Patent Publication Number: US-3878904-A

Title: Core sampling device

Description:
United States Patent Dobson 5] Apr. 22, 1975 CORE SAMPLING DEVICE 2.330.157 9/1943 Stokes 175/236 x 2.544.993 3/1951 Jackson 175/238 x [75] W&#34; REM&#34;! 9mm&#34;, East 3.095.051 6 1963 Robinsky et al. .1 175/236 x MaIflar&#39;fLNeW South Wales, 3.136.376 6 1964 Robinsky 175/243 11 Australia 3.409.094 ll/l968 Kretschmer et a1. 175/242 [73] Assignee: Gilbert Gray &amp; Co. Pty. Limited,  
  New South Wales. Australia Primar liraminer-David H. Brown [22] Fned: June 1973 Attorney, Agent, or Firm-Ladas, Parry, Von Gehr, [2 I] Appl. No.: 367,290 Goldsmith &amp; Deschamps [30] Foreign Application Priority Data [57] ABSTRACT June 9, 1972 Australia 9290172 Apparatus for extracting core samples from loosely [52] U.S. Cl. 175/236; 175/58; l75/240; packed or unconsolidated mated employing 3 175/242 175/243 pling tube having a self-actuating closure at the end of [5 l] Int. Cl E2lb 25/00; E2lb 49/02 the core sampnng tube to prevent &#39;05s 0f the Sample as [58] Fleld Search 2361 it is withdrawn from material. The arrangement being 75/239441 25L particularly suited for sampling materials under the water table, such as wet sands, as well as gravels. [56] References Cited UNITED STATES PATENTS 10 Claims, 4 Drawing Figures 1.655.644 l/l928 Baker l75/240 QHUHECAPRZZEFS 1.878.904  
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 PATENTEDAPR 22 I975 sum u gr 4 FIG.  
 CORE SAMPLING DEVICE BACKGROUND This invention relates to apparatus for extracting core samples and more particularly to a device for extracting core samples from wet or dry loosely consolidated material.  
  Apparatus for extracting core samples from consolidated material have reached a highly advanced state. yet in the practice of obtaining substantially undisturbed cores from loosely packed or unconsolidated material. only limited success has been achieved. For core sampling dry. loosely packed material difficulties are partially avoided as. while the core sampling tube is driven into the material it has the effect of compacting the material to some extent and enables it to be retained in the tube during withdrawal. An innovation employed when obtaining samples from loosely com pacted material has been to introduce a bubble of compressed air below the sample in the tube which assists in retaining the sample during withdrawal ofthe sample tube from the material. However. when core samples are to be taken of moist. loosely compacted material. for example wet sand or clay. the introduction of an air bubble has achieved only limited success. The difficulty encountered in moist materials of this type is due to moisture being forced out of the sample. as the core is being taken. and forming a lubricant between the core and the inside walls of the core sampling tube. This lubricant allows the core to slide out of the tube as the tube is withdrawn from the material and hence the sam ple is lost.  
 OBJECT OF THE INVENTION It is a primary object of the invention to provide apparatus for ameliorating the above stated difficulties associated with obtaining core samples from a variety of materials and provides a sample which is virtually undisturbed thereby retaining a more accurate crosssectional view of the material so sampled.  
 SUMMARY OF THE INVENTION In accordance with the present invention there is pro vided apparatus for obtaining a core sample in a material. comprising a sample tube casing. a sample tube which is sized and shaped to locate within a bore of the casing with a clearance fit. closure means connected to the casing and positioned within the casing bore. and means permitting limited movement of the sample tube with respect to the casing to actuate said closure means to substantially seal a core receiving end of the sample tube and prevent loss of the sample.  
  In a modification of the above apparatus a hollow auger has an openable closure on the head of the auger such that the operation of passing the casing tube and sample tube through the hollow auger. when the sample taking depth is attained. opens said closure to allow insertion of the casing and sample tubes into the material below said depth. Once movement is effected to withdraw the sample tube from the material the closure means adjacent the innermost end of the sample tube actuates to close and thereby retain the sample in the sample tube. whereupon the core sample tube containing the sample and the core tube may be removed from the hollow auger together or the sample tube may be removed from within the core tube and the hollow auger.  
  When the core sample has been removed from the sample tube. the core tube may be reloaded with an empty sample tube having its closure means held in the open position such that the sample tube is readied to accept a further core sample when drilling has progressed to a further sample taking depth.  
 BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of the present invention a preferred embodiment of the apparatus will now be described with reference to the accompanying drawings. in which:  
  FIG. 1 is a cross-sectional view of a core sampling tube within a sample tube casing in the sampling configuration as employed in conjunction with a selfclosing auger head;  
  FIG. .2 is a cross-sectional view. similar to that of FIG. 1. showing the openable closure of the sample tube in position to retain a sample within the sample tube;  
  FIG. 3 is a perspective view of a suitable auger head adapted for use with the sample tube and sample tube casing of the present invention; and  
  FIG. 4 is a perspective view of the sample tube openable closure of FIGS. I and 2.  
 DETAILED DESCRIPTION OF THE DRAWINGS Referring now to FIG. I there is shown an auger head 5 adapted to be coupled with a hollow auger (not shown) by thread means 6. Within and protruding through the self-closing jaws 7 of the auger head 5 is sample tube casing I2 containing sample tube 20. The sample tube casing 12 and the sample tube 20 are shown in the sampling configuration wherein a core of material is forced into the tube 20 through opening 21 as the sampling tube arrangement comprising tubes 12 and 20 is forced into the material to be sampled through the open jaws 7.  
