US20060261663A1

Movatterモバイル変換

Info

Publication number: US20060261663A1
Application number: US11/371,557
Authority: US
Inventors: Jimmie Sollami
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-05-19
Filing date: 2006-03-09
Publication date: 2006-11-23

Abstract

A spring lock mechanism for a ground-engaging tool, or bit. The spring lock mechanism is provided for engaging a bit into a positive engagement with a bit holder, thereby reducing the failure rate of the bit while also allowing the bit to rotate within the bit block. The spring lock mechanism is configured to be received about the shank of a bit between a support block and a retainer. The spring lock mechanism defines a frustoconical configuration having a selected inside diameter, outside diameter, and uncompressed height. The spring lock mechanism is fabricated from a resilient material to allow it to compress. When compressed, the spring lock mechanism biases the bit into the support block receptor.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation-in-part of application Ser. No. 11/132,781, filed May 19, 2005.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

BACKGROUND OF THE INVENTION

1. Field of Invention

The present invention pertains to the field of earth working equipment. More particularly, the present invention is related to a spring lock mechanism for reducing axial movement of a ground-engaging tool or bit within a bit holder block.

2. Description of the Related Art

In the field of earthworking, various types of equipment are used in various applications. Equipment varies from trenchers using chain excavation lines to rotatable drum equipment used for excavating rock, highly compressed earth, and mining materials. A plurality of ground-engaging tools, or bits, is attached to each of these machines for engaging and penetrating into the material being excavated.

Prior to the use of bits the equipment was provided with a plurality of teeth that would eventually wear and need replacing. In order to reduce the time and cost of replacing these teeth, bits were introduced. As is known in the art, bits typically include a bit insert made of a harder, more durable material than that of the bit or holder, thereby increasing the life of the bit. Typically, tungsten carbide is used.

Since their introduction, there have been several ways devised for mounting the bits. Initially the bits were welded to the equipment. However, holders or pockets were eventually introduced. In so doing, the bits have become more easily interchangeable after being worn or broken. In some circumstances, it has also made the bits more effective. Of primary structural note is that the bits have been allowed to rotate within a socket or receptacle defined by the bit mounting block. This has increased the useful life of the bits. To transfer force from the mounting block to the tool, the tool is provided with an annular flange having a planar rear surface which rests upon the planar forward surface of the mounting block surrounding the aperture such that the rear surface of the flange applies force to the forward surface of the mounting block.

In those embodiments where the bit is permitted to rotate within the bit block, axial movement of the bit within the bit mounting block is also permitted to at least a limited extent. As a result of such axial movement, the bits have a higher tendency to fail as compared to bits that are welded onto the earthworking equipment. Specifically, movement of the bit shank within the bit mounting block causes wear within the block, thereby increasing the opening in the block and therefore the wobbling of the bit. As this occurs, dust, dirt, mud and rock eventually build up in the mounting block. While the bit is rotating, centrifugal force pulls the bit further from the mounting block, causing an increased risk of breaking the shank. This is a result of the force being applied to the shank as opposed to the flange. The effects of the movement of the bit within the block are cumulative, causing early failure of both the bit and the bit mounting block.

Typical of the art are those devices disclosed in the following U.S. Pat. Nos:



Patent No.	Inventor(s)	Issue Date

3,830,546	T. J. Kniff	Aug. 20, 1974
3,833,264	G. W. Elders	Sep. 3, 1974
3,841,708	T. J. Kniff et al.	Oct. 15, 1974
4,065,185	G. W. Elders	Dec. 27, 1977
4,247,150	H. Wrulich et al.	Jan. 27, 1981
4,316,636	J. A. Taylor et al.	Feb. 23, 1982
4,342,486	M. L. O'Neill	Aug. 3, 1982
4,711,504	R. Berchem	Dec. 8, 1987
4,736,533	C. R. May et al.	Apr. 12, 1988
5,067,775	M. D. D'Angelo	Nov. 26, 1991
5,230,548	P. W. Southern	Jul. 27, 1993
6,000,153	J. L. Sollami	Dec. 14, 1999

Of these patents, Kniff, in his '546 patent, discloses a mining tool and support block for retaining the mining tool. The tool includes a shank having a circular cross-section such that it is rotatable within the support block. The distal end of the shank defines a radial groove for receiving a retainer in the form of a snap ring, the retainer being provided for preventing unselected removal of the tool from the support block. In order to allow for rotation of the tool, the retained is spaced apart from the support block when the tool is fully inserted therein. This is similar to the construction disclosed by Kniff et al. ('708), Elders ('185), and Bercham ('504), as well.

