WO2007095681A1

WO2007095681A1 - Improved ripper assembly for ground scrapers

Info

Publication number: WO2007095681A1
Application number: PCT/AU2007/000197
Authority: WO
Inventors: Gregory Charles Mclean
Original assignee: LORIDEN Pty Ltd
Current assignee: LORIDEN Pty Ltd
Priority date: 2006-02-21
Filing date: 2007-02-21
Publication date: 2007-08-30
Anticipated expiration: 2008-08-21

Abstract

An improved ripper assembly (30) for a ground scraper (10) is disclosed. The ripper assembly comprises a ripper bar (32) for pivotally coupling to the ground scraper via at least one mounting member (34) and at least two actuators (36) for coupling the ripper bar between the mounting member and the ground scraper. At least one of the at least two actuators is operable to incline the ripper bar with respect to a horizontal datum of the ground scraper. A method of modifying a ground scraper with the improved ripper assembly is also disclosed.

Description

TITLE IMPROVED RIPPER ASSEMBLY FOR GROUND SCRAPERS

FIELD OF THE INVENTION The present invention relates to an improved ripper assembly for ground scrapers. The ripper assembly of the present invention is applicable to a range of designs of ground spraper.

BACKGROUND TO THE INVENTION Ground scrapers are often employed in a wide range of land-levelling and earth-moving applications from agricultural applications to civil engineering applications. Ground scrapers are typically drawn behind a powered vehicle and comprise a cutting edge for excavating the earth and a bowl rearward of the cutting edge in which the excavated material is captured. A pivoting apron is moveable between an open position, which allows excavated material to collect in the bowl, and a closed position, which keeps the excavated earth in the bowl for transportation to another location.

When the ground is hard, the cutting edge often has difficulty in penetrating the surface and thus scraping or grading the earth to the desired level. Conventionally, this problem is addressed with a ripper bar mounted forward of the blade. The ripper bar comprises a row of teeth for penetrating and ripping up the earth making it easier for the following blade to scrape and level the earth. The ripper bar can. be lowered and raised to engage and disengage to ground respectively. Alternatively, it is known to mount ripper adaptors to at least part of the cutting edge. However, the ripper adaptors will only handle moderately hard materials.

Examples of ground scrapers comprising ripper assemblies can be found in US 4,553,608, US 4,015,348, US 5,922,279, US 4,217,962 and US 4,359,103.

For example, For example, US 4,553,608 in the name of Miskin describes a scraper machine having a scraper unit and a ripper assembly. The ripper assembly has means to vertically adjust the teeth of the ripper assembly relative to the cutting edge of the scraper unit wherein the teeth of the ripper assembly remain substantially parallel to the cutting edge of the scraper unit.

Problems with the above solutions are encountered, for example, when the ground scraper is used to excavate channels and/or batters and/or is employed with inclined surfaces in general. For example, when excavating batters, the scraper tends to lean away from the batter, thus causing uneven ripping and thus uneven loading of earth into the scraper. This increases the inclination of the scraper and exacerbates the problem.

Similarly, when excavating channels, as the depth of the channel increases the channel tends to become narrower. The width of the channel may be, for example, 1.5 times the width of the scraper. This would require two passes by the scraper, but with an overlap in the area scraped/levelled. Consequently, earth in the overlap is scraped twice, which is unnecessary and inefficient. Furthermore, the scraper loads with excavated earth unevenly on one side of the scraper causing the scraper to lean. As the scraper fills unevenly, the leaning is exacerbated. In this specification, the terms "comprises", "comprising" or similar terms are intended to mean a non-exclusive inclusion, such that a method, system or apparatus that comprises a list of elements does not include those elements solely, but may well include other elements not listed.

OBJECT OF THE INVENTION

It is an object of the present invention to provide an improved ripper assembly for ground scrapers that addresses, or at least ameliorates, the aforementioned prior art problem of uneven scraping/levelling/ripping of the ground.

