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BACKGROUND OF THE INVENTION 
     Nonrotating kelly sections are shown in a drilling device in U.S. Pat. No. 1,971,922. The weight of the device, which does not have a power downcrowding mechanism, forces the auger into the ground. 
     U.S. Pat. No. 3,216,511 shows a crawler track vehicle with a drop hammer on the end of the boom. 
     U.S. Pat. No. 3,426,857 shows a drilling device with a single kelly bar supported from the end of a boom of a track type vehicle. The single kelly bar slides through a housing of a rotatable guide which rotates the kelly bar. The rotatable guide is supported frame attached to the lower portion of the boom. No means of downcrowding is provided. Another rig with telescoping kelly sections is shown in U.S. Pat. No. 3,753,468. The outer kelly section slides axially within a guidance sleeve supported at its top end by the free end of the boom and at its bottom end by a hydraulic cylinder attached to the track type vehicle. Telescopic sections and control are also described in U.S. Pat. No. 4,035,969. 
     U.S. Pat. No. 4,137,974 shows telescoping kelly sections driven by a rotary table. The housing of the rotary table is mounted at the lower end of relatively tall derrick. The kelly sections when retracted are surrounded by the derrick structure. Downcrowding is achieved by a mechanism which includes a drum having two cables wound in opposite senses thereon. The drum is hydraulically driven. A pulley system is mounted on the top of the derrick and another pulley system is mounted on the top of the outer kelly section. The pulley systems and the derrick would make it difficult to interchange the kelly sections since free access to the top of the kelly sections is not possible in such a rig. 
     An augering device mounted on a backhoe is shown in U.S. Pat. No. 4,199,033. The downward force exerted by the boom of the backhoe drives the auger into the ground. A trunnion device mounted between the end of the boom and the augering device allows a variety of angles of the auger relative to the backhoe. 
     U.S. Pat. No. 4,627,499 shows a drilling device supported on the end of a boom of a track type vehicle. The drilling device is of the drill mast type with a single kelly bar which slides through a housing of a final drive unit. The axis of the mast and kelly bar appear to be the same. Because the mast is directly over the kelly bar a relatively high overhead or ceiling is required for drilling vertical holes. 
     U.S. Pat. No. 4,645,084 discloses a device for drilling holes mounted in the side panels of a truck bed. A hydraulic jack is used to downcrowd the casing relative to the elbow. 
     A more useful downcrowdable augering apparatus having kelly sections is disclosed in U.S. Pat. No. 4,877,091. The apparatus of U.S. Pat. No. 4,877,091 is very useful in sites having low overhead or ceiling. In U.S. Pat. No. 4,877,091 the kelly rotating means is bolted directly to the outer kelly section and as a consequence the outer kelly section is not permitted to slide through the kelly rotating means. Since the top of the kelly assembly is closed changing and/or replacing the kelly sections is more difficult than if the top of the outer kelly section were open. 
     Another useful downcrowdable augering apparatus having kelly sections is disclosed in U.S. Pat. No. 5,746,277 which is concerned with making such apparatus and rigs readily adaptable to mounting on a wide variety of vehicles ranging from light truck beds a to large track type vehicles including caterpillar type machines. The invention facilitates maintenance and changing of kelly assemblies by its unobstructed access to the top of the kelly assembly. For example the top of the kelly assembly is free of rotary drive mechanisms and pulleys associated therewith. U.S. Pat. Nos. 4,877,091 and 5,746,277 are hereby incorporated herein by reference. 
     Non-limiting examples of vehicles in which the augering means of this invention can be used are shown in U.S. Pat. Nos. 4,199,033 and 5,746,277 for backhoes and light trucks, and U.S. Pat. No. 3,216,511, U.S. Pat. No. 4,627,499 and U.S. Pat. No. 4,877,091 for crawler vehicles with rotatable booms. 
     In the present invention the excavation apparatus does not require a winch for letting out and retracting the cable. Nor does the present invention require a reel for storing the retracted cable. Since this invention does not require a winch, it also does not require a motor to drive a winch. Accordingly, the excavation apparatus of this invention is not as heavy. This simplification and other improvements in construction allow this invention to be cheaper to manufacture, maintain and use. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to an excavation apparatus which can be adapted to a variety of vehicles including smaller excavating machines such as backhoes and small trucks. The excavation apparatus can be quickly and easily connected and disconnected to vehicles by a one or two persons with a minimum of tools thereby allowing such vehicles to be converted as needed. For example, the smaller rear bucket on backhoes can quickly removed and the excavation apparatus of this invention installed in place of the rear bucket in about twenty minutes including the required hydraulic lines. 
     Accordingly, there is provided by the principles of the present invention an excavation apparatus comprising kelly assembly means having a kelly assembly housing, an outer kelly section, and an extendable inner kelly section adaptable for attachment of a tool. The excavation apparatus includes kelly rotation means for rotating the kelly sections relative to the kelly assembly housing, support means for supporting the kelly rotation means and the kelly assembly means, frame means for allowing the kelly assembly housing to slide relative to the frame means in a direction parallel to the axis of the kelly assembly means, and downcrowd means for downcrowding the support means relative to the frame means. 
     The downcrowd means has a first end connected to and supported by the frame means, and a second end connected to and supporting the support means. 
     The excavation apparatus also includes kelly deployment and retraction means for deploying the extendable inner kelly section out of the kelly assembly housing and for retracting the extendable inner kelly section back into the kelly assembly housing. The kelly deployment and retraction means has at least one kelly extension sheave supported by the frame means, and a cable having a first end attached to the extendable inner kelly section and a second end attached directly or indirectly to either the support means or the frame means depending on the total number of kelly extension sheaves. The cable is looped alternatively under and over said at least one kelly extension sheave. The downcrowd means also serves as means for letting out and retracting the cable, thereby enabling the excavation apparatus to function without a winch for letting out and retracting the cable and without a reel for storing the retracted cable. 
