US3746105A

US3746105A - Arm extension for drilling foundation holes

Info

Publication number: US3746105A
Application number: US00208215A
Authority: US
Inventors: G Farmer; J Owens
Original assignee: FARMER FOUND CO
Current assignee: FARMER FOUND CO
Priority date: 1971-12-15
Filing date: 1971-12-15
Publication date: 1973-07-17
Anticipated expiration: 1990-07-17

Abstract

An improved arm extension is provided which is mounted at one end to a carrier or the like, and which is capable of supporting an auger or other boring device at the other end. The arm extension is composed of one or more tubular sections coupled together to reach between the carrier and the site of the borehole, and preferably has a dog-leg configuration to elevate the engine mounted on its outer end to a suitable height above the borehole site.

Description

United States Patent 1191 Farmer et al.

I45] July 17,1973

1 1 ARM EXTENSION FOR DRILLING FOUNDATION HOLES [75] Inventors: Glyen D. Farmer; J. C. Owens, both of Houston, Tex.

[73] Assignee: Farmer Foundation Company,

Houston, Tex.

[22] Filed: Dec. 15, 1971 [21] App]. No.: 208,215

[52] US. Cl 173/44, 173/22, 173/151 [51] Int. Cl E211) 3/04 [58] Field of Search ..l73/22-28, 43, 44, 151

[56] References Cited UNITED STATES PATENTS 1,663,833 3/1928 Genung 173/151 X 2,791,399 5/1957 Curtis et al. 173/43 X 3,030,713 4/1962 Hendrickson 173/43 X Primary Examiner-Ernest R. Purser Attorney Donald H. Fidler and Edmund F. Bard [57] ABSTRACT An improved arm extension is provided which is v mounted at one end to a carrier or the like, and which is capable of supporting an auger or other boring device at the other end. The arm extension is composed of one or more tubular sections coupled together to reach between the carrier and the site of' the borehole, and preferably has a'dog-l'eg configuration to elevate the engine mounted on its outer end to a suitable height above the borehole site.

14 Claims, 7 Drawing Figures Patented July 17, 1973 2 Sheets-Sheet z ARM EXTENSION FOR DRILLING FOUNDATION HOLES BACKGROUND OF INVENTION This invention relates to improved methods and apparatus for drilling boreholes in the earth and, more particularly, relates to improved methods and apparatus for drilling foundation holes for the installation of piling and other like foundation structures.

It is well known to construct foundations for buildings, bridges, wharfs and the like, by imbedding piles in the earth. It is further well known that small-diameter wooden piling of relatively short length can be installed by merely driving them into the earth.

It is impractical to drive large piling into the earth,

especially those formed of cast concrete. Accordingly, the process of installing a large concrete piling involves drilling a hole of the desired size and shape, and thereafter molding the pile in the hole. More particularly, a large auger is employed to drill the hole to its desired depth and diameter, and a steel casing is usually inserted for the purpose of preventing'cave-ins as well as to provide a mold for the concrete. Accordingly, after the auger is removed and replaced with an appropriate assembly of reinforcing rods, the casing may be filled with concrete. I

It will be apparent that when concrete piling is to be installed in this manner to support abridge or wharf or the like, most if not all of the piles willnecessarily have to.be located in submerged land. Furthermore, in many instances the piling is installed at locations which may be spaced a considerable distance from the'bank of the river or other body of water. The other facet of the problem arises from the fact that the diameter of drill holes of this character may be 5-6 feet or even larger, and thus a hole of suchsize can only be drilled by equipment which is very large and therefore very heavy.

It will be apparent that acrane composed of a carrier and boom is required for projects of this size. The carrier may be skid-mounted, or it may be acrawler-type or wheel-mounted unit of conventional design. The carrier is preferably provided with an extension arm for supporting a rotary table, and a boom for hoisting and supporting both the extension arm and the upper end of the shank of the auger or other boring means which is rotatably mounted in the rotary table. An engine is also conventionally positioned on the outer end of the extension arm for revolving the rotary table which, in 7 turn, rotates the auger to drill the foundation hole.