SUMMARY OF THE INVENTION

In one form, although it need not be the only or indeed the broadest form, the invention resides in a ripper assembly for a ground scraper comprising: a ripper bar for pivotally coupling to the ground scraper via at least one mounting member; and at least two actuators for coupling the ripper bar between the at least one mounting member and the ground scraper; wherein at least one of the at least two actuators is operable to incline the ripper bar with respect to a horizontal datum of the ground scraper.

Preferably, the at least two actuators are independently operable to incline the ripper bar.

Preferably, the at least two actuators are pivotally coupled to the mounting member. Suitably, the at least two actuators are pivotally coupled to the mounting member via ball studs and caps or self-aligning bearings.

Preferably, the at least two actuators are rotatably coupled to a draft tube of the ground scraper.

Suitably, the at least two actuators are one of the following: hydraulic lift rams, pneumatic lift rams, rack and pinion arrangements.

Preferably, the mounting member is at least partially elongate and pivotally coupled to a pull of the ground scraper.

More preferably, the mounting member is pivotally coupled to a drawbar of the ground scraper. Preferably, the ripper assembly further comprises an elongate transverse member in the form of a tag link pivotally coupled at or toward one end thereof to the ripper bar and pivotally coupled at or toward the opposite end thereof to the draft arm and/or draft tube of the ground scraper to prevent lateral movement of the ripper bar. Preferably, the elongate tag link is pivotally coupled at or toward opposite ends thereof to the ripper bar and the draft arm and/or the draft tube via ball studs and caps or self-aligning bearings.

In another form, although again not necessarily the broadest form, the invention resides a method of modifying a ground scraper including: pivotally coupling a ripper bar of a ripper assembly to the ground scraper via at least one mounting member; and coupling at least two independently operable actuators between the mounting member and the ground scraper such that at least one of the at least two actuators is operable to incline the ripper bar with respect to a horizontal datum of the ground scraper. Further features of the present invention will become apparent from the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS By way of example only, preferred embodiments of the present invention will be described more fully hereinafter with reference to the accompanying drawings, wherein:

FIG 1 is a perspective view of a ground scraper comprising a ripper assembly in accordance with an embodiment of the present invention; FIG 2 is a side elevation of the ground scraper and ripper assembly of

FIG 1 ;

FIG 3 is a front view of the ground scraper and ripper assembly of FIG 1 ; FIG 4 is an underside perspective view of the ground scraper and ripper assembly of FIG 1 ; FIG 5 is a schematic plan perspective view of an elongate transverse member of the ripper assembly of FIG 1 ;

FIG 6 is a flowchart illustrating a method of modifying a ground scraper in accordance with embodiments of the present invention;

FIG 7 is a side elevation of a ripper assembly in accordance with an embodiment of the present invention; and

FIG 8 is a plan view of the ripper assembly shown in FIG 1.

DETAILED DESCRIPTION OF THE INVENTION

The ripper assembly of the present invention will be described fitted to the Applicant's improved ground scraper as described in their co-pending International patent application PCT/AU2005/001918. However, it should be appreciated that the ripper assembly of the present invention can be applied to other designs of ground scraper providing sufficient space is available forward of the cutting edge of the ground scraper to accommodate the ripper assembly. Referring to FIGS 1 and 2, the Applicant's improved ground scraper 10 comprises a bowl 12 for holding excavated material and a cutting edge 14 in the form of a blade for excavating ground material. Bowl 12 is formed from a base 16 and sidewalls 18 and the cutting edge 14 extends the width of the bowl 12. Draft arms 20 are pivotally coupled to the sidewalls 18 and are coupled to a transverse draft tube 22. The ground scraper is pulled by a powered vehicle (not shown), such as a heavy-duty tractor, via a pull 24 coupled to the draft tube 22 and a drawbar 26 coupled to the pull 24. A pivoting apron 28 is pivotally mounted to the sidewalls 18 and is movable between an open and closed position to force excavated earth into the bowl and to maintain the excavated earth in the bowl during transportation.

In accordance with an embodiment of the present invention, there is provided a ripper assembly 30 for the ground scraper 10. The ripper assembly 30 comprises a ripper bar 32 pivotally coupled to the ground scraper 10 via a mounting member 34. At least two actuators 36 are coupled between the mounting member 34 and the ground scraper 10 and at least one of the two actuators 36 provided in this embodiment is operable to incline the ripper bar 32 with respect to a horizontal datum 37 (shown in FIG 3) of the ground scraper.

