Abstract:
A system for extracting drill cores from a borehole. The system enables a semi-resilient sleeve-inserted in a housing—to be sealed about the circumference of a drill rod thereby allowing for upward backpressure against the drill core when activated. The system comprises: a housing assembly having sleeve retaining annular rings with edge treatment that forces outward displacement of the central region of the sleeve so as to ensure utmost clearance from a drill rod, which traverses said sleeve. The system thereby allows extraction of drill core samples without the time-consuming fishing method therefore increasing productivity by a substantial margin.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to a system for extracting drill cores from a borehole. The system enables a semi-resilient sleeve-inserted in a housing—to be sealed about the circumference of a drill rod thereby allowing for upward backpressure against the drill core when activated. The system comprises: a housing assembly having sleeve retaining annular rings with edge treatment that forces outward displacement of the central region of the sleeve so as to ensure utmost clearance from a drill rod, which traverses said sleeve. The system thereby allows extraction of drill cores without the time-consuming fishing method therefore increasing productivity by a substantial margin. 
       BACKGROUND OF THE INVENTION 
       [0002]    One of the many facets of hard rock mining is exploration drilling comprising generally of boring core samples in bed rock to obtain a clearer picture within the ore body. This in presently accomplished by boring through an ore body using a hollow drill bit and drill rods; leaving a central core within an annular cut in the ore body. Cores are left is the center of a core tube within the hollow drill rod for intermittent extraction. Presently, the core tube retrieval process is much like fishing; involving a long wire cable having latching means to a mating receiving portion at the upper end of the core tube. Once latched, the cable is then pulled upward along with the core tube, which contains the core sample. The process is repeated intermittently until the desired core depth is achieved. This retrieval process accounts for nearly 50% of the available drilling time. 
         [0003]    The inventor sought to provide miners with a device and system that greatly reduces core retrieval time so as to increase actual drilling time per work shift. 
         [0004]    The applicant failed in finding attempts in prior art that provide similar methodologies for core extraction. 
         [0005]    While attempts have been made to refine core-extraction systems, no prior art provides sleeve sealing of drill rods as a means to use water backpressure to extract core samples at a much speedier rate. 
       SUMMARY OF THE INVENTION 
       [0006]    It is thus the object of the present invention to provide the hard rock mining industry with a core extraction system-using sleeve sealing of drill rods as a means to utilize water backpressure to extract core samples. 
         [0007]    In one aspect of the invention, the sleeve may comprise any suitable semi-resilient material type, which has low friction quality. 
         [0008]    In another aspect of the invention, inner diameter of the sleeve is directly proportional to the outer diameter of the traversing rod. 
         [0009]    Accordingly, the device of the present invention therefore provides the hard rock mining industry with a core extraction system-using sleeve sealing of drill rods as a means to utilize water backpressure to extract core samples. 
         [0010]    The utility of the present invention includes but is not limited to rock drill-cores. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    These and other advantages of the invention will become apparent upon reading the following brief description and upon referring to the drawings in which:— 
           [0012]      FIG. 1  is a perspective exploded view of the seal assembly of the present invention. 
           [0013]      FIG. 2  is a partially cross-sectioned view of the seal assembly of the present invention. 
           [0014]      FIG. 3  is a cross-sectioned view of the seal assembly of the present invention shown with the rod seal in a rested position. 
           [0015]      FIG. 4  is a cross-sectioned view of the seal assembly of the present invention shown with the rod seal in a compressed position. 
           [0016]      FIG. 5  is a cross-sectional view selected from  FIG. 3  of the seal assembly of the present invention shown prior to full tightening of the assembly. 
           [0017]      FIG. 6  is a cross-sectional view selected from  FIG. 3  of the seal assembly of the present invention shown after full tightening of the assembly. 
           [0018]      FIG. 7  is a cross-sectioned elevation view of the seal assembly of the present invention shown installed ready for drilling. 
           [0019]      FIG. 8  is a cross-sectioned elevation view of the seal assembly of the present invention shown installed ready for core extraction. 
       
    
    
       [0020]    While the invention is described in conjunction with preferred illustrated embodiments, it will be understood that it is not intended to limit the invention to such embodiments. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims. 
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0021]    In the following description, similar features in the drawings have been given similar reference numerals. 