Both the boom and the extension arm are pivotally connected to the carrier, whereby the outer ends of these members can be moved arcuately up and down above the location of the drill hole. Thus, the rotary table is usually positioned horizontally above the mouth of the drill hole by means of the extension arm, while the auger is suspended in the'drill hole from the end of a cable which hangs from the traveling end of the boom. In this way, the engine and rotarytable cause the auger to rotate to drill the hole, while the auger is lowered into the hole (or hoisted out) by means of the cable.

In many instances, the location of the hole to be drilled is much too far from shore for thecarrier to be located'on dry land. Thus, the carrier must bepositioned on a large floating platform which is brought to and moored at the spot where the hole is to be drilled.

In other instances, the holes are to be drilled quite close to the bank or shore. Accordingly, the carrier may be positioned on dryzland with its arm extensionprotruding out over the water to the location where the hole isto be drilled.

A significant factor in the cost of drilling any foundation hole is the time required to complete the project. Accordingly, it will readily be apparent that it is always a time-consuming operationto load thecarrier on a raft or other floating platform, and thereafter to maneuver the platform to the location to'be drilled. In addition,

shore.

It will readily be apparent that it is-=the length of the armextension which determinesthe maximum distance which the carrier or other supporting means can be offsetfrom the site of thedrill hole. There are two factors limiting the length of 'the arm extension, however. The firstand obvious limitation isprovided by the fact that the total weightof the armextension, engine,'rotary table, and (perhaps) the auger-cannot equal the weight of the tractor and boom, orelse' the-carrier will be unable'to stably support the arm extension. Thus, the total weight of the arm extension is a limitation on its overall length.

Thesecond limitation arises, however, out of the fact that the arm extension is subject to heavy stress because of the torquesupplied to it by the revolving auger.'Because-of this, it has been considered essential to 7 provide the arm extension with aconsiderable amount -of internal 'bracingto'pre'ventits becoming deformed. The ill effects of suchstresses are greatly minimized in any arm extension by reducing its'length, of course. On the other hand, braces have weight, and if an arm extension is required to "be internally braced to. resist torque, it will none the less be necessary to reduce the length of the arm extension to compensate for the added weight of the bracing.

The various types of arm extensions presently available to the industry are truss-like structures which are heavily braced against the torque which results from rotation of the auger, and which are therefore relatively short. Accordingly, it has been impossible to reach many drill hole sites with arm extensions of the prior art, without taking elaborate and therefore expensive measures to support the carrier. For example, it has often been necessary to position the carrier on a floatingplatform or raft merely to-drill a foundation hole which islocated only a relatively few feet off of the bank of a river.

The necessity of using a floating platform has, of course, substantially increased the cost of building-piletype foundations at many submerged locations, and this has constituted a significant disadvantage in the methods and apparatus of the-prior art. In some instances,

however, it has been impossible to move a floating plating a temporary causeway.

These disadvantages of the prior art are overcome or substantially reduced with the present invention, however, and novel methods and apparatus are herewith provided for drilling a foundation hole at a much greater distance from the location of the carrier.

SUMMARY OF INVENTION In a particularly suitable form of the present invention, an arm extension is provided which is formed of a tubular member preferably having a dog-leg configuration and a hollow cylindrical cross section. More specifically, the extension is preferably formed of an assembly of sections. In such an embodiment, the aforementioned engine and rotary table are preferably borne by a section which is basically a length of hollow steel casing with closed ends, but which also preferably includes a short hollow section of easing angularly extending from the main section of casing in a manner suggestive of the grip of a pistol. Both the rearward end (i.e., the end opposite the rotary table) of the main section of casing and the end of the so-called pistol grip portion are preferably provided with flanges having bolt holes at appropriate locations. Thus, the aforementioned section of arm may be mounted on the carrier by means of another section of casing having flanges at both ends, this section being bolted either to the main casing portion of the engine-bearing section or to the pistol-grip section.

