CA2367860C

CA2367860C - Excavator tooth, lock, adapter

Info

Publication number: CA2367860C
Application number: CA 2367860
Authority: CA
Inventors: Michael Joseph Jackson
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-01-14
Filing date: 2002-01-14
Publication date: 2006-08-29
Anticipated expiration: 2022-01-14
Also published as: CA2367860A1

Abstract

An excavating tooth and adapter wherein the interfacing of the tooth and adapter is achieved through a twine like structure with a peripheral locking device located in the body of the adapter rather than on the nose section to prevent premature removal by anti-rotation of the tooth. It is unique in design as the bottom rear section of the adapter forms a perfect equilateral triangle providing maximum bearing surface with minimum nose size while allowing for the top to be rather angular for easy of penetration in material of any types.

Description

EXCAVATOR TOOTH, LOCK. ADAPTER
Technical Field [0001] The invention relates to a method of affixing an excavating tooth to an adapter for use on buckets for mass excavation equipment used to dig and move earth and rock material.
Back r [0002] For years construction and mining establishments have used teeth on mass excavation equipment such as front end loaders, back hoes, rippers and draglines. Initially teeth for mass excavation equipment were made of a single unitary piece. When the one piece tooth became dull or broken, a tremendous amount of time was required to remove the tooth. Replacing a single tooth was very expensive in time and material since 60 % -80 % of the old tooth was not damaged but was replaced along with the problematic part of the old tooth. If the tooth was not replaced, the tooth continued to get increasingly blunt and unproductive .

[0003] Some of the difficulties of the unitary tooth system have been minimized in a two part tooth system where the two parts are a tooth (also known as a point) and an adapter. Early two piece teeth systems posed many problems. A shell type structure was prone to breakage. Many two piece teeth were of a delta design wherein the adapter nose and the point socket were predominantly triangular in shape, which when a digging force was exerted on the end of the tooth, an internal part of the tooth would walk off the mating surface, thereby exerting a shearing force on the locking mechanism. Locking mechanisms such as vertical pins would elongate and shear under these circumstances. The point would then break off or the nose of the adapter would shear at the pinhole.

[0004] Tooth breakage would often result in the mating surface of the adapter being destroyed through exposure to material flow.
Shearing of the adapter nose resulted in adapter destruction due to breakage. In both cases, the adapter would have to be replaced and would result in significant loss of production. In many operations, such as mining operations, the breakage and loss of the tooth was secondary to the possible cost incurred if the lost tooth was not recovered and resulted in a breakage of more valuable processing equipment.

[0005] To reduce problems associated with tooth breakage, a number of two piece arrangements have been devised that include vertically driven locking devices . These devices have often been unsuccessful, struggling with pin shearing problems and resulting losses of teeth.

[0006] Manufacturers have reduced breakage by designing massively oversized nose pieces of the edges and providing significantly larger pins in order to prevent breakage of either the tooth or nose piece. The oversized nose pieces and larger pins have led to ineffective digging. Further, if a larger pin was used on a smaller nose, nose breakage would usually occur. This was undesirable.

[0007] Canadian patent application no. 1,172,287 to Hahn et al.
discloses a two part excavating tooth system wherein the nose of the adapter has four to six helical ribs (or threads). The ribs are nearly square-sized and non-uniform in cross-section along their length. The top of the nose is as wide as the bottom of the nose, which can be undesirable for balancing the stress of a load.

[0008] There exists a need for a successful mounting system for connecting a tooth and the nose of an adapter in a two or more piece excavating tooth system.

[0009] There exists a need for a two piece tooth system having a smaller, stronger and more frictionless nose design which will result in fewer tooth breakages and fewer losses of teeth.
Summary of Invention [0010] The past fifty years have seen many mounting methods for a tooth on an adapter. Significant numbers of two piece systems have featured a wedge-shape style that has a female wedge-shape socket at the rear of a tooth which slides over a corresponding wedge-shaped nose.

[0011] Our invention provides a new excavator tooth, lock and adapter using a modified rope design. A common rope is of a 6/19 arrangement, meaning that a core of 6 stands of straight rope is angularly encircled by 19 strands of rope extending the length of the rope in a angular fashion around the core. Our design is much simpler in that we have only one modified centre core that is cone-shaped with three angular raps around the centre core.