     In one embodiment, the kelly assembly means has a kelly assembly housing, a non-extendable outer kelly section, and at least one extendable kelly section which includes an innermost kelly section adaptable for attachment of a tool thereto. In this embodiment, the kelly deployment and retraction means deploys the extendable kelly sections out of the kelly assembly housing and retracts the extendable inner kelly sections back into the kelly assembly housing. 
     In one embodiment, the kelly assembly means includes at least one extendable middle kelly section disposed between the innermost kelly section and the outer and non-extendable kelly section. 
     In another embodiment, the kelly assembly means includes at least guide rail means attached on an outside wall of the kelly assembly housing, and the frame means includes at least bearing channel means effective for sliding along the guide rail means and preventing rotation of the kelly assembly housing relative to the frame means. 
     In still another embodiment, the kelly rotation means includes at least a kelly drive shroud for rotatably driving the outer kelly section. In a further embodiment, the excavation apparatus includes rotary motor means for driving the kelly rotation means, and in a preferred embodiment, the excavation apparatus including two rotary motors for driving the kelly rotation means. 
     In one embodiment, the kelly assembly housing is attached to and supported by the support means. 
     In one embodiment, the downcrowd means is hydraulically powered. In another embodiment, the downcrowd means includes a multistage hydraulic cylinder. 
     In one embodiment, the kelly deployment and retraction means includes at least redirect cable support means for directing the cable between the innermost kelly section and a kelly extension sheave. In a further embodiment, the kelly deployment and retraction means also includes at least one kelly extension sheave rotatably supported by the support means. In a still further embodiment, the cable is looped over the kelly extension sheave rotatably supported by the support means. 
     In another embodiment, said at least one kelly extension sheave includes a plurality of lower kelly extension sheaves rotatably supported by the frame means and a plurality of upper kelly extension sheaves rotatably supported by the support means. In a further embodiment, the cable is alternately deployed under lower, and over upper, kelly extension sheaves. 
     In one embodiment, the second end of the cable is attached directly or indirectly to the support means if the total number of lower and upper sheaves is an odd number. In another embodiment, the second end of the cable is attached directly or indirectly to the frame means if the total number of extension sheaves is an even number. In still another embodiment, the plurality of lower kelly extension sheaves is four and the plurality of upper kelly extension sheaves is three. 
     In one embodiment, the frame means includes vehicle-connection means for connecting to a distal end of the boom means of a vehicle. In a further embodiment, wherein the vehicle has both a boom means and associated tilt means, the frame means includes both boom-connection means for connecting to a distal end of the boom member, and tilt-connection means for connecting to a distal end of the tilt means. 
     In one embodiment, the excavation apparatus further includes hydraulically powered rotary motor means for driving the kelly rotation means. In a further embodiment, wherein the vehicle has a hydraulic system, the excavation apparatus includes means for hydraulically connecting the vehicle&#39;s hydraulic system to the hydraulically powered rotary motor means. In a still further embodiment, where there is a need to use vehicle with multiple excavation tools, the means for hydraulically connecting the vehicle&#39;s hydraulic system to the hydraulically powered rotary motor means includes quick connect hydraulic means. 
     In one embodiment, the downcrowd means is hydraulically powered. In a further embodiment, wherein the vehicle has a hydraulic system, the excavation apparatus further includes means for hydraulically connecting the vehicle&#39;s hydraulic system to the hydraulically powered downcrowd means. In a still further embodiment, the means for hydraulically connecting the vehicle&#39;s hydraulic system to the hydraulically powered downcrowd means includes quick connect hydraulic means. 
     In another embodiment, the excavation apparatus is for removable and pivotable attachment to boom means of an excavation machine. In a further embodiment, wherein the boom means of the excavation machine has a front boom hinged to a back boom, the boom-connection means of the frame means of the excavation apparatus is pivotally connected to a distal end of the front boom. 
     The excavation machines to which the excavation apparatus of this invention are especially useful can be selected from the group consisting of backhoes, including backhoes having a boom extension member. However, this invention can also be used on pick-up trucks and other lighter weight vehicles adapted with an arm effective for connecting to the boom-connection means of the excavation apparatus. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a left side view of a first embodiment of an excavation apparatus of this invention with three kelly sections fully retracted. 
     FIG. 2 is a left side view of the excavation apparatus of FIG. 1 with the kelly sections fully extended. 
     FIG. 3 is a left side view of a second embodiment of an excavation apparatus of this invention with five kelly sections fully retracted. 
     FIG. 4 is a left side view of the excavation apparatus of FIG. 3 with the kelly sections fully extended. 
     FIG. 5 is a left side view of a third embodiment of an excavation apparatus of this invention with two kelly sections fully retracted. 
     FIG. 6 is a left side view of the excavation apparatus of FIG. 1 with the kelly sections fully extended. 
     FIG. 7 is a left side view of a fourth embodiment of an excavation apparatus of this invention mounted on a backhoe. 
     FIG. 8 is a right side view of the excavation apparatus of FIG. 7 this invention with kelly sections fully retracted. 
     FIG. 9 is a left side view of the excavation apparatus of FIG. 8 with the kelly sections fully retracted. 
     FIG. 10 is a rear view of the excavation apparatus of FIG. 7 this invention with kelly sections fully retracted. 
     FIG. 11 is a right side view of the excavation apparatus of FIG. 7 with kelly sections fully extended. 
     FIG. 12 is a left side view of the excavation apparatus of FIG. 7 with the kelly sections fully extended. 
     FIG. 13 is a top view of the excavation apparatus of FIG.  7 . 
