AU2008207576A1 - Tooth lock - Google Patents

Description

00 Locking Assembly Field of the Invention 00 This invention relates to the locking mechanism employed to retain replaceable IND ground engaging tools typically used in the earth moving industry.

Background Art 00 One of the major problems with the use of earth moving equipment is the Saccelerated wear of the components that engage the ground (Ground Engaging Tools) With excavators and other equipment designed to lift and move material there are frequently a number of teeth extending from the leading edge of bucket.

These teeth are subjected to extreme wear and frequently need to be replaced.

In order to facilitate the replacement of the teeth there are several mechanisms that have been proposed. There are numerous systems in existence where an adapter is welded to a bucket and the tooth is mechanically attached using some form of releasable retaining mechanism.

The systems that have previously been proposed have various configurations.

For instance, some configurations utilise a pin as the locking mechanism to secure the tooth to the adaptor. One of the major problems with a conventional pin system for retaining the teeth is that the pin is subjected to the same extreme wear as the tooth. As the pins are subject to extreme wear the pins need to be secured or they will be lost in the field thus resulting in the loss of the tooth.

It is desirable to have a tooth retaining system that is not subject to the significant wear occurring to the tooth or is affected by the wear that occurs between the tooth and the adaptor.

00 SSome systems have been proposed where a pin is place in position so that the tsurface of the pin is below the surface of the teeth. In these types of 0arrangements the pin locks against the adaptor and the tooth to prevent removal 00 CI of the tooth. The pin needs to be retained and prevented form moving and has a locking mechanism that cooperates with the adapter.

The above system is not ideal as the adapter is prone to wear as is moves Oagainst the mating faces of the tooth and thus as the adapter wears and the pin 00 may not be retained properly.

Summary of Invention A tooth and adapter locking system for earth moving equipment including: an adapter with a first end adapted to be attached to a earth moving equipment and an engagement portion adapted to engage with a removable tooth, the adapter having longitudinal recess extending along both sides of the adapter from the engagement portion to the first end and adapter transverse recesses in both sides of the adapter extending across the respective longitudinal recess from the top to the bottom of the adapter a tooth adapted to cooperatively engage with the engagement portion of the adapter having a longitudinal ridge extending along the internal faces of the sidewalls and designed to cooperate with the longitudinal recesses of the adapter, further having transverse recesses in the sidewalls of the tooth designed to cooperate with the transverse recess in the adapter to form a cooperating channels, the tooth having apertures in the top and bottom faces aligning with the tooth transverse recesses and the cooperating channels formed when the tooth is engaged with the adapter two locking pin assemblies each including a pin with a recess adapted to receive a resilient member 00

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wherein the locking surfaces are located on the inside face of the tooth transverse recesses and that are adapted to cooperate with the resilient member of the locking pin assembly to retain the locking pin.

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A resilient member adapted to fit into the recess in the pin and further having at Nleast one hard insert.

A resilient member adapted to fit into the recess in the pin and preferably having 0 at least three hard inserts.

oO ci Preferably the hard inserts are made of a metallic material.

Preferably the locking surface in the transverse recess of the tooth has a series of ridges to form channels that cooperatively accept the at least one hard insert in the resilient member.

Preferably the number of ridges on the locking surface is sufficient to form a locking channel for each of the hard inserts Preferably the locking pin is not symmetrical along the longitudinal axis and the aperture is adapted to accept the locking pin assembly in one orientation only so as to ensure that the resilient member and hard inserts bare against the locking surface.

Brief Description of the Drawings The invention will be better understood by reference to the following description of embodiments of the invention, as shown in the accompanying drawings in which: Figure 1 a is a side view of the adapter of the present invention; Figure lb is a top view of the adapter of the present invention Figure 2 is a perspective view of the tooth of the present invention; 00 Figure 3 is a cross section of the tooth of the present invention; Figure 4 is a cross section of the locking pin assembly of the present invention; 00

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Figure 5 is a side view of locking pin assembly

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Figure 6a is a cross section of the tooth adapter with the locking pins in place; O Figure 6b is a cross section of the tooth adapter assembly through the pins with 00 the locking pins in place; Detailed Description Referring to the Figures, an embodiment of the invention is a system including an adapter 50 and tooth 100 for use on earthmoving or similar machinery with a mechanism to releasably engage the tooth to the adapter. The adapter 50, tooth 100 assembly includes locking pin assembly 240 to lock the tooth 100 to the adapter 50 in service.

