EXCAVATING TOOTH ASSEMBLY AND METHOD FOR ASSEMBLING AND USING THE SAME

Abstract

An excavating tooth assembly comprising a tooth holder and a tooth which are attachable together. The tooth includes a pair of prongs which are inserted into a pair of receptacles in the tooth holder and which embrace a web within the tooth holder. A pair of resilient members are attached either to the prongs or to the web and are compressed between the prongs and the web to aid in frictionally securing the tooth to the tooth holder.

Description

BACKGROUND OF THE INVENTION

The present invention relates to an excavating tooth assembly and a method for assembling and using an excavating tooth assembly.

Various devices and methods have been used to attach excavating teeth to excavating equipment. In most existing devices, a tooth holder is attached to an excavating instrument such as an auger, and an excavating tooth is detachably combined with to the tooth holder. The detachability of the excavating tooth from the excavating equipment allows the tooth to be replaced or repaired when it is worn out or broken. In one type of tooth assembly, the tooth holder includes an elongated web member. The tooth includes two spaced apart prongs which embrace the opposite sides of the web. A resilient member is inserted between the prongs and the web and is frictionally compressed therebetween to aid in holding the tooth to the tooth holder.

Various types of resilient members have been used to secure excavating teeth to their tooth holders. In most prior art devices, the resilient member is a U-shape that surrounds both sides of the web and the end nose of the web. Examples of these types of devices are shown in U.S. Pat. Nos. 5,184,412; 3,323,236; and 2,968,880.

Examples of U-shaped members used in the prior art are shown in FIGS. 5 and 6. With reference to the device shown in FIG. 5, the numeral 66 designates a tooth and the numeral 72 designates a tooth holder. The tooth 66 includes a pair of spaced apart prongs 68, 70. The tooth holder 72 includes a web 74 which is elongated and which includes a nose 80 at its end. A U-shaped resilient member 76 is shown between the prongs 68, 70 and the web 74. This U-shaped member 76 is not attached to the tooth 66, but is instead placed between the prongs 68, 70 and the web 74 during insertion of the web 74 between the prongs 68, 70. One disadvantage of the resilient member 76 in this prior art device is that it is not long enough to extend the entire length of the web 74 or the prongs 68, 70. Consequently, the tooth 66 becomes misaligned with the tooth holder 72 as can be seen at the contact point 82 and at the spaced apart point 84. This misalignment causes uneven wear on the tooth 66, and reduces the useful life of the tooth 66 during the cutting process.

FIG. 6 shows another example of a prior art U-shaped resilient member similar to the device shown in FIG. 5. However, the device shown in FIG. 6 comprises resilient member 78 that is longer than the prongs 68, 70 so that resilient member 78 has ends 86, 88 protruding outwardly from the slot between the two prongs 68, 70. One problem with the device shown in FIG. 6 is that it prevents the nose 80 from fitting tightly into the interior end of the slot between prongs 68, 70. This reduces the area of contact between the resilient member 78 and the side walls of the web 74 thereby reducing the resilient member's 78 ability to secure the excavating tooth 66 to the tooth holder 72. Another problem with this device is that the tooth 66 and tooth holder 72 are allowed to compress and recoil against the resilient member 78 due to the resilient member 78 being between the tooth 66 and tooth holder 72 which reduces the life of the tooth 66.

Therefore, an object of the present invention is the provision of an excavating tooth assembly which permits the nose of the web to engage the inner end of the slot between the two prongs of the tooth.

A further object of the present invention is the provision of an excavating tooth assembly which maximizes the area of contact between the resilient members and the walls of the web.

A further object of the present invention is the provision of an excavating tooth assembly which maximizes the area of contact between the tooth and the resilient members.

A further object of the present invention is the provision of an excavating tooth assembly which minimizes the wear to the tooth during the cutting operation.

A further object of the present invention is the provision of an improved excavating tooth assembly and method which is simple to use, economic to manufacturer, and efficient to operate.