As hereinbefore stated, the ideal embodiment of the invention is a tubular member having a dog-leg configuration and having means to be pivotally coupled to the carrier. In the case of drilling equipment of conventional design, the truss-type arm extensions of the prior art are preferably coupled to the carrier by means of a rocker arm or bolt horizontally interconnected with the carrier. It is desirable for purposes of facilitating acceptance of the present invention that arm extensions embodying the present invention be interchangeable with truss-type arm extensions of the prior art. Accordingly, a pivot section is preferably provided which is cylindrical at one end, which is chisel-like at the other end, and which has a bearing-type sleeve portion fixedly secured along the line of convergence of the two faces of the chisel portions and adapted to receive the cylindrical bolt which is used to couple the truss-type arm extension to the forward end of the carrier. Thus, this sleeve portion is horizontally positioned when the pivot section is connected to the carrier, whereby the pivot section pivots about a horizontally positioned rocker pin mounted in the carrier.

Since the arm extension which is the subject of the present invention is preferably provided with a dog-leg configuration, the cylindrical end of the pivot section is preferably interconnected with one end of a short dog-leg section having its other end coupled to one of the two flanged ends of the engine-bearing section of the arm extension. Alternatively, and even preferably, it is desirable to employ an arm extension which incorporates a dog-leg section sincethis will elevate the engine and rotary table above the pivot point of the arm extension.

It is a feature of the present invention to employ at least a portion of one of the cylindrical sections of the arm extension as a fuel tank to supply the engine which drives the rotary table. It is further a feature to lengthen the arm extension, or to further elevate the engine, by

providing one or more intermediate sections of compatible size and configuration.

These and other features and advantages of the present invention will be apparent from the following detailed description, wherein reference is made to the figtires of the accompanying drawings.

IN THE DRAWINGS FIG. I is a simplified pictorial representation of a tractor carrying an arm extension embodying one form of the present invention.

FIG. 2 is a pictorial representation, partly in cross section, of a portion of the apparatus depicted in FIG. 1.

FIG. 3 is also a pictorial representation of another portion of the apparatus depicted in FIG. 1.

FIG. 4 is a simplified pictorial representation of apparatus of the type generally illustrated in FIG. 1, but wherein an arm extension is shown which is a different embodiment of the present invention.

FIG. 5 is a simplified pictorial representation of another embodiment of the present invention.

FIG. 6 is a simplified representation of an embodiment of the present invention constituting a modification of the apparatus depicted in FIG. 5.

FIG. 7 is a pictorial representation of another embodiment of the apparatus depicted in FIG. 1.

DETAILED DESCRIPTION Referring now to FIG. 1, there may be seen a simplified representation of a mobile carrier 2 mounted in a conventional manner on a pair of endless tracks 6 and supporting a cab 3 of conventional design. Thus, the carrier 2 may include provision (not depicted) for winding in and paying out cables SA and 58 preferably from the end of a hoisting boom 4. Accordingly, the boom 4 is preferably pivotally mounted on the carrier 2, and, as will more clearly be seen in FIG. 4, further adapted to be arcuately movable up and down relative to the area immediately in front of the carrier 2.

Referring again to FIG. 1, there may be seen an arm extension 7 composed of a long dog-leg section 8 connectedat one end to the carrier 2 by a pivot section 9, and having its other end connected to a motor support section 12 by means of a fuel tank section 11. As may further be seen, the pivot section 9 may be rotatably connected at one end to a pivot pin 10 or the like which is suitably mounted adjacent the cab 3 of the carrier 2. The longer portion of the dog-leg section 8 may be seen to be connected to the cylindrical end of the pivot section'9' by means of a flange 8A which is preferably bolted to the flange 9A of the pivot section 9 in a conventional manner. The other shorter end of .he dog-leg section 8 may be seen to be coupled to one end of a fuel tank section 11 which, in turn, is preferably coupled to the rearward end ofthe motor support section 12 opposite the rotary table 18 and table support 14.

