US3017216A - Retriever for auger earth boring tools - Google Patents

Description

Jan. 16, 1962 R. E. HENRY ETAL 3,017,216

RETRIEVER FOR AUGER EARTH BORING TOOLS.

Filed March 14, 1960 NVENTORS BY I VK 14 Q United States Patent 3,017,216 RETRIEVER FOR AUGER EARTH BORING TOOLS Richard E. Henry and Frank Wash, Port Washington, Wis., assignors to Koehring Company, Milwaukee, Wis., a corporation of Wisconsin Filed Mar. 14, 1960, Ser. No. 14,871 8 Claims. (Cl. 294-86) This invention relates to auger retrieving tools and, more particularly, to a retrieving tool designed to be threadingly coupled to a broken or detached auger section which is located in a remote and relatively inaccessible location.

In earth boring operations employing an auger, or an auger string, a problem frequently encountered is that of retrieving a broken auger tip or, on occasion, retrieving an entire section of an auger string which has become detached fromthe main string. The problem of broken augers and detached auger sections is particularly applicable when drilling deep post holes, for example, telephone post holes or holes for pilings.

Various situations arise wherein auger breakage occurs. One of the most common causes for breakage occurs when the auger encounters a solid obstruction, at which time the forces imposed upon the auger string tend to shear the coupling pin between adjacent auger sections. Even where coupling pins are frequently replaced, an anger section that has been used on repeated occasions tends to become weakened due to metal fatigue. Consequently, when an obstruction is encountered the auger section may shear in a weakened area. Another cause of detached auger sections results from the use of faulty or improper positioned coupling pins between adjacent sections.

When an auger section breaks, or becomes detached, the operator is faced with the problem of a practical and economic way to remove the detached section. Prior art attempts to solve the aforementioned problem have taken various forms, however, none of the prior art schemes of which we are aware have provided a rapid and economical means for removing the detached auger section. Perhaps the most rapid prior art method of coping with the problem has been that of abandoning the partially drilled hole, leaving the detached tool section therein, and subsequently drilling a second hole. Such a solution is unsatisfactory not only because of the lost time involved but also because of the expense of having to drill a second hole. Additionally, where an entire auger section has become detached from the auger string, the expense of abantiming the detached section is prohibitive. Another scheme for retrieving a broken or detached auger section has been to arrange a sling and attempt to hook the detached or broken section from the ground level. This solution is not only time consuming but, more often than not, it has been found impossible to hook the tool section. Frequently it is essential that the hole be drilled in a particular location and when this occurs the operator cannot abandon the hole and equipment and drill a second hole. Thus, he has been formed to excavate to the depth of the broken or detached auger, again resulting in loss of valuable time and increased expense. On occasion, and where the hole is large enough, a man is lowered into the hole to secure a line to the broken or .detached section. Such a course of action is not only dangerous but frequently requires the welding of an eye or ring to the end of the detached auger section in order to provide something to which a line can be attached.

Accordingly, it is the general object of this invention to overcome the aforementioned difficulties and to provide an improved tool capable of retrieving broken and ice detached augers rapidly and at a minimum expense in use and permits of economic fabrication from readily available materials. In this connection it is an object of our invention to provide an auger retriever tool that is guided to the broken auger by the drilled hole.

It is another object of this invention to provide an auger retriever tool that may be connected to and used with drilling equipment already in use and that requires no special apparatus or the expense attending the moving of such apparatus to the site.

A more specific object of this invention is to provide an auger retriever tool that may be threadingly coupled to the broken or detached auger section from a remote point, thereby providing a positive coupling for withdrawing the auger. Such a retriever obviates any need for lowering a man to secure a line to the broken or detached auger section, thus eliminating a major source of danger.

These and other objects and advantages of the invention are attained by the construction and arrangement shown by Way of illustration in the drawing, in which:

FIGURE 1 is a side elevation, partly in section, of an auger retriever embodying the invention just prior to being threadingly coupled to a broken auger section;

FIG. 2 is a perspective view, partly in section, of an auger retriever embodying the invention that has been partially threaded on a broken auger section;

FIG. 3 is a top view, partly in section, taken along the line 33 of FIG. 1 and disclosing the torque transmitting member used in conjunction with the auger retriever; and

FIG. 4 is a bottom view taken along the line 4-4 of FIG. 1.