Other devices of the prior art define similar mechanisms for securing a bit within a support block. Elders, in his '264 patent, discloses a bit having a shank defining an annular groove in its distal end. The mounting block carries a rubber insert, through which is received a locking pin. The locking pin defines a pointed distal end configured to engage the annular groove defined by the bit shank.

In the '150 patent, H. Wrulich et al., teach a similar bit held in the mounting block with a spring clip inserted into the annular groove. This spring clip defines a C-shaped configuration having an opening for receiving the annular groove of the bit shank. Further, the clip defines a curvature for encouraging the bit shank into the mounting block to prevent fluttering of the bit. It is seen that the spring clip engages the bit shank annular groove at two points, and the bit holder at a single point.

Taylor et al., in the '636 patent, disclose an expansible clip configured to be received within an annular groove defined by the bit shank, and within the receptacle of the mounting block. In this embodiment, an annular groove is defined within the mounting block receptacle, and is configured to receive a plurality of protrusions defined by the expansible clip. Thus, the expansible clip serves to selectively retain the bit within the mounting block receptacle. This configuration is similar to mounting devices disclosed by May et al. ('533) and in the '153 patent issued to the inventor of the present invention.

In the '486 patent issued to O'Neill, a locking means which appears to be in the form of a torsion spring is used to maintain the bit within the mounting block. While there is no specific discussion of the structure or function of the locking means, it appears to define a pair of tabs which are engaged to enlarge the diameter of the locking means in order to facilitate application on and removal from an annular groove defined in the distal end of the bit shank.

Southern, in his '548 patent, discloses a cutter drum having a sump ring and a plurality of vanes, each defining holes for receiving and removably mounting cutting bits for cutting material to be mined. Retaining blocks are removably mounted in the vanes or sump ring for engaging a base portion of the cutting bit and retaining the cutting bit in the cutting drum. In the illustrated embodiment of the '548 device, the cutting bits are allowed limited axial movement within the holes.

Finally, D'Angelo, in his '775 patent, discloses a retainer for rotatable bits. The '775 retainer includes a removable collar consisting of at least two semi-annular members each having a flange extending from its inside diameter and a groove disposed about its outside diameter. The removable collar is circumferentially mountable about a rearward portion of either the mining tool or the wear resistant sleeve extending from the support block when mounted therein. The extending rearward portion has a groove circumferentially disposed therein. When the semi-annular members are mated thereabout, the flange of each member cooperates with the groove in the rearward portion of either the mining tool or the wear resistant sleeve. The groove about each semi-annular member defines in combination a substantially continuous groove about the collar. A snap ring is removably mounted in the substantially continuous groove about the removable collar.

BRIEF SUMMARY OF THE INVENTION

The present invention is a spring lock mechanism for an earthworking bit. The spring lock mechanism is provided for engaging an earthworking bit, or bit, into a positive engagement with a bit holder, thereby reducing the failure rate of the bit while also allowing the bit to rotate within the bit block.

The bit used in association with the present invention includes a body which defines a bit and a shank. The shank is adapted to be received within a receptor defined by a support block. The bit and the support block receptor are cooperatively configured such that when the bit is inserted into the support block receptor, the bit is permitted to rotate within the receptor. When the shank is fully inserted into the receptor, a distal end of the shank is extended from the receptor. The distal end of the shank defines a radial groove adapted to receive a retainer. The radial groove is disposed on the shank distal end such that it is exposed when the shank is fully inserted into the support block receptor. A retainer is received within the radial groove for preventing unselected removal of the bit from the support block.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The above-mentioned features of the invention will become more clearly understood from the following detailed description of the invention read together with the drawings in which:

FIG. 1 is an exploded view of the spring lock mechanism of the present invention shown in association with a bit, support block, and retainer;

FIG. 1A is an assembled view of the spring lock mechanism, bit, support block, and retainer ofFIG. 1, wherein the spring lock mechanism is not compressed, and a gap is defined between the spring lock mechanism and the support block;

FIG. 2 is a top plan view of the spring lock mechanism ofFIG. 1;

FIG. 3A is a cross-sectional view of the spring lock mechanism, taken along3-3 inFIG. 2, the spring lock mechanism being shown in an uncompressed state;

FIG. 3B is a cross-sectional view of the spring lock mechanism, taken along3-3 inFIG. 2, the spring lock mechanism being shown in a compressed state;

FIG. 4 is an assembled view of the various elements depicted inFIG. 1;

