Earth Boring Apparatus

1. Field of the Invention

This invention generally relates to improvements in earth boring apparatus, and more particular, to an attachment for use with a backhoe in boring shallow depth, substantially horizontal holes through the earth.

2. Description of the Prior Art

As is well known in the installation of utility services, it is frequently necessary or desirable to extend service transmission lines at shallow depths beneath the surface of the earth underneath sidewalks, driveways and the like. Various types of devices have been devised in the past for forming horizontally extending bores through the earth, but most of these prior art devices are complicated, cumbersome to use and expensive as such devices have been designed to be affixed directly to the boom of a vehicular means such as a backhoe. Such structures require specially designed attaching means wherein the bucket must be removed from the boom for attaching the boring devices thereto.

Accordingly, it is desirable to produce a boring attachment, that includes a earth boring device, which is easily connected to the bucket of a backhoe or the like.

As contemplated by the invention, an earth boring apparatus is directly connectable to a conventional backhoe bucket and generally includes a rotatably driven auger, means for driving the auger and means for detachable securing the driving means to the bucket. More specifically, the means for detachable securing the driving means to the bucket includes a frame means which is adapted to be rigidly secured to the bucket.

In one embodiment, the frame means includes an upper portion which is adapted to snugly engage the marginal reinforcing flanges surrounding the walls defining the opening of the backhoe bucket and the back surface of the bucket teeth for providing a stiff, rigid extension on which the driving means is detachably mounted. An elongate rod extending across the upper frame portion, projects through apertures provided in the side walls of the bucket and the upper portion for rigidly locking the frame means to the bucket.

In another embodiment, the frame means includes an upper horizontal plate for contacting the outer curvature of the bucket. A pair of positionable hooks are pivotablly mounted along one side of the plate for engaging the cutting edge of the bucket between the teeth. A length of chain is anchored to one corner on the opposed side of the plate. The chain is passed through a tensioning device mounted on the pin attaching the piston rod of the actuating cylinder to the bucket. The free end of the chain is detachably secured to the other corner of the opposed side. By this structural arrangement, the frame means may be quickly and securely attached to the backhoe bucket.

In both embodiments a surface engaging skid, affixed to the lower end of the frame means, supports the frame, driving means and auger from the bottom surface of a hole provided for producing the subsurface, horizontally extending bore in the earth. The means for detachable mounting the driving means to the frame means includes a plate which directly absorbs thrust loads produced by the driven auger and transmits such loads to the frame.

The above as well as other objects of the invention will become readily apparent to one skilled in the art from reading the following detailed description of the preferred embodiments of the invention when considered in the light of the accompanying drawings in which:

FIG. 1 is a perspective view illustrating the earth boring attachment attached to the bucket of a backhoe in accordance with the present invention;

FIG. 2 is an enlarged, exploded perspective view of the earth boring attachment illustrated in FIG. 1;

FIG. 3 is a partial cross-sectional view of the power drive unit taken substantially along line 3--3 of FIG. 2;

FIG. 4 is an exploded perspective view of another embodiment of the earth boring attachment;

FIG. 5 is a partial cross-sectional view of the power drive unit illustrated in FIG. 4 and taken substantially along line 5--5 thereof;

FIG. 6 is a partially exploded perspective of another embodiment of an earth boring attachment;

FIG. 7 is an enlarged fragmentary perspective view of the lower portion of the tensioning device; and

FIG. 8 is a side elevational view illustrating the frame means attached to a bucket shown in phantom.

Referring now to FIG. 1, wherein like reference numerals designate similar parts throughout, there is illustrated an earth boring apparatus 10 adapted to be detachably secured to a bucket 12 of a conventional backhoe (not shown) or like vehicular means, as it would appear in actual use. As illustrated therein, the earth boring attachment 10 is detachably secured to the bucket 12 which is pivotally mounted on the end of a boom 14. The attitude and reach of the bucket 12 is adjusted by an actuating cylinder 16. Accordingly, the position of the earth boring apparatus 10 is controlled by movement of the bucket 12 and is primarily employed in boring horizontally extending holes such as hole 18 at a desired shallow depth beneath a driveway 20 or the like, for placing cables and etc. below the surface of the earth.

