|Publication number||US20060261662 A1|
|Application number||US 11/132,781|
|Publication date||Nov 23, 2006|
|Filing date||May 19, 2005|
|Priority date||May 19, 2005|
|Publication number||11132781, 132781, US 2006/0261662 A1, US 2006/261662 A1, US 20060261662 A1, US 20060261662A1, US 2006261662 A1, US 2006261662A1, US-A1-20060261662, US-A1-2006261662, US2006/0261662A1, US2006/261662A1, US20060261662 A1, US20060261662A1, US2006261662 A1, US2006261662A1|
|Original Assignee||Sollami Jimmie L|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (21), Referenced by (1), Classifications (4)|
|External Links: USPTO, USPTO Assignment, Espacenet|
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. Patents:
Pat. No. Inventor(s) Issue Date 3,830,546 T. J. Kniff Aug. 20, 1974 3,833,264 G. W. Elders Sept. 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.
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.
At least one spring lock mechanism is provided. Each spring lock mechanism is configured to be received about the shank between the support block and the retainer. The spring lock mechanism defines a frustoconical configuration having a selected inside diameter, outside diameter, and uncompressed height. The spring lock mechanism defines an upper end at the inside diameter, and a lower end at the outside diameter. The spring lock mechanism is fabricated from a resilient material to allow it to compress. When compressed, the spring lock mechanism defines a compressed height. However, when the retainer is removed, the spring lock mechanism returns to its uncompressed height.
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:
A spring lock mechanism for an earthworking bit is disclosed. The spring lock mechanism is illustrated in the Figures generally at 10. The spring lock mechanism 10 is provided for engaging an earthworking bit, or bit 20, into a positive engagement with a bit holder, or support block 30, thereby reducing the failure rate of the bit 20 while also allowing the bit 20 to rotate within the support block 30.
As illustrated in
Further, the bit 20 and support block 30 are cooperatively configured such that when the shank 24 is fully inserted into the receptor 32, a distal end 26 of the shank 24 is extended from the receptor 32. The distal end 26 of the shank 24 defines a radial groove 28 adapted to receive a retainer 36. The radial groove 28 is disposed on the shank distal end 26 such that it is exposed when the shank 24 is fully inserted into the support block receptor 32. A retainer 36 is received within the radial groove 28 for preventing unselected removal of the bit 20 from the support block 30.
In the present invention, at least one spring lock mechanism 10 is provided. Each spring lock mechanism 10 is configured to be received about the shank 24 between the support block 30 and the retainer 36. In the illustrated embodiment, the spring lock mechanism 10 is a conical spring washer.
In the preferred embodiment, the spring lock mechanism 10 is oriented such that the lower end 14 is engaged with the bottom surface 34 of the support block 32 and the upper end 12 is engaged with the retainer 36. However, it will be understood by those skilled in the art that the orientation of the spring lock mechanism 10 may be reversed.
As illustrated in
A further alternate embodiment of the spring lock mechanism 10B is illustrated in
As illustrated in
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 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. 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.
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