     FIG. 14 is a bottom view of the excavation apparatus of FIG.  7 . 
     FIG. 15 is an enlarge right side view of the tilt-connection assembly shown in FIG.  8 . 
     FIG. 16 is a rear view of tilt-connection assembly of FIG.  15 . 
     FIG. 17 is an enlarged top view of the gear box body of the kelly rotation means of FIG. 13 but with the cover removed. 
     FIG. 18 is a cross-sectional view of the gear box body taken through line  18 — 18  of FIG.  17 . 
     FIG. 19 is an enlarged top view of the cover for the gear box body of the kelly rotation means of FIG.  13 . 
     FIG. 20 is a cross-sectional view of the cover taken through line  20 — 20  of FIG.  19 . 
     FIG. 21 is a top view of the gear box body of FIG. 13 showing the central circular opening for the outer kelly section and the two smaller right and left circular openings for the two rotary motors. 
     FIG. 22 is a front view of the gear box body of FIG.  21 . 
     FIG. 23 is a greatly enlarged top view of the central ring gear and ball bearing race assembly shown in FIG.  18 . 
     FIG. 24 is a cross-sectional view of the central ring gear and ball bearing race assembly taken through line  24 — 24  of FIG.  23 . 
     FIG. 25 is a greatly enlarged top view of the kelly drive shroud shown in FIG.  17 . 
     FIG. 26 is a cross-sectional view of the kelly drive shroud taken through line  26 — 26  of FIG.  25 . 
     FIG. 27 is a bottom view of the support means of FIG. 14 showing the extended flange portion with upper kelly sheave extension assembly, and the annular flange portion with several bolt holes. 
     FIG. 28 is a right side view of the support means of FIG.  27 . 
     FIG. 29 is a side view of the outer kelly section, the opposite side view being identical. 
     FIG. 30 is a side view of the top portion of the outer kelly section rotated 90° from that shown in FIG. 29, the opposite side view being identical. 
     FIG. 31 is a cross-sectional view of the kelly assembly housing of FIG. 8 with kelly sections fully retracted. 
     FIG. 32 is an enlarged rear detailed view in cross section of the upper kelly extension sheave assembly. 
     FIG. 33 is a cross-sectional left side view taken through line  33 — 33  of the upper kelly extension sheave assembly of FIG.  32 . 
     FIG. 34 is an enlarged rear detailed view in cross section of the lower kelly extension sheave assembly. 
     FIG. 35 is a cross-sectional left side view taken through line  35 — 35  of the lower kelly extension sheave assembly of FIG.  34 . 
     FIG. 36 is a schematic diagram of the hydraulic system for the rotary motors of the excavating apparatus of FIG.  7 . 
     FIG. 37 is a schematic diagram of the hydraulic system for the downcrowd means of FIG.  7 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A first embodiment  30  of the excavation apparatus of this invention is shown functionally and schematically in FIGS. 1 and 2 which comprises kelly assembly means  31 , kelly rotation means  32 , support means  33 , frame means  34 , downcrowd means  35 , and kelly retraction means  36 . 
     Kelly assembly means  31  comprises kelly assembly housing  38  which houses three kelly sections, specifically outer kelly section  39 , middle kelly section  40  and inner kelly section  41 . Outer kelly section  39  remains within kelly assembly housing  38  at all times and does not extend therefrom. Kelly rotation means  32  rotates outer kelly section  39  which in turn rotates middle kelly section  40  which in turn rotates inner kelly section  41 . Augering tool means  42  is attached to the bottom of inner kelly section  41  and rotates therewith. 
     Support means  33  directly or indirectly supports kelly assembly means  31 , kelly rotation means  32  and rotary motor  43 . Rotary motor  43  drives kelly rotation means  32 . 
     Frame means  34  permits kelly assembly housing  38  to slide in a direction which is parallel to the axis  45  of kelly assembly means  31 . In embodiment  30  the direction of the movement of the kelly assembly means is also coaxial with axis  45 . Frame means  34  supports downcrowd means  35  which, in this embodiment, comprises two stage hydraulic cylinder  47  having the top distal end of the inner rod  48  pivotally connected by pin means  49  to support means  33 , with the hydraulic cylinder housing  50  pivotally connected by pin means  51  directly or indirectly to frame means  34 . 
     In embodiment  30  kelly retraction means  36  comprises cable  52  having one end  53  swivelly attached to the top  54  of inner kelly section  41  and its other end  55  attached to frame means  34 . Cable  52  runs from end  53  upwards and over cable redirect sheaves  56  and  57  which are rotatably mounted on redirect sheaves support means  58 , downward and under kelly extension sheave  59  which is rotatably mounted directly or indirectly on frame means  34 , upwards and over kelly extension sheave  60  which is rotatably mounted directly, or indirectly by bracket  64 , on support means  33 , and downward to frame means  34  where cable end  55  is attached. Redirect sheaves support means  58  is supported directly or indirectly by support means  33 . Kelly extension sheave  59  is shown directly supported by bracket  67  with is supported by frame means  34 . 
     It can be seen that when hydraulic cylinder  47  is in its fully extended position shown in FIG. 1, middle and inner kelly sections are  40  and  41 , respectively, are fully retracted into kelly assembly housing  38 . However, as hydraulic cylinder  47  is retracted, as shown in FIG. 2, support means  33  is pulled towards frame means  34  while simultaneously permitting cable  52  to be played out thereby allowing the middle and inner kelly sections to extend out of and below the lower end  46  of kelly assembly housing  38 . The combined weight of the middle and inner kelly sections  40  and  41 , respectively, and augering tool means  42  keeps the cable taut. 