Referring particularly to FIG. 2, the earth boring apparatus 10 generally includes a vertically disposed, frame means 22 (preferably a weldment structure) having a lower surface engaging skid 24, a pair of rectangularly shaped upright members 26 and 26a affixed to the mid section of the skid 24 and bucket attaching means 28 affixed to the upper ends of the members 26 and 26a. More specifically, the attaching means 28 includes a horizontally extending web 30 affixed, in a symmetrical manner, to the upper ends of the upright members 26 and 26a. A pair of spaced apart vertically extending members 32 and 32a are respectively affixed to the ends of the web 30 for forming a U-shaped configuration. An abutment flange 34 extends along one marginal edge of the web 30 and a pair of vertically extending abutment flange 36 and 36a respectively extend along the adjacent marginal edge of each vertical member 32 and 32a, the purpose of which will be described hereinafter.

As is conventional in the construction of earth scooping buckets, the bucket 12 includes spaced digging teeth 12a extending along one edge and stiffening flanges 12b extending around the open, marginal side edges of the bucket 12. Accordingly, the spacing between the inner facing surfaces of the vertical members 32 and 32a and the thicknesses of the flanges 34, 36 and 36a is designed to correspond to the spacing between the opposite outside surfaces of the side wall bucket flanges 12b and the thicknesses of the bucket teeth 12a and stiffening flanges 12b, respectively. In this manner, the flanges 34, 36 and 36a will abut the adjacent back surfaces of the bucket teeth 12a and the bucket flanges 12b when the frame means 22 is mounted thereon. The frame means 22 is secured to the bucket 12 by an elongate rod 23 extending through aligned apertures 25 and 25a provided in each vertical member of the attaching means 28 and the side walls of the bucket 12, respectively. The rod 23 is held in assembled relation thereto by lock pins 27 extending through holes 23a provided in each end of the rod 23.

A motor, such as a hydraulic motor 38 or the like, is detachably mounted at the bottom portion of the frame means 22 adjacent the skid 24 and is connected to a source of fluid power provided by the backhoe tractor (not shown) by the way of fittings 40 and 40a and hoses 42 and 42a respectively, extending along the boom 14 (see FIGS. 1 and 2). The motor 38 is secured to a mounting plate 44 by a plurality of cap screws 46 (only one shown in FIG. 2). The opposite vertical marginal edges of the mounting plate 44 are telescopically received in opposed vertically disposed guideways 48 and 48a each defined by pairs of spaced upright bar members 50 affixed to the inner facing surfaces of the upright plates 26 and 26a adjacent the skid 24. It will be noted that mounting plate 44 may be pushed or pulled by the frame 22 and can be removed from the guideways and reversed for producing the bore hole 18 in either axial direction.

As best illustrated in FIG. 1, an earth boring auger 52 having multiple segments 52a, 52b and 52c, but not limited to that number, is coupled to the driven output shaft of the motor 38 by a direct drive coupling 54. The direct drive coupling 54 is mounted on the face opposite the face on which the motor 38 is mounted (See FIGS. 2 and 3) by cap screws 56.

Referring to FIG. 3, the direct drive coupling 54 includes an externally splined output shaft 58 journalled for rotation in spaced taper roller bearings 60 and 60a mounted in an annular housing 62. The end of the output shaft 58, contained within the housing 62, is provided with a bore 58a for receiving the output shaft 38a of the motor 38. A key (not shown) disposed in the motor shaft 38a and seated in a keyway 58e provided in the bore 58a, locks the spline shaft 58 thereto for rotation. It will be noted that the shaft 38a is spaced from the bottom of the bore 58a so that no axial thrust loads can be transmitted between the motor 38 and the coupling 54. The output shaft 58 is provided with an enlarged portion 58b whose opposed faces 58c and 58d each seat one of the taper bearings 60 and 60a, respectively. A retainer 68 secured to the annular housing 62 as by cap screws 66, has a portion abutting the bearing 60 and secures the assembly against the mounting plate 44. An O-ring seal 70 disposed within an internal groove 68a provided in the retainer 68 prevents the ingress of dirt into and egress of lubricant from the coupling 54.

In the embodiment of the earth boring apparatus 10' illustrated in FIG. 4, the structure of the frame means 22' is substantially the same as the structure of the frame means 22 previously described. The frame means 22' only differs in two respects, one is the top marginal edge of each vertical member 32' and 32a' of the attaching means 28' is outwardly flared as at 33, for guiding the bucket 12 into the means 28'. In the other respect, the guideways 48 and 48a are replaced by horizontally extending, vertically spaced bars 78 and 80, the purpose of which will be described hereinafter.

