly attached to a central main frame 52. Slave pressure actuator 53, 54 are mounted on the wing sections to maintain the same compensating balance and ground following capability. The slave pressure actuators 53, 54 are connected through hydraulic conduit 55 to the master lo pressure actuator 16. Each wing frame 50,51 has ground wheels 56 which are within the frame and adjacent the tynes (not illustrated) to provide good tracking ability to the frame.

The mounting point of the slave actuators can be adjustable in 1 height so as to have the ability to adjust the compensation effect. That is, the compensation can be more or less by altering the working radius of the cylinder about its pivot point. The adjustment can also be used to add extra compensation for the effects of different attachments added to the implement such as rear mounted or in frame mounted springloaded presswheels.

}If desired, a hydraulic valve can be added which locks the slave ram circuit when the apparatus is lifted out of the ground. This causes the front set of wheels to lift from the ground and causes the apparatus to ride on the rear wheels only for travelling.

The overturning moment compensating system can be used for any ground engaging operation which requires such compensation such as might be used in earthmoving, roadworks, mining and the like.

It should be appreciated that various other changes and modifications can be made to the embodiment described without departing from the scope of the invention.

For instance, the tractor can pull directly on the master pressure actuator, or can pull through a sliding bar on to the master actuator. Other configurations are envisaged utilising the same principle.

Claims (9)

1. A ground working apparatus having a frame, ground engaging wheels, a hitch frame pivotally mounted to the apparatus and attachable to a tractor or other prime mover, at least one ground working implement, and an overturning moment reducing arrangement comprising a master pressure actuator operated upon movement of the tractor, and at least one slave pressure actuator to provide a overturning moment compensating force to a rear portion of the apparatus.

2. The apparatus of claim 1, wherein the master pressure actuator is in a forward part of the hitch and the actuator is connected to the tractor, such that forward pulling of the tractor actuates the pressure actuator.

3. The apparatus of claim 1 or claim 2, wherein the master and the i slave pressure actuators comprise fluid operated rams such as hydraulic or S-pneumatic rams and/or gas bags or fluid bags and/or a mechanical pressure 15 actuator.

4. The apparatus of any one of the preceding claims, wherein the at least one slave pressure actuator may be positioned on the frame and adjacent and above the hitch point.

5. The apparatus of claim 4, wherein a plurality of slave actuators is p 20 provided.

6. The apparatus of any one of the preceding claims, wherein the slave actuator(s) function to force the hitch to pivot relative to the frame.

7. The apparatus of any one of the preceding claims, wherein the apparatus has a main frame assembly and at least one wing frame assembly.

8. The apparatus of claim 7, wherein a central main frame assembly is provided with a wing frame assembly extending from each side edge of the main frame assembly.

9. The apparatus of claim 7 or claim 8, wherein the wing frame assembly is hingedly connected to the main frame assembly to allow it to track the ground independently of the main frame assembly. The apparatus of any one of claims 7 9, wherein each said wing I I frame assembly is provided with a said slave pressure actuator to compensate for the overturning moment. DATED this ek day of January 1998 LIMTHONO PTY. LTD. C. N. 002 208 826) PRIME GRAIN PTY. LTD. 001 264 799) By their Patent Attorneys CULLEN CO.