As may be further seen in FIG. I, the motor support section 12 is adapted to suitably support an engine 13 so as to rotatably drive a rotary table 18 of conventional design and adapted to slidably contain an appropriate boring tool or the like. More particularly, the rotary table 18 itself is preferably rotatably mounted in a table support portion 14 of conventional design, and the upper end of the shank portion 15 of an anger 17 may be suspended from a suitable cable link 16 fastened on the end of the cable 5A, whereby the lower bit portion of the auger 17 is permitted to engage and bore into the earth when the rotary table 18 is revolved in the proper direction by the engine 13. The other depicted cable 58 may be seen to be attached to the engine 13 to provide means for raising and lowering the arm extension 7.

Referring now to FIG. 2, there may be seen a more detailed representation of the fuel tank section 11 depicted only generally in FIG. 1. Accordingly, the fuel tank section 11 may be seen to be composed of a relatively short length of cylindrical casing which is stoppered at each end to form a container suitable tohold a quantity of gasoline or other liquid-type fuel 20. A fill pipe 22 of conventional design may be mounted in the upper portion of the fuel tank section 11 for receiving the fuel when the tank section 11 is to be filled, and an exit pipe 21, which preferably extends to the bottom of the inside of the fuel tank 11, is conventionally provided so that fuel 20 may be withdrawn by a fuel pump (not depicted) in the engine 13.

Referring again to FIG. 2, it may be seenthat the fuel tank section 11 'may be provided at one end with a conventional flange 25 which is preferably bolted, in turn, to the flange 26 mounted on the short portion of the dog-leg section 8. Similarly, the opposite end of the fuel tank section 11 is also preferably equipped with a similar flange 23 which is preferably bolted to a similar flange 24 on the rearward motor supportsection 12.

Referring now to FIG. 3, there may be seen a more detailed pictorial view of the pivot section 9 depicted only generally in FIG. 1. More particularly, the pivot section 9 may be seen to have a cylindrical end portion 27A adjacent the flange 9A and a chisel end portion 27B at its other end having

flat surfaces

28 and 29 which terminate at a hollow tube-like sleeve 19. Accordingly, the pivot section 9 may be pivotally coupled to the cab 3 of the carrier 2 by a suitable pin 10 which is preferably inserted slidably through the sleeve 19 and into bearing portions (not depicted) in appropriate 10- cations on the housing or frame portion of the cab 3. Thus, the arm extension 7 will be pivotally movable by the cable 5B about the pivot pin 10 in a plane which is vertical with respect to the earth.

Referring now to FIG. 4, there may be seen a pictorial representation of apparatus generally similar to the apparatus depicted in FIG. 1 but having an arm extension 7A which is substantially different in several re-' spects. More particularly, the modified arm extension 7A may be connected to the cab 3 by the same pivot section depicted in FIG. 1 and also to include the same fuel tank section 11 and motor support section 12 depicted in FIGS. 1 and 2. Instead of the dog-leg section 8 illustrated in FIG. 1, however, there may preferably be provided a relatively long and straight hollow tubular arm section 30 which is interconnected at one end to the pivot section 9 and at the other end to the fuel tank section II. It is a particular feature of a long and straight arm section 30 such as depicted in FIG. 4 that it is completely hollow and thus is not equipped with any interior bracing of any type. Accordingly, although the long and straight arm section 30 is substantially longer than any equivalent truss-type arm extension of the prior art, it is not only proportionally lighter in weight but also capable of maintaining and supporting the engine 13 and rotary table 18 at a greater distance from the cab 3 than that heretofore obtainable with the truss-type arm extensions heretofore in substantially universal employment throughout this industry.

Referring now to FIG. 5, there may be seen another form of arm extension 7B embodying the concepts of the present invention, and more particularly including a special arm section 41 having a cylindrical motor support portion 42 adapted to support the engine 13, and a pistol-grip portion 43 preferably provided with a conventional flange 43A. Further, there is provided another flange 42A at the rearward end of the motor support portion 42. As will also be apparent in FIG. 5, the engine 13 may be removably attached to the top of the special arm section 41 by means of two

pins

46 and 47 which may be slidably inserted through two pairs of coaxially arranged eye loops or

brackets

44 and 45, respectively. As further depicted in FIG. 5, the arm extension 73 preferably includes a short dog-leg arm section 38 having its short portion connected to a flange 388 which, in turn, is bolted removably to the flange 42A on the rearward end of the motor support portion 42 of the special arm section 41. The long arm portion of the dog-leg section 38 is also provided with a similar flange 3813 which, in turn, is bolted to flange 42A.

