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[0001]    References Cited—U.S. Patents  
                                               656994   Aug. 28, 1900   Munn    37/63       1071199   Aug. 26, 1913   Andrews    37/63       1533465   Apr. 17, 1922   Rowe    37/63       1525235   Feb. 3, 1925   Hansen    37/63       2255167   Sep. 9, 1941   Hunn    37/57       3486570   Dec. 30, 1969   Richardson   175/5       3790213   Feb. 5, 1974   Grable   299/8       3856355   Dec. 24, 1974   Grable   299/8       3917326   Nov. 4, 1975   Grable   299/8       4497519   Feb. 5, 1985   Grable   299/8                  
 
         BACKGROUND OF THE INVENTION  
         [0002]    This invention relates to a portable placer exploration and sampling apparatus designed for rapid and low-cost evaluation of valuable mineral content of alluvial, eluvial residual placers. Historically, placers have been one of the most important sources of precious minerals and gems such as gold, diamonds, platinum, emeralds, rubies and sapphires. Valuable minerals are not distributed uniformly through the typical placer deposit. Heavy minerals, in general, and gold, in particular, typically are confined to narrow, discontinuous pay streaks with little or no value between them and typically are concentrated at bedrock levels beneath a great amount of relatively barren overburden. Therefore, representative samples, although critical to exploration, selection and future development of placers are difficult to obtain.  
           [0003]    Typically, land-based placer sampling methods have evolved into two categories—a large number of small samples or a lesser number of bulk samples. Small samples typically have been taken with gasoline powered churn drill, 6″ drive pipe casing and sample baler. Bulk samples typically are taken by several methods, including hand dug excavation, machine-dug shafts, backhoe pits or trenches and bulldozer trenches.  
           [0004]    With the exception of hand excavation, all of the above sampling methods are expensive and difficult, if not impossible, to transport into inaccessible areas. As a result, most placer development has occurred in the relatively accessible placer deposits of the world. One of the primary limitations on opening up virgin placer areas has, therefore, been the high cost of evaluating the economic risk and feasibility of further development of relatively inaccessible sites. This invention addresses this limitation by providing features which have not previously been available in traditional placer sampling methods, including  
           [0005]    light weight and ease of assembly of components permits sampling of placers considered inaccessible to traditional sampling methods,  
           [0006]    low capital and operating costs and simplicity of operation allows application of a large number of systems and employment of a large number of unskilled workers for wide scale testing of candidate placers,  
           [0007]    large sample volumes provide for increased sampling accuracy and, in many cases, financing of the sampling program through recovered precious mineral values,  
           [0008]    rapidly samples to bedrock without sloughing or handling of overburden,  
           [0009]    cleans and recovers materials trapped in bedrock cracks and fissures,  
           [0010]    enables sampling of mineral values from up to one and a half cubic foot per foot of depth to bedrock,  
           [0011]    maximizes sampled volume with minimum processing, i.e. only about 2% of sampled volume need be processed,  
           [0012]    reduces sampling costs to a fraction of traditional methods, and  
           [0013]    minimizes environmental damage.  
           [0014]    To my knowledge, no prior art has been capable of providing all of the above functions, as a self-contained, integral unit, capable of being disassembled and transported into inaccessible areas. The references cited are described as large units adapted primarily for water-based operation from barges with land-based operation as an afterthought. Since most of the placers of the world are in areas inaccessible to motorized equipment, portability by means of manpower, pack animal, small boat or helicopter must be a prime consideration.  
         SUMMARY OF THE INVENTION  
         [0015]    The present invention comprises an apparatus which operates on a principle of power augering and water jetting a sampling pipe to bedrock while concurrently recovering ¾″ minus materials, including particles and nuggets of valuable minerals and gemstones, through a concentric center pipe, such recovery powered by a water ring jet venturi. Assuming the presence, and removal, of a reasonable percentage of ¾″ minus materials, the jetting point and the auger will displace larger materials into the voids created by the removed materials, allowing a relatively unobstructed penetration to bedrock. The recovered materials and transport water are discharged into the manifold of a sampling sluice, leading to final determination of values by panning or other hydraulic concentrating device.  
