Apparatus for Directing Forward Movement of a Rod

The present invention relates to apparatus employed to direct forward movement of a rod as it is pushed through a loose medium such as the ground. More particularly, the present invention relates to a directing apparatus having the versatility to direct or not to direct the movement to increase the efficiency of the movement. For convenience, the term "rod" as used herein refers to both a solid shaft or a hollow pipe and is not intended to be limited to any particular type of rod or pipe.

It is well known to push a rod through the ground from one location to another predetermined location beneath the surface of the ground. For example, a rod may be pushed under a road from one side of the road to the other side without creating a trench in the road. As a rod is pushed through a loose medium such as the ground, it encounters variations in density of the medium and may encounter obstacles which cause the rod to deviate from the intended course or path which would result in it arriving at its predetermined destination. It is therefore necessary to correct the forward movement of the rod to bring it back onto the course of movement needed to have the rod arrive at its predetermined destination.

Generally speaking, apparatus for directing forward movement of a rod through a loose medium such as the ground beneath the surface of the ground are known in the art. Typically, these known devices have a directional tip which is fixed in a directing position such that the forward movement of the rod is continuously being directed. In these prior devices, there is no way to disengage or disable the directional feature without removing the entire rod from the ground and removing the directing apparatus from the end of the rod. The removal of a long length of rod from the ground and reinsertion is a time-consuming operation. Therefore, when these prior devices are used, the operator of the pushing apparatus must continuously change direction of the movement of the rod in order to try to effect movement of the rod along a desired path or course. Because the rod is continuously being directed, the continuous changes result in a zig-zag pattern of movement as the rod is pushed through the ground.

As will become apparent from the following disclosure, the apparatus of the present invention includes various features which provide the versatility of either directing the forward movement of the rod or not directing such movement to improve the efficiency of the overall operation of pushing rod through a loose medium such as the ground.

One object of the present invention is to provide an apparatus for directing forward movement of a rod having both the capability of directing the forward movement of the rod or not directing the forward movement of the rod.

Another object of the present invention is to provide an apparatus for directing the forward movement of a rod which permits the rod to be pushed in a straight direction or in a plurality of directions other than the straight direction without withdrawing the rod from the ground and removing the directing apparatus from the end of the rod. Accordingly, the apparatus of the present invention improves the efficiency of movement of the rod along a desired course or path required for the rod to arrive at its predetermined destination.

It is a further object of the present invention to provide a way to direct a fluid such as water or drilling mud into the loose medium in the direction of the forward movement of a rod to condition the loose medium in front of the rod and thereby facilitate the movement of the rod.

Yet another object of the present invention is to provide a directing member that is coupled at the distal end of the directing apparatus so that when it is enabled the leading portion extends beyond the longitudinal plane defined by the outer surface of the directing apparatus to facilitate circumvention of a solid obstacle in the ground.

According to the present invention, an apparatus for directing the forward movement of a rod as it is moved through a loose medium includes a first member having a proximal end and a distal end, a second member sleeved onto the first member so that the first member is movable relative to the second member, the second member also having a proximal end and a distal end, a directing member provided on either the first member or the second member but in the preferred embodiment, provided on the first member, a connector for coupling the proximal end of the first member to the rod, drive-engaging means on both the first and second members which cooperate to provide driving engagement between the first and second members wherein the directing member is disabled in a first driving position and the directing member is enabled in a second directing position and control means for controlling the disengagement and engagement of the drive-engaging means selectively to permit forward movement of the rod in a desired direction as the rod is being moved through the loose medium.

A further feature of the present invention is that the apparatus for directing forward movement of the rod further includes a first fluid passageway in the first member for transmitting fluid from the proximal end of the first member to the distal end of the first member, a first nozzle means for dispensing the fluid into the loose medium in the direction of the forward movement of the rod when the directing member is disabled, and a second nozzle means for dispensing fluid into the loose medium in the direction of forward movement of the rod when the directing member is enabled. In the preferred embodiment, the first nozzle means includes a first valve means for closing the first nozzle means when the directing member is enabled and for opening the first nozzle means when the directing member is disabled. Further, the second nozzle means includes a second valve means for closing the second nozzle means when the directing member is disenabled and for opening the second nozzle means when the directing member is enabled. The first valve means includes a sealing means and bypass means for bypassing the sealing means when the directing member is disabled.

Another feature of the present invention is that the directing member is coupled to the first member so that when the directing member is enabled the leading portion extends beyond the longitudinal plane defined by the outer surface of the second member to engage the loose medium surrounding the second member to facilitate movement around an obstacle.

Other objects, features, and advantages of the present invention will become apparent to those skilled in the art from the following detailed description of preferred embodiments thereof exemplifying the best mode of carrying out the invention as presently perceived.

The detailed, description particularly refers to the accompanying figures in which:

FIG. 1 is a perspective view of the apparatus for directing forward movement of a rod through a loose medium constructed according to the present invention;

FIG. 2 is an exploded fragmentary view of the apparatus shown in FIG. 1 showing in detail the drive-engaging and control assemblies of the present invention;

FIG. 3 is a cross-sectional view of the apparatus shown in FIG. 1 taken generally along section lines 3--3 of FIG. 1;

FIG. 4 is a longitudinal transverse view of the apparatus shown in FIG. 1 showing the directing member of the apparatus in its disabled position;

FIG. 5 is a longitudinal transverse view of the apparatus shown in FIG. 1 showing the position of the control assembly for disengaging the drive-engaging assembly and permitting the directing member to be

FIG. 6 is a longitudinal transverse view of the apparatus shown in FIG. 1 showing the directing member in its enabled position;

FIG. 7 is a fragmentary transverse view of another embodiment of the apparatus shown in FIG. 1 including apparatus for transmitting and dispensing a fluid in the direction of forward movement of the rod;

FIG. 8 is a fragmentary transverse view of the embodiment of the apparatus shown in FIG. 7 showing the directing member in its enabled position with fluid being dispense the direction of movement of the rod;

FIG. 9 is a transverse view of the distal end of the apparatus of FIG. 7 showing operation of the valve assemblies when the directing member is disabled and when the directing member is enabled;

FIG. 10 is a longitudinal transverse view of another embodiment of an apparatus for directing forward movement of a rod through a loose medium constructed according to the present invention showing the directing member of the apparatus in its disabled position;

FIG. 11 is a longitudinal transverse view of the apparatus shown in FIG. 10 showing the position of the control assembly for disengaging the drive-engaging assembly and permitting the directing member to be enabled;

FIG. 12 is a longitudinal transverse view of the apparatus shown in FIG. 10 showing the directing rod in its enabled position;

FIG. 13 is a longitudinal transverse view of another embodiment of an apparatus for directing forward movement of a rod through a loose medium constructed according to the present invention showing the directing member of the apparatus in its disabled position;

FIG. 14 is a longitudinal transverse view of the apparatus shown in FIG. 13 showing the position of the control assembly for disengaging the drive-engaging assembly and permitting the directing member to be enabled;

FIG. 15 is a longitudinal transverse view of the apparatus shown in FIG. 13 showing the directing member in its enabled position;

FIG. 16 is a fragmentary transverse view of another embodiment of a drive-engaging assembly for the embodiments of the apparatus shown in FIGS. 10-15;

FIG. 17 is an exploded view of an embodiment of a pivotal directing member for use with the apparatus shown in FIGS. 1-12;

FIG. 18 is a transverse view of the distal end of the apparatus shown in FIG. 1-12 showing an apparatus for directing forward movement constructed according to the present invention showing operation of the pivotal directing member in its disabled and enabled positions;

FIG. 19 is a transverse view of a section of loose medium showing an apparatus for directing forward movement constructed according to the present invention with a pivotal directing member in its disabled position encountering an obstacle; and

FIG. 20 is a transverse view of a section of loose medium showing the apparatus in FIG. 19 with the pivotal member in its enabled position circumventing an obstacle.