SUMMARY OF THE INVENTION

The foregoing objects may be achieved with an excavating tooth assembly comprising a tooth holder having upper and lower members and a web extending between the upper and lower members. The web is elongated and includes a nose end and an inner end. It also has elongated first and second opposite side walls extending along the length thereof between the nose end and the inner end. A tooth includes a cutting end and an attachment end. The attachment end has first and second spaced apart prongs adapted to embrace the first and second opposite side walls of the web, respectively. In one embodiment, a first resilient member is attached to the first prong and a second resilient member is attached to the second prong. In use, the first resilient member is compressed between the first prong and the first side wall of the web and the second resilient member is compressed between the second prong and the second side wall of the web for frictionally securing the tooth to the tooth holder.

According to one feature of the invention the first and second spaced apart prongs define an elongated slot having a closed inner end and an open outer end. The first and second resilient members each have an outer end adjacent the outer end of the slot and an inner end adjacent the inner end of the slot. The nose end of the web engages the inner end of the slot and the first and second resilient members engage the first and second opposite side walls of the web along substantially the entire length thereof between the nose and the inner end of the web.

The method of assembling and using the present invention comprises attaching the first and second resilient members to either the first and second prongs or to the first and second side walls of the web. The prongs are then moved into an attached position engaging the first and second opposite side walls of the web so that the first resilient member is compressed between the first prong and the first side wall of the web and the second resilient member is compressed between the second prong and the second side wall of the web.

It should be understood that although the present invention has particular application to earth augers, trenching machines, and the like, its may be used to secure teeth to other machinery including graters, dippers, backhoes, harrows, scarifiers, cable plows.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the excavating tooth assembly of the present invention showing the tooth separated from the tooth holder;

FIG. 2 is a sectional view taken along line 2-2 of FIG. 1;

FIG. 3 is a sectional view similar to FIG. 2 showing the tooth attached to the tooth holder;

FIG. 4 is a sectional view taken along line 4-4 of FIG. 3;

FIG. 5 is a sectional view of a prior art excavating tooth assembly having a U-shaped resilient member that is shorter than the prongs; and

FIG. 6 is a sectional view of a prior art excavating tooth assembly having a U-shaped resilient member that is longer than the prongs.

DETAILED DESCRIPTION OF THE INVENTION

Referring to the drawings, the numeral 10 generally designates the excavating tooth assembly of the present invention. Assembly 10 includes a tooth 12 and a tooth holder 14. The tooth holder 14 is combined with a machine such as an auger or backhoe. Tooth 12 includes a cutting end 16 and an attachment end 18. Cutting end 16 has a tooth edge 20 and a pair of side reinforcing ribs 22. Tooth 12 also includes at the opposite end a first prong 24 and a second prong 26 which are spaced apart and which form a U-shaped slot 28. Slot 28 includes an open end 30 and a closed end 32. In one embodiment the tooth 16 is comprised of steel, however any other suitable material may be used.

As seen best in FIGS. 1-4, attached to the prongs 24, 26 are a first resilient member 34 and a second resilient member 36, respectively. Resilient members 34, 36 may be comprised of rubber or any other suitable material which is capable of compressing and which is capable of exerting a friction against an elongated member on the tooth holder 14. The elongated member is sometimes referred to in the industry as a web 50. In one embodiment, the resilient members 34, 36 comprise a tapered outer end 38 and a tapered inner end 40. The tapered outer end 38 is tapered to help the tooth 12 combine with the tooth holder 14 without damage to the resilient member 34, 36. Tapered inner end 40 is tapered to help the resilient members 34, 36 fit properly against the curved portion of the tooth's 12 closed inner end 32. It should be noted that the two resilient members 34, 36 leave the closed end 32 of the slot 28 exposed so as to not cover the closed inner end 32 (FIG. 2).

The resilient member 34, 36 may be combined with the inner edges of the prongs 24, 26 by any suitable means, including adhesively, mechanically (such as screws or rivets), or by a process of vulcanization. The preferred method of combining the resilient members 34, 36 with the prongs 24, 26 is by a vulcanization process in which an adhesive is vulcanized to the metal prongs 24, 26. In this vulcanization process, adhesives are applied between the resilient material 34, 36 and the prongs 24, 26. The rubber of the resilient material 34, 36 is held to its respective prong 24, 26 by an adhesive that is exposed to a temperature of about 160° C. for about eight minutes. Then, a compressed set of the adhesive is applied at about 70° C. for about twenty-two hours. The resulting resilient material has a hardness of about 67(a), which is measured on the Durometer scale. It has a tinsel strength of about 17.32 Mega Pascals (Mpa).