FIG. 5 is an end view, in section taken along5-5 ofFIG. 4;

FIG. 6 is an exploded view of an alternate assembly using two of the spring lock mechanisms of the present invention shown in association with a bit, support block, and retainer, wherein the two spring lock mechanisms are oriented such that the respective upper ends are engaged;

FIG. 7 is an exploded view of an alternate assembly using two of the spring lock mechanisms of the present invention shown in association with a bit, support block, and retainer, wherein the two spring lock mechanisms are oriented such that the respective lower ends are engaged;

FIG. 8 is a top plan view of an alternate embodiment of a spring lock mechanism incorporating various features of the present invention;

FIG. 9 is a side elevation view of the spring lock mechanism ofFIG. 8;

FIG. 10 is a top plan view of a further alternate embodiment of a spring lock mechanism incorporating various features of the present invention;

FIG. 11 is a side elevation view of the spring lock mechanism ofFIG. 10; and

FIG. 12 is an exploded view of an assembly using one spring lock mechanism ofFIG. 2, one spring lock mechanism ofFIG. 8, and one spring lock mechanism ofFIG. 10 in combination and in association with a bit, support block, and retainer.

DETAILED DESCRIPTION OF THE INVENTION

A spring lock mechanism for an earthworking bit is disclosed. The spring lock mechanism is illustrated in the Figures generally at10. Thespring lock mechanism10 is provided for engaging an earthworking bit, orbit20, into a positive engagement with a bit holder, orsupport block30, thereby reducing the failure rate of thebit20 while also allowing thebit20 to rotate within thesupport block30.

As illustrated inFIG. 1, thebit20 used in association with the present invention includes a body which defines abit22 and ashank24. Theshank24 is adapted to be received within areceptor32 defined by a holder, orsupport block30, carried by an implement of earth working equipment such as the chain excavator or a rotatable drum, or the like. Thebit20 and thesupport block receptor32 are cooperatively configured such that when thebit20 is inserted into thesupport block receptor32, thebit20 is permitted to rotate within thereceptor32.

Further, thebit20 andsupport block30 are cooperatively configured such that when theshank24 is fully inserted into thereceptor32, adistal end26 of theshank24 is extended from thereceptor32. Thedistal end26 of theshank24 defines aradial groove28 adapted to receive aretainer36. Theradial groove28 is disposed on the shankdistal end26 such that it is exposed when theshank24 is fully inserted into thesupport block receptor32. Aretainer36 is received within theradial groove28 for preventing unselected removal of thebit20 from thesupport block30.

In the present invention, at least onespring lock mechanism10 is provided. Eachspring lock mechanism10 is configured to be received about theshank24 between thesupport block30 and theretainer36. In the illustrated embodiment, thespring lock mechanism10 is a conical spring washer.

FIGS. 2, 3A and3B better illustrate thespring lock mechanism10 of the present invention. As best illustrated inFIGS. 3A and 3B, thespring lock mechanism10 defines a frustoconical configuration having a selected inside diameter d_i, outside diameter d_o, and uncompressed height h_u. For discussion purposes, thespring lock mechanism10 defines anupper end12 at the inside diameter d_i, and alower end14 at the outside diameter d_o. The inside diameter d_iis selected to receive the bit shankdistal end26. Thespring lock mechanism10 is fabricated from a resilient material to allow it to compress. When compressed, thespring lock mechanism10 defines a compressed height h_c. However, when theretainer36 is removed, thespring lock mechanism10 returns to its uncompressed height h_u.

While thespring lock mechanism10 may be compressed when assembled on theshank24, it will be understood that the present invention includes the embodiment wherein thespring lock mechanism10 is not compressed. In one embodiment, this is accomplished by incorporating one or morespring lock mechanisms10 configured to be closely received about theshank24 in an uncompressed state. Alternatively, at least onespring lock mechanism10 is incorporated in a compressed state and, over time and with use, thespring lock mechanism10 is worn until it is uncompressed. In either embodiment, asmall gap38 is defined to allow thebit20 to freely rotate within thesupport block30. This is best illustrated inFIG. 1A.

In the preferred embodiment, thespring lock mechanism10 is oriented such that thelower end14 is engaged with thebottom surface34 of thesupport block32 and theupper end12 is engaged with theretainer36. However, it will be understood by those skilled in the art that the orientation of thespring lock mechanism10 may be reversed.