In general, the apparatus of the present invention has a high degree of versatility and efficiency otherwise not associated with conventional rod-directing apparatus. As will be described in more detail hereinafter, use of the present invention permits the operator to push a rod selectively in a straight direction or in a plurality of desired directions other than the straight direction without removing the rod from the loose medium through which it is being moved.

Referring now to FIG. 1, there is shown an apparatus 10 for directing the forward movement of a rod 12 as it is moved through a loose medium such as the ground (not shown) beneath the surface of the medium. The rod 12 is typically pushed through the ground using a rod pusher or presser 20 to cause forward movement 22 of the rod 12. These rod pushers or pressers 20 also are capable of rearward movement 23 of the rod 12. The rod pusher or presser 20 may be of the type disclosed in U.S. Pat. No. 4,368,873, issued Jan. 18, 1983, and entitled VEHICULAR MOUNTED PIPE PRESSER or it may be of the type identified as Model P40 or P80 Rod Pusher, manufactured by The Charles Machine Works, Inc., Perry, Okla.

It is known to employ a power-driven apparatus 24 for rotating the rod 12 in a counterclockwise direction 26 or a clockwise direction (not shown). For example, a power-driven apparatus of the type disclosed in U.S. Pat. No. 4,333,365, issued June 8, 1982, and entitled POWER PIPE TONGS, may be employed for rotating the rod 12. The power-driven apparatus 24 may either be mounted on the rod pusher 20 or provided separately from the rod pusher 20.

It should be understood that the present invention is also adaptable to other well-known pipe-handling mechanisms and apparatus for rotating the rod 12, and therefore, its use and operation is not intended to be limited to the particular pipe-handling mechanism 20 and power-driven apparatus 24 shown in FIG. 1 or the type described above for illustrative purposes. Specifically, the rod 12 may be manually rotated by using a wrench or other hand-held device for gripping the pipe or, in some instances, rotated simply by hand. Any pipe-handling mechanism or pipe-rotating device could be employed without departing from the scope of the present invention.

When a rod 12 is pushed through the ground, the operator of the pipe pusher 20 is usually pushing the rod 12 to a predetermined location where the rod 12 is supposed to exit from the ground. In order to exit at the predetermined location, the rod 12 must follow a particular course or path through the ground. In order to know whether the rod 12 is moving along the desired course or path, it is necessary to monitor the forward movement 22 of the rod 12 through the ground. For this purpose, it is well known to employ a locating system 30 such as the model RD300 transmitter locator sold by The Charles Machine Works, Inc., Perry, Okla. These locating systems 30 include a transmitter 32 (see FIG. 4) located on or in the distal end of the rod 12 for transmitting a signal 34 from beneath the surface of the ground to a receiver 36 above the surface of the ground. These locating systems 30 work to various depths and give the operator both the location and depth of the rod 12.

Continuing to refer to FIG. 1, the rod-directing apparatus 10 of the present invention includes a first member 40 which is an elongated shaft having a proximal end 42 and a distal end 44. The proximal end 42 includes threads 46 (see FIG. 2) for coupling the first member 40 to the rod 12. The rod 12 also includes threads (not shown). A coupler 48 having internal threads (not shown) is used to connect the first member 40 to the rod 12.

The rod-directing apparatus 10 of the present invention also includes a second member 50 which is an elongated hollow pipe having a proximal end 52 and a distal end 54. The second member 50 is sleeved onto the first member 40 so that the first member 40 is slidably received in the second member 50. As will be explained later, the first member 40 is movable relative to the second member 50 in response to both forward movement 22 and rearward movement 23 of the rod 12. In the illustrative embodiment, both the first member 40 and the second member 50 are shown to be cylindrical, but it should be understood that the members 40, 50 do not need to be cylindrical and could be another shape without departing from the scope of the present invention.

One or more elongated slots 56 may be cut in the wall of the second member 50 to facilitate passage of the signals 34 from the transmitter 32 through the second member 50. The slots 56 are filled with a signal transmitting material 58 which will permit signals generated by the transmitter 32 to pass through it. Such material could be a plastic or epoxy material. The slots 56 are filled to prevent the loose medium from clogging the slots 56 as the rod 12 is pushed through the ground. In the preferred embodiment, the first member 40 and the second member 50 are constructed from steel. The steel could be a stainless steel or could be coated with a non-corrosive coating to prevent corrosion from moisture in the ground. However, it will be understood that the composition of the first and second members 40, 50 is not a feature of the present invention and that any strong non-corrosive material, could be used without departing from the scope of the present invention.

Referring to FIGS. 1 and 4-6, the distal end 44 of the first member 40 has a cavity 60 formed therein and an opening 62 communicating with the cavity 60 for placement and location of the transmitter 32. The opening 62 is internally threaded (not shown) for attaching a directing member 70 to the distal end 44 of the first member 40. The directing member 70 includes a threaded portion 72 for attaching the directing member 70 to the distal end 44 of the first member 40. The directing member 70 is generally cylindrical and is cut diagonally to provide a sloped or inclined surface 74 which is generally elliptical in shape. In operation, the sloped surface 74 engages the loose medium or ground 76 to direct the rod-directing apparatus 10 and rod 12 in the direction of the slope of the surface 74 in response to forward movement 22 of the rod 12.

Referring to FIGS. 2 and 3, a radially outwardly opening chamber 80 is formed in the first member 40 for receiving a drive assembly 90. The chamber 80 is generally cylindrical and includes a reduced portion 82 of the first member 40. A bore 84 is formed in the reduced portion 82 of the first member 40. Two bosses 86 are provided on the external surface of the first member 40 adjacent the chamber 80 in diametrically opposed relationship. Two keyways 88 are formed in a wall 89 of the chamber 80 and extend radially outwardly through the bosses 86.

The drive assembly 90 includes two drive shoulders 92, 94 positioned in the chamber 80. Each drive shoulder 92, 94 includes an elongated key 96 which is received in one of the keyways 88 to align the drive shoulders 92, 94 in the chamber 80. The drive shoulders 92, 94 are biased radially outwardly from the chamber 80 by one or more helical springs 98 which are contained in the bore 84 in the reduced portion 82 of the first member 40.

Each of the drive shoulders 92, 94 includes an axially facing side wall 100 on the opposite side of the key 96 providing an axially facing drive surface. Each drive shoulder 92, 94 also includes an arcuate bottom surface 102 having a substantially semicircular shape to receive the reduced portion 82 of the first member 40 when the drive shoulders 92, 94 are compressed against the spring 98 into the chamber 80. The arcuate surfaces 102 include a retainer cup 104 for retaining the spring 98. Each drive shoulder 92, 94 includes two cam followers 110 on opposite sides of the drive shoulder 92, 94. The cam followers 110 extend radially outwardly providing cam surfaces 112 which are slightly inclined or sloped as shown in FIG. 2.