In the embodiment of the invention depicted in FIG. 5, the pivot section 9 is joined to the short dog-leg section 38 by means of a relatively short tubular member or cylindrical lengthening section 39, having a flange 39A at one end for interconnecting with flange 9A on the pivot section 9, and having a flange 39B at the other end for interconnecting with the flange 38A on the dog-leg section 38. The lengthening section 39 may be omitted, of course, and

flanges

38A and 9A may be bolted directly together. Alternatively,

flanges

38A and 9A may be spaced even farther apart than as illustrated in FIG. 5 by the substitution of a lengthening section even longer than as inferred from an examination of the apparatus depicted in FIG. 5. For example, the lengthening section 39 may be replaced in the apparatus illustrated in FIG. 5 by the long cylindrical section 40 depicted in FIG. 6. l

I As will hereinafter be apparent to those with working. experience in the art'of profitably drilling foundation holes of the type hereinbefore discussed, there are many occasions when the condition of the earth is such that the carrier 2 must be kept back an unacceptable distance from the site of the drill hole. For example, it may be that the drill hole situs is immediately off of a crumbling bank or a pier or wharf of unstable condition. Irrespective of the reason, however, it will be essential to pitch the cable support portion 14 of the engine 13 as far as possible forward from the center of gravity of the carrier 2 in order to reach the site of the drill hole with the auger I7. 7

There are other cases, of course, when it is not so essential to position the auger 17 any unusual distance forward from the carrier 2, but for various reasons it is desirable to elevate the rotary table as much as possible while rotating the auger 17. For example, it is frequently necessary to drill the foundation hole along a tilted axis rather than in a vertical'direction as is the usual case, and sometimes the angle of tilt is such that the hole is aimed back under the carrier. Accordingly, and as indicated in FIG. 6, the arm extension 78 depicted in FIG. 5 may be altered to form the arm extension 7BB, and this may be accomplished by removing the short dog-leg section 38 and short tubular section 39, and by coupling the long tubular section 40 hereinbefore mentioned to the pistol-grip extension or portion 43 of the special arm section 41. More particularly, the flange 408 at one end of the section 40 may be bolted in a conventional manner to the flange 43A of the special arm section 41, and the flange 40A is then bolted to the flange 9A of the pivot. section 9. Accordingly, the configuration of the special arm section 41 is such that, when the lengthening section 40 is interconnected between the pivot mount section 9 and the branch 43 of the special arm section 41, this will elevate the position of the engine 13 to a greater height than if the special arm section 41 is connected as illustrated in FIG. 5.

In a further modification of the present invention, the arm extension 7 depicted in FIG. 1 may be altered for certain purposes by replacing-the long dog-leg section 8 with the short dog-leg section 38 and either the short lengthening section 39 or the longer lengthening section 40, or both. Thus, a version of the arm extension 7 may be selected which will provide (within limits) an extremely useful variety of heights of the rotary table 18 above the site of the drill hole. Further, it will be apparent that it is a relatively simple matter to assemble an varm extension 7 which is suitable to the hole to be drilled, whereas use of the truss-type arms of the prior art require that the hole be drilled in a manner and at a cost determined by the configuration of the drilling equipment.

Referring to FIG. 7, there may be seen a pictorial representation of another type of arm extension 7C, which may be characterized as a modified form of the arm extension 7 depicted in FIG. 1. More particularly, however, the arm extension 7C may be seen to include a pivot section 31 also having a chisel portion 34 composed of

beveled surfaces

35 and 36 converging to a tubular sleeve portion 33, as hereinbefore explained, and a cylindrical portion having a flange 32 and an eye bracket 37 preferably located on top of the pivot section. The piv'ot section 31 may be connected to the long end of a hollow dog-legsection 58 by

interconnected flanges

32 and 58B, and a fuel tank section 52 may conveniently be coupled to the other shorter portion of the dog-leg section 58 by flanges 58A and 528. Thus, a motor support section 60 is coupled by'flanges 52A and 60A to the other end of the fuel tank section 52.