[0012] Our nose incorporates a stress beam at the blind end of the nose. The stress beam takes up stress from the tooth when a digging force is applied to the digging end of the tooth. Our stress beam strength is enhanced by two of the three outside strands of the rope structure. The three twine structure has greatly improved the locking system due to our system not putting the lock pin in direct shear.

[0013] The improved twine and locking system puts it in diagonal compression, meaning that in order to fail it would virtually have to be extruded out of its position. Because of this we can incorporate a smaller pin and nose section. The integrity of the nose is enhanced since there is no large hole in the centre of the nose for a large locking pin, therefore the nose is not nearly as likely to shear. Further, our nose forms an equilateral triangle with the base forming the largest parallel plane to the highest stress point on the tooth at its rear bottom extremity. This provides the tooth with a greater area to dissipate stress. Our tooth has one ear which, unlike most tips, is made parallel to the cone, not the side of the adapter. This is done in order to not jeopardize the integrity of the adapter with a deep cut into the nose for the locking device. Rather, the cut is made in the much heavier section of the adapter. Since our locking pin is vertical (although it does not necessarily have to be) as most pins are, the pin is easily removed when no force is exerted on the tooth.

[0014] To remove the pin, a little force is required to drive it down. Our pin does not require a positive static locking device, as do most vertically arranged noses, because it is in compression when in use. A horizontal pin (an alternative locking device) is much less desirable because it bisects the nosepiece and is most difficult to remove when changing a tooth since little room can generally be found between the teeth.

[0015] Since our pin can be easily removed, time and money can be saved. Our pin is essentially in two parts, one steel with a two-part polymer insert, the inner part of the polymer being resilient and foamy and the outer part that locks into the recess in the tooth extremely hard but not hard enough to fracture under either load or cold temperature.

Brief Description of Drawings [0016] In drawings that illustrate non-limiting embodiments of the invention:
Figures 1, 2 and 3 are end views of adapters according to embodiments of the invention;
Figure 4 is a side view of an adapter in accordance with an embodiment of the invention, the adapter having front and rear stabilizers;
Figure 5 is a top view of the adapter of Figure 4;
Figure 6 is a rear end view of a tooth having an ear and having grooves for receipt of the threads of an adapter;
Figure 7 is a side view of the tooth in figure 6 having receiving pockets in the tooth cavity and a locking pin recess;
Figure 8 is a side perspective of a locking device in accordance with an embodiment of the invention;
Figure 9 is a cross sectional view of a locking device embodiment engaged to an ear of a tooth in accordance with an embodiment of the invention;
Figure 10 is a perspective view of an adapter, tooth and locking device;
Figure 11 is a cross-sectional view of a tooth and adapter in fully engaged position.
Description [0017] Throughout the following description, specific details are set forth in order to provide a more thorough understanding of the invention. However, the invention may be practiced without these particulars. In other instances, well known elements have not been shown or described in detail to avoid unnecessarily obscuring the invention. Accordingly, the specification and drawings are to be regarded in an illustrative, rather than a restrictive, sense.

[0018] The design and evolution of the adapter 105 nose 130 is represented in Figures 1 through 3. The nose design 130 was essentially derived from a rope formation with a center core 162 and three outer twines of rope 150 all modified to form a cone-shape, and further modified to develop stabilization. Three twines or ribs 150 were selected to enable us to develop a large bearing surface on the back bottom section of the tooth while maintaining a fiction free top section.

[0019] Our excavating tooth system 100 shown in Figure 10 comprises an adapter 105, locking device 115 and tooth 110. The construction consists of a base with a nose portion 130 arranged in a tripod formation, forming an equilateral triangle 165. This allows for a narrow topside for penetration and a double-wide base for a bearing surface when the tooth 110 is subjected to stress. Tapered section cords 150 have a cylindrical angular-shape, which rotates the tooth 110 during assembly to the nose 130, thereby ensuring that once the locking device (pin) 115 is installed and force is transformed to the tip, the locking device 115 is under side compression holding it firmly in place. The end beam stabilizer 160 and the locking slots form the same angular-shape. It transfers force from adapter 105 to tooth 110 and stabilizes the tooth 110. The general shape of the nose 130 with the three wide modified sectional cords 150 and conical bearing base give us one of the strongest assemblies possible.