Referring now to particularly to FIG. 3, the second member 50 has formed on its inner surface an annular ridge 120 providing an axially facing drive face 22. The second member 50 also has formed on its inner surface another annular ridge 124 in longitudinal spaced relationship to the annular ridge 120. Annular ridge 124 provides another axially facing drive face 126 on the inner surface of second member 50. As shown in FIGS. 3 and 4, annular ridge 120 is closest to the proximal end 52 of second member 50 and annular ridge 124 is spaced longitudinally therefrom in the direction of the distal end 54. Further, a ramp 128 is provided on the inner surface of the second member 50 between the ridges 120 and 124. The ramp 128 extends radially inwardly from a radially outer point of ridge 124 to a radially inner point of ridge 120 as shown in FIG. 4. The purpose of ramp 128 will become apparent in the description of the operation of apparatus 10.

The drive shoulders 92, 94 are biased radially outwardly from the first member 40 by spring 98 toward the inner surface of second member 50 to engage the drive faces 122 and 126. When drive shoulders 92, 94 are engaging a drive face 122, 126, the second member 50 is driven simultaneously with first member 40 through the loose medium 76 in response to forward movement 22 of rod 12. As shown in FIG. 2, a control mechanism 130 is carried on first member 40 and frictionally engages first member 40. The frictional engagement is such that first member 40 is movable relative to control mechanism 130 when movement of control mechanism 130 is limited or stopped. Control mechanism 130 controls the engagement and disengagement of the drive shoulders 92, 94 with the drive faces 122, 126 in a manner which will be explained later.

Referring to FIG. 2, the control mechanism 130 includes an annular ring 132 sleeved onto the first member 40. As will be explained later, annular ring 132 cooperates with the second member 50 to limit or stop movement of the control mechanism 130 to permit the first member 40 to move relative to the control mechanism 130. A cylindrical portion 134 of control mechanism 130 extends longitudinally from the annular ring 132. The cylindrical portion 134 is slightly tapered radially inwardly from the ring 132 toward its distal end 136 to provide frictional contact with the outer surface of first member 40. The cylindrical portion 134 includes two diametrically opposed generally rectangular shaped openings 138 which are elongated and open at the distal end 136 to receive bosses 86 on the external surface of first member 40 when the control mechanism is sleeved onto the first member 40. As will be noted more particularly in the description of the operation of the control mechanism 130, the longitudinal length of the cylindrical portion 134 is substantially equivalent to the longitudinal spacing between ridges 120 and 124 on the inner surface of the second member 50. The cylindrical portion 134 also includes two diametrically opposed tapered openings 140 which are elongated and open at the distal end 136 to receive the cam followers 110 on the drive shoulders 92, 94. Each tapered opening 140 includes diametrically opposed cam surfaces 142 for engaging the cam surfaces 112 of the cam followers 110 on the drive shoulders 92, 94. As shown in FIG. 2, the greatest spacing between the cam surfaces 142 in a tapered opening 140 is at the distal end 136 and the spacing becomes narrower toward the ring 132 Cam followers 110 follow cam surfaces 142 in response to movement of the first member 40 relative to the control mechanism 130 to move drive shoulders 92, 94 radially inwardly against the spring 98 and to permit radially outward movement of drive shoulders 92, 94 in response to the bias of spring 98. This action controls the engagement and disengagement of shoulders 92, 94 with drive faces 122, 126.

The operation of the rod-directing apparatus 10 can best be explained by referring to FIGS. 4, 5, and 6. In FIG. 4, rod-directing apparatus 10 is shown with the directing member 70 disabled and the first member 40 in driving engagement with the second member 50 (through drive shoulders 92, 94 and drive face 122) so that in response to forward movement 22 of rod 12, rod-directing apparatus 10 and rod 12 are moved through the loose medium 76 without being directed in any particular direction. In FIG. 5, rod-directing apparatus 10 is shown in an intermediate stage of operation for enabling the directing member 70. In FIG. 6, the rod-directing apparatus 10 is shown with the directing member 70 enabled and the first member 40 in driving engagement with the second member 50 (through drive shoulders 92, 94 and drive face 126) so that in response to forward movement 22 of the rod 12, the rod-directing apparatus 10 and rod 12 are moved in the direction of the sloped or inclined surface 74 of the directing member 70 through the loose medium 76.

As shown in each of FIGS. 4, 5, and 6, an end member 150 is threadably connected to the proximal end 52 of the second member 50. End member 150 includes an axially inwardly facing surface 152 spaced longitudinally from the drive face 122 a distance substantially equivalent to the longitudinal length of the entire control mechanism 130. Surface 152 provides a limit which engages annular ring 132 of control mechanism 130 to stop movement of control mechanism 130 when the first member 40 is moved rearward in response to backward movement 23 of rod 12. A sealing ring 154 is provided in the inner surface of end member 150 to provide a seal between the end member 150 and the first member 40 at the proximal end 52 of the second member 50. Another sealing ring 156 is provided in the inner surface of the second member 50 adjacent the annular ridge 124 to provide a seal between the second member 50 and the first member 40 in proximity to ridge 124. The seals 154 and 156 serve to create a sealed chamber in the second member 50 within which the drive shoulders 92, 94 and control mechanism 130 are operable. Within this sealed chamber, a lubricating fluid (not shown) may be included to facilitate operation of the drive shoulders 92, 94 and control mechanism 130.

Referring to FIG. 4, when directing member 70 is in its disabled position, it is withdrawn into the hollow interior of the second member 50, and drive shoulders 92, 94 engage the axially facing drive face 122 to provide a driving relationship between first member 40 and second member 50 for movement of rod-directing apparatus 10 in response to forward movement 22 of rod.

As shown in FIG. 4, when directing member 70 is disabled, annular ring 132 of control mechanism 130 is in proximity to the axially inwardly facing limit surface 152 of end member 150. Thus, cam followers 110 on drive shoulders 92, 94 are positioned in tapered openings 140 near the distal end 136 of the cylindrical portion 134 of control mechanism 130. Since the tapered openings 140 are widest near the distal end 136, the drive shoulders 92, 94 are biased radially outwardly toward the inner surface of the second member 50 to engage the axially facing drive face 122. When the directing member 70 is disabled, forward movement 22 of rod 12 is not directed in any particular direction. Thus, as rod 12 is moved through the loose medium 76, the intended course or path of movement is straight. However, because of differences in density in the loose medium 76 or obstacles, forward movement 22 of rod 12 may deviate from the intended straight course or path. In case of such deviation, it is necessary to be able to selectively direct forward movement 22 of rod 12 in a desired direction to bring forward movement 22 back onto the desired course or path.

Referring to FIG. 5, in order to enable the directing member 70 so that the forward movement 22 of the rod 12 can be directed in a desired direction, rod 12 is pulled by pipe pusher 20 (shown in FIG. 1) causing rearward movement 23 of first member 40 relative to the second member 50. Rearward movement of second member 50 is restricted or prevented by friction between the outer surface of second member 50 and the loose medium 76. As rearward movement 23 of the first member 40 occurs, annular ring 132 engages the axially inwardly facing limit surface 152 to stop movement of the control mechanism 130. As rearward movement 23 of the first member 40 continues, cam surfaces 112 of cam followers 110 on drive shoulders 92, 94 follow the cam surfaces 142 of the control mechanism 130. As the cam surfaces 142 taper toward each other, drive shoulders 92, 94 are moved radially inwardly away from the inner surface of the second member 50 and into the chamber 80 against the bias of spring 98 to disengage the drive shoulders 92, 94 from the axially facing drive face 122. Drive shoulders 92, 94 are moved radially inwardly so that the distance between the radial outer surfaces of the drive shoulders 92, 94 is less than the internal diameter of the annular ridge 120 so that drive shoulders 92, 94 will move past ridge 120 in response to forward movement 22 of rod 12. In the intermediate stage of operation of the rod-directing apparatus 10 shown in FIG. 5, the apparatus 10 is now ready to be reengaged with the directing member 70 enabled to direct the rod 12 in a desired direction.

