Casing Block

Abstract

A preset recessed casing block for retaining a cutter bit is provided that can be mass-produced and easily installed in the casing of a core barrel. The block has a size and shape that provides for quick and easy insertion and welding into a casing. The block has a cavity that receives and retains a cutter bit while allowing for the removal or extraction of the cutter bit when the bit becomes worn or broken. Because the block is manufactured to fit inside the casing, wear on the block is minimized and it's lifetime extended. The cavity in the block and the shape of the block itself may have different, preset angles and pitches, to allow for the same size block to be placed in a variety of locations around the casing, thereby enabling the manufacturer to produce a variable, raking pattern of the cutter bits for improved annulus cutting.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Patent App. No. 61/483,665 filed on May 7, 2011, the entirety of which is hereby incorporated by reference.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

This invention was not federally sponsored.

BACKGROUND OF THE INVENTION

Field of the Invention

This invention relates to the general field of drilling equipment for the foundation drilling and mining industries, and more specifically toward a preset recessed casing block for retaining a cutter bit. The invention provides a casing block that can be mass-produced and easily installed in the casing of a core barrel. The block can be molded or cut into a size and shape that can be quickly and easily inserted into a casing, and welded into place. The block has a cavity manufactured into it that is designed to receive and retain a cutter bit, but still allow for the removal or extraction of the cutter bit when the bit becomes worn or broken. Because the block is manufactured to fit flush to the surface of the casing, wear on the block is minimized and it's lifetime is much greater than prior art blocks. The cavity in the block can be manufactured with different, preset angles and pitches, to allow for the same size of block to be placed in a variety of locations around the casing, thereby enabling the manufacturer to produce a variable, raking pattern of the cutter bits for improved annulus cutting. This feature also provides efficient initial placement, and replacement of blocks.

Foundation drilling and mining has evolved over time and continues to be an essential industry for all modern civilizations. In the effort to improve the production and quality of drilled foundations, there has been huge investment, and advancement in the equipment and tools of the trade.

One of the most common tools used by foundation drillers is the core barrel. Core barrels are used to core through hard layers of dirt and rock and are known for their ability to keep holes true and straight.

The following invention provides important advancements in the manufacturing and use of core barrel tools. The improved core barrel has a “cutting end” that comprises a casing, which is a metal substrate with a number of cavities. “Casing blocks” (or simply “blocks”) can be welded into the cavities, and cutter bits can be inserted into the blocks. The blocks can have a side opening that allows an operator to access the bottom portion of the cutter bit to make removal easier than with currently practiced methods.

The cutter teeth cut through rock and dirt as the core barrel advances. Because of the hard earth into which the holes are cut, the wear and tear on the cutter bits is considerable, and they often break and/or wear out and have to be replaced. A high-quality drilling rig can cost $1,000 or more per hour to operate, and operations have to stop whenever the operator has to replace a cutter bit and/or block. Thus, it is highly advantageous to have a product that allows for a rapid and efficient replacement of blocks and cutter bits.

Core barrels that use carbide cutter bits with recessed blocks are the preferred design in the industry at present because the blocks are protected from excess wear and impact by the surrounding casing. Although preferred, they tend to be more expensive and difficult to manufacture due to the additional installation steps and fabrication required.

One of the most important and time-consuming steps is setting the height, angle, and pitch of each cutter bit and block. This procedure requires two fabricators to take numerous measurements and do calculations to ensure that each cutter bit block is in the proper location before it is welded into place. For example, a cutter bit set to cut and located at the outside cutting surface will have a much different ideal height, angle and pitch than would a cutter bit set to cut and located on the inside portion of the casing.

Under the prior art methods, one of the workers must take three separate measurements while he adjusts and holds the block into position. When he gives the “OK”, a second worker must tack weld the block to the casing. This current method has two disadvantages. First, considering the high operating cost of even an average sized drilling rig, any “down time” can translate into thousands of dollars very quickly. Second, because two fabricators are required, there has to be an additional person standing by to assist the operator in case a cutter bit breaks or wears out.

Prior art blocks are designed to be welded to the edge of a casing making them susceptible to wear and impact. Prior art blocks are difficult to recess into casing and must have their height, angle, and pitch manually set to cut clearances.

Thus there has existed a long-felt need for preset recessed casing blocks that resist wear and impact, easy to manufacture and install, and provide multiple heights, angles and pitches to allow for use in a wide variety of situations.