           [0016]    The sampling unit consists of a number of individual elements, as shown on the attached drawings, including  
           [0017]    two concentric pipes, with high pressure water connected to the annular space between the inner and outer pipe (FIG. 1),  
           [0018]    a rotary joint to allow rotation of the sampling pipe independent of the stationary high pressure water manifold (FIG. 1),  
           [0019]    a hydraulic drive unit mounted to the stationary water manifold and chain connected to a drive sprocket on the sampling pipe (FIG. 2),  
           [0020]    a single-turn auger helix near the lower extremity of the sampling pipe (FIG. 1) and immediately above a set of four high pressure spray nozzles (FIG. 5),  
           [0021]    a jetting head assembly at the lower extremity of the sampling pipe (FIG. 7) consisting of two high pressure jetting nozzles, an auger point, suction port screen, threaded attachment to the outer sampling pipe and a slip-fit annular ringjet venturi formed at the joining of the inner return pipe with the jetting head, and  
           [0022]    a sample hole plug assembly.  
           [0023]    The combination of the above features results in a light-weight, integral unit which can be disassembled and transported into inaccessible candidate placers for rapid sampling to bedrock.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0024]    [0024]FIG. 1 is an elevation of the sampling unit consisting of a stationary water manifold, a rotary coupling and a hydraulic/chain driven sampling pipe. Not shown are the commercially available high pressure water pump which supplies water to the annular space between the outer and inner concentric pipes, the sampling sluice for concentrating materials recovered through the center return pipe and the hydraulic power unit which powers the rotary motion of the sampling pipe.  
         [0025]    [0025]FIG. 2 is a plan view of the sampling pipe chain drive and the tie-downs which oppose the torque transmitted to the stationary water manifold.  
         [0026]    [0026]FIG. 3 is a plan view of the sampling hole plug.  
         [0027]    [0027]FIG. 4 is a sectional view of the sample hole plug.  
         [0028]    [0028]FIG. 5 is a sectional view of the sampling and return pipe, also showing location of the high-pressure spray nozzles.  
         [0029]    [0029]FIG. 6 is a partial elevation of the sampling and return pipes and the high-pressure spray nozzles.  
         [0030]    [0030]FIG. 7 is an elevation of the jetting head consisting of high-pressure jetting nozzles, the ring jet venturi which provides suction into the center return pipe, the suction port screen to classify recovered materials and an auger point for penetration of the soil to bedrock. 
     
    
     DESCRIPTION OF THE INVENTION  
       [0031]    The preferred embodiment of the present invention is shown in FIG. 1, generally designated  10 , penetrating into placer sand, gravel and cobble  11  to a depth of typically 5 to 20 ft. to bedrock. The three main components of the apparatus comprise a stationary water manifold assembly  12 , a rotary coupling  13  and the sampling pipe assembly  14  which is capable of rotating motion, driven by the hydraulic motor  15  and chain assembly  16 .  
         [0032]    The stationary water manifold assembly  12  is comprised of a high-pressure water intake  17  supplied from a commercially available water pump (not shown), typically referred to as a fire pump. The high pressure water is introduced into the annular space between the concentric outer sampling pipe  18  and the inner return pipe  19  to service the high-pressure water sprays  20 , the high-pressure water jets  28  and the ring jet venturi  22 , such venturi creating the vacuum to recover and transport water and classified materials to the center return pipe  19  and thence a connection  21  to the manifold of a commercially available sampling sluice (not shown), leading to final determination of mineral and gemstone values by panning or other hydraulic concentrating device.  
         [0033]    Attached to the water manifold assembly  12  is a support for the hydraulic drive motor  15 , a tripod arrangement  23  to assist in setup and retrieval of the unit and tie-downs  24 , as required to oppose the torque transmitted to the stationary utility head assembly. This tie-down arrangement may be replaced by two telescoping torque bars at 180° displacement and/or manual handle bars to control torque and to guide the unit for vertical penetration.  
         [0034]    The assembly to transmit rotary motion to the sampling pipe assembly  14 , shown in plan view FIG. 2, comprises an hydraulic motor  15 , supported to the stationary water manifold  12  and powered by a commercially available hydraulic power unit; a chain drive and sprocket assembly  16  to reduce speed and increase torque to the sampling pipe assembly  14 ; and a rotary coupling  13 .  