The ripper bar 32 comprises a plurality of tynes 33 extending therefrom and each tyne 33 has a tooth 35 at the end thereof for engaging and ripping up the ground in advance of the following cutting edge 14. However, it will be appreciated that the length, angle, number and spacing of the tynes 33 and teeth 35 can vary depending on the particular application, the type of ground scraper, the type of ground being scraped and the prevailing conditions, e.g. dry, waterlogged etc. Referring additionally to FIGS 3 and 4, according to one embodiment, the mounting member 34 is at least partially elongate and is pivotally coupled to the drawbar 26 of the pull 24. In the embodiment shown, the mounting member 34 comprises a shoulder 38 at a distal end 39 adjacent the ripper bar 32 to provide a mounting surface for the at least two actuators 36 and to provide added strength to the ripper assembly 30. An elongate section 40 of the mounting member 34 tapers from the shoulder 38 to a proximal end 42 coupled to the drawbar 26. In this embodiment, proximal end 42 of the mounting member 34 is pivotally coupled to the drawbar 26 using a conventional ball, cap and bearing assembly 43 (more clearly visible in FIGS 1 and 2) comprising replaceable shims, which will be familiar to one skilled in the art.

Referring additionally to FIG 5, the at least two actuators 36 are rotatably mounted by any suitable means known in the art to the draft tube 22 of the ground scraper 10. According to one embodiment, a compensating collar 41 is welded to the draft tube 22 and each of the at least two actuators 36 is rotatably mounted to the compensating collar 41 by means of a housing 45 and a yoke 47. The housing 45 comprises bearings (not shown), which allow the yoke 47 to rotate within the housing 45 and short shafts 49 are welded to each of the at least two actuators 36 to enable pivoting of each actuator 36 in its respective yoke 47. Hence, this arrangement permits rotation of the actuators 36 with respect to the draft tube 22 about orthogonal axes. In the embodiment shown, the at least two actuators 36 are in the form of hydraulic lift rams powered by respective hydraulic circuits. In particular, the at least two actuators 36 can be in the form trunnion mount rams. The at least two actuators 36 are pivotally coupled to the shoulder 38 of the mounting member 34 via conventional ball studs 44 and caps 46. Alternatively, self-aligning bearings can be used instead of the ball studs and caps. The at least two actuators 36 are spaced apart and are independently operable by virtue of the separate hydraulic circuit provided for each actuator 36. The spacing between the at least two actuators 36 can vary according to the type and design of ground scraper to which the ripper assembly 30 of the present invention is fitted.

In alternative embodiments, actuators 36 can be in the form of pneumatic rams powered by respective pneumatic circuits, in the form of rack and pinion arrangements powered by, for example, electric motors, or in the form of other mechanical actuators. With further reference to FIG 5, the ripper assembly 30 further comprises an elongate transverse member in the form of a tag link 48. Tag link 48 is pivotally coupled at, or toward, one end thereof to the ripper bar 32 and the tag link 48 is pivotally coupled at, or toward, an opposite end thereof to one of the draft arms 20 and/or the draft tube 22 of the ground scraper 10. In the embodiment shown in FIG 5, the opposite end of the tag link 48 is welded to a bracket 50, which is welded to the draft tube 22. According to one embodiment, the tag link 48 is pivotally coupled at opposite ends thereof to the ripper bar 32 and one of the draft arms 20 and/or the draft tube 22 via ball studs 52 and caps 54. In an alternative embodiment, self-aligning bearings can be used instead of the ball studs and caps. When the ripper assembly 30 is required to break up the ground in advance of the following cutting edge 14, the at least two actuators 36 are activated to extend and thus lower the ripper bar 32 such that the teeth 35 are in engagement with the ground. Similarly, the at least two actuators 36 can be activated to retract and raise the ripper bar 32 to disengage the teeth 35 from the ground.

