AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Applicant(s): DARRYL BATES Invention Title: EXCAVATOR TOOLS The following statement is a full description of this invention, including the best method of performing it known to me/us: -2 TITLE EXCAVATOR TOOLS 5 INTRODUCTION This invention relates to excavator tools, in particular buckets, cutting tools and like equipment that are used with excavators. 10 BACKGROUND OF THE INVENTION Excavators usually comprise a boom that is pivotally secured to an arm which is in turn pivotally 15 secured to a head or tool. The head or tool may be in the form of a variety of types of buckets with or without cutting teeth. Other tools include single toothed rippers. 20 The tools are conventionally attached to the excavator arm by a pair of spaced apart ears that support transversely located pins. The pins can be pivotally secured across the arm of the excavator or alternately a product known as a "quick hitch" is interposed between the 25 end of the excavator arm and the tool to engage and clamp against the pins to secure the tool to the arm. Because excavators use a variety of different tools, the suppliers of such equipment have to stock a variety of tools. This problem is made worse by the fact that each manufacturer 30 of excavators uses different dimensions with regard to the arm which means that tools have to be custom built for a particular model of excavator. Thus, in a situation where a user, hirer or supplier of excavators carries a wide range of different models there is a need to also have a 35 large range of tools to cover the variations in excavator designs. \\melbfiles\home$\MCooper\Keep\Speci\excavator tools.doc 18/03/04 - 3 What the industry needs is a degree of universality that allows one tool to be attachable to all types of excavator. It is this need that has brought about the present invention. 5 SUMMARY OF THE INVENTION In accordance with the present invention there is provided an excavator tool for attachment to an arm of an 10 excavator, the tool comprising an operative head supported about a pair of spaced mounting ears, each ear defining a pair of spaced apertures adapted to support location pins that extend across the ears, at least one pair of opposed apertures being in the form of elongate slots to 15 accommodate variations in the spacing of the location pins, a pair of links each defining spaced apertures adapted to be coaxial with the axes of the pins to determine the spacing of the pins, each link being positioned outside the ear and means to hold the links on 20 the pins against the ears. Preferably, each link is provided with a pair of spaced inwardly extending lugs adapted to extend through the ear whereby the ends of each pair lugs provide 25 surfaces defining a gap to guide the location of attachment means. The excavator tool described above is thus able to be used with the great majority of excavator makes and 30 models. It is the custom built links that ensure compatibility with the various makes and models. DESCRIPTION OF THE DRAWINGS 35 An embodiment of the present invention will now be described by way of example only with reference to the accompanying drawings in which: Figure 1A is a side elevational view of the arm N:\Melbourne\Cases\Patent\49000-49999\P49070.AU.1\Specis\P49070.AU.1 Specification 2009-6-24.doc 7/07/09 -4 of an excavator attached to a standard bucket through use of a quick hitch assembly, Figure 1B is a plan view of the quick hitch assembly taken along the arrow X of Figure 1A, 5 Figure 1C is a detailed side elevation view of quick hitch assembly, Figure 2 is a side elevational view of a single tine ripper with modified ears in accordance with the invention, 10 Figure 3 is a front elevational view of the ripper, Figure 4 is a plan view of the ripper, Figure 5 is a side elevational view of a sieve bucket incorporating ears of the subject invention, 15 Figure 6 is a side elevational view-of one ear, Figure 7 is a plan view of a pair of ears supporting location pins, Figure 8 is a plan view of an attachment link, Figure 9 is a side elevational view of the 20 attachment link, Figure 10 is a side elevational view of a front location pin, Figure 11 is a plan view of a second displaceable location pin, 25 Figure 12 is a view taken along the lines A-A of Figure 11, Figure 13 is a elevational view taken along the lines B-B of Figure 11, and Figures 14a and 14b are plan and side elevational 30 views of a retaining washer. Figures 1A, 1B, & 1C illustrate the standard assembly of a bucket B to the arm R of an excavator E. The bucket B has a pair of trailing ears E that are joined 35 by upper and lower location pins P1 and P2. The end of the arm R supports a quick hitch assembly Q that is in the form of pick up member M that has a bearing surface or \\melbfiles\home$\MCooper\Keep\Speci\excavator tools.doc 18/03/04 - 5 heel S from which depends a pair of spaced pick up hooks H. An elbow linkage L driven by a hydraulic ram causes the pick up member to pivot from an open position to a closed position in which the hooks engage an upper 5 location pin P1 and the bearing surface abuts the lower location pin P2. The quick hitch assembly Q allows the excavator arm R to quickly couple to a bucket B or other similar tool that is used with the excavator E. 10 Unfortunately, the spacing between the location pins P1 and P2 shown as dimension A in Figure 1A varies between different makes and models of excavators. The quick hitch assembly Q is designed to specifically fit these specifications which means that one particular make 15 or model of excavator can only be attached to a matching tool. The solution to this problem is shown with reference to Figures 2 to 14. The tool is designed to 20 allow for some adjustability between the spacing of the location pins and specifically designed brackets or attachment links