As further illustrated in FIG. 7, the motor support section 60 may be generally similar to the motor sup port section 12 depicted in FIG. 1,except it is preferably provided with a rest or support bracket 61 under the end opposite the flange60A to support it when the arm extension 7C is lowered to the earth for some purpose such as to repair or to replace either of the cables A and 5B. In addition, two pairs of

eye brackets

48 and 49 may be included for the purpose of attaching an engine (not depicted).

Referring now to the fuel tank section 52, there may be included a conventional fill pipe 53 inserted in itsupper surface, a fuel outlet line 50 which preferably extends to the bottom of the fuel tank 52 and which is adapted at its upper end to be interconnected with an engine (not depicted) on the motor support section 60. In addition, there may be provided a fuel return pipe 51, whereby fuel from the engine may be re-routed to the fuel tank 52 to avoid the necessity of having to discharge it onto the ground. Finally, a suitable drain plug 54 may be installed in the lower portion of the fuel tank section 52.

Referring again to FIG. 7, and in particular to the dog-leg section 58 depicted therein, it may be seen that another rest bracket 62 may conveniently be attached under the end adjacent the flange 588 to protect the extension 7C .if it is removed and deposited on the earth. In addition, it is desirable to provide a walkway 59 or the like, which may be composed of a series of steps leading to a catwalk running along the long and short legs of the dog-leg section 58 and extending past the fuel tank section 52 to the motor support section 60, whereby the operator in the cab 3 may conveniently reach and service the engine 13 if necessary. Accordingly, the operator of the carrier may service any engine equipment mounted on the motor support section 60 without having to stop the drilling operation and removing the auger 17 from the drill hole. Thus, a handrail 57 may also be conveniently installed along the length of the dog-leg section 58.

Referring again to FIG. 7, it should be noted that a triangular brace 55 is preferably installed to strengthen the joint between the long and short legs of the dog-leg section 58. In addition, further support is preferably included in the form of a strengthening patch 56 welded across the joint. Although only one such patch 56 is depicted in FIG. 7. it should be understood that another patch is provided on the opposite side of the dog-leg 58. Furthermore, eye brackets 37 and '63 may be included for the purpose of providing means whereby the arm extension 7C may be lifted and carried about from one location to another.

Various other modifications and alternatives will be apparent which will be within the scope of the present invention. Accordingly, it should be clearly understood that the methods and structures hereinbefore described and illustrated in the accompanying drawings are exemplary only and are not intended as limitations on the scope of the invention.

What is claimed is:

1. In a drilling system for boring a foundation hole at an unstable or otherwise inaccessible drilling location and including i l a carrier adapted to be stationed at a stable location offset from said drilling location,

boring means for drilling said foundation hole,

engine means for rotating said boring means, and

pivot pin means horizontally positioned relative to said drilling location and detachably connected to said carrier,

the improvement in combination therewith comprising an arm extension means for reaching from said carrier to said drilling location, including a hollow pivot member having a cylindrical configuration at one end and a pair of bevel surfaces converging and terminating at the other end to form a sleeve portion slidably receiving said pivot pin and rotatably interconnecting said pivot member with said carrier,

a hollow tube-like engine carrying member detachably supporting and carrying said engine means for driving said boring means, and

a hollow tube-like support member having one end coaxially and detachably interconnected with said "pivot member for pivotal movement about said pivot pin means and having its other end interconnected with said carrying member for supporting said engine and boring means in an operating posture relative to said drilling location.

2. The improvement described in claim 1, wherein one end of said tubular support member joins with the other end thereof at an angle providing said arm extension with a generally dog-leg configuration.

3. The improvement described in claim 2, wherein said one end of said tubular support member is longer than said other end thereof to thereby provide said arm extension means with a dog-leg configuration.

4. The improvement described in claim 3, further.

comprising a cylindrical fuel tank member for containing a supply of liquid fuel for said engine means and coaxially and detachably interconnected between said engine support means and said other shorter end of said tubular support member.