The adapter 50 as shown in Figure 1 and has a first end (not shown) that is adapted to be attached to the leading edge of a bucket on a piece of earth moving equipment. In practice the adapter 50 is usually attached to the leading edge of a bucket by welding. As the adapter 50 is welded to the bucket compromises in material properties of the adapter 50 have to be made. Such compromises are usually in the form of material hardness. Welding of hard materials is difficult as they are prone to crack.

The adapter 50 has an engagement portion 60 designed to cooperatively engage with a portion of a tooth (discussed later). The adapter 50 has top 65, bottom and side faces 75. In each of the side faces 75 there is a longitudinal recess extending generally from the engagement portion 60 of the adapter to the first end 55 that is attached to the leading edge of the bucket. A transverse recess extends across the adapter form the top 65 to the bottom 70 and bisects to the longitudinal recess 00 (Throughout this specification reference will be made to the transverse recess of the adapter 50 or to the longitudinal recess 80 of the adapter 50, this 0description refers equally to the transverse or longitudinal recess on each side of oO C the adapter.

IDThe tooth 100 has a first end 110 that is adapted to mate with the engagement n portion 60 of the adapter 50, the tooth 100 is designed to releasably retained.

O The first end 110 of the tooth 100 has a top 115, bottom 120 and two sidewalls 00oO 125 that are of a complementary profile to the adapter 50 engagement portion The second end of the tooth 100 is designed to engage with the material being moved by the equipment The sidewalls 125 of the tooth 100 each have a longitudinal ridge 130 that is complementary to the longitudinal recess 80 in the side faces 75 of the adapter Each sidewall 125 also has a tooth transverse recess 135 that when the tooth 100 is assembled with the adapter 50 forms a cooperating channel 200 defined by the adapter transverse recess 85 and the tooth transverse recess 135 The top 115 of the tooth 100 has two apertures 140 that are in general alignment with the transverse recess 135. When the tooth 100 is assembled with the adapter 50 a cooperating channel 200 is formed defined by the adapter transverse recess 85 and the tooth transverse recess 135 the aperture 140 is of a similar cross-section as the resulting cooperating channel 200.

The bottom 120 of the tooth 100 also has two apertures (not shown) that are in line with the apertures 140 in the top 115 of the tooth 100. The apertures 140 and the cooperating channel 200 form a passage extending through the top 115 surface of the tooth 100 and through the cooperating channel 200 defined by the adapter transverse recess 85 and the tooth transverse recess 135 and extend to the aperture passing through the bottom 120 of the tooth 100. Because of the above arrangement of components an a continuous channel is formed through 00 the top115 of the tooth 100 passing along the cooperating channel 200 and passing through the bottom 120 of the tooth 100.

oO 00The tooth transverse recess 135 has a locking surface 150 and includes a series of ridges 155 extending at approximately right angles to the cooperating channel O 200. The ridges 155 define either side of an at least one locking channel S(Figure The locking surface 150 is used to hold the locking pin assembly 240 0 in position (discussed later).

00oO Referring to Figure 4 and 5 there is shown a locking pin assembly 240 the locking pin 250 is of such cross section that it can pass through the apertures 140 of the tooth 100 and fit into the cooperating recess 200. Thus when the locking pin 250 is located in the cooperating recess 200 the tooth 100 is held to the adapter 50. This retention of the tooth 100 is by the locking pin 250 being captured by the adapter transverse recess 85 and the tooth transverse recess 135 thus preventing the removal of the tooth 100.

The locking pin assembly 240 includes a locking pin 250, which has a recess 260 in a side that is adapted to receive a resilient member 270. When the resilient member 270 is in place the locking pin assembly 240 has a larger cross section than the aperture 140 and the cooperating recess 200. To pass the locking pin assembly 240 through the aperture 140 and into the cooperating recess 200 the resilient member 270 need to be deformed. Once the locking pin assembly 240 is located in the cooperating recess 200 the resilient member 270 presses against the locking surface 150 located in the tooth transverse recess 135.

