Abstract:
An enclosed articulating joint for coupling a drive motor to an auger type earth anchor. The joint comprises a socket member attached to the drive motor and a ball member attached to the anchor. The socket member has a polygonal internal cross section which matingly engages the contour of the ball member. A locking assembly is included for locking the ball and socket members together during operation of the system. An optional non-locking coupler is provided for bypassing the locking assembly for rapid, successive driving operations. An optional offset coupler is provided to accommodate greater degrees of axial and longitudinal misalignment between the anchor and the socket member. This drive system is particularly suitable for use with horizontal boring machines, but has many other applications.

Description:
REFERENCES TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 60/060,706, filed on Sep. 19, 1997. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to coupling devices for rotational drive systems and more particularly to coupling devices for driving earth augers. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a polygonal ball drive system for use with a motor assembly to implant and withdraw an apparatus from the ground. The polygonal ball drive system comprises a drive member operatively connectable to the drive motor assembly, a drive ball member having an upper portion, a non-circular central portion and a lower portion, a drive socket member having a first end and a second end, and a drive socket locking assembly. 
     The first end of the drive socket member is connectable to the drive member and the second end comprises a tubular portion defining a drive ball receiving chamber for torque transmitting engagement with the central portion of the drive ball member. The lower portion of the drive ball member in turn is drivingly connectable to the apparatus. The drive socket locking assembly is adapted to releasably lock the drive socket member and the drive ball member in operative engagement. The upper and lower portions of the drive ball member are such that the diameters are smaller than the central portion so as to permit angular axial misalignment of the drive ball member within the drive socket member. 
     The present invention is further directed toward a polygonal ball drive system for use with a drive motor assembly and an apparatus. The polygonal ball drive system comprises a drive member operatively connectable to the drive motor assembly, a drive socket member having a first end and a second end, and a drive ball member having an upper portion, a noncircular central portion and a lower portion. 
     The first end of the drive socket member is connectable to the drive member, and the second end comprises a tubular portion defining a drive ball receiving chamber. The upper and central portions of the drive ball member are connectable in torque transmitting engagement with the drive ball receiving chamber and the lower portion is drivingly connectable to the apparatus. The upper and lower portions of the drive ball member are such that the diameters are smaller than the central portion so as to permit angular axial misalignment of the drive ball member within the drive socket member. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a horizontal boring machine comprising two front earth auger anchors, one implanted and one unimplanted, constructed in accordance with the present invention. 
     FIG. 2 is side elevational, fragmented, partly sectional view of the drive system of the present invention, showing the socket member and the ball member of the main coupler in exploded form. 
     FIG. 3 is a side elevational, partly sectional view of a non-locking coupler made in accordance with the present invention. 
     FIG. 4 is a side elevational, partly sectional view of an offset coupler made in accordance with the present invention. 
     FIG. 5 is a side elevational, fragmented, partly sectional view of the socket member in the receiving position. 
     FIG. 6 is a sectional view of the drive socket locking assembly in the locking position; 
     FIG. 7 similarly is a sectional view taken along the line  5 — 5  of FIG. 5 of the drive socket locking assembly in the receiving position. 
     FIG. 8 is a side elevational, fragmented, partly sectional view similar to FIG. 2 showing the drive ball member releasably locked in the drive socket member with the drive ball member and drive socket member substantially aligned; FIGS. 9 and 10 are similar to FIG. 8 showing the axial misalignment of the drive ball member and drive socket member. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Horizontal boring machines are being used with increasing frequency to form or enlarge horizontal boreholes underground for utility cables and conduits and the like. Most of these machines need to be anchored to the ground during the boring operation. While it is known to use screw or auger type anchors for this purpose, there remains a need for a quick drive system for implanting and withdrawing these devices. The present invention meets this need by providing a ball and socket joint for connecting a drive system to the anchor. While the preferred application of this invention is to horizontal boring machines, the drive system of this invention may be applied to other machines and devices which require similar stabilization. 
     Turning now to the drawings in general and to FIG. 1 in particular, shown therein is a horizontal boring machine  10 . The machine  10  is shown in the process of driving a drill string  12  into the ground  14 . The machine  10  is provided with a pair of earth anchors  16  and  18 . The anchor  16  is shown implanted in the ground  14 . The anchor  18  is shown connected to a drive system  20  constructed in accordance with the present invention. The drive system  20  is operatively connected to the drive motor  22 . The drive motor may be any type, such as hydraulic or electric. The drive motor  22  shown herein is a small ground based unit. However, cranes and various other mechanisms may be substituted for this purpose. 
