AU2015100242A4 - Replaceable Tooth for Dredger Bucket - Google Patents

Abstract

A replaceable tooth for a dredger bucket has a cavity for receiving a mount projecting from the edge of the bucket floor. The body of the tooth is a 42CrMo steel alloy forging. The leading edge of the tooth is drilled to accommodate a row of tungsten carbide cutters each with intersecting faces pitched at 80-1 000 C. 20 153-02,C:\Users\Sharlene\Docments\SPECIFICATONSwerliCe inpata.pd.6 -9 3. s~2 7- 4 3 ~ -U Nm / 2) £ /7 /0~ N -H '9 / /7 jul / /w 0 2± 3 -s £S2A 3 __ 'S. Fm'> ---- __

Description

TITLE OF INVENTION Replaceable Tooth for Dredger Bucket TECHNICAL FIELD [0001] This invention concerns teeth for the buckets of digging and dredging machines. BACKGROUND [0002] It is common for the steel teeth of such machines to be replaceable in order to match the life of the bucket to the other components of the machine. In machines such as dredgers and coal handling plants, daily wear is observable and routine servicing is needed to replace worn and damaged teeth. [0003] The buckets commonly have bevelled or V-section edges to receive individual teeth mounts. A typical tooth is a gravity casting with a V-section cavity intended to match the V section of the mount which projects from the bucket edge. Triangular side walls close the sides of the tooth and a pin housing in the top face and bottom face of the tooth receives a pin which passes through the tooth mount and is captured by a fastener. The teeth are 70-80mm wide. [0004] A dredger bucket would typically need nine teeth. A rotary dredge may have 20 buckets. SUMMARY OF INVENTION [00051 The apparatus aspect of the invention provides a replacement tooth for a dredger bucket having a prismatic body with a cavity for the reception of the tooth mount of the bucket, a top face and a bottom face which converge across the width of the tooth body toward a leading edge, wherein the linear cutting edge is formed by a row of tungsten carbide cutters embedded in the leading edge. 20 5-03-02.C:\Um 0SlurknAIocunwnits\SPECEFICATIONS\wearlife innpatawpd&1 2 [0006] The tooth body is a forging. [0007] The cutters are joined to the body by brazing. [0008] The leading edge has multiple side by side bores, each of which receive a cylindrical tungsten carbide cutter which has intersecting faces pitched at 80-100'C. [0009] The body metal is 42CrMo alloy steel. The 41 range of CrMo alloys is suitable but the 42 range is preferred. Advantageous Effects of Invention [00101 1. The dense forging extends service life. [00111 2. The cutters reduce the load on the bucket drive and extends service life. [0012] 3. The teeth have a longer working life than teeth without such cutters. BRIEF DESCRIPTION OF DRAWINGS [0013] One embodiment of the invention is now described with reference to the accompanying drawings, in which: [0014] Figure 1 is a side section through the tooth. [0015] Figure 2 is a front section through the tooth. [0016] Figure 3 is a side elevation. [0017] Figure 4 is an opposite side elevation. 2015-03-02,C:\UsedShadna.kDcumemis\SPECiF[CATIONS\weatLifeinnpatlwpd,2 3 [0018] Figure 5 is a perspective of a cutter. [0019] Figure 6 is a perspective of the crest of the tooth. DESCRIPTION OF EMBODIMENTS [0020] Referring now to the drawings, the tooth body 2 is initially forged from 42CrMo, a commercially available steel alloy. It is 75mm wide and 142mm long. The lower face 4 has flat outer strips 6 separated by a concave intermediate strip 8. The tipper parts 10 of outer strips 6 are convex. The pitched crest face 12 is almost planar and inclined. The lower part of the intermediate strip 8 has a shallow housing 14. The upper face 16 extends from the pitched crest face 18. [0021] Side walls 20, 11.5mm thick and 74mm long partly define prismatic cavity 22 which accommodates the tapered tooth mount (not shown) of the bucket. The diverging tipper and lower walls 24, 26 are pierced by 13 x 22mn paired, aligned apertures 28, 30, the purpose of which is to accommodate a fastener pin (not shown) to clamp the tooth to the mount. The purpose of the mount is to act as an adapter so that the tooth need not match the bucket edge. [0022] The crest of the forging is drilled to create six side by side bores, each of which houses a cylindrical tungsten carbide cutter 30, 10nn in diameter with pitched cutting faces 32, disposed at 840. The cutters are brazed to the drilled crest with a silver based brazing alloy mix by an inductive process performed at 700'C. Faces 32 are cleaned with a grindstone. [0023] It is to be understood that the word "comprising" as used throughout the specification is to be interpreted in its inclusive form, ie. use of the word "comprising" does not exclude the addition of other elements. [0024] It is to be understood that various modifications of and/or additions to the invention can be made without departing from the basic nature of the invention. The carbide cutters may instead be cutters made of wear resistant steel. These modifications and/or additions are 2015-03-02,C:\Uses\Shalkn ocume nts\SPECFFICATIONS\weaslife innpt.wpd,3 4 therefore considered to fall within the scope of the invention. 20]S-03-02,C:\Users\Sldeirn&Documnts\PEC1FICATIONS\weadifeinnpatxwpd,4

Claims (4)

1. 2. A replacement tooth as claimed in Claim 1, wherein the tooth body is a forging.
2. 3. A replacement tooth as claimed in Claim 1 or 2, wherein the cutters are joined to the body by brazing.
3. 4. A replacement tooth as claimed in any one of Claims 1-3, wherein the leading edge has multiple side by side bores, each of which receive a cylindrical cutter which has intersecting faces pitched at 80-100'C.
4. 5. A replacement tooth as claimed in any one of Claims 1-4, wherein the body metal is 42CrMo alloy steel. 201 5-03-02,C:\Users\SharleneDocuments\SPECIFICATIONS~warife innpatwpd.5