Referring to FIG. 6, from the intermediate stage shown in FIG. 5, rod 12 is again pushed by rod pusher 20 to cause forward movement 22 of first member 40. As the first member 40 is moved forward (forward movement 22), drive shoulders 92, 94 pass annular ridge 120 and the control mechanism 130 is carried in frictional engagement with the first member 40 in the relationship with drive shoulders 92, 94 as shown in FIG. 5 until the annular ring 132 engages the axially facing drive face 122 on annular ridge 120. Upon engagement of annular ring 132 with drive face 122, movement of the control mechanism 130 is stopped while forward movement 22 of the first member 40 continues. As the forward movement 22 of the first member 40 continues, cam surfaces 112 of the cam followers 110 on drive shoulders 92, 94 follow the cam surfaces 142 in the cylindrical portion 134 of control mechanism 130. As the drive shoulders 92, 94 are moved forward toward the distal end 136 of control mechanism 130, drive shoulders 92, 94 are permitted to move radially outwardly toward the inner surface of second member 50 in response to bias of spring 98 so that they engage the axially facing drive face 126 on the inner surface of the second member 50. As forward movement 22 of rod 12 and the first member 40 continues, the second member 50 is also driven. As shown in FIG. 6, when drive shoulders 92, 94 are engaged with the axially facing drive surface 126, directing member 70 is enabled to direct forward movement 22 of the rod 12 in the direction of the sloped surface 74 of directing member 70.

Once forward movement 22 of the rod 12 has been directed in a desired direction for a sufficient distance, it may again be desirable to disable the directing member 70. To disable the directing member 70 from its enabled position as shown in FIG. 6, pusher 20 (shown in FIG. 1) is again employed to pull rod 12, causing rearward movement 23 of the first member 40. As first member 40 is moved rearwardly 23, control mechanism 130 is again carried on the first member 40. Drive shoulders 92, 94 are compressed inwardly against the bias of spring 98 as they move along the ramp 128 on the inner surface of the second member 50 between ridges 120 and 124. Once the axially facing drive surfaces 100 of the drive shoulders 92, 94 have passed annular ridge 120, the drive shoulders 92, 94 are released to spring radially outwardly toward the inner surface of the second member 50 so that drive shoulders 92, 94 engage the axially facing drive face 122 in the position shown in FIG. 4. At this point, rearward movement 23 of rod 12 and first member 40 must stop. Otherwise, continued rearward movement 23 will cause ring 132 to engage face 152 and drive shoulders 92, 94 will be retracted by control mechanism 130 to a position as shown in FIG. 5. Since the apparatus 10 cannot be seen by the operator of pusher 20, a mark can be made on the rod 12 above the ground surface to provide an indication of the distance of travel of rearward movement 23. In this position, the directing member 70 is disabled and the control mechanism 130 is in position to enable the directing member 70 again if necessary.

Referring again to FIG. 1, the desired direction for forward movement of the rod 12 can be selectively determined by rotating the rod 12 using the power-driven apparatus 24, a hand-held rotating device, such as a wrench (not shown), or by hand which in turn rotates the rod-directing apparatus 10 in the loose medium to position the sloped surface or face 74 in a desired position for directing the rod 12 in the desired direction. In order for the operator to know which direction the sloped surface 74 is facing in the loose medium 76, some calibration should be provided on the pusher 20 or the power-driven apparatus 24 as an indication of the direction the sloped surface 74 is facing. Illustratively, as shown in FIG. 1, the power-driven apparatus 24 or the pusher 20 can include markings 158 indicating increments such as 90.degree. of rotation of rod 12 with the uppermost marking indicating that the sloped surface 74 is facing up. With the sloped surface 74 facing up, the rod 12 and apparatus 10 will be directed downward in FIGS. 4-6.

Referring now to FIGS. 7, 8, and 9, it is sometimes desirable to condition the loose medium 76 through which a rod 12 is being moved to facilitate forward movement 22 of the rod 12. For example, it may be desirable to soften the loose medium 76. In this instance, it is desirable to dispense a fluid such as water or drilling mud under pressure into the loose medium 76 in front of the movement of the rod 12. In connection with the rod-directing apparatus 10 of the Present invention, forward movement 22 of the rod 12 may be either undirected as shown in FIG. 7 or directed as shown in FIG. 8. In order to provide the fluid to the distal end 44 of the first member 40, a rod-directing apparatus 10' is shown in FIGS. 7, 8, and 9. In FIGS. 7, 8, and 9, the elements of rod-directing apparatus 10' which are identical to the elements of rod-directing apparatus 10 shown in FIGS. 1-6 have been given the same reference numerals. Elements that have been Changed or added in rod-directing apparatus 10' have been given different reference numerals. Operation of rod-directing apparatus 10' is the same as rod-directing apparatus 10 except as otherwise described differently hereinafter.

In rod-directing apparatus 10', a first member 160 includes a first fluid passageway 162 extending longitudinally the length of first member 160 from its proximal end 164 to its distal end 166. Further, rod-directing directional apparatus 10' includes a directing member 170 that includes an extension 172 of the first fluid passageway 162. Thus, fluid is transmittable from the proximal end 164 of the first member 160 into the directional member 170 through first fluid passageway 162, 172.

First member 160 also includes a second fluid passageway 180 connected to the first fluid passageway 162. The second fluid passageway 180 includes one or more passageways 181 extending radially outwardly from the first fluid passageway 162 and opening on the outer surface 182 of the first member 160, permitting fluid to flow between the outer surface 182 of the first member 160 and the inner surface 184 of the second member 50. The annular seal 156 (shown in FIGS. 4-6) prevents the fluid from flowing backward into the chamber housing the drive shoulders 92, 94 and control mechanism 130. The second fluid passageway 180 including the extension thereof between the outer surface 182 of first member 160 and the inner surface 184 of the second member 50 serves to provide a nozzle for dispensing the fluid into the loose medium 76 when the directing member 170 is disabled as shown in FIGS. 7 and 9. This nozzle includes a valve assembly 190 for opening and closing the second fluid passageway 180 in response to forward movement 22 and rearward movement 23 of the first member 160.

As best shown in FIGS. 7 and 9, valve assembly 190 includes an annular sealing ring 192 in the inner surface 184 of the second member 50 which provides a seal with the outer surface 182 of the first member 160 when the directing member 170 is enabled as shown in FIG. 8. The seal between inner surface 184 of second member 50 and outer surface 182 of first member 160 closes the second fluid passageway 180 to prevent the dispensing of fluid through the nozzle. Bypass means 194 is provided on the outer surface 182 of the first member 160 and on the outer surface 196 of the directing member 170. In the illustrative embodiment, bypass means 194 includes a series of splines or channels cut in the outer surfaces 182 and 196 of the first member 160 and directing member 170, respectively, to permit fluid to flow past seal 192 when the directing member 170 is disabled as shown in FIG. 7. It will be understood that instead of a plurality of individual splines or channels it may be possible to reduce the diameter of the first member 160 at its distal end 166 all around the circumference thereof and to reduce the diameter of the directing member 170 to correspond to the reduced diameter of the distal end 166.