SUMMARY OF THE INVENTION

The current invention provides just such a solution by having a block capable of being placed in a cavity in a casing used for core barrels and other drilling apparatus. The block is molded or cut into a size and shape that can be quickly and easily inserted into a casing, and welded into place. The block has a cavity manufactured into it that can receive a cutter bit. Because the block is manufactured to fit flush to the surface of the casing, wear on the block in minimized. The cavity in the block can be manufactured with different, preset angles and pitches to allow for the same size of block to be placed in a variety of locations around the casing, thereby enabling the manufacturer to produce a variable raking pattern of the cutter bits for improved annulus cutting. This feature also provides efficient initial placement, and replacement of blocks.

An object of the invention is to provide the industry with a preset recessed casing block that can be installed faster and easier with only one worker needed to perform the work. The invention comprises a square or rectangular outer shape to make it easy to lay out and cut casing when installing. Each block is designed to mount flush with the top edge of casing so there is no need to measure or set the height. Each block is preset with optional angles and pitches and only needs to be selected and centered into the casing. Blocks can be preset to inside, outside, middle cutter and other miscellaneous positions. All a worker will need to do is cut the typical block size out the casing, choose a block, (outside, inside, middle, etc.) and weld it into place.

A wedge shaped tool can be used to easily remove the cutter bits from the blocks. By accessing the bottom of the cutter bit through the hole in the side of the block, a worker can hammer or otherwise push up on the cutter bit from the bottom, dislodging it and popping it out the top of the block cavity. Blocks can be made with or without the snap ring access hole in the side. The sides of the block can be beveled to allow for welds. Block settings can be purchased with different attack angles, and can be purchased preset as outside, inside, middle, middle inside, middle outside, etc., or any other of the preferred combinations of height, angle and pitch found in different locations on the casing. Blocks can be made to accept any type of cutter including rotating, non-rotating, and can be made in different materials, shapes and sizes.

It is a principal object of the invention to provide a casing block that is easily installed and removed from the casing of a drilling apparatus.

It is another object of the invention is to provide a means to allow cutter bits to be inserted and removed easily from the casing block, which can be a recessed cavity in the block that is shaped to accommodate a cutter bit.

It is an additional object of the invention that the casing block be made in a variety of shapes to accommodate a variety of casings and drilling plans.

It is a further object of the invention that the casing block can be manufactured with a wide range of angles and pitches with respect to the recessed cavity, such that a cutter bit with a desired angle of attack can be inserted into a particular type of casing block for a particular location on the casing.

It is also an object of this invention that the casing block has beveled edges that allow for welding of the block into the casing.

It is yet another object of this invention that the invention allow for a more efficient drilling operation by reducing the number of workers required to remove and replace a casing block, and by allowing this work to be done more quickly than is currently possible using the prior art materials and methods.

There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof may be better understood, and in order that the present contribution to the art may be better appreciated. There are additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto. The features listed herein and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims.

BRIEF DESCRIPTION OF THE FIGURES

The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments of the invention and together with the description, serve to explain the principles of this invention.

FIG. 1 is a perspective view of a casing block according to selected embodiments of the current disclosure.

FIG. 2 is a partial bottom view of a core barrel with three casing blocks secured thereto according to selected embodiments of the current disclosure.

FIG. 3 is a partial bottom view of a core barrel with a single middle casing block secured thereto according to selected embodiments of the current disclosure.

FIG. 4 is a side view of a casing block secured to a core barrel and a cutter bit according to selected embodiments of the current disclosure.

FIG. 5 is a front view of a casing block according to selected embodiments of the current disclosure.

FIG. 6 is a cutaway side view of a casing block according to selected embodiments of the current disclosure.

DETAILED DESCRIPTION OF THE INVENTION

Many aspects of the invention can be better understood with the references made to the drawings below. The components in the drawings are not necessarily drawn to scale. Instead, emphasis is placed upon clearly illustrating the components of the present invention. Moreover, like reference numerals designate corresponding parts through the several views in the drawings.