         [0035]    The sampling pipe assembly  10  comprises concentric outer sampling pipe  18  and inner return pipe  19  with an annular space between as a means of supplying high pressure water to the spray jets  20 , the jetting head  25  and the ring jet venturi  22 ; spray jets  20 , shown in plan and elevation views in FIGS. 5 and 6, oriented at an angle to wash and assist in recovery of materials surrounding the sampling pipe  18  which, in turn, creates space for displacing the larger cobble; a single turn helix  26  attached to the sampling pipe  18  to create the downward force for penetration to bedrock; and a jetting head assembly  25  to provide a number of functions as described below. The sampling pipe  18  and the return pipe  19  can be extended by coupling additional five foot sections as the unit penetrates to bedrock.  
         [0036]    The jetting head assembly  25 , shown in elevation and partial section in FIG. 7, comprises a machined body which creates the inner ring of the ring jet venturi  22  and the opening for recovery of materials through the center return pipe  19 ; adapts to the jetting nozzles  28  and the suction port screen bars  29 ; and includes a threaded connection to the sampling pipe  18 . The jetting nozzles  28  create turbulence to assist in penetration to bedrock and create a water reservoir to transport materials to the return pipe  19  via the suction port screen  29 , which classifies the materials to a size which will pass through the return pipe without plugging. An auger point  30  is attached to the lower extremity of the screen bars  29  and the jetting nozzles  28  to complete the screen bar assembly and assist in penetration to bedrock.  
         [0037]    A sample hole plug  31  is also incorporated to seal off the flow of excess water out of the top of the sample hole, both as a means of controlling water runoff and increasing water pressure in the sample hole to assist in recovery of materials through the return pipe  19 . The sample hole plug  31 , as shown in FIGS. 3 and 4, comprises two retainer plates  32  enclosing an oversize inner tube  33  which can be inflated to seal off the sample hole. Neoprene seals  34  are provided to seal off leakage around the sampling pipe  18 . A relief valve may also be incorporated in the sample hole plug  31  to regulate the pressure in the sample hole and to facilitate operation on a closed-water cycle, wherein all of the discharged water would be retained in a settling tank which, in turn, would provide the main water supply supplemented by a small amount of makeup water.  
         [0038]    The method of operation basically involves transport of the disassembled unit to a candidate placer by means of manpower, pack animal, small boat, helicopter, or similar means; reassembly of the unit and tripod; and raising the unit into vertical position by means of the winch attached to the tripod. Connections are made to the high-pressure water source, the return line to the sluice box and the hydraulic supply from the hydraulic power unit. As the unit is lowered by means of the winch, high pressure water (typically 200 gpm @ 60 psi) enters the connection at the top of the sampling unit and continues into the annular space between the outer pipe and the inner pipe. At the lower extremity of the unit, the high pressure water is released through the spray nozzles, the jetting nozzles and through the ring jet venturi into the inner return pipe. The high pressure spray and jets dislodge the smaller materials in the sampling hole which, in turn, are transported and drawn into the inner return pipe through the suction port screen.  
         [0039]    The suction created by the ring jet venturi is assisted by the pressure increase in the sampling hole resulting from restriction of water outflow past the sample hole plug assembly. The rotation of the sampling pipe provides a dual function of clearing oversize material from the suction port screen and developing a downward force by means of the auger helix to assist in penetration to bedrock.  
         [0040]    As the smaller materials are removed, space is created such that the jetting point can displace larger materials as it continues to penetrate to bedrock.. The smaller materials which enter the suction ports are transported by high velocity water up the inner return pipe and released via a hose connection to a sampling sluice. The higher density materials, i.e. magnetite, gold flakes, nuggets and/or other valuable minerals and gemstones are retained by the sluice while barren sands and gravels are carried over and rejected. The denser particles retained by the sluice may be concentrated and visually inspected in the field by panning or other hydraulic concentrating device or, as an alternative, transported to home base for further concentration and laboratory analysis. The water from the sluice can either be wasted or returned to a settling basin for recirculation by means of a closed water loop.  
         [0041]    The unit can be extended in 5 ft. increments, employing screw couplings on the inner return pipe and the outer pipe. Removal of the sampling unit is accomplished by reversing the power auger and lifting by means of a portable tripod and cable hoist.

Summary:
A portable apparatus for exploration and sampling of placers which is capable of being disassembled for transport into areas not accessible to traditional sampling methods. The sampling unit operates on a principle of power augering and water jetting a sampling pipe to bedrock while concurrently recovering ¾″ minus materials, including particles and nuggets of valuable minerals and gemstones, through a concentric center pipe, such recovery powered by a ring jet venturi and supplemented by a sample hole plug to increase the water pressure in the sampling hole.