Therefore, as can be seen in FIGS. 7, 8, and 9, when the directing member 170 is disabled, fluid is permitted to flow through second fluid passageway 180 past seal 192 and is dispensed in the direction of forward movement 22 as indicated by the arrows at the distal end 54 of the second member 50. However, when the directing member 170 is enabled as shown in FIG. 8, seal 192 provides a seal between the outer surface 182 of the first member 160 and the inner surface 184 of the second member 50 to close the second fluid passageway 180 and prevent fluid from being dispensed through the second fluid passageway 180.

Referring to FIGS. 8 and 9, the directing member 170 includes a third fluid passageway 200 connected to the extension 172 of the first fluid passageway 162. The third fluid passageway 200 extends from the extension 172 of the first fluid passageway 162 in spaced parallel relationship to the slope of the sloped surface 174 of the directing member 170. The second fluid passageway 200 serves to provide another nozzle for dispensing fluid in the direction of forward movement 22 as the rod 12 is directed by the directing member 170. The nozzle in directing member 170 includes another valve assembly 210 for closing the third fluid passageway 200 when the directing member 170 is disabled as shown in FIG. 9. and for opening the third fluid passageway 200 when the directing member 170 is enabled as shown in FIG. 8. Valve assembly 210 includes a first ball 212, a second ball 214, and a compression spring 216 between the first ball 212 and the second ball 214 biasing the balls 212, 214 away from each other. The balls 212, 214 and the spring 216 are contained in cavity 218 opening into first and third fluid passageways 162 and 200 and opening outwardly through the outer surface 196 of directing member 170. In the disabled position of the directing member 170, as best seen in FIG. 9, first ball 212 is seated against a valve seat 220 provided at the interconnection of the first fluid passageway 162, 172 and the third fluid passageway 200 and ball 214 is compressed toward ball 212 by the inner surface 184 of the second member 50, thereby forcing the first ball 212 against the valve seat 220 to close the third fluid passageway 200.

As the directing member 170 is moved forward to its enabled position as shown in FIG. 8 and in broken lines in FIG. 9, the pressure applied by the inner surface 184 of the second member 50 is released as the ball 214 passes beyond the distal end 54 of the second member 50, thereby permitting the ball 212 to be unseated from seat valve 220 so that fluid can flow through the third passageway 200 and be dispensed from the end of the directing member 170 in the direction of forward movement of the rod 12, as shown by the arrows in FIG. 8. Although not specifically shown in FIGS. 7, 8, or 9, it will be appreciated that ball 214 is retained in the cavity 218 in the directing member 170 when it passes the distal end 54 of the second member 50 by a retaining lip or ridge 222 at the edge of the opening of the cavity 218 containing the balls 212, 214.

In operation, when the directing member 170 is disabled as shown in FIG. 7, fluid flows through second fluid passageway 180 and bypasses the seal 192 so that it is dispensed through the distal end 54 of the second member 50 and at the same time ball 212 is seated on valve seat 220 and so that the third fluid passageway 200 is closed. When the directing member 170 is enabled as shown in FIG. 8, seal 192 provides a seal between the outer surface 182 of first member 160 and the inner surface 184 of second member 50 to close the second fluid passageway 180 and ball 214 is released as shown in FIGS. 8 and 9 to permit ball 212 to be unseated from valve seat 220 and thereby to permit fluid to pass through third fluid passageway 200 and to be dispensed in the direction of movement of the rod 12.

Other embodiments of an apparatus for directing forward movement 22 of a rod 12 through a loose medium 76 such as the ground beneath the surface of the medium are illustrated in FIGS. 10-20. It will be understood that the previous descriptions associated with FIG. 1 and an apparatus for directing the forward movement of a rod constructed in accordance with the present invention are also applicable to the embodiments shown in FIGS. 10-20. Further, where the same elements previously described in connection with the embodiment shown in FIGS. 1-9 are also shown in FIGS. 10-20, the same reference numerals have been applied to those elements.

Referring now to FIG. 10, there is shown an apparatus 250 for directing the forward movement 22 of a rod 12 as it is moved through a loose medium such as the ground 76 beneath the surface. The embodiment of the rod-directing apparatus 250 shown in FIGS. 10-12 includes a first member 252 which is an elongated shaft having a proximal end 254 and a distal end 256. The proximal end 254 includes an opening 257 having internal threads (not shown) for coupling the first member 252 to the rod 12. A coupler 48 having an external threaded portion 258 is used to connect the first member 252 to the rod 12.

The rod-directing apparatus 250 also includes a second member 260 which is an elongated hollow pipe having a proximal end 262 and a distal end 264. The second member 260 is sleeved onto the first member 252 so that the first member 252 is slidably received in the second member 260. The first member 252 is movable relative to the second member 260 in response to both forward movement 22 and rearward movement 23 of the rod 12. It should be understood that the members 252 and 260 do not need to be cylindrical and could be another shape without departing from the scope of the present invention.

The proximal end 254 of the first member 250 has a cavity 270 formed therein communicating with the opening 257 for placement and location of a transmitter 32. One or more elongated slots 272 may be cut in the wall of the first member 252 to facilitate passage of the signals 34 (FIG. 1) from the transmitter 32 through the wall of the first member 252. The slots 272 are filled with a signal-transmitting material 274 which will permit signals generated by the transmitter 32 to pass through it. Materials for the signal-transmitting material and the composition of the first and second members 252, 260 may be the same as the materials previously described with respect to the rod-directing apparatus 10.

Continuing to refer to FIGS. 10, 11, and 12, the distal end 256 of the first member 252 has an opening 280 formed therein. The opening 280 is internally threaded (not shown) for attaching a directing member 282 to the distal end 256 of the first member 252. The directing member 282 includes a threaded portion 284 for coupling the directing member 282 to the distal end 256 of the first member 252. The directing member 282 is generally cylindrical and is cut diagonally to provide a sloped or inclined surface 286 which is generally elliptical in shape. The construction of the directing member 282 is substantially the same as the structure of the directing member 70 previously described with the exception that a sealing ring 288 is provided on the external surface of directing member 282 to provide a seal between the inner surface of the second member 260 and the directing member 282. The operation of directing member 282 is the same as previously described with respect to the directing member 70.

A radially outwardly opening chamber 290 is formed in the first member 252 for receiving a drive assembly 292. The chamber 290 is generally cylindrical and extends around the circumference of the second member 252 between the cavity 270 and opening 280. The drive assembly 292 includes a plurality of drive shoulders 294 in the form of balls positioned in the chamber 290 about the circumference of first member 252. It will be appreciated that the number of drive balls 294 will depend upon the circumference of the outer surface of the first member 252, but the number should be sufficient to substantially fill the chamber 290 about the circumference of the first member 252. The drive shoulders or balls 294 are biased radially outwardly from the chamber 290 by a circular flat spring 296 which is contained in the chamber 290. One of the edges of the chamber 290 is inclined at an angle as shown in FIGS. 10-12 to provide a support surface 298 for the drive shoulders 294 when they are biased radially outwardly from chamber 290.