[0020] Certain dimensions of the embodiment of the adapter 105 shown in the figures 4 and 5 are described herein with reference to a center line 170 that extends longitudinally through the center of adapter 105. The angles 175 upon which the ribs 150 and the stress beam 160 of adapter 105 are rotated in relation to the center line 170 are approximately 22. 5 ° . The angle 240 that the outer edge of the center cone 155 forms with the center line 170 is approximately 22 ° . The angle 245 formed from the inner edge 250 of the angled retainer slot (or channel) 125 to the center line 170 is approximately 17.2 ° . Rear stabilizers 168 form an angle 172 of 50 ° from the center line 170. The examples provided will result in an angular rotation of the tooth 110 by 22.5 ° about the center line 170 relative to the adapter 105 for engagement or disengagement.

[0021] Generally a tooth 110 is either worn out and has to be replaced or it is lost because of failure of the locking device 115. Our design minimizes or completely avoids the latter since our angular modified cords 150 create a situation whereby the locking device 115 is not put in total shear as with most other designs. Our locking device 115 is primarily put in angular compression thereby significantly reducing or eliminating pin shear and tooth loss.

[0022] The top and bottom surfaces of the adapter slope downwards toward the free end of the adapter (Fig. 5).

[0023] The adapter has three well defined modified directional cords 150 at 1 /8 of revolution, or 22.5 ° , sloping from a location starting about lh of the distance from the front of the nose. These tapered sectioned cords 150 can be formed to start from a position and extending through to the rear of the nose 130. These cords 150 can either be formed to start from a position extending left to right or right to left (i.e. extending in a clockwise or counter clockwise direction about the nose) .

[0024] The angled retainer slot 125 is located at the back of the nose 130, although the angled retainer slot could be located on the left _ g _ side, right side, top or bottom of the nose depending on the location of the corresponding single extended ear 140 on the excavating tooth 110.

[0025] The rear section of the adapter nose 130 is unique in that it forms a reverse angle as a result of a 22 . 5 ° (from the horizontal center line at front view) segment of an arc formed at the rear section of the nose 130 and extends at an angle of approximately 50° upwards (Fig.
4). This forms a resulting third bearing service or rear stabilizers 168 to take up stress on the tooth 110 when it is in a digging mode. This is advantageous in that most designs only utilize two bearing surfaces as opposed to our three.

[0026] The tooth 110 is formed as a result of casting and can only be accomplished in this manner because of the three twining sectioned cords 150 around the center core 162.

[0027] The tooth 110 is cast and forms a blind cavity 135 with the large opening of this cavity 135 facing to one end and generally angling down to the blind end (Fig. 11). The tooth 110 incorporates an angular stabilizer 230, which is generally horizontal, extending from the center of the end of the cone on both corners and incorporating an angular gusset of 22 ° in a continuation of the cords to strengthen and harmonize the existing cords allowing the tooth 110 to move on to the nose 105 effortlessly (Fig 5) .

[0028] The cavity 135 of the tooth 110 generally conforms to the mating surfaces of the nose 105 consisting of a beam stabilizer 230 at smallest end of the cavity 135 and three modified female cords 225 at 22. 5 ° sloping from a position half way back in the cavity 135 to the rear or open end of this cavity 135. The modified cords 225 may be initiated from either from right to left or left to right (i.e. extending clockwise or counterclockwise) and a reversed angular surface at the open end of the cavity 135 to mate with the adapter 105.

[0029] The tooth 110 has one extended ear 140 containing a recess 215 generally in the center of the ear 140. The ear 140 can be located on the tooth 110 at the rear side of the cavity 135 and extends rearward of this cavity 135. The ear 140 can also be located at the top, bottom or either side of the rear cavity 135 depending on the desired locking position.