In an alternate embodiment, the resilient members 34, 36 are attached to the side walls 56, 58 of web 50 instead of attaching the resilient members 34, 36 to the inner surfaces of prongs 24, 26. This attachment may be by any of the same attachment means described in the previous paragraph including adhesively, mechanically (such as screws or rivets), or by a process of vulcanization.

As best seen in FIGS. 1 and 2, the tooth holder 14 includes a closed portion 42 at one end to which are joined an upper jaw member 44 and a lower jaw member 46 which are spaced apart from one another. A notch 48 is formed in the lower jaw member 46. The notch 48 is adapted to receive a drift punch, screw driver head, or any other suitable tool that can be used to pry the tooth 12 from the tooth holder 12. As best seen in FIG. 2, an elongated web 50 extends from the closed portion 42 into the space between the upper jaw member 44 and the lower jaw member 46. A closed side wall 51 extends along one side of the tooth holder 14 between the upper jaw member 44 and the lower jaw member 46. Web 50 includes an inner end 52 adjacent the closed portion 42 and a nose end 54. Nose end 54 conforms to the closed inner end 32 of the slot 28 of tooth 16. Web 50 includes first and second elongated concave side walls 56, 58. The concave side walls 56, 58 are adapted to receive a locking means such as a ribbed rubber lock to help secure the tooth 12 to the tooth holder 14. Spaces on the opposite side of web 50 form prong receiving slots 60, 62 for receiving the prongs 24, 26 of the tooth 16.

As best seen in FIG. 1, the upper surfaces of prongs 24, 26 include V-shaped notches 64 therein. These V-shaped notches 64 are configured to receive inserts or pegs (not shown) as disclosed in U.S. Pat. No. 2,968,880, the disclosure of which is incorporated herein by reference.

In order to attach the tooth 16 to the tooth holder 14, the prongs 24, 26 are inserted into the receptacles 60, 62 respectively so that the prongs 24, 26 engage the opposite side walls of the web 50. The dimensions of the slot 28 and the thickness of the web 50 are chosen so that the resilient members 34, 36 are tightly compressed against the opposite side walls 56, 58 of the web 50. This compression causes frictional engagement of the tooth 16 to the tooth holder 42.

Referring to FIG. 3, several features of the excavating tooth assembly 10 are shown. First, the nose end 54 of the web 50 engages the inner end 32 of slot 28. This metal to metal contact is not achieved in known prior devices. The metal to metal contact increases the life of the tooth 12 because the tooth's 12 movement relative to the tooth holder 14 is reduced relative to prior art devices (FIGS. 5 and 6) in which the tooth 66 and tooth holder 72 would compress and recoil due to the resilient member 76, 78 being between the tooth 66 and tooth holder 72. Second, the resilient members 34, 36, engage the side walls 56, 58 along substantially the entire length thereof. This increases the surface area of frictional engagement, and provides a tighter attachment. Third, the resilient members 34, 36 are evenly compressed on the opposite sides of the web 50 so as to insure that the tooth 20 is not misaligned, and that it is securely held in place.

In the drawings and specification there has been set forth a preferred embodiment of the invention, and although specific terms are employed, these are used in an illustrative and descriptive sense only and not for purposes of limitation. Changes in the form and the proportion of parts as well as in the substitution of equivalents are contemplated as circumstances may suggest or render expedient without departing from the spirit or scope of the invention as further defined in the following claims.

Claims

1. A tooth assembly comprising:

a tooth holder;

a tooth adapted to be combined with the tooth holder;

a first resilient member combined with the tooth and adapted to frictionally secure the tooth to the tooth holder;

a second resilient member combined with the tooth and adapted to frictionally secure the tooth to the tooth holder.

2. The tooth assembly of claim 1 wherein the tooth has an opening adapted to receive a portion of the tooth holder, said opening having an inner end and an outer end.

