GB2093325A

GB2093325A - Wear-protection assemblies

Info

Publication number: GB2093325A
Application number: GB8136375A
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: 1981-01-09
Filing date: 1981-12-02
Publication date: 1982-09-02

Abstract

An assembly 10 for protecting from wear the otherwise exposed portion 12 of a sub-soiler leg or the like comprises a stack of wear- resistant tiles 14 mounted on a mild steel extrusion 25 tack-welded to the portion 12 to be protected. Loud transmission plates 16 may be interposed between the tiles 14. <IMAGE>

Description

SPECIFICATION Wear protection assemblies The present invention relates to assemblies for protecting from wear an otherwise exposed portion of a material-working tool or the like e.g. in agricultural or earth-working equipment.

Agricultural assemblies of this sort using ceramics have previously been considered somewhat impracticable because of the expense involved in replacing the ceramic should it fracture after striking against large stones in the soil.

An object of the present invention is to mitigate this problem.

According to the present invention an assembly for protecting from wear an otherwise exposed portion of a material-working tool or the like comprises one or more wear-resistant reinforcement parts e.g. of ceramic or other hard material, carried, or together carried, by a mounting member adapted to be secured to the part to be protected e.g. by tack-welding.

Conveniently, the one or more reinforcement parts will include a slotted portion adapted to interlock with a correspondingly shaped rib portion of the mounting member. In an alternative arrangement, the mounting member could provide the slotted portion and the one or more reinforcement parts could provide the correspondingly shaped rib portion.

Conveniently, that part of the mounting member adapted to embrace the part to be protected is provided by a mild steel extrusion.

Conveniently, that part of the mounting member adapted to provide the rib portion is provided either by a rolled steel section or by an appropriately shaped portion of the mild steer extrusion. In the latter case the rib portion will conveniently be hollow so as to allow a number of such mounting members to be linked together by a common lock bar passing through the hollow rib portions to give the assembly greater rigidity.

Although one or more elongate reinforcement members may if desired be used to provide the desired protection, in preferred arrangements the wear-resistance is instead provided by one or more stacks of wear-resistant elements carried either on a single mounting member if only one stack is present or each carried on its own individual mounting member if more than one stack is present.

When one or more stacks of wear-resistant elements are provided, as above described, then the elements of at least one of these stacks are conveniently at least in part protected from impact and other compressive loads by load-transmission elements interposed between the wear-resistant elements and adapted to transmit these loads direct from the outer regions of the wear-resistant elements to non-brittle mounting means for the elements. In this way the risk of fracturing is significantly reduced. Moreover it allows the wearresistant material to be present until the wearresistant elements and the load-transmission elements have been work right down to the mounting means for the elements.

The wear-resistant elements are conveniently in tile form. Suitable materials are ceramic, Nihard, cermet, brittle cast iron or any other wearresistant material which can be sintered and coldpressed to form tiles of the desired hardness and strength. One such material is for example Deranoc 975, a 97.5% alumina material currently being used in conventionally shaped tiles available from Anderman and Ryder Ltd., East Molesey, Surrey.

When tiles are used for the wear-resistant elements, the load-transmission elements are conveniently in plate form, e.g. heat-treated alloy steel leaves.

Conveniently, rather than have the load transmission plates initially extend to the same degree as the tiles, the tiles have both faces recessed and a single ioad-transmission plate is nested in the co-operating recesses of each pair of adjacent faces.

Conveniently, the tiles and the loadtransmission plates are first assembled as subassemblies (typically of five tiles each) e.g. by gluing them together with a hot-set or cold-set epoxy resin or, in the case of metallic or cermet tiles, alternatively by brazing, each sub-assembly including its own individual mounting member.

Preferably, the wear-resistant elements each have a rounded nose portion tapering over a length direction which is in excess of its greatest width and which lies in its intended direction of travel through the material to be worked.