While the invention has been illustrated and will be described with particularity in connection with a preferred embodiment, it will be understood that it is not intended to be limited to this specific embodiment, but rather to cover such equivalent and alternative constructions as may be included within the spirit and scope of the appended claims.

Referring to the drawing there is illustrated in FIG. 1 an auger retrieving tool, indicated at 10, embodying the invention and which has been inserted into a hole 11 that had been bored in the earth 12 by an auger 14. It will be noted that the auger 14, which comprises a central shaft 15 having a helical flight or blade 16 mounted thereon, is embedded in the bottom of the hole 11 and, as indicated at 18, has broken off of the main auger section. The auger retrieving tool 10 has been illustrated in FIG. 1 as in position to engage auger 14 and just prior to engagement therewith.

It will be understood that in order to retrieve a broken or detachedauger section that has been solidly embedded within the ground, the retrieving tool employed must positively and securely engage the section so as" to apply thereto the considerable force that must be exerted in order to withdraw the detached section from its embedded position.

According to th-e'preferred embodiment of our invention, the auger retrieving tool is provided witha hollow, cylindrical tube or pipe 20, preferably made of steel; The tube is open at one end 21, as has'been' more clearly illustrated in FIGS. 2 and 4. The opposite end of the tube is partially closed by a plate 22 which is made rigid with the tube 20 as by welding about its periphery as indicated at 24. Means are provided for effecting a driving and supporting connection between the retriever and the drilling apparatus with which it is to be used. In the illustrative device hexagonal stub shaft 25 is rigidly secured is to be used. The hexagonal stub shaft may vary in size according to the size of the auger and the size of the retriever that is to be used. It will be understood that the flight extension 28 is secured to suitable rotatable power driving means (not shown). Radial holes 29 and 30 are formed in the flight extension and the stub shaft respectively, and serve to receive a locking pin 31, thus preventing relative axial movement between the flight extension 28 and the stub shaft 25.

Rotational movement is imparted to the flight extension 28 from any suitable power means and is transmitted to the pipe 22 through the driving connection constituted by the flight extension and the hexagonal shaft. Plate 22 serves as a torque transmitting member for the auger retrieving tool and imparts rotational movement to the tube 20.

In accordance with one of the important aspects of the invention, the auger retrieving tool 10 is provided with means positioned to engage and exert thrust against the bottom surface of the detached auger flight. More particularly, the tool includes a plurality of lugs 32 which are disposed on and welded to the inner surface 34 of the tube 20. The lugs are arranged in a helical pattern, as has been clearly illustrated in FIGS. 1 and 2, and extend substantially radially toward the axis of the tube. This is the preferred embodiment. It is to be understood, however, that a continuous section of helical flight could be used in place of lugs. The auger to be retrieved has a helical flight or blade 16 having a predetermined external diameter D and a predetermined pitch P as indicated in FIG. 1. The hollow, cylindrical tube 20 has an inside diameter D, that is slightly larger than the diameter D of the helical flight, thus allowing the detached auger to be received within the tube. The internal diameter D of the lugs 32 is substantially smaller than the diameter D,, of the auger flight, as can best be seen in FIG. 4. Thus, the tip portions 35 of the lugs 32 define a tubular passage having a diameter D which diameter is smaller than diameter D,, of the auger flight 16 but greater than diameter D of the auger shaft 15, thereby allowing the auger shaft to be received within the aforesaid tubular passage. Moreover, since the lugs are disposed in a helical pattern having a pitch P which corresponds substantially to the pitch P of the auger flight, and since the internal diameter of the tube D is greater than the external diameter of the flight D,,, it is apparent that clockwise rotational movement imparted to the retrieving tool causes the tool to be threadingly coupled to the auger section to be retrieved.

Turning to FIG. 2, there is illustrated a broken auger section 14 which is partially coupled with the auger retrieving tool 10. It will be noted that each of the lugs 32 extends a substantial distance under the adjacent auger flight 16. As the pitch P,, of the auger flight 16 is substantially the same as the pitch P of the helically disposed lugs 32, the upper portion of each lug engages the juxtaposed lower portion of the auger flight. Thus, when the auger section is to be retrieved and an upward force is exerted on the retrieving tool 10, as indicated by arrow T in FIG. 2, substantially proportionate and equal forces are exerted in an upward direction against the auger flight 16 by each of the lugs 32 as indicated by the arrows t. It will therefore be obvious that no single concentrated force is exerted against any one portion of the auger flight and consequently the danger of damage to the auger flight is minimized. This is of particular importance when retrieving entire auger sections that have not been broken but merely detached from the auger string.