3. The tooth assembly of claim 2 wherein the inner end of the opening is adapted to engage a portion of the tooth holder when the tooth and tooth holder are combined.

4. The tooth assembly of claim 2 wherein the tooth's opening further comprises a first wall substantially parallel to a second wall;

wherein the first resilient member is combined with substantially the entire length of the tooth opening's first wall; and

wherein the second resilient member is combined with substantially the entire length of the tooth opening's second walls.

5. A tooth assembly comprising:

a tooth holder;

a tooth adapted to be combined with the tooth holder;

a first resilient member combined with the tooth holder and adapted to frictionally secure the tooth to the tooth holder;

a second resilient member combined with the tooth holder and adapted to frictionally secure the tooth to the tooth holder.

6. The tooth assembly of claim 5 wherein the tooth has an opening adapted to receive a portion of the tooth holder, said opening having an inner end and an outer end.

7. The tooth assembly of claim 6 wherein the inner end of the opening is adapted to engage a portion of the tooth holder when the tooth and tooth holder are combined.

8. The tooth assembly of claim 6 wherein the tooth holder further comprises a web adapted to be received by the tooth's opening, said web having a first wall substantially parallel to a second wall;

wherein the first resilient member is combined with substantially the entire length of the web's first wall; and

wherein the second resilient member is combined with substantially the entire length of the web's second wall.

9. A tooth assembly comprising:

a tooth holder having upper and lower members and a web extending between said upper and lower members;

said web being elongated and having a nose end, an inner end, and an elongated first and second opposite side walls extending along the length thereof between said nose end and said inner end;

a tooth having a cutting end and an attachment end, said attachment end having first and second spaced apart prongs adapted to engage said first and second opposite side walls of said web;

a first resilient member attached to one of said first prong and said first side wall of said web and a second resilient member attached to one of said second prong or said second side wall of said web;

said first resilient member adapted to be compressed between said first prong and said first side wall of said web to frictionally secure the tooth to the tooth holder, and said second resilient member adapted to be compressed between said second prong and said second side wall of said web to frictionally secure the tooth to the tooth holder.

10. The tooth assembly according to claim 9 wherein said first and second spaced apart prongs define an elongated slot having a closed inner end and an open outer end, said first and second resilient members each having an outer end adjacent said outer end of said slot and an inner end adjacent said inner end of said slot.

11. The tooth assembly according to claim 10 wherein said nose end of said web is adapted to engage said inner end of said slot.

12. The tooth assembly of claim 10 wherein the first and second resilient members are adapted to engage said first and second opposite side walls along substantially the entire length thereof between said nose end and said inner end of said web.

13. The tooth assembly according to claim 9 wherein each of said first and second resilient members are attached to the assembly by a vulcanization process.

14. The tooth assembly according to claim 9 wherein each of said first and second side walls of said web are concave in cross section.

15. A method for detachably securing a tooth to a tooth holder comprising:

providing said tooth holder with upper and lower members and a web extending between said upper and lower members, said web being elongated, having a nose end, an inner end, and an elongated first and second opposite side walls extending along the length thereof between said nose end and said inner end;

providing said tooth with a cutting end and an attachment end, said attachment end having a first and second spaced apart prongs forming an elongated slot, said slot having a closed inner end and an open outer end;

attaching first and second resilient members either to said first and second prongs respectively or to said first and second side walls respectively of said web;

moving said first and second prongs of said tooth holder into an attached position engaging said first and second opposite side walls respectively of said web, so that said first resilient member is compressed between said first prong and said first side wall of said web and said second resilient member is compressed between said second prong and said second side wall of said web.

16. The method according to claim 15 wherein said attaching step comprises vulcanizing said first and second resilient members either to said first and second prongs respectively or to said first end second side walls respectively of said web.

17. The method according to claim 15 wherein said first and second resilient members are elongated and include an inner end adjacent said inner end of said slot and an outer end adjacent said outer end of said slot, said step of moving said tooth holder to said attached position includes moving said closed inner end of said slot into contact with said nose end of said web whereby said first and second resilient members engage said first and second side walls respectively along substantially their entire lengths between said inner end and said nose end of said web.