Where the ground being excavated and/or leveled is not inclined or oriented such that the aforementioned prior art problems would be encountered, the at least two actuators 36 can be extended equally such that the ripper bar 32 remains level and substantially all of the teeth 35 of the ripper bar 32 engage the ground to rip up the ground evenly substantially across the width of the scraper 10.

Where the aforementioned prior art problems would be encountered, at least one of the at least two actuators 36 is activated to lower the side of the ripper bar 32 to which the activated actuator 36 is connected and thus incline the ripper bar 32 with respect to a horizontal datum 37 of the ground scraper. Therefore, the teeth 35 of the lowered side of the ripper bar 32 engage the ground, but the other side of the ripper bar 32 remains elevated such that the teeth 35 on that side of the ripper bar 32 do not engage the ground. Alternatively, both of the at least two actuators 36 are activated, but such that the actuators 36 extend to different extents. In one case, substantially all of the teeth 35 engage the ground, but the teeth 35 on one side of the ripper bar 32 engage the ground further than the teeth on the other side. In another case where both of the actuators 36 are activated, the difference in extension of the at least two actuators 36 can cause only the teeth 35 on the most lowered side to engage the ground.

Hence, independent activation or operation of one or both of the at least two actuators 36 enables the ripper bar 32 to be inclined with respect to a horizontal datum 37 of the ground scraper to suit the terrain being excavated or leveled.

The elongate transverse member in the form of tag link 48 prevents or at least minimizes lateral movement of the ripper bar 32, especially when only some of the teeth 35 of the ripper bar 32 engage the ground. In this case, force due to ground engagement acts on only some of the teeth, which, in the absence of the tag link 48, would cause lateral movement of the ripper bar 32 potentially causing ripping of ground that was not in line with the scraper, which is undesirable.

The angles of inclination achievable by the ripper bar 32 with respect to a horizontal datum 37 of the ground scraper are determined by the extension achievable by the at least two actuators 36 and, to a lesser extent, the spacing between the at least two actuators 36.

The ripper assembly 30 of the present invention can be factory fitted to a range of ground scraper types and designs or it can be retrofitted to existing ground scrapers. Hence, with reference to FIG 6, according to another aspect, the present invention resides a method 600 of modifying a ground scraper. The method 600 includes at 610 pivotally coupling the ripper bar 32 of the ripper assembly 30 to the ground scraper 10 via the mounting member 34. The method

600 includes at 620 coupling at least two independently operable actuators 36 between the mounting member 34 and the ground scraper 10 such that at least one of the at least two actuators 36 is operable to incline the ripper bar 32 with respect to a horizontal datum of the ground scraper. According to one embodiment, the method 600 includes at 630 pivotally coupling one end of the elongate transverse member 48 to the ripper bar 32 and pivotally coupling the opposite end thereof to a draft arm and/or a draft tube of the ground scraper to prevent lateral movement of the ripper bar 32.

Another embodiment of the ripper assembly of the present invention is shown in FIGS 7 and 8. In this embodiment, the ripper bar 32 is pivotally coupled to the ground scraper 10 via a plurality of mounting members in the form of arcuate members or links 70. Links 70 are pivotally coupled to the ripper bar 32 and to the draft tube 22 of the ground scraper respectively via brackets 72 extending from the ripper bar 32 and via brackets 74, 76 extending from the draft tube 22. Four links 70 are provided in this embodiment approximately 14 and % of the length along the draft tube 22 and the links 70 form a parallelogram. Links 70 are pivotally coupled to the brackets 72, 74, 76 via self-aligning bearings 78. Each brackets 72 is pivotally coupled at a first end to a link 70 and is pivotally coupled at a, second, opposite end to both a link 70 and the ripper bar 32. In contrast with previously described embodiments, in this embodiment the actuators 36 are rotatably mounted to the compensating collar 41 facing toward, rather than away from, the bowl 12 of the ground scraper 10. In this embodiment, tag link 48 is pivotally coupled at one end to the ripper bar 32 and pivotally coupled at the opposite end to one of the draft arms 20.