     Retracting the kelly sections merely requires reversing the procedure; specifically, extending the rods of the hydraulic cylinder  47  to their fully extended positions, as shown in FIG. 1, which automatically and simultaneously retrieves that portion of the cable which was played out during downcrowding of the support means  33  by the retraction of the rods of the hydraulic cylinder  47 . 
     Thus, it can be seen that in this invention, no winch is required to retract the cable or the kelly sections, thereby simplifying the excavation apparatus and lowering the manufacturing cost. 
     In this embodiment, for every foot that support means  33  is pulled towards frame means  34 , three feet of cable  52  is lowered into kelly assembly means  31  thereby lowering augering means  42  the aforementioned three feet plus one foot more due to downcrowding of the kelly assembly means itself or four foot total below frame means  34 . 
     Frame means  34  comprises a right member  62 , a left member  63 , and four cross members  343 ,  344 ,  345  and  346  which secure left member  63  rigidly to right member  62 . Both right and left members  62  and  63  have a channel forming members  65  for receiving right and left guide rails  66  mounted on diagonally opposed sides of kelly assembly housing  38 . Channel forming members  65  are designed to permit guide rails  66  and hence kelly assembly means  32  to slide up and down only in the direction of axis  45 . 
     The excavation apparatus  30  can be mounted on a support structure (not shown in FIGS. 1 and 2) using pins or bolts placed through bores  68  and  69  in the tilt-connection portion of frame means  34 . For example, the distal end of a fixed boom (not shown in FIGS. 1 and 2) can be pivotally connected to frame means  34  by a pin or bolt through bore  68  thereby enabling excavation apparatus  30  to be pivoted about the axis of bore  68 . Likewise the distal end of a hydraulic cylinder rod can be pivotally connected to frame means  34  by a pin or bolt through bore  69  with the distal end of the hydraulic cylinder body pivotally connected near the other end of the boom. With such an arrangement the excavation apparatus can be controllably tilted off vertical as desired. 
     A second embodiment  70  of the excavation apparatus of this invention is shown functionally and schematically in FIGS. 3 and 4 which, as in the first embodiment  30 , also comprises kelly assembly means  31 , kelly rotation means  32 , support means  33 , frame means  34 , downcrowd means  35 , and a kelly retraction means  75 . 
     Components of embodiment  70  having the same element number as that of embodiment  30  perform the same function in the same manner as described above with reference to FIGS. 1 and 2. 
     Kelly assembly means  31  comprises kelly assembly housing  38  which houses five kelly sections, specifically outer kelly section  39 , middle kelly sections  71 ,  72  and  73  and inner kelly section  41 . As in all embodiments of this invention, outer kelly section  39  remains within kelly assembly housing  38  at all times and does not extend therefrom. Kelly rotation means  32  rotates outer kelly section  39  which in turn rotate middle kelly sections  71 ,  72  and  73 , which in turn rotates inner kelly section  41 . Augering tool means  42  is attached to the bottom of inner kelly section  41  and rotates therewith. 
     In embodiment  70 , however, kelly retraction means  75  comprises seven kelly extension sheaves, three of which are rotatably supported directly or indirectly by support means  33 , and four of which are rotatably supported directly or indirectly by frame means  34 . In this embodiment, cable  52  has one end  53  swivelly attached to the top  54  of inner kelly section  41  and its other end  76  attached to frame means  34 . Cable  52  runs from end  53  upwards and over cable redirect sheaves  56  and  57 , downward and under kelly extension sheave  59 , upwards and over kelly extension sheave  60 , downward and under kelly extension sheave  78 , upwards and over kelly extension sheave  79 , downward and under kelly extension sheave  80 , upwards and over kelly extension sheave  81 , downward and under kelly extension sheave  82 , and upward to support means  32  where cable end  76  is attached. 
     It can be seen that when hydraulic cylinder  47  is in its fully extended position shown in FIG. 3, middle and inner kelly sections  71 ,  72 ,  73  and  41 , are fully retracted into kelly assembly housing  38 . However, as hydraulic cylinder  47  is retracted, as shown in FIG. 4, support means  33  is pulled towards frame means  34  while simultaneously permitting cable  52  to be played out thereby allowing the middle and inner kelly sections to extend out of and below the lower end  46  of kelly assembly housing  38 . The combined weight of the middle and inner kelly sections  71 ,  72 ,  73  and  41 , and augering tool means  42  keeps the cable taut. 
     As in embodiment  30 , retracting the kelly sections in embodiment  70  merely requires reversing the procedure; specifically, extending the rods of the hydraulic cylinder  47  to their fully extended positions, as shown in FIG. 3, which automatically and simultaneously retrieves that portion of the cable which was played out during downcrowding of the support means  33 . Thus, it can be seen that in embodiment  70 , no winch is required to retract the cable or the kelly sections, thereby simplifying the excavation apparatus and lowering the manufacturing cost. 
     In embodiment  70 , for every foot that support means  33  is pulled towards frame means  34 , eight feet of cable  52  is lowered into kelly assembly means  31  thereby lowering augering means  42  the aforementioned eight feet plus one foot more due to downcrowding of the kelly assembly means itself or nine foot total below frame means  34 . 
     A third embodiment  85  of the excavation apparatus of this invention is shown functionally and schematically in FIGS. 5 and 6 which, are similar to the first embodiment  30  except that there are only two kelly sections and kelly extension sheave  60  has been omitted. 
     Components of embodiment  85  having the same element number as that of embodiments  30  and  70  perform the same function in the same manner as described above with reference to FIGS. 1-4. 
     Kelly assembly means  31  comprises kelly assembly housing  38  which houses two kelly sections, specifically outer kelly section  39  and inner kelly section  41 . As in all embodiments of this invention, outer kelly section  39  remains within kelly assembly housing  38  at all times and does not extend therefrom. Kelly rotation means  32  rotates outer kelly section  39  which in turn rotates inner kelly section  41  which rotates augering tool means  42 . 