Conveniently, the length dimensions of the nose-portions are between 11 and 3 times their maximum width.

In one such embodiment the wear-resistant elements have a roughly parabolic shape.

It is an advantage of these parabolic and related shapes in assemblies intended for use with agricultural and earth-working equipment that they represent the most efficient shapes for travel through the soil in so far as they are the shapes to which the assembly will be worn during use. A further advantage is that stones etc., in the soil will tend to be deflected by these shapes rather than be met "head on".

The invention also extends to a machine, tool, or other implement fitted with an assembly according to the present invention and in particular, amongst other things, it includes, when so fitted, agricultural equipment (e.g. the legs or points of sub-soilers, mole ploughs, heavy cultivators, chisel ploughs, etc.) and earth-moving equipment (e.g. bulldozer blades, bucket teeth etc.).

In particular, the invention extends to a subsoiler in which the leg of the sub-soiler and the sloping upper surface of the sub-soiler foot are each protected by an assembly according to the present invention.

Conveniently, the tip of the sub-soiler foot is made of cast iron or it can be protected by another assembly according to the present invention. In either case, the tip of the sub-soiler foot, when viewed in plan, may have its side faces sloping inwardly towards the front of the tip e.g. in a fairly flat parabolic or roughly parabolic fashion.

The invention also includes a sub-soiler or other implement as above described in which the, or at least one of the, said mounting members is releasably secured to the part to be protected by one of more axially-split spring-sleeves passing through aligned apertures in the or each said mounting member and the part to be protected.

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is a simplified perspective view of an assembly according to the invention, the assembly being shown mounted on the vertical leg of a subsoiler; Figure 2 is a part section, part perspective, view of the same assembly seen from above and showing one of the load-transmission plates removed; Figure 3 is a side view of the assembly prior to its completion; Figure 4 is a side view of one of the wearresistant tiles used in the assembly; Figure 5 is a simplified side view of another assembly shown mounted on the downwardly inclined share blade of a sub-soiler; Figures 6 and 7 are perspective views of two alternative assemblies;; Figure 8 is a partially exploded perspective view of a sub-soiler fitted with a different arrangement of wear-resistant tiles to that shown in Figure 5; and Figure 9 is a vertical section of the tip portion of the sub-soiler shown in Figure 8.

Thus referring first to Figures 1 to 4, an assembly 10 for protecting the otherwise exposed edge of a vertical sub-soiler leg 12 comprises a stack of ceramic tiles 14 interlaced with heattreated alloy steel leaves or plates 1 6.

As best seen from Figure 4, the nose portions 1 8 (shown shaded) of the tiles 14 are substantially parabolic in shape although related shapes may be chosen if desired provided always that the tiles desirably have their nose portions rounded and tapering over a length dimension (/) which is in excess of its greatest width dimension (w).

Preferably, as already pointed out, /is between 1 2w and 3w.

As best seen from Figures 2 and 3, the tiles have both faces recessed (as indicated for three tiles at 20, 21 in Figure 2) and the loadtransmission plates 16 are iocated one in each pair of co-operating recesses 20, 21 with the outer edges of the plates engaging the inner edges of the recesses.

In the illustrated embodiment, groups of adjacent tiles and plates are preassembled and glued together as sub-assemblies, typically of five tiles each, using a hot-set or cold-set epoxy resin.

One such sub-assembly is indicated at 23 in Figure 1 together with its associated mounting member 25 which embraces and is tack-welded onto the leg 12 to be protected.

Each mounting member 25 comprises a section of mild steel extrusion formed with forwardly turned flange portions 26 designed to accept the root portions 27 of the tiles 14. Member 25 also has a hollow circular-section rib-portion 29 about which the tiles and metal plates of the assembly almost wholly extend to lock them into place on the mounting member. This is most clearly shown in Figures 1 and 2 whilst in Figures 2 and 4 the rib-accepting slots in the tiles and plates are identified by numerals 31,32 respectively.