In a preferred embodiment the resilient member 270 includes at least one metallic insert 280. These metallic insets 280 reduce the friction between the tooth 100, adapter 50 and the locking pin assembly 240 during assembly or disassembly. Without the metallic insert 280 it was found that the resilient member 270 had a tendency to be torn when the locking pin assembly 240 was being inserted in to place.

00 SIn a preferred embodiment the resilient member 270 has multiple metallic inserts 280 cast into the surface of the resilient member 270 that will be bearing against the locking surface 150. As well as the resilient member having a number of 00 c metallic inserts 280 the locking surface 150 has a number of ridges 155 so as to form a sufficient number of locking channels 160 to cooperate with the metallic inserts 280.

o When in operation the metallic inserts 280 aids the locking pin assembly 240 to

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00 be inserted into the cooperating channel 200. The metallic inserts 280 acts to Sreduce friction between the resilient member 270, the aperture 140 and the cooperating channel 200. The metallic inserts 280 act as a starter when the locking pin assembly in inserted into the aperture 140.

Once the metallic inserts 280 interact with the locking surface 150 and the ridges 155 there are a series of increased forces as the metallic inserts 280 deform the resilient member 270 as the metallic inserts 280 passes over the ridges 155.

Knowing how many metallic inserts 280 are employed allows the operator to establish that all of the metallic inserts 280 are in contact with the locking surface 150 and that the locking pin assembly 240 is firmly held.

In a preferred embodiment the apertures 140 are not symmetrical. Also the locking pin assembly 240 is not symmetrical along the longitudinal axis so that it can only be inserted into the aperture 140 one-way. In this embodiment this is to ensure that the resilient member 270 and hard inserts 280 bear against the locking surface 150.

In this description reference has been made to metallic inserts 280, while metallic inserts 280 are a preferred embodiment a number of non metallic materials may be suitable for this application. The main requirements of the insert are that they are relatively tough and hard so that they are able to reduce friction between the resilient member 270 and the aperture 140 but not breakup or spall when subject to a shock loading such as the locking pin assembly 240 being hit by a hammer.

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In another embodiment the resilient member 270 has a tapered leading edge 290 ;Z such that when in use the tapered edge 290 can enter the aperture140 and with the application of further force deform and pass through the aperture 140. The 00 Cadvantage of the tapered edge 290 is that is acts and a starter and allows for the progressive deformation of the resilient member 270. If the tapered leading edge 290 was not present a relatively large force may be required to start the deformation of the resilient member 270 and as a result the resilient member 270

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c may be pulled out of the recess 260 in the locking pin 250.

00 OThe advantage of this system over previously suggested systems is that the major locking component subject to wear are either relatively cheep i.e. the locking pin assembly 240 or are replaced when the tooth 100 is replaced i.e. the locking surface 150. The only part of the locking system that is retained when a tooth 100 is changed out is the adapter transverse recess 85 and this recess is well protected by the tooth 100 when in operation.

The adapter transverse recess 85 may be subject to some damage due to working of the tooth 100 relative to the adapter 50 but it has been found that damage to the adapter transverse recess 85 does not effect operation of the locking pin assembly 240. By having the resilient member bear on the locking surface 150 in the replacement tooth 100 the locking surface 150 is replaced every time a tooth 100 is replaced this ensuring a tight fit of the locking pin assembly 240 with the tooth 100 and adapter When in use the locking pins 250 are located such that their ends are below the outer surface of the tooth 100 and are therefore protected from abrasion in service.

When removing a tooth 100 for whatever reason but typically for replacement due to excessive wear or mechanical damage the locking pin assembly 240 are remove by passing a tool through one of the apertures 140 and subjecting the locking pin assembly 2400 to the application of force. The application of force 00 deforms the resilient member 270 and allows the locking pin assembly 240 to be displaced out of the cooperating cannel 200.

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