Referring to FIG. 3, it will be noted that the torque transmitting plate 22 has been provided with a plurality of axially disposed openings 36. Such openings provide a passage for fluid, dirt and other foreign materials in an upward direction therethrough when the auger retrieving tool is being lowered into a hole. Consequently, in-

gress of the tool into the hole 11 is unimpeded thereby. In like manner, when the tool and the retrieved auger are being withdrawn from the hole, fluid, dirt and other foreign materials can pass downwardly through the openings 36 and egress of the tool will not be restrained. It will be apparent to one skilled in the art that the provision of openings in the torque transmitting plate will have particular significance when boring deep holes to receive pilings and where the holes are often filled, or partially filled, with water.

In operation, and assuming that an auger section has either broken or become detached while drilling a hole, it is merely necessary for the operator to withdraw the intact portion of the auger string and to secure the hexagonal stub shaft 25 of retrieving tool 10 within the hexagonal bore 26 of the lowermost flight extension 28. The tool 10 is then lowered into the hole 11 and guided thereby until it engages the broken or detached auger section 14. Since the tool 10 is of a diameter slightly larger than the diameter of the auger flight, the tool will in turn be slightly larger than the diameter of the bored hole. Consequently, as the tool is forced into the hole, the hole will, in effect, be reamed and the earth scraped away from the sides of the hole 11 will fall to the bottom thereof. While the external diameter of the tool is not critical so long as the internal diameter thereof is greater than the diameter of the auger flight, it will be understood that the retrieving tool should be maintained as small as possible in order to minimize the amount of earth that will be reamed from the sides of the hole. While rotational movement of the tool is desirable during lowering thereof, it is not essential.

When the retrieving tool engages the broken or detached auger section 14, rotational movement of the tool causes the tool to be screwed onto the auger section, thus threadingly coupling the two members together. Rotational movement of the tool is continued until the broken or detached auger section is fully coupled with the helically disposed lugs 32 at which time the upper portion 18 of the broken or detached auger section 14 engages the bottom of the torque transmitting plate 22 and relative rotation between the retrieving tool 10 and the auger section 14 ceases. The flight extension 28 or other similar connect-ing and supporting means can then be connected to a winch or boom line and the tool and retrieved auger section can be withdrawn from the hole.

While the invention has been described primarily for use in retrieving broken or detached auger sections from the bottom of a vertically drilled hole, it will be obvious that the tool is equally susceptible to use in a horizontally drilled hole, or for that matter, any other angularly disposed hole. Moreover, while the invention has been described in terms of a preferred embodiment, numerous changes might be made and still fall within the scope and spirit of the invention. For example, the torque transmitting plate 22 might take the form of a spider, in which case it would be unnecessary to provide additional axial holes therethrough. Moreover, while the helically disposed lugs have been described as being welded to the interior surface of the tube, it will be obvious that they might be secured thereto in other ways, or they might 'be struck in from the side walls of the tool itself. Additionally, it will be understood that the particular means disclosed for coupling the retrieving tool It} to the drive means do not form an essential part of our invention and other coupling means could be employed. Consequently, it is intended that such modifications be included within the spirit and scope of the appended claims.

We claim as our invention:

1. For use with earth drilling apparatus, an auger retriever for removing from a drilled hole a detached auger section and the like of the type having a helical blade, said retriever comprising, in combination, a tubular shell, drive means for effecting with the drilling apparatus a supporting and driving connection for said shell,

and a plurality of lugs secured to said shell and extending substantially radially inward into said shell, said lugs defining a substantially helical surface for engagement with the bottom surface of the helical blade of said detached auger sections.

2. A retriever for removing detached auger sections and the like from a drilled hole comprising, in combination, a tubular shell, drive means for inserting said shell into the hole and withdrawing said shell out of the hole, torque transmitting means coupling said drive means and said shell, and means disposed on the inner surface of said shell for threadingly engaging the detached auger section so that the auger section can be removed from the drilled hole.