are provided to determine the spacing of the location pins in accordance with each particular make or model of excavator. The attachment links also include 25 means which is described later that ensures that the quick hitch assembly Q picks up centrally of the tool. Figures 2 to 4 illustrate a tool 10 that is in the form of a ripper. The ripper comprises an operative 30 head in the form of a single tine 11 that is welded centrally of a support flange 12. The support flange 12 supports a pair of vertically extending spaced apart mounting ears 20, 21 that, in use, support transversely extending location pins 22, 23 (Fig. 7) which are engaged 35 by the quick hitch assembly Q to attach the tool to the arm A of the excavator E. The assembly that provides that means of attachment is shown in Figure 7. \\melbfiles\home$\MCooper\Keep\Speci\excavator tools.doc 18/03/04 -6 Figure 5 is a side elevational view of a sieve bucket 15 that also includes vertically extending spaced mounting ears 20, 21 in the same manner as the embodiment 5 shown in Figures 2 to 4. As shown in Figure 2 the tool 10 has a first pair of fixed circular apertures 24 on the leading edge 26 of the ears 20, 21 and then spaced towards the rear 27 of the 10 ears are elongate rectangular slots 25 of width that substantially corresponds to the diameter of the circular aperture 24. The slots 25 of each ear 20, 21 are in axial alignment. 15 As shown in Figure 1, the location pins 22, 23 are picked up by a quick hitch Q. Because the position of the axes of the pick up points vary from excavator to excavator there is a need to accommodate these variations by providing some adjustability in the position of the 20 location pins 22, 23 on the tool. Furthermore, there is also a small variation between the gap between ears 20, 21 or more importantly in the effective width of the quick hitch Q. To ensure that the hitch Q picks up the bucket centrally of the bucket, it is desirable that there are 25 surfaces on the inside of the ears 20, 21 that guide the quick hitch Q into a central position. Variations in the pin spacing and the necessary ear width are accommodated by the provision of the elongate slots 25 that provides a degree of variation of pin spacing, and the use of custom 30 built attachment links shown in Figures 8 and 9. The links 30 comprise elongate steel strips with spaced fixed circular apertures 31, 32 at either end that engage on the ends of the location pins 22, 23 to position the axes of the pins in accordance with the desired spacings as 35 dictated by the model of excavator. The attachment links 30 are also provided with a pair of inwardly projecting lugs 33, 34 that extend through a square aperture 38 and \\melbfiles\home$\MCooper\Keep\Speci\excavator tools.doc 18/03/04 - 7 the slot 25 in the ears 20, 21 of the tool 10 to define guiding surfaces 35, 36 on the inside of the ears 20, 21 which, in use, guide the hooks H of the quick hitch Q into engagement with the location pins 22, 23. 5 As shown in Figures 10 to 13 the location pins 22, 23 vary in design with the forward pin 22 being a simple cylindrical body that locates in the circular apertures 24 in the ears 20, 21. The ends 41, 42 of the 10 pin are drilled and internally threaded 43 to accommodate a retaining bolt 55 (Figure 7) that locates in a countersunk hole 45 formed centrally of a retaining washer 50 shown in Figures 14a and 14b. The rear location pin 23 is shown in Figures 11 to 13 and is substantially 15 cylindrical but has at each end a pair of spaced parallel lands 51, 52 that engage opposite sides of the slots 25. The pin 23 also includes an internally threaded bore 43 at each end to accommodate a retaining bolt 55 that holds on retaining washers 50 in the same manner as the forward pin 20 22. In order to provide tools 10 of a variety of kinds such as buckets, rippers or other cutting implements that can be fitted to a variety of different excavator 25 makes and models, the tools 10 are provided with mounting ears 20, 21 of the kind described above, the specially designed location pins 22, 23 and pairs of custom built attachment links 30. The attachment links 30 are specifically designed to accommodate the variations in 30 make and model of excavator by varying the spacing of the circular apertures 31, 32 in the links 30 and the spacing and depth of penetration of the lugs 33, 34. To assemble a particular tool 10 to an excavator E the pins 22, 23 are first located through the forward and rear apertures 24, 35 25 in the ears 20, 21 of the tool 10 and the particular attachment links 30 placed onto the tool with the lugs 33, 34 extending through the apertures 38, 25 in the wall of \\melb_files\home$\MCooper\Keep\Speci\excavator tools.doc 18/03/04 - 8 the ears 20, 21. Positioning of the particular attachment links 30 onto the pins 22, 23 positively positions the pins in the desired spacing. The retaining washers 50 are then held in position on either end of the pins 22, 23 5 through use of the retaining bolts 55 in the countersunk central aperture 45 in the washers 50 and in threaded engagement with the internally threaded bore 43 in the ends of the pins 22, 23. Thus, the attachment links 30 define the axial spacing of the location pins 22, 23 and 10 the inwardly projecting lugs 33, 34 act as guides to cause the quick hitch Q to centrally locate on the pins 22, 23 when the excavator arm is attached to the tool 10. In this manner, by use of specifically designed 15 attachment links 30, and modification of the ears 20, 21 of the tools 10 as described above, one range of tools can be used on any make and model of excavator whilst using a "quick hitch" fitting system Q. 20 In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, 25 i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention. 30 \\melb-files\home$\MCooper\Keep\Speci\excavator tools.doc 18/03/04