Patent Application
20150130258
1. Field of Invention
This invention pertains to a cutting bit for use in mining, construction, and road surface removal. More particularly, this invention relates to a cutting bit including at least one substantially conical or frustoconical carbide or steel pin member for engaging the cutting bit tool holder in order to prevent unwanted rotation of the cutting bit tool with respect to the tool holder.
2. Description of the Related Art
It is well known in the mining, construction/earth moving, and road removal industries to use cutting bits on the perimeter and across the width of a rotary drum, or continuous chain or the like. In this regard, the cutting bits are mounted on bit holders which are in turn mounted on the drum or the chain. These cutting bits are then moved through an orbit and engage the ground, a mine face, or a road surface for the purpose of removing a portion of the surface of these environments. The cutting bits frequently include a tip, or other cutting tool, and a shank. The shank is received in a bit holder; which in turn is mounted on the drum or chain of the cutting or mining machine. It is common in the art for the shank to be rotatably received in the bit holder. However, once it is mounted, in the case of certain configurations of cutting bits, rotation of the cutting bit once secured, and during cutting or mining, is undesired.
Typical of the known art for cutting bits in the mining, construction/earth moving, and road removal industries is U.S. Pat. No. 6,371,567, issued to the Phillip A. Sollami, on Apr. 16, 2002; U.S. Pat. No. 5,374,111, issued to Den Besten et al on Dec. 20, 1994; U.S. Pat. No. 5,833,323 issued to Massa et al on Nov. 10, 1998; and U.S. Pat. No. 7,165,922 issued to Inuzuka on Jan. 23, 2007. Because it is known that debris from the cutting process can foul the junction of the bit holder and bit block making removal of the bit holder from the bit block difficult, much of the known art pertains to providing a means for forcibly removing the bit holder from the bit block. Further, it is known in this and other arts to use keys and associated keyways when it is desirable to limit or prevent rotation of a shank received within a bore or receiver. However, it is also known that breakage of a key or fouling of the keyway makes removal of the tool secured in such manner time consuming and necessitates a repair. What is missing in the art is a dirt and rock cutting tool assembly that includes at least one hardened member for engaging the bit block so as to substantially prevent rotation of a cutting bit secured to the bit block.
Accordingly, it is an object of the present invention to provide an improved dirt and rock cutting bit tool that allows infinite rotational positioning of the cutting bit and that substantially prevents rotation of the cutting bit upon securing the cutting bit holder to the bit block.
Another object of the present invention is to provide a dirt and rock cutting bit tool that utilizes at least one hardened pin member carried by one of the bit holder and bit block in such a manner that the hardened pin bites into the softer metal of the bit block thereby substantially preventing rotation of the bit holder within the bit block upon securement of the bit holder to the bit block.
Yet another object of the present invention is to provide a dirt and rock cutting tool assembly in which the bit holder is secured to the bit block by means of a single bolt thereby making removal of the bit holder from the bit block less difficult.
According to one embodiment of the present invention, an improved dirt and rock cutting tool assembly that substantially prevents rotation of the cutting bit upon securing the cutting bit to the bit block includes a cutting bit secured to, or otherwise integral with, a bit holder. The bit holder includes a planar shoulder and a shank having a terminal end extending from the planar shoulder of the bit holder. In the preferred embodiment, the terminal end of the shank includes a threaded bore member. The bit block includes a receiver, defined by a bore, having a diameter selected for receiving the terminal end of the shank of the bit holder. The receiver extends through the length of the bit block. In order to secure the bit holder to the bit block, the shank is inserted into the receiver, extending less than the length of the bore. A bolt is threadably received by the threaded bore in the shank.
In order to prevent rotation of the bit holder within the bit block when the bit holder is secured to the bit block, at least one hardened pin member is carried, preferably by the bit holder. In this regard, at least one, preferably blind, bore is disposed on the planar shoulder of the shank. A hardened substantially conical, or frustoconical pin, for example a carbide pin, can be press fit or brazed into the blind bore such that at least a portion of the tip of the hardened pin extends beyond the surface of the shoulder. It will be appreciated that the hardened pin member could also be secured in the blind bore by means of glue or a silicone adhesive or other known methods or adhesives. As the bolt that is threadably received in the threaded bore of the terminal end of the shank is tightened, this hardened pin is pulled into the softer metal of the bit block, thereby biting into the bit block and substantially preventing rotation of the bit holder within the bit block.