     In embodiment  85 , however, kelly retraction means  86  has but one kelly extension sheave  59  which is rotatably supported directly or indirectly by frame means  34 . In this embodiment, cable  52  has one end  53  swivelly attached to the top  54  of inner kelly section  41  and its other end  76  attached to support means  33 . Cable  52  runs from end  53  upwards and over cable redirect sheaves  56  and  57 , downward and under kelly extension sheave  59 , and upward to support means  32  where cable end  76  is attached. 
     When hydraulic cylinder  47  is in its fully extended position as shown in FIG. 5, inner kelly section  41  is fully retracted into kelly assembly housing  38 . However, as hydraulic cylinder  47  is retracted, as shown in FIG. 6, support means  33  is pulled towards frame means  34  while simultaneously permitting cable  52  to be played out thereby allowing the inner kelly section to extend out of and below the lower end  46  of kelly assembly housing  38 . The combined weight of the inner kelly section  41  and augering tool means  42  keeps the cable taut. 
     As in embodiments  30  and  70 , retracting the kelly sections in embodiment  85  merely requires reversing the procedure; specifically, extending the rods of the hydraulic cylinder  47  to their fully extended positions, as shown in FIG. 5, which automatically and simultaneously retrieves that portion of the cable which was played out during downcrowding of the support means  33 . Thus, it can be seen that in embodiment  85 , no winch is required to retract the cable or the kelly sections, thereby simplifying the excavation apparatus and lowering the manufacturing cost. 
     In embodiment  85 , for every foot that support means  33  is pulled towards frame means  34 , two feet of cable  52  is lowered into kelly assembly means  31  thereby lowering augering means  42  the aforementioned two feet plus one foot more due to downcrowding of the kelly assembly means itself or three foot total below frame means  34 . 
     FIGS. 1-6 are schematic diagrams to show how the kelly extension sheaves function to extend the cable into and out of the kelly assembly means. In practice, however, the upper and lower kelly extension sheaves are preferably rotatably mounted on a common upper and lower shafts, respectively, with the axis of the common shafts perpendicular to that shown in FIGS. 1-6. Such arrangement produces a more compact design as will be seen in the following embodiment where, as in embodiment  70 , there are seven kelly extension sheaves. 
     A fourth embodiment  100  of the excavation apparatus of this invention is shown in FIGS. 7 to  35  which, is similar in some aspects to the second embodiment  70 . 
     Accordingly, FIG. 7 shows a fourth embodiment  100  of this invention illustrating an excavation apparatus pivotally connected to a conventional backhoe  200 . Backhoe  200  has a primary boom  202  pivotally connected at point  204  to backhoe support frame member  206 . Secondary boom  208  is pivotally connected at point  210  to primary boom  202 . The base of hydraulic cylinder  212  is pivotally connected at point  214  to boom  202 . The distal end of the hydraulic cylinder rod is pivotally connected at point  216  to boom  208 , thereby enabling boom  208  to be pivoted in the plane of boom  202  in a conventional manner. 
     Referring also to FIGS. 8 and 16, a distal end of boom  208  is pivotally connected to the excavation apparatus  100  at a point functionally similar to bore  68  in FIGS. 1-6 and specifically by pin means  681  in a conventional manner. The housing base of hydraulic cylinder  218  is pivotally connected at point  220  to boom  208  and a distal end of rod  222  is pivotally connected to the excavation apparatus  100  at a point functionally similar to bore  69  in FIGS. 1-6 and specifically by pin means  691  in a conventional manner, thereby enabling excavation apparatus  100  to be pivoted in the plane of booms  202  and  208 . Both hydraulic cylinders  212  and  218  are controlled by conventional hydraulic system control means located in or near shielded operator area  230  of backhoe  200 . 
     Excavation apparatus  100  is similar to above described embodiment  70  in that it has five kelly sections and seven kelly extension sheaves. Excavation apparatus  100  comprises kelly assembly means  31 , kelly rotation means  32 , support means  33 , an frame means  340 , downcrowd means  35 , and a kelly retraction means  750 . In particular, FIGS. 8,  9  and  10  show the right side, left side and rear views, respectively, of excavation apparatus  100  having all its kelly sections fully retracted into annular kelly assembly housing  38 . FIGS. 11 and 12 show the right and left side views, respectively, of excavation apparatus  100  with all the extendable kelly sections, i.e.  71 ,  72 ,  73  and  41 , fully extended from the kelly assembly housing  38 . FIGS. 13 and 14 show the top and bottom views, respectively, of excavation apparatus  100 . Auguring tool means  42  is not attached in FIG. 14 in order to more clearly show the components of this invention. 
     Kelly assembly means  31  comprises the kelly assembly housing  38  which houses five kelly sections, specifically outer kelly section  39 , middle kelly sections  71 ,  72  and  73  and inner kelly section  41  as shown in FIGS. 11 and 31. Non-rotatable kelly assembly housing  38  is cylindrical in cross section. Rotatable kelly sections  39 ,  71 ,  72 ,  73  and  41  are square-shaped annuluses in cross section. As in all embodiments of this invention, the kelly assembly housing  38  is slidable relative to the frame means  340 , and outer kelly section  39  remains within kelly assembly housing  38  at all times and is not extendable therefrom. Kelly rotation means  32  rotates outer kelly section  39  which in turn rotate middle kelly sections  71 ,  72  and  73 , which in turn rotates inner kelly section  41 . Augering tool means  42  is attached to the bottom of inner kelly section  41  and rotates therewith. 