A hydraulic motor 38' and a coupling 54' are commonly affixed on the outer face of a box type housing 72 secured, as by cap screws 74, to a mounting plate 44', one above the other. The opposite face of the mounting plate 44' is provided with two pairs of spaced downwardly depending hook members 76 and 76a which cooperate with the horizontally disposed bars 78 and 80 respectively, extending between an affixed to the inner surfaces of the upright plates 26 and 26a of the frame means 22'. A locking pin 82 is received in aligned apertures 44" and 80a provided in the mounting plate 44' and the frame bar 80 respectively, for locking the members together. In most other respects, the boring apparatus 10' is the same as previously described for the boring apparatus 10.

Referring now to FIG. 5, the motor 38' drivingly rotates the coupling 54' through intermeshing gears 84 and 86 keyed to the output shaft 38" of the motor 38' and an extending portion 58" of the output shaft 58', respectively. However, other types of suitable drive mechanisms may be substituted for the intermeshing gears 84 and 86.

Referring now to FIGS. 6 through 8, there is illustrated an earth boring apparatus 110 which is substantially the same as the embodiment shown in FIG. 2 except for the bucket attaching means 128. Accordingly, only the bucket attaching means 128 will be described as the previous description and reference numbers employed for the embodiment illustrated in FIG. 2 will suffice for the similar elements.

As illustrated, the bucket attaching means 128 includes a horizontally disposed, rectangular plate 130 having depending side flanges 132 and 132a extending along the opposite sides 130a and 130b, respectively. The mid portion of the plate 130 is affixed, in a symmetrical manner, to the upper ends of the upright members 26 and 26a.

Two spaced hooks 134 and 134a are pivotally mounted on a transversely extending rod 136. The rod 136 is mounted at one end 130c of the plate 130 in brackets 138 and 138a projecting beyond the flanges 132 and 132a, respectively. Each hook 134 and 134a is slidable along the rod 136 and each is provided with a V-shaped notch 140 for engagement with the cutting edge of the bucket 12 between the teeth 12a (see FIG. 8).

A length of chain 142 is provided at the opposite end 130d of the plate 130 for attaching the frame means to the bucket 12. More particularly, one end of the chain 142 is anchored as at 142a to a bracket 144 extending beyond the rail 132. A chain hook 146 is attached, as at 146a, to a bracket 144a extending beyond the flange 132a.

As best illustrated in FIG. 8, a curl pin hook device 148 is provided for securing the apparatus 110 to the bucket 12. Referring now to FIG. 6, the hook device 148 includes a pair of hooks 150 and 150a pivotally mounted on a rod 152. Locking pins 154 (only one shown) are provided at the ends of the rod 152 for retaining the hooks on the rod. Each hook 150 and 150a is provided with a notch 156 for engagement with a curl pin 158 conventionally forming part of the bucket operating mechanism.

An eye bracket 160 provided with a pad 160a, is dependingly mounted on an elongated threaded member 162 slidably passing through the rod 152. The member 162 is moved relative to the rod 152 by a nut 164 normally seated against a washer 166.

In attaching the apparatus 110 to the bucket 12, the curved portion of the bucket is first set on the plate 130. Next the hooks 134 and 134a are moved to a position between the bucket teeth 12a to engage the cutting edge of the bucket. The curl pin device 148 is then attached to the bucket's curl pin 158 where it is free to pivotally move. The chain 142 is then passes through the eye bracket 160 and pulled taut until the curved portion of the bucket snugly engages the plate 130 as well as the pad 116a of the eye bracket 160. The free end of the chain is secured by the hook 146. The nut 164 is then tightened drawing up the eye bolt 160 and tensioning the chain 142 until the apparatus 110 is rigidly attached to the bucket.

One of the advantages of the afore-described coupling structure mounting is that axial thrust loads are accommodated by the coupling and transmitted directly to the plate and frame means without transmitting such loads to the motor. Accordingly, the useful life of the earth boring apparatus is substantially increased before repairs or replacement of the components may be repaired.

In use, the earth boring apparatus is capable of being readily positioned in a relatively short, shallow trench such as illustrated in FIG. 1, adjacent the driveway 20 under which the bore hole 18 is to be formed. In operation, the rotatably driven earth auger 52 is moved forwardly or rearwardly, as the case may be, by manipulation of boom 14 of the bucket operating mechanism. When the auger section 52a is fully extended into the bore hole 18, it is uncoupled from the coupling output shaft 58 and an additional length of shaft such as the section 52b is added. Then, the boring cycle is continued until the desired length of the bore hole 18 is achieved.

In accordance with the provisions of the patent statutes, the principles and mode of use of the invention has been explained and what is considered to represent its preferred embodiments have been illustrated and described. It should, however, be understood that the invention may be practiced otherwise and as specifically illustrated and described without departing from its spirit and scope.