3. A retriever for removing detached auger sections and the like from a drilled hole comprising, in combination, a tubular shell, drive means for inserting said shell into the hole and withdrawing said shell out of the hole, torque transmitting means coupling said drive means and said shell, means disposed on the inner surface of said shell for threadingly engaging the detached auger section so that the auger section may be removed from the drilled hole, and stop means for preventing relative rotation between said shell and the detached auger section when the auger section is threadingly coupled to said shell.

4. In an auger retriever for recovering detached auger sections having a helical blade thereon, said retriever having a tubular shell, the improvement which comprises a plurality of inwardly projecting, substantially radial lugs secured to said shell in a helical pattern, said helical pattern having a pitch substantially similar to the pitch of the helical blade, and drive means for imparting rotational movement to said shell for threaded engagement of said lugs with the detached auger section.

5. A retriever for removing from a drilled hole detached auger sections and the like of the type having a helical blade, said retriever comprising, in combination, a tubular shell having an internal diameter slightly larger than the diameter of the auger blade, drive means for inserting said shell into the drilled hole and withdrawing said shell out of the drilled hole, torque transmitting means interposed between said drive means and said shell, and a plurality of inwardly projecting, substantially radial lugs secured to said shell in a helical pattern of a pitch substantially corresponding to the pitch of the helical auger blade, said helical pattern defined by said lugs having an internal diameter substantially smaller than the diameter of the auger blade, said drive means imparting rotational movement to said shell so that said lugs are threadingly coupled to the detached auger section.

6. A retriever for removing from a drilled hole detached auger sections and the like of the type having a helical blade, said retriever comprising, in combination, a tubular shell having an internal diameter slightly larger than the diameter of the auger blade, drive means elfecting a supporting and driving connection for inserting said shell into the drilled hole and for withdrawing said shell out of the drilled hole, torque transmitting means coupling said drive means and said shell, said torque transmitting means having at least one axial opening extending therethrough, and a plurality of inwardly projecting substantially radial lugs secured to said shell in a helical pattern having a pitch substantially similar to the pitch of the helical blade, said helical pattern defined by said lugs having an internal diameter substantially smaller than the diameter of the auger blade, said drive means imparting rotational movement to said shell so as to threadingly couple said lugs to the auger section for retrieving the latter.

7. A retriever for removing from a drilled hole detached auger sections and the like of the type having a helical blade, said retriever comprising, in combination, a tubular shell having an internal diameter slightly larger than the diameter of the auger blade, drive means effecting a supporting and driving connection for inserting said shell into the drilled hole and for withdrawing said shell out of the drilled hole, torque transmitting means interposed between said drive means and said shell, said torque transmitting means constituting a fixed stop which serves to prevent relative rotation between said shell and the detached auger section when said shell is threadingly coupled to the auger section and a plurality of inwardly projecting, substantially radial lugs secured to said shell in a helical pattern having a pitch substantial-1y similar to the pitch of the helical blade, said helical pattern defined by said lugs having an internal diameter substantially smaller than the diameter of the auger blade, said drive means imparting rotational movement to said shell so as to threadingly couple said lugs to the detached auger section for retrieving the latter.

8. A retriever for recovering from a drilled hole detached auger sections and the like of the type having a central shaft wit-h a helical blade disposed thereon, said retriever comprising, in combination, a tubular shell, drive means effecting a supporting and driving connection for inserting said shell into the drilled hole and withdrawing said shell out of the drilled hole, torque transmitting means interposed between said drive means and said shell, and means disposed on the inner surface of said shell for threadingly engaging the detached auger section so that the auger section may be removed from the drilled hole, said last named means comprising a plurality of lugs rigidly secured to the inner surface of said shell, said lugs arranged in a helical pattern on said shell and projecting substantially radially into said shell, said lugs having end portions which terminate short of the axis of said shell so that the end portions of said lugs define a tubular passage extending through said shell and along the axis thereof, said shell having an internal diameter greater than the diameter of the helical blade and said tubular passage having a diameter greater than the auger shaft but less than the helical auger blade.

References Cited in the file of this patent UNITED STATES PATENTS 2,449,841 Claypool et al Sept. 21, 1948

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