     Referring to FIGS. 17,  18 ,  19  and  20 , the kelly rotation means  32  comprises a gearbox body  321  and gearbox cover  323 . Gearbox body  321  houses two small pinion gears  322 , a large central ring gear and ball bearing race assembly  324 , and a kelly drive shroud  325 . Gearbox cover  323  has been removed and is not shown in FIG.  17 . 
     Referring also to FIGS. 21 and 22, gearbox body  321  has sidewall portion  326  containing peripheral threaded holes  327 , and base portion  328  containing large central opening  329 . Gearbox body  321  can be made of 6061-T6 aluminum plate welded together to produce the desired shape. The bottom portion of gearbox body  321  can be machined from 1.5 inch aluminum plate. 
     Referring also to FIGS. 23 and 24, ring gear and ball bearing race assembly  324  comprises ring gear portion  435  having threaded holes  436 , and ball bearing portion  437  having threaded holes  438 . Portions  435  and  437  are separated by ball bearings  439 . Assembly  324  is a Kaydon gear which may be purchased from Kaydon Corporation, Muskegon, Mich. 
     Referring also to FIGS. 18,  25  and  26 , kelly drive shroud  325  comprises central square opening  441  and flange  442  having holes  445 . The kelly rotation means  32  is positioned so that the center of kelly drive shroud  325  coincides with axis  45  of kelly assembly means  31 . Opening  441  and flange  442  are separated by wall portion  443 . Kelly drive shroud  325  is rotatably attached to assembly  324  by tightening bolts  444  extending through holes  445  in flange  442  and into threaded holes  436  in ring gear portion  435 . 
     Referring also to FIGS. 27 and 28, the upper most portion of kelly assembly housing  38  comprises an extended flange which, in this embodiment, also function as the support means  33 . Support means  33  is bolted to kelly rotation means  32  by tightening bolts  331  passing through holes  332  in the annular flange portion  334  of support means  33 , then through holes  481  in base portion  328  of gearbox body  321 , then into threaded holes  438  in ball bearing portion of assembly  324 , thereby causing base portion  328  to be sandwiched fixedly between support means  33  and the ball bearing portion  437  of assembly  324  as shown in FIG.  18 . 
     Two hydraulically powered rotary motors  43  are mounted in axial alignment with shaped mounting holes  431  in the base portion  328  of gearbox body  321 . The shafts  432  of rotary motors  43  drive pinion gears  322 , which in turn drive ring gear portion  435  of assembly  324 , which in turn drives kelly drive shroud  325 , which in turn drives outer kelly section  39 . Rotary motors  43  useful for this invention are Danfoss motor model no. OMV500, #151B2157, with a splined 2.125 inch shaft. 
     Before kelly drive shroud  325  is attached to assembly  324 , it is preferable to first attached support means  33  to gearbox body  321  and assembly  324  so that bolts  331  can be seen as they are screwed into threaded holes  438 . Thereafter kelly drive shroud  325  is attached to assembly  324  as described above. 
     Next a seal ring  446  with an annular flexible dust gasket  447  is installed on gearbox cover  323  by bolts  448  screwed into threaded holes  449  in cover  323 . Then cover  323  is installed on gearbox body  321  by bolts  371  fed through peripheral holes  372  in cover  323  and screwed into peripheral threaded holes  327  in sidewall portion  326  of gearbox body  321  with gasket  447  being pressed down into large central circular opening  373  in cover  323  against the outside diameter of wall portion  443  of shroud  325 . 
     Referring to FIGS. 29,  30  and  31 , outer kelly section  39  has near the top and bottom thereof four metal strips  461  and  462 , respectively, on the four sides of outer kelly section  39 , and closest to the bottom distal end thereof, a bottom ring  391 . Confined between strips  462  and ring  391  is a lower annular bearing  465 . Bearing  465  can be made of solid nylon or teflon or any other effective solid plastic or bronze material. An effective material is Nylatron™ brand solid nylon made by Polymer Corp., Reading, Pa. Such plastic bearing is split longitudinally along a radius and can be installed by stretching the plastic bearing apart enough to allow slippage around outer kelly section  39 ; and when released, the plastic bearing reforms itself into an annulus. 
     With hydraulic cylinder  47  fully extended, outer kelly section  39  and the four extendable kelly sections  71 ,  72 ,  73  and  41  are installed as a concentric unit through the bottom of, and into, kelly assembly housing  38  and into square opening  441  in kelly drive shroud  325  until upper strips  461  abut the lower surface  463  of shroud  325  as shown in FIGS. 13,  18  and  29  to  31 . Retainer member  374  is then secured to the top of outer kelly section  39  by screwing bolts  376  through holes  394  into mating threaded holes  379  in retainer member  374 , thereby securing outer kelly section  39  in kelly assembly housing  38 . Kelly drive shroud  325  and lower annular bearing  465  keep outer kelly section  39  axially centered in housing  38  during rotation of the kelly sections. 
     The lengths of the kelly sections  39 ,  71 ,  72 ,  73  and  41  are designs so that when the kelly sections are fully retracted into kelly assembly housing  38 , their bottom annular lift members  711 ,  721 ,  731  and  411 , respectively, will be abutted in a stacked relationship against bottom annular member  391  of kelly sections  39 , and the top  54  of inner kelly section  41  will be above retainer member  374 , after passing through axial hole  375  in member  374 , as shown in FIGS. 13 and 31. While maintaining the kelly sections fully retracted into kelly assembly housing  39 , swivel  531  is attached to the top end  54  of inner kelly section  41 , and cable end  53  is attached to swivel  531  thereby securing the extendable kelly sections,  71 ,  72   73  and  41 , in kelly assembly means  31 . 