FIG. 1 is a perspective view of a casing block according to selected embodiments of the current disclosure. The casing block 10 has a cavity manufactured into it during production. The cavity of the casing block 10 has two general parts, a retaining section 13, designed to seat the bottom half of a cutter bit, and a terminal cavity 12 designed to retain a snap ring on a cutter bit (not shown in this figure), and to allow for a wedge-shaped implement to easily pry loose any worn or broken cutter bits for removal and replacement. The block 10 has a trailing support edge 14 that provides support to the trailing edge of the cutter bit as it is moved forward by the drilling rig. Each corner of the casing block 10 has a beveled edge 11 to allow for easy welding into openings in the core barrel.

The casing blocks are generally made of steel, iron, or some alloy, and are sometimes heat-treated. The common means by which casing blocks are retained in the casing is to weld them in place, although other means of attachment are contemplated.

FIG. 2 is a partial bottom view of a core barrel with three casing blocks secured thereto according to selected embodiments of the current disclosure. The left-most casing block 10 in this figure is secured in the casing 51 of the core barrel 50 at an inside position, whereby a cutter bit retained therein is angled towards the inside of the core barrel. The center casing block 10 in this figure is secured in the casing 51 of the core barrel 50 at a middle position, whereby a cutter bit retained therein is angled in the same direction as the longitudinal axis of the core barrel. The right-most casing block 10 in this figure is secured in the casing 51 of the core barrel 50 at an outside position, whereby a cutter bit retained therein is angled towards the outside of the core barrel.

FIG. 3 is a partial bottom view of a core barrel with a single middle casing block secured thereto according to selected embodiments of the current disclosure. The casing block resides in the casing 51. The retaining section 13 and the trailing support edge 14 are visible in this figure, as well as the beveled edges 11 in each of its four outer corners.

FIG. 4 is a side view of a casing block secured to a core barrel and a cutter bit according to selected embodiments of the current disclosure. The function of the block can be seen in this figure. As the drilling rig turns the drill bit, the casing rotates, pushing the cutter bits against the soil and rock point first. As the point of the cutter bit digs into the soil, the trailing support edge 14 and the retaining section 13 keep the cutter bit 40 at the proper angle and pitch to maximize the efficiency of the cutting. It should be noted that the casing 51 has a variety of cutter bits located on different parts of the casing, so that different casing blocks that have cavities that point the cutter bit in different directions are needed. In an ideal drilling setup, having cutter bits pointing downward, inward, and outward to the sides produces maximum “raking” of the soil, which results in maximum efficiency.

Over time, the cutter bit 40 will either break or wear out and have to be replaced. When it becomes necessary to remove and replace a cutter bit, the cutter bit is pulled out after removal of the snap ring. Access for removing the snap ring is provided through the terminal cavity 12. If after removing the snap ring the cutter but 40 is still stuck in the casing block 10, the cutter bit may be levered out by use of a wedge-shaped tool. The average casing block will last through about fifteen to twenty cutter bits. When it is time to replace the casing block, the welded portion is cut through and the block removed. Another casing block can be quickly installed in the cavity, welded into place, have a cutter bit installed, and then the drilling operation can resume. This method is considerably more efficient than the current method of individually welding irregular shaped blocks and cutter bits into the preferred combination of heights, angles and pitches.

The casing 51 has a cavity into which the casing block 10 has been inserted. There is adequate space between the edge of the cavity of the casing 51 and the sides of the casing block 10 for welding. The trailing support edge 14 buttresses the first retaining portion 16 of the retaining section in the block 10 into which the cutter bit 40 is inserted. The retaining portion 14 includes two different sections with two different diameters; the second retaining portion 17, which is proximate to the terminal cavity, has a smaller diameter than the first retaining portion 16. The shank portion of the cutter bit 41, 42 (which also has two different sections with two different diameters) rests on and is retained by difference in diameter of the first retaining portion 16 and the second retaining portion 17.

The cutter bit 40 has two different shank sections: a first shank section 41 and a second shank section 42. The first shank section 41 has a larger diameter than the second shank section 42. The distal end of the second shank section 42 includes an indentation 44 (or groove) around its entire circumference. The snap ring discussed above extends around this indentation 44. A rotating protective sleeve 43 facilitates the rotation of the cutter bit 40 within the casing block 10 while also reducing the wear and tear on the casing block 10 from the rotation of the cutter bit 40.

A more thorough description of the cutter bit can be found in U.S. Pat. No. D601,592, U.S. patent application Ser. No. 12/465,851, and European Union Pat. No. 001113039-0001, all of which, including any priority-related applications, are hereby incorporated by reference.