FIG. 4 illustrates an assembly including thebit20,support block30,spring lock mechanism10 of the present invention, and theretainer36 illustrated inFIG. 1. It is noted that in the unassembled illustration ofFIG. 1, thespring lock mechanism10 is shown uncompressed, while in the assembled illustration ofFIG. 4, thespring lock mechanism10 is compressed. This is in contrast to the embodiment ofFIG. 1A, where thespring lock mechanism10 remains uncompressed when assembled. In this state, thespring lock mechanism10 exerts a force between thesupport block30 and theretainer36. Because thesupport block30 is fixed, the force from thespring lock mechanism10 is applied to theretainer36 and is transferred to theradial groove28 of thebit shank24. Thebit20 is thus biased intosupport block receptor32. However, thebit20 is allowed to rotate within thereceptor32, thereby providing the benefit of prolonged life.

FIG. 5 is an end view of the assembly ofFIG. 4 better illustrating the configuration of theretainer36. In the illustrated embodiment, theretainer36 is a hairpin style retainer. However, it will be understood that other retainer configurations such as, but not limited to, a lock washer, a snap ring, or a hose clamp, may be used with similar results and within the scope of the present invention.

As illustrated inFIGS. 6 and 7, more than onespring lock mechanism10 may be incorporated. In the embodiment ofFIG. 6, the respective upper ends12 of twospring lock mechanisms10 are disposed in contact one with the other. InFIG. 7, the respective lower ends14 are in contact with each other. Although not illustrated, it will be understood that more than onespring lock mechanism10 may be provided with each being oriented similarly and nested within each otherspring lock mechanism10. It will further be understood that any combination of the number and orientation ofspring lock mechanisms10 may be incorporated within the scope of the present invention. A plurality ofspring lock mechanisms10 is used specifically in situations where thebottom surface34 of thesupport block30 has been worn, thus rendering a singlespring lock mechanism10 less effective.

Illustrated inFIGS. 8 and 9 is an alternate embodiment of thespring lock mechanism10A of the present invention. In this embodiment, anotch16 is defined for receiving the bit shankdistal end26 as illustrated inFIG. 12. Thenotch16 provides a mechanism whereby thespring lock mechanism10A may be removed and replaced while thebit20 is mounted within thesupport block30 without requiring the removal of theretainer36.

A further alternate embodiment of thespring lock mechanism10B is illustrated inFIGS. 10 and 11. Thespring lock mechanism10B defines anotch16 as in the previous embodiment for insertion and removal from the bit shankdistal end26. Thespring lock mechanism10B further defines adeformed portion18 to assist in manipulating thespring lock mechanism10B. Thespring lock mechanism10B further serves to replace theconventional retainer36.

As illustrated inFIG. 12, thespring lock mechanism10,spring lock mechanism10A, andspring lock mechanism10B are compatible with each other, and can be used in cooperation with one another in various combinations. Illustrated is aspring lock mechanism10 inserted over the bit shankdistal end26. Aspring lock mechanism10A is then placed by either receiving the bit shankdistal end26 through theopening12A, or by inserting the bit shankdistal end26 through thenotch16. Finally, aspring lock mechanism10B is then placed by inserting the bit shankdistal end26 through thenotch16. In so doing, the combination of the

spring lock mechanisms

10,10A,10B maintain the position of thebit20 within thesupport block30. It will be understood by those skilled in the art that various other combinations and arrangements of the

spring lock mechanisms

10,10A,10B are within the scope of the present invention.

While a conical spring washer is illustrated and described, it will be understood that other devices may be used within the scope of the present invention. For example, at least one wave spring, compression spring, tension spring, or other type of spring may be used in lieu of the conical spring washer.

From the foregoing description, it will be recognized by those skilled in the art that a spring lock mechanism for an earthworking bit has been provided. The spring lock mechanism is provided for engaging an earthworking bit, or bit, into a proximate relationship with a bit holder, thereby reducing the failure rate of the bit while also allowing the bit to rotate within the bit block. Because the spring lock mechanism biases the bit into the support block receptor, the flange defined by the upper end of the bit is drawn into close engagement with the upper surface of the support block. This not only prevents the bit from rocking relative to the support block, but also prevents contaminants such as dust, dirt, mud and rocks from entering the support block receptor. Thus, the cumulative effects of the bit shank being loosely received within the support block receptor are substantially eliminated. In the field, it has been shown that the life of the bit has been increased on an average of 25%. Further, because of the reduction of wear in the support block receptor, the life of the support block has been increased as well.

While the present invention has been illustrated by description of several embodiments and while the illustrative embodiments have been described in considerable detail, it is not the intention of the applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and methods, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of applicant's general inventive concept.