Continuing to refer to FIGS. 10, 11, and 12, the second member 260 has formed on its inner surface an annular ridge 300 providing an axially facing drive face 302 in a plane substantially parallel to the inclined support surface 294. The drive face 302 extends along the inner surface of the second member 260 in a circle to engage each of the drive balls 294. Annular ridge 300 also provides an axially facing inclined limit surface 304. The second member 260 also includes an end member 310 inserted into the proximal end 262 of the second member 260. The end member 310 has a beveled distal end providing a cam surface 312 in longitudinal spaced relationship to the annular ridge 300. The cam surface 312 extends radially inwardly from the inner surface of the second member 260. The inner surface of end member 310 has a portion 313 in spaced relationship to the outer surface of first member 252 providing an opening 314 between the inner surface of end member 310 and the outer surface of first member 252. The purpose of the cam surface 312 and the opening 314 will be described later. The end member 310 also includes a sealing ring 316 engaging the outer surface of first member 252. The sealing rings 288 and 316 form a sealed chamber therebetween for containing a lubricant. The proximal end 262 of second member 260 and end member 310 provide an axially facing drive face 320 at the proximal end 262 of second member 260. The proximal end 254 of the first member 252 has an external diameter which is greater than the external diameter of the remainder of the first member 252 so that another axially facing drive shoulder 322 is provided on the first member 252 for driving engagement with the axially facing drive face 320 on the second member 260.

The drive shoulders or balls 294 are biased radially outwardly from the first member 252 by spring 296 to engage the drive face 302. When the drive shoulders 294 are engaging drive face 302, they are supported on support surface 298 at the edge of chamber 290 so that the second member 260 is driven simultaneously with the first member 252 through the loose medium 76 in response to forward movement 22 of the rod 12.

As shown in FIGS. 10, 11, and 12, a control mechanism 330 includes the cam surface 312 and an annular cylindrical retaining ring 332 that is sleeved onto the first member 252. The retaining ring 332 is carried on the first member 252 and frictionally engages the first member 252. The frictional engagement between the retaining ring 332 and the outer surface of first member 252 is such that the first member 252 is movable relative to the retaining ring 332 when movement of the retaining ring 332 is limited or stopped. The retaining ring 332 has a longitudinal length which is substantially equal to the longitudinal length of the opening 314 between the inner surface of the end member 310 and the outer surface of the first member 352. Control mechanism 330 controls the engagement and disengagement of drive shoulders 294 with the drive face 302 in a manner which will be explained later.

The operation of the rod-directing apparatus 250 can best be explained by referring to FIGS. 10, 11, and 12. In FIG. 10, the rod-directing apparatus 250 is shown with the directing member 282 disabled and the first member 252 in driving engagement with the second member 260 (through drive balls 294 and drive face 302) so that in response to forward movement 22 of rod 12, rod-directing apparatus 250 and rod 12 are moved through the loose medium 76 without being directed in any particular direction. In FIG. 11, rod-directing apparatus 250 is shown in an intermediate stage of operation for enabling the directing member 282. In FIG. 12, the rod-directing apparatus is shown with the directing member 282 enabled and the first member 252 in driving engagement with the second member 260 (through engagement of drive face 320 and drive shoulder 322) so that in response to forward movement 22 of rod 12, the rod-directing apparatus 250 and rod 12 are moved in the direction of the sloped or inclined surface 286 of the directing member 282 through the loose medium 76.

As shown in FIG. 10, when directing member 282 is in its disabled position, drive shoulders (balls) 294 engage the axially facing drive face 302 and support surface 298 to provide a driving relationship between the first member 252 and the second member 260. Also, when directing member 282 is disabled, retaining ring 332 of control mechanism 330 is located in the opening 314 between the outer surface of the first member 252 and the reduced portion of the end member 310 of the second member 260.

Referring to FIG. 11, in order to enable the directing member 282 so that forward movement 22 of the rod 12 can be directed in a desired direction, rod 12 is pulled by pipe pusher 20 (shown in FIG. 1), causing rearward movement 23 of first member 252 relative to the second member 260. As rearward movement 23 of the first member 252 occurs, retaining ring 332 is retained in the opening 314 and first member 252 moves relative to the retaining ring 332. As rearward movement 23 of the first member 252 continues, drive shoulders 294 follow the cam surface 312 on end member 310 and are urged radially inwardly against the spring 296 until they are retained within the chamber 290 by the retaining ring 332 as shown in FIG. 11. Upon further rearward movement 23, the directing member 282 engages the limit surface 304 on annular ridge 300 to prevent further rearward movement 23 of the first member 252 relative to the second member 260. In the intermediate stage of operation of the rod-directing apparatus 250 shown in FIG. 11, the apparatus 250 is now ready to be reengaged with the directing member 282 enabled to direct the rod in a desired direction.

Referring to FIG. 12, from the intermediate stage shown in FIG. 11, the rod 12 is again pushed by rod pusher 20 to cause forward movement 22 of the first member 252. As the first member 252 is moved forward (forward movement 22), the drive shoulders 294 are retained in the chamber 290 by retaining ring 332. As the first member 252 is moved forward 22, the retaining ring 332 is carried on first member 252. The retaining ring 332 engages the drive face 302 on annular ridge 300 so that drive shoulders 294 pass annular ridge 300. Upon engagement of the retaining ring 332 with drive face 302, movement of the retaining ring 332 is stopped while forward movement 22 of the first member 252 continues. As the forward movement 22 of the first member 252 continues, the drive shoulders 294 are released to engage the inner surface of the second member 260 and drive shoulder 322 engages the axially facing drive face 320 provided by the proximal end 262 of second member 260 and the end member 310. As shown in FIG. 12, when drive face 320 is engaged by drive shoulder 322, directing member 282 is enabled to direct forward movement 22 of the rod in the direction of the sloped surface 286 of the directing member 282.

Once forward movement 22 of the rod 12 has been directed in a desired direction for a sufficient distance, it may again be desirable to disable the directing member 282. To disable the directing member 282 from its enabled position as shown in FIG. 12, pusher 20 (shown in FIG. 1) is again employed to pull rod 12, causing rearward movement 23 of the first member 252. As first member 252 is moved rearwardly 23, drive shoulders 294 engage inclined limit surface 304 on annular ridge 300 and are compressed inwardly against the bias of spring 296, retaining ring 332 is carried on the external surface of first member 252 until it is positioned in the opening 214 between the external surface of the first member 252 and the reduced portion 313 of the end member 310. In this position, retaining ring 332 is prohibited from traveling further in the rearward direction 23 of movement of first member 252. Once the drive shoulders 294 have passed annular ridge 300, the drive shoulders 294 are released to spring radially outwardly toward the inner surface of the second member 260 to engage drive face 302 and to be supported by surface 298 in the position shown in FIG. 10. At this point, rearward movement 23 of rod 12 and first member 252 must stop. Otherwise, continued rearward movement 23 will cause the drive shoulders 294 to engage the cam surface 312 and the drive shoulders 294 will be retracted by retaining ring 332 to a position as shown in FIG. 11. As previously described, a mark can be made on the rod 12 above the ground surface to provide an indication of the distance of travel of rearward movement 23.