     More kelly sections can be included in any given cross sectional area by having upper stops only on two adjacent sides rather than all four sides of kelly sections  41 ,  73 ,  72 , and  71  as illustrated in FIG.  31 . The four faces of the kelly sections will be referred to as the west, north, east and south faces. This is achieved by having upper stops  412  and  722  on the kelly sections  41  and  72 , respectively, only on their west and north outer faces while kelly sections  73  and  71  have upper stops  732  and  712 , respectively, only on their east and south outer faces. Thus the location of the upper stops on the outer faces is alternated between the west and north pair and the east and south pair of adjacent kelly sections. 
     Lower stops  733 ,  723 ,  713  and  393  on the inner faces of kelly section  73 ,  72 ,  71  and  39 , respectively, are also provided on the opposite faces as the upper stops. In such arrangement the axes of inner kelly section  41  and outer kelly section  39  can be made to coincide if the total number of kelly sections is an odd number as shown in FIG.  31 . If an even number of kelly sections is used then one way of minimizing any eccentricity between the axes of outer kelly section and inner kelly section, if desired, is to make the number of lower stops between the outer kelly section and upper stops on the kelly section adjacent thereto four, thereby insuring that the axes of the inner kelly section  41  and the kelly assembly housing  38  coincides. However, since an even complement of kelly sections would cause a concentric error of only about one eighth of an inch, such corrective measures are generally of little or no concern. 
     Referring again to FIGS. 7-16, frame means  340  comprises right and left side plate members  341  and  342 , respectively, which are rigidly bolted by bolts  348  to upper front and rear traverse members  343  and  344 , respectively, and lower front and rear traverse members  345  and  346 , respectively. Frame means  340  further comprises tilt-connection assembly  670  having bores  680  and  690  which serves the same function as tilt-connection portion and bores  68  and  69 , respectively, shown in FIGS. 1-6. Tilt-connection assembly  670  comprises side members  671  and  672 , which are welded to, and separated by, large traverse plate  673  and smaller traverse members  674  and  675 . Side member  672  is bolted to right side plate member  341  by screwing bolts  349  extending through holes  677  in right side plate member  341  into mating threaded holes  676  in side member  672 , thereby insuring that side plate member  341  moves with side member  672  at all times. A bore  221  in the distal end of boom  208  is positioned between side members  671  and  672  and aligned with bores  680 . While so aligned, a boom pin means  681  is inserted through side members  671  and  672  and into bores  221  and  680  and locked into place. A coupling  224  with a bore  225  attached to the distal end of hydraulic cylinder rod  222  is positioned between side members  671  and  672  and aligned with bores  690 . While so aligned, a rod pin means  691  is inserted through side members  671  and  672  and into the bores  225  and  690  and locked into place thereby pivotally securing excavation apparatus  100  in a tiltable relationship to boom  208  of backhoe  200 . 
     Frame means  340  also permits kelly assembly housing  38  to slide relative to frame means  340  in a direction which is parallel to, and coaxial with, the axis  45  of kelly assembly means  31 . Side members  341  and  342  have bolted thereto a pair of channel forming members  65  which form side bearing channels adaptable for receiving right and left guide rails  66  mounted on diagonally opposed sides of kelly assembly housing  38 . Channels formed between channel forming members  65 , are designed to permit guide rails  66  and hence kelly assembly means  32  to slide up and down relative to frame means  340  only in the direction of axis  45  of kelly assembly means  31 . 
     With reference to FIGS. 8,  14 ,  27  and  28 , frame means  340  also supports downcrowd means  35  which, in this embodiment, comprises two stage hydraulic cylinder  47 . The top distal end of the inner rod  48  of hydraulic cylinder  47  is pivotally connected by pin means  49  to a brace  491  welded to the lower surface of extended flange portion  333  of support means  33 . The base of hydraulic cylinder housing  50  is pivotally connected by pin  51  to a brace  501  secured to lower rear traverse member  346  of frame means  340 . 
     Referring additionally to FIGS. 8,  10 ,  13 ,  27 ,  28 , and  32  through  35 , kelly retraction means  750  comprises redirect sheaves support means  58  with cable redirect sheaves  56  and  57 , upper kelly extension sheave assembly  601  with kelly extension sheaves  60 ,  79  and  81 , and lower kelly extension sheave assembly  591  with kelly extension sheaves  59 ,  78 ,  80  and  82 . Thus in excavation apparatus  100  there are seven kelly extension sheaves. Kelly extension sheaves  60 ,  79  and  81  are rotatably mounted on a common axle  602  of an upper bracket means  603  which is welded to the lower surface of the extended flange portion  333  of support means  33 . Kelly extension sheaves  59 ,  78 ,  80  and  82  are rotatably mounted on a common axle  592  of a lower bracket means  593  which is welded to, and supported by, upper rear traverse member  344  of frame means  340 . Semi-cylindrical members  594  and  604  prevent cable  52  from dislodging from the seven kelly extension sheaves should any slack develop in the cable when the excavation apparatus is in use. 
     In this embodiment, cable  52  has one end  53  attached to swivel  531  which is attached to the top  54  of inner kelly section  41 . The other end  76  of cable  52  attached to flange  605  which is welded to upper bracket means  603 . Cable end  53 , swivel  531  and inner kelly top  54  are seen in FIGS. 8 and 31. Cable  52  runs from end  53  upwards and over cable redirect sheaves  56  and  57 , downward and under kelly extension sheave  59 , upwards and over kelly extension sheave  60 , downward and under kelly extension sheave  78 , upwards and over kelly extension sheave  79 , downward and under kelly extension sheave  80 , upwards and over kelly extension sheave  81 , downward and under kelly extension sheave  82 , and upward to flange  605  of upper bracket means  603  where the cable end  76  is attached. 