     With reference now to FIG. 2, the drive system of this invention comprises a main coupler  30 . The coupler  30  comprises a socket member  32  having a tubular portion  34  having a flange  36  at one end. The flange  36  is attached by means of bolts  38  to the flange  40  of a drive member  42  extending from the drive motor  22  (FIG.  1 ). Thus, rotation of the drive motor  22  is transmitted to the coupler  30 . The tubular portion  34  internally defines a receiving chamber  46  which is polygonal in cross section. Preferably, the receiving chamber is hexagonal in cross section. 
     The coupler  30  further comprises a ball member  50  which is attached to the upper end of the earth anchor  52 . The auger portion  54  of the earth anchor  52  is of conventional design and is not shown in its entirety. As shown in FIGS. 8-10, the ball member  50  is sized to be receivable in the receiving chamber  46  of the socket member  32 . More specifically, the ball member has a polygonal central portion  55  sized to be engaged by the polygonal walls of the receiving chamber  46  whereby torque will be transmitted from the socket member  32  to the anchor  52 . In a preferred embodiment the central portion  55  is hexagonal in cross section. The upper portion  56  of the ball member  50  is rounded or generally hemispherical, and the bottom of the ball member  50  narrows to form a neck  58 . Thus, as shown in FIGS. 9 and 10 the ball member  50  can be tilted to a certain extent while still transmitting torque. This allows the driving or withdrawing operation to continue even though the axis Xa of the anchor  52  is misaligned with the axis Xb of the socket member  32 . 
     In many situations it will be desirable to lock the ball member  50  in the receiving chamber  46  of the socket member  32  so that the axial movement of the ball member  50  is prevented. To that end, and referring still to FIG. 2, a locking assembly  60  may be provided. The locking assembly  60  comprises a locking collar  62  slidably received over the tubular portion  34  of the main coupler  30 . 
     The locking collar  62  is movable between an upper or receiving position and a lower or locking position. Preferably, the collar  62  is continuously urged toward the locking position by a biasing member such as a spring  64  between the top of the collar  62  and flange  36 . 
     The locking assembly  60  preferably includes a first retaining assembly for retaining the locking collar  62  in the receiving position. The first retaining assembly comprises a plurality of upper balls  65  trapped inside an opening in the wall of the tubular portion  34 . The upper balls  65  are positioned high enough in the tubular portion  34  to be adjacent the upper portion  56  of the ball member  50  when the ball member is engaged with the socket member  32 . 
     With continuing reference to FIG. 2, the collar  62  is provided with a circumferential groove  66  sized to receive a portion of each of the upper balls  65 . The groove  66  is positioned longitudinally so that the groove is aligned with the upper balls  65  only when the collar  62  is in the receiving position. The locking assembly  60  further comprises a biasing assembly for continuously urging the upper balls  65  radially outward toward the collar  62 . For applications where the anchor being driven is substantially vertical, the biasing assembly may take the form of a weighted plug  68  suspended in the tubular portion  34  so that the weight, by gravity, causes the plug  68  to move downwardly on the upper balls  65 , urging the upper balls outwardly. Accordingly, as shown in FIGS. 5-7, when the collar  62  is moved up to the receiving position, the plug  68  pushes the balls into the groove  66 . It will be appreciated that for applications where the driving system will be operated in a substantially horizontal direction, other type of biasing devices may be employed, such as a spring. 
     The locking assembly  60  preferably also includes a second retaining assembly for retaining the ball member  50  inside the tubular portion  34  of the socket member  32  during use of the drive system. More specifically, the second retaining assembly prevents the ball from pulling out of the receiving chamber  46  when the anchor is being withdrawn. The second retaining assembly comprises a second set of lower balls  70  which are supported in openings in the wall of the tubular portion  34 . The lower balls  70  are positioned relative to the neck  58  of the ball member  50  so that when the ball member and the socket member  32  are engaged the ball member cannot be pulled out of the receiving chamber  46 . 