         [0022]    Although exploration drilling is generally oriented to a downward and upward vertical axis, mild angles are at times used. However, for clarity and illustration of the present invention, the specification will depict the common downward vertical orientation. 
         [0023]    Turning now to  FIG. 1 , a perspective exploded view of the seal assembly  2  of the present invention generally comprising; a male casing adapter  10 , a grip ring  20 , a sleeve housing  30 , a retainer ring  40 , an upper oil seal  45 , a lower oil seal  48 , a sleeve  50 , a form ring  52 , a water inlet  60 , a water outlet  70 , and an oil inlet. 
         [0024]    Turning to  FIG. 2 , a partially cross-sectioned view of the seal assembly of the present invention further comprising:—a male casing adapter  10  having a rigid tubular body threaded at a lower end to mate with a female casing adapter, and a forming end  12 , water ports  14 , and an attachment flange  16  about the full circumference of the tubular adapter  10  wherein said flange further comprises a plurality of fastener perforations therethrough,—a semi-resilient grip ring  20  having a plurality of fastener perforations therethrough and in direct alignment with those of the male casing adapter  10 , and a plurality of grip slots  21  arrayed about the grip ring&#39;s  20  outer circumference for use to apply a wrench therein for rotable insertion and removal of the assembly  2  on and off a female casing adapter,—a sleeve housing  30  having a round tubular body with a lower flange  22  having a plurality of fastener perforations therethrough in direct alignment with those of the male casing adapter  10  and the grip ring  20 , and an upper flange  23  also having a plurality of fastener perforations therethrough in direct alignment with those of a retainer ring  40 , a water inlet  60  angularly and threadedly engaged above the base of the sleeve housing  30  and in direct alignment with a first water port  14  within the male casing adapter  10 , a water outlet  70  also angularly and threadedly engaged above the base of the sleeve housing  30  distal from the inlet  60  and also in direct alignment with a second water port  14  within the male casing adapter  10 , an outwardly raised continuous annular depression  81  located centrally within the sleeve housing  30  through which an oil inlet  81  is adapted,—a retainer ring  40  comprising a annular flanged body with a raised central diameter adapted to engage frictionally within an opening of the upper portion of the sleeve housing  30  and said flanged body also having a plurality of fastener perforations therethrough in direct alignment with those of the upper flange  23  of the sleeve housing  30 ,—an upper oil seal  45  frictionally retained within a seal slot at the upper inner portion of the sleeve housing  30 , which said upper oil seal  45  also engages frictionally against the outer circumference of the raised central portion of the retainer ring  40  thus forming a positive seal therebetween,—a lower oil seal  48  also frictionally retained within a seal slot at the lower inner portion of the sleeve housing  30 , which said upper oil seal  48  also engages frictionally against the outer circumference of the male casing adapter  10  also forming a positive seal therebetween,—a sleeve  50  fabricated of a semi-resilient rubber-like compound, which said sleeve  50  having an outer diameter generally equal to that of the inner diameter of the sleeve housing  30  and a length slightly greater than the distance between a form ring  52  and the forming end  12  at the uppermost portion of the male casing adapter,—a form ring  52  having an annular body wherein its upper face is planar and its inner face is adapted with two circumferential peaks,—an oil inlet  80  threadedly engaged through the sleeve housing  30  wherein the oil inlet  80  is in communication with the outwardly raised continuous annular depression  81  located centrally within said sleeve housing  30 , and fasteners  85  securedly holding the assembly as one. 
         [0025]    Turning to  FIG. 3 , a cross-sectioned view of the seal assembly  2  of the present invention shown with the sleeve  50  in a rested position wherein a drill rod  35  traverses the assembly  2  and said rod  35  is free to rotate within the assembly  2 . This configuration is thus used during the drilling process where water is pumped at a lower rate through and down the drill rod, out the drill bit, up the drill rod then ejected out the water outlet  70  to provide cooling of the drill bit down the bore. Conversely, the water inlet  60  may be adapted to alternate in use between inlet and outlet. 
         [0026]    Turning now to  FIG. 4 , a similar cross-sectioned view of the seal assembly  2  of the present invention shown with the sleeve  50  in a compressed position wherein—rotation of the drill rod is halted and hydraulic oil is compressed at a high rate via the oil inlet. The oil then pressurizes the space between the inner surface of the sleeve housing  30  and the sleeve  50 . The sleeve&#39;s  50  end seal is maintained by being compressed between the form ring  52  above said sleeve  50  and the forming end  12  at the uppermost portion of the male casing adapter  10  thereby creating an annular pinch valve about the circumference of the drill rod. 