The assembly is completed by a locking bar 33 engaging the hollow rib-portions 29 of the different sub-assemblies and anchored at its ends against accidental removal.

Throughout the assembly, all the load-bearing parts are formed with rounded corners so as to minimise the stress in these regions. This is of particular importance in the shape of the tile root portions 27 and their relationship to the flange portions 26 of the supports 25 (see Figure 2).

It will be appreciated that in use of the assembly above described, the length dimensions / of the tiles will lie in the direction of movement of the assembly through the soil while the horizontal width dimensions w and the axis of rod 33 will lie perpendicular to this direction.

As the assembly moves through the soil in this way, any impact or other compressive loads experienced by the tiles 14 will pass to the edges of the recesses 20,21 from whence the load will be taken by the load-transmission plates 1 6 engaging these edges. Accordingly, those portions of the tiles fianked by the plates 1 6 will be protected from impact and other compressive loads by the plates 1 6 thereby significantly reducing the risk of tile fracture. Ultimately, of course, the load is carried by the leg 1 2 to which it is transmitted by the plates 1 6 via mounting member 25.

After prolonged use, the ceramic will wear down to such an extent that the outer edges of the load-transmission plates will also become exposed. Indeed in an alternative embodiment, not illustrated, the plates 1 6 are enlarged relative to those shown in the drawings so as initially to be coterminous with the intervening tiles 14.

Although specific materials for the illustrated assembly have been given above, it will be understood from the earlier portions of this specification that other materials may also be used if desired provided always that these give the desired wear-resistance etc.

As also indicated above, the assemblies of the present invention are suited to a variety of alternative applications. One such alternative is shown in Figure 5 where the assembly 10 is shown mounted on the downwardly inclined share blade 35 of a sub-soiler or the like. The assembly 10 of Figure 5 is to all intents and purposes identical to that described above with reference to Figures 1 to 4 except for the important difference that the design of the mounting member 25, the tiles 14 and the load-transmission plates 1 6 have all had to be modified so that in use the length dimension 1 of the assembly (Figure 4) is aligned with its intended direction of movement B (Figure 5) through the soil as before.

In the embodiment of Figure 6, a mild steel extrusion 40 provides both the leg-embracing part of member 25 and the rib-portion 29. This latter is wrapped around and welded to an appropriately shaped rolled steel core 41. In this embodiment, the tiles 14 are held captive on mounting member 25 solely by virtue of the interlock between their slotted portions 32 and the rib portion 29.

The tile portions 27 of the earlier embodiments are absent and because rib-portion 29 is no longer hollow, the tiles 14 have to be glued together to give the sub-assembly the desired rigidity.

Member 25 is secured in place by tack-welding it to the leg as before.

The embodiment of Figure 7 uses similarly shaped tiles to those shown in Figure 6 and the same method of mounting the tiles on rib-portion 29. However the embodiment of Figure 7 differs from all the previously illustrated embodiments in that the mounting member 25 is made entirely of rolled steel. A key portion 44 engages with a correspondingly-dimensioned key-way milled in the leading edge face of the leg to be protected.

Member 25 is tack-welded to the leg as before.

Figure 8 shows the tiles 14 of Figure 7 in place on the leg 48 of a sub-soiler 50 which is arranged to move through the soil in direction B. Reference numeral 52 indicates the key-way referred to above.

The sub-soiler foot 54 comprises two side plates 56, 57 inter-connected by rigid crossmembers 58, 59 (Figure 9).

The tip of the foot is protected by a stack of tiles 14 carried on a modified form of mounting member 61. These tiles will preferably be provided with load transmission elements such as the plates 1 6 shown ir the tile assemblies of Figures 2 and 3.

At its rear, member 61 is provided with a step portion which is secured in the recess 63 of a base member 65 by two cap-headed Allen screws 67.