     The collar  62  is provided with a second circumferential groove  72  sized to receive a portion of each of the lower balls  70  when the groove is aligned with the balls. The groove  72  is positioned low enough so as to be aligned with the lower balls only when the collar  62  is in the receiving position. 
     Referring still to FIG. 2, the openings in the wall of the tubular portion  34  which contain the upper and lower balls  65  and  70  are large enough to permit the balls to move between a receiving position, where the balls are partially received in the circumferential grooves, and a locking position where the balls extend partially inside the receiving chamber  46  above and below the ball member  50 . The openings are countersunk (FIGS. 6 and 7) on the inside to prevent the balls from falling through into the receiving chamber  46 . 
     To use the drive system  20 , the locking collar  62  first is moved into the receiving position, so that the upper balls  65  move into the groove  66  and lock the collar into place. Next, the ball member  50  of the anchor  52  is inserted into the receiving chamber  46 , which allows the balls  65  to move back toward the inside of the tubular portion  34  of the socket member  32  adjacent the top portion  56  of the ball member  50 , releasing the collar  62 . Now, the spring  64  forces the collar  62  down so that the lower balls  70  are also pushed back toward the inside of the tubular portion  34  of the socket member  32 . This places the balls  70  inside the neck  58  of the ball member  50  and prevents downward movement of the anchor  52 . 
     Turning now to FIG. 3, the present invention provides a non-locking coupler  80  for those situations where no locking mechanism is desired between the anchor  52  and the non-locking coupler  80 . The locking assembly  60  of the socket member  32  retains the non-locking coupler  80 . 
     The non-locking coupler  80  is a short tubular element with a polygonal head  82  on one end and a receiving chamber  46 A on the other end. The receiving chamber  46 A is shaped identically to the receiving chamber  46  in the tubular portion  34  (FIG.  2 ). However, there are no upper or lower balls and no openings therefor. 
     The polygonal head  82  has a straight central portion  84  which is sized to engage the receiving chamber  46  of the tubular portion  34 . The lower end of the head  82  narrows to form a neck  86  and the top portion  88  is beveled. The spherical configuration of the ball member  50  is not used as there is no tilt occurring at this joint. Rather, tilt occurs as described above as the ball member  50  moves inside the receiving chamber  46 A. To receive the upper balls  65  while the head  82  is engaged with the tubular portion  34 , the upper ends of the planar side in the central portion  84  of the head  82  have recesses  89 . 
     Thus, the polygonal head  82  can be locked into engagement with the socket member  32  in the same manner as described previously. Yet, the drive system can be moved readily from one anchor to the next, driving them in succession and without having to operate the locking collar for each connection and disconnection. 
     Attention now is directed to FIG. 4 which illustrates an offset coupler  90  which forms a part of the present invention. The offset coupler  90  may be employed in cases where the angle of misalignment is greater than one joint can accommodate. The offset coupler  90  comprises a tubular member  92  having one end which defines a receiving chamber  46 B, a locking collar  62 A, a biasing spring  64 A, and a first locking assembly and a second locking assembly including the upper and lower balls  65 A and  70 A, the grooves  66 A and  72 A, and the weighted plug  68 A, all identical to the those corresponding elements of the socket member  32  described above in reference to FIG.  2 . The receiving chamber  46 B can engage the ball member  50  of the anchor (FIG. 2) or the head  82  of the non-locking coupler  80  (FIG.  3 ). 
     The upper end of the offset coupler  90  comprises a ball member  50 A having a hemispherical upper portion  56 A, a curved neck  58 A and planar side portions  55 A, all as described above in reference to the earth anchor  52  of FIG.  2 . Thus, the ball member  50 A is similarly receivable in the receiving chamber  46  of the tubular portion  34  of the socket member  32 . Now it will be appreciated that by using the offset coupler  90  between the socket member  32  and the ball member  50  on the earth anchor, two articulating joints are provided instead of one. Thus, the degree of misalignment which can be tolerated while driving or withdrawing the anchor is substantially increased. 
     Now it will be appreciated that the drive system of the present invention provides a main coupler which is easy to use. This system allows rotation even where there is some degree of misalignment between the anchor and the drive system, and the degree of tolerable misalignment is extended by using the offset coupler accessory. The locking assembly of this invention allows the ball member to be moved in multiple planes while locking the ball and socket members together.