     With regard to the downcrowd means  35 , it can be seen that when hydraulic cylinder  47  is in its fully extended position shown in FIGS. 8 through 10, middle and inner kelly sections  71 ,  72 ,  73  and  41 , are fully retracted into kelly assembly housing  38 . However, as hydraulic cylinder  47  is retracted, as shown in FIGS. 11 and 12, support means  33  is pulled towards frame means  340  while simultaneously permitting cable  52  to be played out thereby allowing the middle and inner kelly sections to extend out of and below the lower end  46  of kelly assembly housing  38 . The combined weight of the middle and inner kelly sections  71 ,  72 ,  73  and  41 , and augering tool means  42  helps to keep the cable taut. 
     As in the previously described embodiments, retracting the kelly sections in embodiment  100  merely requires reversing the procedure; specifically, extending the rods of the hydraulic cylinder  47  to their fully extended positions, as shown in FIGS. 8,  9  and  10 , which automatically and simultaneously retrieves that portion of the cable which was played out during downcrowding of the support means  33 . Thus, it can be seen that in embodiment  100 , no winch is required to retract the cable or the kelly sections, thereby simplifying the excavation apparatus and lowering the manufacturing cost. 
     In embodiment  100 , for every foot that support means  33  is pulled towards frame means  340 , eight feet of cable  52  is lowered into kelly assembly means  31  thereby lowering augering means  42  the aforementioned eight feet plus one foot more due to downcrowding of the kelly assembly means itself or nine foot total below frame means  340 . 
     The hydraulic systems for embodiment  100  are shown schematically in FIGS. 36 and 37. In particular, FIG. 36 illustrates an effective hydraulic circuit for powering and controlling the operation of the rotary motors  43 . Control valve  902  having foot peddle  904  is mounted in a convenient operator position in operator area  230  of backhoe  200 . Relief valve means  905  can be set to a predetermined pressure, for example 3100 psi to prevent damage to valve  902  and the other hydraulic components in the circuit. Any over pressurization occurring in control valve  902  is relieved through line  906  directly to tank  908 . 
     Hydraulic pump  907  provides a continual source of pressurized hydraulic fluid from hydraulic fluid storage tank  908 . Depending on the foot action of the operator on peddle  904 , hydraulic fluid flows in forward mode into line  910  into two speed valve block assembly  900  and returns in line  911 , or flows in a reverse mode into line  911  into two speed valve block assembly  900  and returns in line  910 , thereby causing rotary motors to operate in a forward or drilling mode or a reverse or removal mode, respectively. Two speed valve block assembly  900  is connected to lines  910  and  911  by quick-disconnect fittings  912  and  913 , respectively. Two speed valve block assembly  900  comprises pilot operated valves  914  and  915 , respectively, and kick down valve  916 . Shuttle valve  917  enables forward and reverse flow to occur. Any excess hydraulic fluid leakage from rotary motors  43  into gearbox body  321  (FIG. 22) is drained through line  918  which is connected by quick-disconnect fitting  920  directly to tank  908  thereby preventing over-pressurization of the gearbox. 
     FIG. 37 illustrates an effective hydraulic circuit for powering and controlling the operation of the downcrowd means  35 . Control valve  932  having foot peddle  934  is mounted in a convenient operator position in operator area  230  of backhoe  200 . Relief valve means  935  can be set to a predetermined pressure, for example 3100 psi to prevent damage to valve  932  and the other hydraulic components in the circuit. Any over pressurization occurring in control valve  932  is relieved through line  936  directly to tank  908 . 
     Hydraulic pump  907  provides a continual source of pressurized hydraulic fluid from hydraulic fluid storage tank  908 . Depending on the foot action of the operator on peddle  934 , hydraulic fluid flows in downcrowd mode into line  940  into downcrowd means  35  and returns in line  941 , or flows in a retract mode into line  941  into downcrowd means  35  and returns in line  940 , thereby causing downcrowd means  35  downcrowd or retract, respectively. Downcrowd means  35  is connected to lines  940  and  941  by quick-disconnect fittings  942  and  943 , respectively. Flow control valve means  947  reduces actuation speed to a more controllable rate by metering flow to downcrowd means  35 . 
     Both hydraulic circuits in FIGS. 36 and 37 employ the same hydraulic pump  907  and the same tank  908 . It is understood that there is actually only one tank  908 . 
     While the preferred embodiments of the present invention have been described, various changes, adaptations and modifications may be made thereto without departing from the spirit of the invention and the scope of the appended claims. The present disclosure and embodiments of this invention described herein are for purposes of illustration and example and modifications and improvements may be made thereto without departing from the spirit of the invention or from the scope of the claims. The claims, therefore, are to be accorded a range of equivalents commensurate in scope with the advances made over the art.

Summary:
An excavation apparatus especially useful when mounted on backhoes and other lighter vehicles used in the construction industry. The excavation apparatus does not require a winch for letting out and retracting its cable nor a reel for storing retracted cable which reduces the weight of the excavation apparatus, lowers its cost while facilitating both operation and servicing. The apparatus has a kelly assembly housing which houses an outer kelly section, and an extendable innermost kelly section adaptable for attachment of a tool. More than one extendable kelly section can be used. A rotary table rotates the kelly sections. A support structure supports the rotary table and the housing. A frame allows the housing to slide relative to the frame in a direction parallel to the axis of the assembly. A downcrowd mechanism, supported by the frame, downcrowds the support structure relative to the frame. A kelly deployment and retraction mechanism deploys all extendable inner kelly sections out of the housing and retracts them back into the housing. This mechanism has at least one kelly extension sheave supported by the frame, and a cable having one end attached to the innermost kelly section and a second end attached to either the support mechanism or the frame. The cable is alternately looped under lower extension, and over upper, extension sheaves so that the downcrowd mechanism also serves for letting out and retracting the cable.