Hence, the ripper assembly 30 of the present invention thus provides a solution to the aforementioned prior art problems by virtue of at least two actuators 36 pivotally coupling the ripper bar 32 to the ground scraper 10 wherein the at least one of the at least two actuators is operable to incline the ripper bar 32 with respect to a horizontal datum 37 of the ground scraper according to the terrain being leveled and/or excavated. The selectively operable actuators 36 enable the ripper bar 32 to be angled such that only the required ground is ripped up, even where the ground is inclined or channels or batters are being excavated or the width of the channel/excavation is not an integral multiple of the width of the ground scraper. Even leveling of excavations such as channels and batters can be achieved and uneven loading of the bowl of the scraper can be avoided or at least minimized by virtue of the present invention. More efficient leveling/excavation can also be achieved because further leveling/excavation to rectify earlier uneven excavation is not required.

Throughout the specification the aim has been to describe the invention without limiting the invention to any one embodiment or specific collection of features. Persons skilled in the relevant art may realize variations from the specific embodiments that will nonetheless fall within the scope of the invention. For example, the invention is not limited by the type of ripper bar 32 or number of tynes 33 or by the proportion of the mounting member 34 comprising the shoulder 38 and elongated section 40. The particular size and type of actuators 36 and their spacing and the pivoting means 43, 44, 46, 52, 54 described herein may vary according to, for example, the type and design of the ground scraper to which the ripper assembly of the present invention is fitted and the space available.

Claims

CLAIMS:

1. A ripper assembly for a ground scraper comprising: a ripper bar for pivotally coupling to the ground scraper via at least one mounting member; and at least two actuators for coupling the ripper bar between the at least one mounting member and the ground scraper; wherein at least one of the at least two actuators is operable to incline the ripper bar with respect to a horizontal datum of the ground scraper.

2. The ripper assembly of claim 1 , wherein the at least two actuators are independently operable to incline the ripper bar.

3. The ripper assembly of claim 1 , wherein the at least two actuators are pivotally coupled to the at least one mounting member.

4. The ripper assembly of claim 3, wherein the at least two actuators are pivotally coupled to the at least one mounting member via ball studs and caps or self-aligning bearings.

5. The ripper assembly of claim 1 , wherein the at least two actuators are rotatably coupled to a draft tube of the ground scraper.

6. The ripper assembly of claim 1 , wherein the at least two actuators are of the following type: hydraulic lift rams, pneumatic lift rams, rack and pinion arrangements.

7. The ripper assembly of claim 6, wherein a hydraulic circuit is provided for each hydraulic lift ram.

8. The ripper assembly of claim 6, wherein a pneumatic circuit is provided for each pneumatic lift ram.

9. The ripper assembly of claim 1 , wherein the at least one mounting member is at least partially elongate and is pivotally coupled to a pull of the ground scraper.

10. The ripper assembly of claim 9, wherein the at least one mounting member is pivotally coupled to a drawbar of the ground scraper.

11. The ripper assembly of claim 1 , wherein a plurality of mounting members are pivotally coupled to a draft tube of the ground scraper.

12. The ripper assembly of claim 1 , further comprising an elongate transverse member pivotally coupled at, or toward, one end thereof to the ripper bar.

13. The ripper assembly of claim 12, wherein the elongate transverse member is pivotally coupled at, or toward, the opposite end thereof to a draft arm and/or a draft tube of the ground scraper.

14. The ripper assembly of claim 12 or 13, wherein the elongate transverse member is pivotally coupled at, or toward, opposite ends thereof to the ripper bar, the draft arm and/or the draft tube via ball studs and caps or self-aligning bearings.

15. A ground scraper comprising the ripper assembly of claim 1.

16. A method of modifying a ground scraper including: pivotally coupling a ripper bar of a ripper assembly to the ground scraper via at least.one mounting member; coupling at least two independently operable actuators between the at least one mounting member and the ground scraper such that at least one of the at least two actuators is operable to incline the ripper bar with respect to a horizontal datum of the ground scraper.

17. The method of claim 16, further including pivotally coupling one end of an elongate transverse member to the ripper bar and pivotally coupling the opposite end of the elongate transverse member to a draft arm and/or a draft tube of the ground scraper to prevent lateral movement of the ripper bar.