FIG. 5 is a front view of a casing block according to selected embodiments of the current disclosure. The bottom of the casing block 10 includes a flat base portion 20 and two angled base portions 19. The base angle 21, which is the difference in angle between the flat base portion 20 and the angled base portion, enables the casing block 10 to be installed into a core barrel at that angle. In other words, the casing block 10 may be installed at an angle into the cavity of a casing such that one of the angled base portions mates flush with the bottom of the cavity. In this manner, casing blocks, and thus cutter bits, may be quickly and efficiently installed into a casing at one of three predetermined orientations: middle, inner, and outer. It will be appreciated by those in the art that different casing blocks may be manufactured with different base angles. Furthermore, it will be appreciated by those in the art that the same casing bock with two angled base portions 19 may have different base angles 21 for each of the two angled base portions 19.

FIG. 6 is a cutaway side view of a casing block according to selected embodiments of the current disclosure. This view is taken along line 6 shown in FIG. 5. The casing block 10 includes a terminal cavity 12, a first retaining portion 16 and a second retaining portion 17. The back end of the first retaining portion 16 is supported by the trailing support edge 14. The trailing support edge 14 is a raised section proximate to the retaining section. The pitch of the cutter bit is set by the angle of the retaining section. A low pitch results in a cutter bit that is relatively parallel to the top of the casing block. A high pitch results in a cutter bat that is almost or actually perpendicular to the top of the casing block. A medium pitch results in a cutter bit that is somewhere between a low pitch and a high pitch.

It should be understood that while the preferred embodiments of the invention are described in some detail herein, the present disclosure is made by way of example only and that variations and changes thereto are possible without departing from the subject matter coming within the scope of the following claims, and a reasonable equivalency thereof, which claims I regard as my invention.

All of the material in this patent document is subject to copyright protection under the copyright laws of the United States and other countries. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in official governmental records but, otherwise, all other copyright rights whatsoever are reserved.

Claims

1. A device for retaining a cutter bit in a casing comprising: a bottom, four sides, a top, and a cutter bit retaining section, where the bottom and the four sides are capable of fitting into a cavity of a casing.

2. The device of claim 1, wherein one of the four sides comprises an opening through which a bottom of a shaft portion of a cutter bit can be accessed, wherein this opening is a terminal cavity.

3. The device of claim 1, where the four sides are of equal length, thereby making a square.

4. The device of claim 1, where the four sides have two sides of one length and two sides of another length, thereby making a rectangle.

5. The device of claim 1, wherein the device further comprises four beveled edges, where there is a beveled edge between each of the four sides, and where the beveled edges allow for welding material to be inserted in between the device and the casing.

6. The device of claim 1, further comprising a trailing support edge, where the trailing support edge is a raised section proximate to the cutter bit retaining section.

7. The device of claim 1, where the device further comprises a terminal cavity, where the terminal cavity is proximate to the cutter bit retaining section, wherein the cutter bit retaining section comprises a first retaining portion and a second retaining portion, and wherein the terminal cavity has an opening.

8. The device of claim 7, wherein the cutter bit retaining section is shaped to mate with a shank section of a cutter bit.

9. The device of claim 7, wherein the first retaining portion and second retaining portion each have a diameter, where the diameter of the first retaining portion is greater than the diameter of the second retaining portion.

10. The device of claim 1, wherein the cutter bit retaining section is manufactured in a low pitch.

11. The device of claim 1, wherein the cutter bit retaining section is manufactured in a high pitch.

12. The device of claim 1, wherein the cutter bit retaining section is manufactured in a medium pitch.

13. The device of claim 1, wherein the device is manufactured for an inside position on a casing.

14. The device of claim 1, wherein the device is manufactured for a middle position on a casing.

15. The device of claim 1, wherein the device is manufactured for an outside position on a casing.

16. The device of claim 1, wherein the bottom of the device comprises a flat base portion and two angled base portions, whereby the flat base portion and angled base portions enable the same device to be used for an inside position, middle position, or outside position in a casing.

17. The device of claim 1, additionally comprising a terminal cavity, wherein the terminal cavity is accessible though one of the four sides.

18. The device of claim 17, wherein a cutter bit can be removed from the device through the use of a wedge shaped tool.

19. The device of claim 1, wherein the cutter bit retaining section is designed to accommodate a rotating cutter bit.

20. The device of claim 1, wherein the cutter bit retaining section is designed to accommodate a non-rotating cutter bit.