5. The improvement described in claim 4, further comprising a tubular lengthening member coaxially and detachably interconnected between said cylindrical portion of said pivot member and said longer end of said support member for positioning said carrying member at a higher elevation relative to said drilling location.

6. In a drilling system for boring a foundation hole at an unstable or otherwise inaccessible drilling location and including i a carrier adapted to bestationed at a stable location offset from said drilling location,

. boring means for drilling said foundation hole,

engine means for rotating said boring means, and pivot pin means horizontally positioned relative to said drilling location and detachably connected to said carrier,

a hollow carrying member having a generally cylindrical body portion for carrying said engine means in a position for drivingsaid boring means and having a cylindrical branch portion obliquely diverging from said body portion at a location between the ends of said body portion thereof, and hollow tube-like support member having one end coaxially and detachably interconnected with said pivot member and having its other end coaxially and detachably interconnected with said hollow carrying member.

7. The improvement described. in claim 6, wherein said support member is axially and detachably connected at its other end to the branch portion of said carrying member. 1

8. The improvement described in claim'6, wherein said support member is axially and detachably connected at its other end to said body portion of said carrying member.

9. The improvement described in claim, 8, wherein said support member; has a dog-leg configuration with one end longer than its other end.

10. The improvement described in claim 9, wherein said support member is connected at its shorter end to said longer end of said support member is detachably fastened to said cylindrical portion of said pivot memher for positioning said body portion of said carrying member at a relatively lower elevation above said drilling location.

13. An arm extension assembly for reaching a drilling location spaced laterally from a base location, comprising a hollow pivot link member having a cylindrical configuration atone end and converging bevel surfaces at the other end terminating to form a sleeve pivotally securable at said base location, a hollow tube-like carrying member-adapted to be disposed adjacent said drilling location, and a hollow tube-like support member having one end coaxially and detachably interconnected with said cylindrical end of said pivot link 'member and having its other end detachably and coaxially interconnected with said carrying member. 14. In a system for drilling a foundation hole and comprising a carrier positionable at a base location, rotatableboring means for drilling a borehole in the earth at a drilling location spaced laterally from said base location, an engine or the like for rotating said boring means, and pivot pin means detachably linked in a horizontal 'manner with said carrier at a position between said base and drilling locations,

an improved arm assembly for interconnecting said engine and boring means with said carrier and pin means, including a hollow chisel-like linking member having'a cylindrical configuration at one end and a pair of bevel surfaces at the other end converging and terminating at a sleeve-like portion pivotally attachable to said pin means on said carrier means,

a hollow tube-like extension member having one end coaxially and detachably locked to said cylindrical end of said linking member,

a hollow support member having a cylindrical body portion having two pair of aligned eye-like brackets detachably linkable with said engine means and having a cylindrical branch portion obliquely and divergingly extending from said body portion from a point between the end of said body portion, and

' a hollow cylindrical angle member having a longer end portion detachably and coaxially matable with the other end of said extension member and having a shorter end portion detachably and coaxially matable with said body portion of said support member for spacing said engine means at a relatively farther distance from said base location and at a relatively shorter elevation above said drilling location,

said branch member also being detachably and coaxially matable with said other end of said extension member for spacing said engine means at a relatively nearer distance from said base location and at a relatively higher elevation above said drilling location.

Claims

1. In a drilling system for boring a foundation hole at an unstable or otherwise inaccessible drilling location and including a carrier adapted to be stationed at a stable location offset from said drilling location, boring means for drilling said foundation hole, engine means for rotating said boring means, and pivot pin means horizontally positioned relative to said drilling location and detachably connected to said carrier, the improvement in combination therewith comprising an arm extension means for reaching from said carrier to said drilling location, including a hollow pivot member having a cylindrical configuration at one end and a pair of bevel surfaces converging and terminating at the other end to form a sleeVe portion slidably receiving said pivot pin and rotatably interconnecting said pivot member with said carrier, a hollow tube-like engine carrying member detachably supporting and carrying said engine means for driving said boring means, and a hollow tube-like support member having one end coaxially and detachably interconnected with said pivot member for pivotal movement about said pivot pin means and having its other end interconnected with said carrying member for supporting said engine and boring means in an operating posture relative to said drilling location.