         [0027]    Referring now to  FIG. 5 , depicting a better cross-sectional view selected from  FIG. 3  of the seal assembly of the present invention shown prior to full tightening of the fasteners of the assembly wherein an upper oil seal  45  frictionally retained within a seal slot at the upper inner portion of the sleeve housing  30 , which said upper oil seal  45  also engages frictionally against the outer circumference of the raised central portion of the retainer ring  40  thus forming a positive seal therebetween. A closer look at the contacting area adjacent each end of the sleeve  50  is also depicted wherein a form ring  52  having an annular body wherein its upper face is planar and its inner face is adapted with two circumferential peaks  55  &amp;  56 . The innermost peak  55  extending toward the sleeve more so than the outer peak  56 , which said peak  56  is rather slightly recessed. This arrangement is simply mirrored at the sleeve&#39;s  50  opposing end with the exception that the peak formation at the opposing end is integral with the uppermost edge of the male casing adapter. Conversely, the upper form ring  52  may be integral to the retainer ring  40 . 
         [0028]      FIG. 6 , also a cross-sectional view selected from  FIG. 3  of the seal assembly of the present invention shown after full tightening of the assembly wherein once the assembly is fully assembled and tightened, the sleeve  50  becomes compressed while the offset peaks  55  &amp;  56  encourage an outward central bulge tendency at the sleeve&#39;s circumference thereby ensuring maximum clearance between the sleeve&#39;s inner surface and the drill rod&#39;s outer surface as best illustrated in  FIG. 3 . 
         [0029]    Turning now to  FIG. 7 , a cross-sectioned elevation view of the seal assembly of the present invention as shown installed and ready for drilling wherein the configuration entails: an ore body  90  in which a pit  91  is bored so as to insert a female casing  92  set in place within the pit  91  using grout  93  so as to seal and immobilize the casing  92  with the ore body  90 . The seal assembly  2  is threadedly engaged with the female casing  92 , and a drilling rig attached to the drill rod  35  as per current practice. 
         [0030]    In the drilling process, the sleeve  50  is depressurized, allowing it to retract away from the drill rod  35  with sufficient clearance so as to prevent friction against the rotating drill rod  35 . Water is pumped down through the center of the drill rod  35  where it reaches the drill bit  36  to cool said bit  36 . The water then exits the bit end through a plurality of slots at the bit&#39;s lower periphery where said water finds its way up the drilled bore wall where it is forcedly directed to one or more water outlets  60  &amp;  70 . 
         [0031]    Let&#39;s turn to  FIG. 8 , a cross-sectioned elevation view of the seal assembly of the present invention shown installed ready for core extraction wherein the configuration similarly entails: an ore body  90  in which a pit  91  is bored so as to insert a female casing  92  set in place within the pit  91  using grout  93  so as to seal and immobilize the casing  92  with the ore body  90 . The seal assembly  2  is threadedly engaged with the female casing  92 , and a drilling rig attached to the drill rod  35 . 
         [0032]    In the core extraction process, rotation of the drill rod  35  is halted and only the drill head is removed. Hydraulic oil is compressed at a high rate via the oil inlet  80 ; pressurizing the space between the inner surface of the sleeve housing  30  and the sleeve  50  creating an annular pinch valve about the circumference of the drill rod  35 . Water is now pumped into the water inlet  60  down along the drill rod  35  outer wall within the bore where it reaches the drill bit  36 . The pressurized water then enters the bit end through a plurality of slots at the bit&#39;s lower periphery where said water finds its way up the drill rod&#39;s  35  center applying upward force against the base of the core sample  100  thereby extracting the core  100  longitudinally up the drill rod  35 . Once surfaced, the core sample is collected. Water pressure is then removed at the drill head re-installed onto the drill core for yet another drilling cycle. 
         [0033]    Upon referring to the drawing figures and the above specification, it can now be understood how pinch-sealing the immobilized drill rod can afford miners the ability to reverse the water flow to use existing systems along with the present invention to speed the core retrieval process.