In one embodiment, the terminal end of the shank has a selected diameter that is less than the diameter of the portion of the shank in closest proximity to the shoulder of the bit holder. A second planar shoulder is defined by this region of reduced diameter. In an alternate embodiment, the hardened pin is received within a blind bore carried by the second planar shoulder. It will also be appreciated that the hardened pin could be received within a blind bore carried by the planar end of the bit block that engages the shoulder of the bit holder.
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:
Referring to
It will be appreciated by those skilled in the art, that the cutting bit of the dirt and rock cutting tool assembly 10 can be configured in multiple ways depending on the desired cutting environment, i.e. compacted soil, rocky soil, bedrock consisting of granite, shale, limestone, or admixtures of these types. For instance, the bevel of the cutting edge of the cutting bit 20 can be angled outwardly, as seen in
The bit holder 30 includes a planar shoulder 50 and a shank 60 extending from the planar shoulder of the bit holder 30. Shank 60 has a terminal end 70. In the preferred embodiment, the terminal end 70 of the shank 60 includes a threaded bore member 80. The bit block 40 includes a receiver 90, defined by a bore, having a diameter selected for receiving the terminal end 70 of the shank 60 of the bit holder 30. The receiver 90 extends through the length of the bit block 40. In order to secure the bit holder 30 to the bit block 40, the shank 60 is inserted into the receiver 90, extending there through. A bolt 95 is threadably received by the threaded bore 80 in the shank 60. It will be appreciated by those skilled in the art that a washer, such as washer 98, or a combination of washers could also be utilized with bolt 95.
In order to prevent rotation of the bit holder 30 within the bit block 40 when the bit holder 30 is secured to the bit block 40, at least one substantially conical or frustoconical hardened pin member 100 is carried by the bit holder 30. In this regard, at least one, preferably blind, bore 105 is disposed on the planar shoulder 50 of the bit holder 30. The hardened pin 100 is secured in the blind bore 105 such that at least a portion of the tip of the hardened pin extends beyond the surface of the shoulder 50. While brazing is the one method of securing hardened pin member 100 in the blind bore 105, those skilled in the art will recognize that other means of securement could be utilized. For example pin 100 could be press fit into blind bore 105 or an adhesive, such as a glue or a silicone-based adhesive could also be utilized. In the preferred embodiment, hardened pin 100 is fabricated from tungsten carbide. Hardened pin member 100 could also be fabricated from steel or any other material known to be harder than the material from which the bit block 40 is fabricated. As the bolt 95 that is threadably received in the threaded bore 80 of the terminal end 70 of the shank 60 is tightened, hardened pin 100 is pulled into the softer metal of the bit block 40, thereby biting into the bit block 40 and substantially preventing rotation of the bit holder 30 within the bit block 40. While hardened pin 100 is preferably fabricated from tungsten carbide or steel, it will be appreciated by those skilled in the art that pin 100 can be fabricated from any material that is harder and less deformable than the material from which the bit block 40 is constructed.
In one embodiment, the terminal end 70 of the shank 60 has a selected diameter that is less than the diameter of the portion 65 of the shank 60 in closest proximity to the shoulder 50 of the bit holder 30. A second planar shoulder 110 is defined by this region of reduced diameter. And, receiver 90 is provided with a counter-sink region 120 in communication with receiver 90. In this regard, the diameter of receiver 90 is selected to receive terminal end 70 of the shank; and counter-sink region 120 has a second selected diameter selected to receive the portion 65 of the shank 60 in closest proximity to the shoulder 50. A shoulder 115 is thus defined at the junction of the counter-sink region 120 and the receiver 90. In an alternate embodiment dirt and rock cutting tool assembly, referenced as 10′ and illustrated in
Referring to
Alternatively, as illustrated in
From the foregoing description, it will be recognized by those skilled in the art that a dirt and rock cutting tool assembly that allows infinite rotational positioning of the cutting bit but substantially prevents rotation of the cutting bit upon securing the bit holder to the bit block, and that offers advantages over the known cutting tools in the art has been provided. In this regard, the dirt and rock cutting bit tool assembly utilizes at least one hardened pin member carried by the bit holder in such a manner that the hardened pin bites into the softer metal of the bit block thereby substantially preventing rotation of the bit holder within the bit block upon securement of the bit holder to the bit block. Further, the dirt and rock cutting tool assembly of the present invention is secured to the bit block by means of a single bolt thereby making removal of the bit holder from the bit block less difficult.
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.