Instead of screws 67, any other fixing may be used which allows for the removal and replacement of the tip protection assembly 14, 61 when the tiles 14 become too worn.

The base member 65 is itself mounted in two recesses 69 in each of the side plates 56, 57 in such a manner as to be inclined at 50 to the horizontal. At its rear edge, member 65 wedges into a lug member 71. This latter is removably held in place between the side plates 56, 57 by two axially-split spring-sleeves 73, 74 passing through appropriately aligned apertures in the member 71 and the side plates. Convenient proprietary articles for items 73, 74 are the "Rollpins" currently manufactured in the UK by the Tempered Spring Co. Ltd. At its front end, member 65 is formed with a triangular location lug 75 as shown.

The upper surface of the tip portion shown in Figure 9, which typically slopes at 22210 to the horizontal, is protected by two rectangular tiles 76 of the same material as the tiles 14 used elsewhere on the sub-soiler. The tiles 76 and the rectangular-form mounting member 78 to which they are secured, are both recessed at 80 to accommodate the bottom tiles 1 4 on the front edge of leg 48.

Downwardly extending lugs 82, 83 of mounting member 78 fit between the two side plates 56, 57 of foot portion 54 to which they are secured by Rollpins 85, 86. These latter are able to pass through apertures in the plates 56, 57 and the lugs 82, 83 only when these apertures have been correctly aligned by forcing member 78 and its lug 82 into ciamping engagement with the adjacent faces of cross member 58, mounting member 51 and base member 65 and its location lug 75. In this way the internal parts of the foot assembly, and in particular the Allen screws 67 holding member 61 in place, are protected from soil abrasive wear.

By removal of the appropriate Rollpins with a drift, the various parts of the sub-soiler referred to above may easily be removed and replaced as may mounting member 61 and this provides the illustrated embodiment with an additional advantage over conventional sub-soiler constructions where the standard bolt fixings are very difficult to replace once the bolt heads become worn. If desired, the protection for leg 48 may be modified and fitted in a similar way.

In a modification (not shown) of the last embodiment, the tip protection assembly 14, 61 is replaced by an appropriately-shaped solid chilled cast iron tip which fits on to a tapered tongue portion of a modified mounting member 65. In one such arrangement, for example, the cast iron tip will have a similar overali shape to the assembly 14, 61 shown in Figures 8 and 9 but in a preferred version, the shape of the tip will be modified so as in plan view to have its side faces sloping inwardly towards the front of the tip e.g. in a fairly flat parabolic or roughly parabolic fashion.

In other variations of the above embodiments, the illustrated tiles 14 may be replaced by one or more elongate wear-resistant elements each equivalent to four or five tiles and hence able to protect a correspondingly greater length of the leg 12. These elongate elements are conveniently formed from the same material as the tiles 14 by cold pressing and sintering.

Claims

1. An assembly for protecting from wear an otherwise exposed portion of a material-working tool or the like comprises one or more wearresistant reinforcement parts carried, or together carried, by a mounting member adapted to be secured to the part to be protected.

2. An assembly as claimed in Claim 1 in which the one or more reinforcement parts include a slotted portion adapted to interlock with a correspondingly shaped rib portion of the mounting member so as to hold the reinforcement parts captive on the mounting member.

3. An assembly as claimed in Claim 1 in which the mounting member includes a slotted portion adapted to interlock with a correspondingly shaped rib portion on the one or more reinforcement parts so as to hold the reinforcement parts captive on the mounting member.

4. An assembly as claimed in any preceding claim in which that part of the mounting member adapted to embrace the part to be protected is provided by a mild steel extrusion.

5. An assembly as claimed in Claim 4 in which that part of the mounting member adapted to provide the rib portion is provided by a rolled steel section.

6. An assembly as claimed in Claim 4 in which that part of the mounting member adapted to provide the rib portion is provided by a portion of the mild steel extrusion.