[0030] The locking device or pin 115, for locking the tooth 110 to the adapter 105, has a rigid shell 222, which may be made of steel construction, with a recess formed in such a way as to allow a dual polymer insert 220 to slide into place. The lock itself is made of a dual polymer. The inner section 220 is a resilient material with air bubbles such that when the pin 115 is driven into the locked position the bubbles are compressed and create an outward force on the non-resilient polymer that makes the rigid polymer contact the walls of the recess in the steel tooth 110.

[0031] The locking pin 115 when driven into position locks into the recess 215 formed in the inside ear 140 of the tooth 110 thereby holding the pin 115 securely in the tooth 110 in the correct position with the adapter 105. The design of the pin 115 is such that when stress is brought to bear on the tooth 110 it does not become ridged in the adapter 105 but moves freely with the tooth 110.

[0032] As will be apparent to those skilled in the art in the light of the foregoing disclosure, many alterations and modifications are possible in the practice of this invention without departing from the spirit or scope thereof. Accordingly, the scope of the invention is to be construed in accordance with the substance defined by the following claims .

Claims

1. An excavating apparatus comprising:
an adapter comprising a forwardly protruding nose, a channel and a body, the nose comprising three ribs arranged in a helical fashion around the nose, the body configured to be secured to excavating equipment;
a tooth comprising a rearwardly opening cavity for receiving the nose therein, and an ear extending from a side wall of the tooth, the ear having a recess, the cavity comprising three grooves for receiving the three ribs;
a locking device comprising a rigid body and a depressible protrusion, the rigid body configured for receipt in the channel, the depressible protrusion configured for receipt in the recess;
whereby the protrusion resiliently engages the recess for tightening the tooth to the adapter.

2. An excavating apparatus as in claim 1 wherein the nose is configured in a general cone-shape.

3. An excavating apparatus as in claim 2 wherein the ribs are configured in a rearwardly spiraling formation about the nose of the adapter.

4. An excavating apparatus as in claim 2 wherein a front portion of the nose of the adapter comprises a front stabilizer and a rear portion of the cavity comprises a stabilizer receiving depression for receiving the front stabilizer.

5. An excavating apparatus as in claim 4 wherein stabilizer gussets are coupled to the front stabilizer, the gussets configured in a rearwardly spiraling formation about the nose of the adapter.

6. An excavating apparatus as in any of claims 1-5 wherein the channel is located on the body of the adapter.

7. An excavating apparatus as in claim 2 wherein the ribs on the nose form an equilateral triangle.

8. An excavating apparatus as in claim 2 wherein the locking device is arranged to be vertical.

9. An excavating apparatus as in claim 7 or 8 wherein the channel is approximately normal to a base plane of the equilateral triangle.

10. An excavating apparatus as in claim 1 wherein the depressible protrusion comprises a polymer.

11. An excavating apparatus as in claim 1 wherein the depressible protrusion comprises an inner polymer insert member being resilient and foamy and an outer polymer insert member being hard.

12. An excavating apparatus as in claim 4 wherein the front stabilizer is generally horizontal.

13. An excavating apparatus as in claim 4 wherein the ribs and the front stabilizer form an angle of approximately 22.5° with a longitudinal axis passing through the center of the adapter.

14. An excavating apparatus as in claim 2 wherein an outer edge of the nose forms an angle of approximately 22° with a longitudinal axis passing through the center of the adapter.

15. An excavating apparatus as in claim 1 wherein the channel forms an angle of approximately 17° with a longitudinal axis passing through the center of the adapter.

16. An excavating apparatus as in claim 4 wherein the adapter further comprises rear stabilizers.

17. An excavating apparatus as in claim 16 wherein the rear stabilizers form a load bearing surface.

18. An excavating apparatus as in claim 17 wherein the rear stabilizers form an angle of approximately 50° with a longitudinal axis passing through the center of the adapter.

19. An excavating apparatus as in claim 2 wherein the tooth and adapter are configured to engage and disengage upon 1/8 turn of a full rotation.

20. An excavating apparatus as in claim 2 wherein the location of the locking device is configured to be put in angular compression upon stress on the tooth.

21. An excavating apparatus as in claim 2 wherein the protrusion of the locking device extends outwardly from the longitudinal axis passing through the center of the adapter.