Another embodiment of a rod-directing apparatus 350 constructed according to the present invention is shown in FIGS. 13, 14, and 15. The rod-directing apparatus 350 includes a first member 352 which is an elongated shaft having a proximal end (not shown) and a distal end 356. In the same manner as previously described, the proximal end includes threads for coupling the first member 352 to the rod 12. A coupler (not shown) is used to connect the first member 352 to the rod 12 in the manner previously described.

The rod-directing apparatus 350 shown in FIGS. 13-15 also includes a second member 360 which is an elongated hollow pipe having a proximal end (not shown) and a distal end 364. The second member 360 is sleeved onto the first member 352 so that the first member 352 is slidably received in the second member 360. As will be explained later, the first member 352 is movable relative to the second member 360 in response to both forward movement 22 and rearward movement 23 of the rod 12. Again, it should be understood that the members 352 and 360 do not need to be cylindrical and could be another shape without departing from the scope of the present invention. Further, the composition of the first and second members 352, 360 could be a stainless steel or could be coated with a non-corrosive coating to prevent corrosion from moisture in the ground.

The first member 352 has a cavity 370 formed therein and an opening (not shown) at the proximal end (not shown) communicating with the cavity 370 for placement and location of a transmitter 32. As described with respect to the rod-directing member 250, one or more elongated slots (not shown) may be cut in the wall of the first member 352 to facilitate passage of the signals 34 from the transmitter 32 through the first member 352. The slots may be filled with a signal-transmitting material which will permit signals generated by the transmitter 32 to pass through it. Materials suitable for use have been previously described.

The distal end 356 of the first member 352 has an opening 372 that is internally threaded (not shown) for attaching a directing member 380 to the distal end of the first member 352. The first member 352 also includes a drive shoulder 374 provided on its outer surface and a drive shoulder 376 provided at its distal end 356.

The directing member 380 has a distal portion 382 that is generally cylindrical and is cut diagonally to provide a sloped or inclined surface 384 which is generally elliptical in shape. The distal portion 382 is pivotally connected to an intermediate portion 388 by a pivot 386. The directing member 380 also includes a proximal portion 390 having a reduced outer diameter and a threaded portion 392 for threadably engaging the opening 372 in the first member 352. The intermediate portion 388 includes a sealing ring 394 engaging the inner surface of the second member 360. A radially inwardly sloping surface 396 joins the intermediate portion 388 and the proximal portion 390 and provides a limit surface for limiting rearward movement 23 of the first member 352 in a manner which will be explained later. The proximal end of the proximal portion 390 adjacent the threaded section 392 is beveled to provide a cam surface 398 to control drive-engaging means in a manner that will be explained later. In operation, when the directing member 380 is enabled, the rod-directing apparatus 350 and rod 12 are directed in the direction of the slop of the surface 384 in response to forward movement 22 of the rod 12. The pivotal connection 386 between the distal portion 382 and the intermediate portion 388 of the directing member 380 facilitates circumvention of an obstacle in the ground in a manner which will be explained later.

A radially inwardly opening chamber 400 is formed in the second member 360 for receiving a drive assembly 402. The chamber 400 is generally cylindrical and extends circumferentially on the inner surface of the second member 360. The drive assembly 402 includes a plurality of drive balls 404, each providing an axially facing drive surface 405 for engaging the drive shoulder 376 on the first member 352. It will be appreciated that the number of drive balls 404 will depend upon the inner circumference of the second member 360, but the member should be sufficient to substantially fill the chamber 400 about the inner circumference of the second member 360. Each of the drive balls 404 is biased radially inwardly toward the first member 352 from the chamber 400 by a cylindrical spring 406 which is contained in the chamber 400 to engage the drive shoulder 376 on the first member 352. One of the edges of the chamber 400 is inclined at an angle as shown in FIGS. 13-15 to provide a support surface 408 for the drive balls 404 when they are biased radially inwardly toward the first member 352.

The second member 360 has formed on its inner surface an annular ridge 410 in which the chamber 400 is formed. The annular ridge 410 provides an axially facing drive face 412 for engaging the drive shoulder 374 on the first member 352. The annular ridge 410 also includes an axially facing limit surface 414 for engaging the limit surface 396 on the directing member 380 to limit rearward movement 23 of the first member 352.

The drive balls 404 are biased radially inwardly from the second member 360 toward the outer surface of the first member 352 by spring 406 to engage the drive shoulder 376 and to rest on support surface 408. When drive balls 404 are engaging drive shoulder 376, the second member 360 is driven simultaneously with the first member 352 through the loose medium 76 in response to forward movement 22 of rod 12.

As shown in FIGS. 13-15, a control mechanism 420 includes the cam surface 398 and an annular cylindrical retaining ring 422 that is sleeved into the proximal portion 390 of the directing member 380. The retaining ring 422 is carried on the proximal portion 390 of the directing member 380 and frictionally engages the proximal portion 390. The frictional engagement between the retaining ring 422 and the outer surface of the proximal portion 390 of the directing member 380 is such that the first member 352 and directing member 380 are movable relative to the retaining ring 422 when movement of retaining ring 422 is limited or stopped. The retaining ring 422 has a longitudinal length which is substantially equal to the longitudinal length of the outer surface of the proximal portion 390 of directing member 380. Control mechanism 420 controls the engagement and disengagement of the drive faces 405 on drive balls 404 with the drive shoulder 376 in a manner which will be explained later.

The operation of the rod-directing apparatus 350 can best be explained by referring to FIGS. 13, 14, and 15. In FIG. 13, rod-directing apparatus 350 is shown with the directing member 380 disabled and the first member 352 in driving engagement with the second member 360 (through drive shoulder 376 and drive faces 405) so that in response to forward movement 22 of rod 12, rod-directing apparatus 350 and rod 12 are moved through the loose medium 76 without being directed in any particular direction. In FIG. 14, rod-directing apparatus 350 is shown in an intermediate stage of operation for enabling the directing member 380. In FIG. 15, the rod-directing apparatus 350 is shown with the directing member 380 enabled and the first member 352 in driving engagement with the second member 360 (through engagement of drive shoulder 374 and drive face 412) so that in response to forward movement 22 of the rod 12, the rod-directing apparatus 350 and rod 12 are moved in the direction of the sloped or inclined surface 384 of the directing member 380 through the loose medium 76.

Referring to FIG. 13, when directing member 380 is in its disabled position, it is withdrawn into the hollow interior of the second member 360, and drive shoulder 376 engages the drive faces 405 to provide a driving relationship between first member 352 and second member 360 for movement of the rod-directing apparatus 350 in response to forward movement 22 of rod 12.

Referring to FIG. 14, in order to enable the directing member 380 so that the forward movement 22 of the rod 12 can be directed in a desired direction, rod 12 is pulled by pipe pusher 20 (shown in FIG. 1), causing rearward movement 23 of first member 352 relative to the second member 360. As rearward movement 23 of the first member 352 occurs, the drive balls 404 engage the cam surface 398 and are urged radially inwardly against the spring 406. The drive balls 404 are urged radially inwardly away from the outer surface of the first member 352 and into the chamber 400 to disengage the drive faces 405 from the drive shoulder 376. Drive balls 404 are forced radially inwardly so that retaining ring 422 is interposed between the drive balls 404 and the external surface of the proximal portion 390 of the directing member 380. Rearward movement 23 of the first member 352 is limited by engagement of the limit surface 396 on the intermediate portion 388 of the directing member 380 and the limit surface 414 provided by the annular ridge 410 on the inner surface of the second member 360. In the intermediate stage of operation of the rod-directing apparatus 350 shown in FIG. 14, the apparatus 350 is now ready to be reengaged with the directing member 380 enabled to direct the rod 12 in a desired direction.