4. The improvement described in claim 3, further comprising a cylindrical fuel tank member for containing a supply of liquid fuel for said engine means and coaxially and detachably interconnected between said engine support means and said other shorter end of said tubular support member.

6. In a drilling system for boring a foundation hole at an unstable or otherwise inaccessible drilling location and including a carrier adapted to be stationed at a stable location offset from said drilling location, boring means for drilling said foundation hole, engine means for rotating said boring means, and pivot pin means horizontally positioned relative to said drilling location and detachably connected to said carrier, the improvement in combination therewith comprising an arm extension means for reaching from said carrier to said drilling location, including a hollow pivot member having a cylindrical configuration at one end and a pair of bevel surfaces converging and terminating at the other end to form a sleeve portion slidably receiving said pivot pin and rotatably interconnecting said pivot member with said carrier, a hollow carrying member having a generally cylindrical body portion for carrying said engine means in a position for driving said boring means and having a cylindrical branch portion obliquely diverging from said body portion at a location between the ends of said body portion thereof, and a hollow tube-like support member having one end coaxially and detachably interconnected with said pivot member and having its other end coaxially and detachably interconnected with said hollow carrying member.

7. The improvement described in claim 6, wherein said support member is axially and detachably connected at its other end to the branch portion of said carrying member.

8. The improvement described in claim 6, wherein said support member is axially and detachably connected at its other end to said body portion of said carrying member.

9. The improvement described in claim 8, wherein said support member has a dog-leg configuration with one end longer than its other end.

10. The improvement described in claim 9, wherein said support member is connected at its shorter end to said body portion of said carrying member and interconnected by its longer end with said pivot member.

11. The improvement described in claim 10, further including a tubular lengthening member coaxially and detachably fastened at one end to said cylindrical portion of said pivot member and at the other end to said longer end of said support member for positioning said body portion of said carrying member at a relatively higher elevAtion above said drilling location.

12. The improvement described in claim 10, wherein said longer end of said support member is detachably fastened to said cylindrical portion of said pivot member for positioning said body portion of said carrying member at a relatively lower elevation above said drilling location.

13. An arm extension assembly for reaching a drilling location spaced laterally from a base location, comprising a hollow pivot link member having a cylindrical configuration at one end and converging bevel surfaces at the other end terminating to form a sleeve pivotally securable at said base location, a hollow tube-like carrying member adapted to be disposed adjacent said drilling location, and a hollow tube-like support member having one end coaxially and detachably interconnected with said cylindrical end of said pivot link member and having its other end detachably and coaxially interconnected with said carrying member.

14. In a system for drilling a foundation hole and comprising a carrier positionable at a base location, rotatable boring means for drilling a borehole in the earth at a drilling location spaced laterally from said base location, an engine or the like for rotating said boring means, and pivot pin means detachably linked in a horizontal manner with said carrier at a position between said base and drilling locations, an improved arm assembly for interconnecting said engine and boring means with said carrier and pin means, including a hollow chisel-like linking member having a cylindrical configuration at one end and a pair of bevel surfaces at the other end converging and terminating at a sleeve-like portion pivotally attachable to said pin means on said carrier means, a hollow tube-like extension member having one end coaxially and detachably locked to said cylindrical end of said linking member, a hollow support member having a cylindrical body portion having two pair of aligned eye-like brackets detachably linkable with said engine means and having a cylindrical branch portion obliquely and divergingly extending from said body portion from a point between the end of said body portion, and a hollow cylindrical angle member having a longer end portion detachably and coaxially matable with the other end of said extension member and having a shorter end portion detachably and coaxially matable with said body portion of said support member for spacing said engine means at a relatively farther distance from said base location and at a relatively shorter elevation above said drilling location, said branch member also being detachably and coaxially matable with said other end of said extension member for spacing said engine means at a relatively nearer distance from said base location and at a relatively higher elevation above said drilling location.