7. An assembly as claimed in Claim 6 in which the rib portion is hollow so as to allow a number of said mounting members to be linked together by a common lock bar passing through the hollow rib portions to give the assembly greater rigidity.

8. An assembly as claimed in any preceding claim in which one or more elongate reinforcement members are used to provide the desired protection.

9. An assembly as claimed in Claim 8 in which the reinforcement members are cold pressed and sintered.

10. An assembly as claimed in any of Claims 1 to 7 in which one or more stacks of wear-resistant elements are used to provide the desired protection, the stacks of wear-resistant elements being carried either on a single mounting member if only one stack is present or each carried on its own individual mounting member if more than one stack is present.

11. An assembly as claimed in Claim 10 in which the wear-resistant elements are in tile form.

12. An assembly as claimed in Claim 11 in which the tiles are made from ceramic, Nihard, cermet, brittle cast iron or any other wearresistant material which can be cold-pressed and sintered to form tiles of the desired hardness and strength.

13. An assembly as claimed in any of Claims 10 to 12 in which the wear-resistant elements of the or at least one of the stacks are at least in part protected from impact and other compressive loads by load-transmission elements interposed between the wear-resistant elements and adapted to transmit these loads direct from the outer regions of the wear-resistant elements to nonbrittle mounting means for the assembly.

14. An assembly as claimed in Claim 13 in which the load-transmission elements are in plate form.

15. An assembly as claimed in Claim 14 in which the plate-form load-transmission elements comprise heat-treated alloy steel leaves.

1 6. An assembly as claimed in Claim 14 or Claim 1 5 in which the wear-resistant elements have both faces recessed and a single loadtransmission plate is nested in the co-operating recesses of each pair of adjacent faces.

1 7. An assembly as claimed in any of Claims 14 to 1 6 in which the wear-resistant elements and the load-transmission plates are assembled in sub-assemblies by gluing them together with a hot-set or cold-set epoxy resin or, in the case of metallic or cermet tiles, alternatively by brazing.

18. An assembly as claimed in Claim 17 in which the sub-assemblies each include an individual mounting member which can be tackwelded onto the edge to be protected, these mounting members together making up the support means for the assembly.

19. An assembly as claimed in any preceding claim in which the wear-resistant elements each have a rounded nose portion tapering over a length direction which is in excess of its greatest width and which lies in its intended direction of travel through the material to be worked.

20. An assembly as claimed in Claim 19 in which the length dimensions of the nose-portions are between 12 and 3 times their maximum width.

21. An assembly as claimed in Claim 20 in which the wear-resistant elements have a substantially parabolic shape.

22. An assembly substantially as hereinbefore described with reference to and as illustrated in Figures 1 to 4 or Figures 5, 6 or 7 of the accompanying drawings.

23. A machine, tool or other implement fitted with an assembly according to any preceding claim.

24. A machine, tool or other implement as claimed in Claim 23 and designed specifically for agricultural or earth-moving equipment.

25. A sub-soiler in which the leg of the subsoiler and the sloping upper surface of the subsoiler point are each protected by an assembly according to any of Claims 1 to 22.

26. A sub-soiier as claimed in Claim 25 in which the tip of the sub-soiler foot is protected by an assembly according to any of Claims 1 to 22.

27. A sub-soiler as claimed in Claim 25 in which the tip of the sub-soiler foot is made of cast iron.

28. A sub-soiler as claimed in Claim 26 or Claim 27 in which the tip of the sub-soiler foot, when viewed in plan, has its side faces sloping inwardly towards the front of the tip.

29. A sub-soiler as claimed in Claim 28 in which the side faces of the sub-soiler foot slope inwardly in a fairly flat parabolic or roughly parabolic fashion.

30. A sub-soiler or other implement as claimed in any of Claims 23 to 29 in which the, or at least one of the, said mounting members is releasably secured to the part to be protected by one or more axially-split spring-sleeves passing through aligned apertures in the or each said mounting member of the part to be protected.