Referring to FIG. 15, from the intermediate stage shown in FIG. 14, rod 12 is again pushed by rod pusher 20 to cause forward movement 22 of the first member 352. As the first member 352 is moved forward (forward movement 22), the drive balls 404 frictionally engage the retaining ring 422 so that the proximal portion 390 of directing member 380 moves relative to the retaining ring 422 until the retaining ring 422 engages the drive shoulder 376 on first member 352. Upon engagement of the retaining ring 422 with drive shoulder 376, the drive shoulder 376 moves past drive balls 404 to permit continued forward movement 22 of the first member 352. Forward movement 22 of the first member 352 continues until drive shoulder 374 on first member 352 engages drive face 412 provided by the annular ridge 410 on the inner surface of second member 360. As forward movement 22 of first member 352 continues, the second member 360 is also driven. As shown in FIG. 15, when drive shoulder 374 and drive face 412 are engaged, directing member 380 is enabled to direct forward movement 22 of the rod 12 in the direction of the sloped surface 384 of the directing member 380.

Once forward movement 22 of the rod 12 has been directed in a desired direction for a sufficient distance, it may again be desirable to disable the directing member 380. To disable the directing member 380 from its enabled position as shown in FIG. 15, pusher 20 (shown in FIG. 1) is again employed to pull rod 12, causing rearward movement 23 of the first member 352. As first member 352 is moved rearwardly 23, the drive balls 404 engage the slight gap 424 between the retaining ring 422 and the angular drive shoulder 376 so that movement of the retaining ring 422 is stopped momentarily to permit the drive balls 404 to be urged radially inwardly to engage drive shoulder 376 in the position shown in FIG. 13. At this point, rearward movement 23 of rod 12 and first member 352 must stop. Otherwise, continued rearward movement will cause the drive balls 404 to be forced radially inwardly against the cam surface 398 on the proximal end 390 of directing member 380 and drive balls 404 will be retracted by the retaining ring 422 to a position shown in FIG. 14. Again, since the apparatus 350 cannot be seen by the operator of pusher 20, a mark can be made on the rod 12 above the ground surface to provide an indication of the distance of travel of rearward movement 23.

Referring to FIG. 16, it will be understood that the drive balls 294 of rod-directing apparatus 250 and the drive balls 404 of rod-directing apparatus 350 do not need to be balls in order for the apparatus 250, 350 to operate. For example, for apparatus 350, the second member 360 may include a chamber 430 containing a drive assembly 432. The drive assembly 432 may include a plurality of rectangular drive members 434 biased radially inwardly by spring 436. Each drive member 434 includes an inclined surface 438 and an axially facing drive surface 440. In the apparatus 350 shown in FIGS. 13, 14, and 15, the inclined surface 438 engages the retaining ring 422 on the proximal potion 390 of the directing member 380 and the axially facing drive face 440 would engage a drive shoulder 376 on the distal end 356 of first member 352. It will further be understood that instead of the drive members 434 being biased radially inwardly from the inner surface of the second member 360, they could be biased radially outwardly, for example, in the manner shown in FIGS. 10, 11, and 12 where the drive members 434 provide a driving engagement between the first member 252 and the second member 260 when the directing member 282 is disabled. Other configurations for drive members that are biased either radially inwardly from the second member 260, 360 or radially outwardly from the first member 252, 352 to provide driving engagement between the first 252, 352 and second members 260, 360 may be adapted to either the apparatus 250 or 350 without departing from the scope of the present invention.

Referring to FIGS. 17 and 18, another embodiment of a directing member 450 having a pivotal distal end portion 452 is shown in these figures. The directing member 450 shown in FIGS. 17 and 18 is adapted for use with either the rod-directing apparatus 10 or the rod-directing apparatus 250 described previously. The directing member 450 includes a distal end portion 452 that is generally cylindrical in shape and a proximal end portion 454 also generally cylindrical in shape. The distal end portion 452 is cut diagonally to provide a sloped or inclined surface 456 which is generally elliptical in shape as shown in FIG. 17. The distal end portion 452 includes an opening 460 having side walls 462 and 464. A bore 466 extends through side walls 462 and 464.

The proximal end portion 454 includes a tongue 470 having a lower angular surface 472 and an upper arcuate surface 474. Tongue 470 has a bore 476 formed therein. Tongue 470 fits into opening 460 in the distal end portion 452 so that bores 466 and 476 are aligned. A pin 478 is positioned in bores 466 and 476 to pivotally connect the distal end portion 452 to the proximal end portion 454 of the driving member 450. The proximal end portion also includes an annular groove 480 for a sealing member (not shown) and a threaded portion 482.

Referring more particularly to FIG. 18 and the embodiment of rod-directing apparatus 250 shown in FIGS. 10, 11, and 12, the threaded portion 482 on the proximal end portion 454 of directing member 450 is threaded into the opening 280 in the first member 252 of apparatus 250. A sealing ring 484 is retained in the annular groove 480 to provide a seal between the inner surface of the second member 260 and the outer surface of the directing member 450.

As shown in FIG. 18, when the directing member 450 is disabled, the rod-directing apparatus 250 is moved through the ground 760 in a channel 490 formed by pushing the rod-directing apparatus 250 in a forward direction 22. When the directing member 450 is enabled, the distal end portion 452 pivots downwardly engaging a lower wall of the channel 490 and creating a new channel 492 as the rod-directing apparatus is moved in a forward direction 22. Continuing to refer to FIG. 18, when the distal end portion 452 pivots downwardly, the tip 486 extends beyond the longitudinal plane 488 of the outer surface of the second member 260 so that the tip 452 engages the loose medium 76 surrounding the apparatus 250 instead of the front of the apparatus.

Referring to FIGS. 19 and 20, the pivotal nature of directing member 450 facilitates circumvention of obstacles 494 which may be encountered in the loose medium 76 as the rod-directing apparatus 250, 350 is moved through the loose medium 76 in channel 490 with the pivotal directing member 382, 450 disabled. By moving the rod 12 in a rearward direction 23 after encountering an obstacle 494 and then enabling the pivotal directing member 382, 450, a new channel 490 in the loose medium 76 can be formed beyond the longitudinal plane 488 of the outer surface of the second member 260, 360 in response to forward movement 22 of the rod 12, thereby to circumvent the obstacle 494 as shown in FIG. 20. Once the obstacle 494 has been circumvented, the rod 12 and rod-directing apparatus 250, 350 can be either disabled or rotated in a manner previously described so that the rod 12 is directed upwardly to bypass the obstacle 494 and continue in a desired path.

It will be appreciated that the distal end portion 452 of the directing member 450 can be connected to the proximal end portion 454 in other ways so that the tip 486 extends beyond the longitudinal plane 488 of the outer surface of second member 260 when the directing member is enabled without departing from the scope of the present invention. For example, the distal end portion 452 may include an elongated slot engaging a post on the proximal end portion 454 which would permit the distal end portion 452 to slide relative to the proximal end portion 454 when the directing member 450 is enabled.

Although the invention has been described in detail with reference to certain preferred embodiments, variations and modifications exist within the scope and spirit of the invention as described and defined in the following claims.