  Within the depicted sample tube 20 there is located a disc valve 22 shown in an open position to allow gases and/or liquids. such as air and water. which may be ingested with the core sample. to escape from the sample via passage 23 and one or more orifices 24 located around the perimeter of the sample tube retaining adaptor 30. The sample tube 20 is retained on the adaptor by means of pin 25 located through the adaptor 30 and the walls of the tube 20. As shown. pin 25 is retained in position by ring 26.  
  The coupled adaptor 30 and tube 20 are located with respect to tube casing 12 by spring-loaded retaining pins 27 and 28 through slots 13 in the sample tube casing I2.  
  In the sampling configuration of FIG. 1 the innermost end of tube 20 abuts against the face 14 of tube 12, thereby maintaining the sample tube self-closing jaws IS in open position as shown. Jaws 15 comprise a separable unit 16 which is retained in fixed relation to tube [2 by screw on nose piece 17 of tube 12.  
  After a sample length of material is taken in the sample tube 20, the entire sampling tube arrangement may then be withdrawn into the auger FIG. 2) such that the initial withdrawal movement acts only upon adaptor 30 and its affixed sample tube 20.  
  Adaptor 30 is coupled to a withdrawal means by spigot 3| such that the initial withdrawal movement compresses spring-loaded retaining pin 27 and the adaptor 30 and tube 20 are withdrawn to a position (FIG. 2) where spring-loaded retaining pin 28 abuts against the end of slot 13 (as shown by FIG. 2) to prevent complete withdrawal of the adaptor and tube 20 from within tube casing 12. When this position is attained the spring-loaded jaws close to seal off the end of sample tube 20, thereby retaining the sample.  
  The tube casing 12 and sample tube may then be completely withdrawn from the hollow auger where upon the sample tube 20 is withdrawn from within the tube casing 12 by compressing pin 28 and sliding adaptor 30 and tube 20 out of the casing. The sample tube [2 containing the sample is then separated from the adaptor by removing ring 26 from about the pin and sliding the pin out of its location. An empty sample tube may then be coupled with adaptor and relocated within the tube casing 12 in readiness for taking a further sample.  
  FIG. 3 shows an auger head 5 of the type shown in FIGS. 1 and 2 which comprises threaded portion 6 for connecting the head to a hollow auger. The jaws 7 are biased toward a closed position by return springs 4 and cutting prongs 8 of any suitable configuration are mounted as shown.  
  FIG. 4 shows the separable unit 16 comprising jaws I5 and springs 18 which functions as a closure for the sample tube during withdrawal from the auger and retains the sample within the tube 20. The unit 16 is retained within casing tube [2 by the screw-on nose piece 17.  
  Even though the apparatus described is particularly related to the use of an auger head with an openable closure in conjunction with the sampling arrangement it is to be understood that such an auger head is not essential to the performance of the present invention.  
 Particular advantages of the described auger head enable samples to be taken at various depths by sampling at one depth then drilling further and sampling again. This procedure is very advantageous when sam pling under the water table as wet flowing sands or disturbed material are prevented from entering the hollow auger. Also in some applications the valve arrangement may be deleted from the apparatus or modified. for example. to a ball valve.  
  The method and apparatus of this invention have enabled extremely accurate core samples to be taken of very moist unconsolidated materials. such as wet sands. as well as gravel type materials, virtually without disturbing the material profile and loss of any portion of the core sample.  
 What I claim is:  
  1. Apparatus for obtaining a core sample in a material. comprising a sample tube casing. a sample tube which is sized and shaped to locate within a bore of the casing with a clearance fit. closure means connected to the casing and positioned within the casing bore. and means permitting limited movement of the sample tube with respect to the casing to actuate said closure means to substantially seal a core receiving end ofthe sample tube and prevent loss of the sample.  
  2. Apparatus according to claim I wherein said closure means comprises spring-loaded self-closing jaws.  
  3. Apparatus according to claim 1 wherein said sample tube is adapted to cover said closure means during core receiving operations, thereby preventing said clo sure means from being exposed to the material during said core receiving operations.  
  4. Apparatus according to claim 1, wherein said closure means to seal the end of said sample tube comprises a separable unit retained within said sample tube casing and fixedly retained with respect to said casing by a removable nose piece of said casing.  
  5. Apparatus according to claim 1. including a hollow auger head having an openable closure on the head. said openable closure being sized and shaped and adapted to allow said sample tube casing containing said sample tube to pass thcrethrough.  
  6. Apparatus according to claim 5, wherein said auger head openable closure comprises spring-loaded self-closing jaws.  
  7. Apparatus according to claim 1, wherein said sample tube is connected to an adaptor. for permitting said limited movement of said sample tube with respect to said sample tube casing to actuate said closure means to seal the end of said sample tube.  
  8. Apparatus according to claim 7, wherein said adaptor is slidably located within said sample tube casing such that limited withdrawal of said adaptor from said casing is provided by a spring-loaded retaining pin on said adaptor co-operating with a slot in an adjacent portion of said casing.  
  9. Apparatus according to claim 7, wherein said adaptor comprises at least one valve adjacent the other end of said sample tube, said valve being operative to permit egress of gases and/or liquids from said sample tube during sampling.  
  10. Apparatus according to claim 9. wherein said adaptor is slidably located within said sample tube casing such that limited withdrawal of said adaptor from said casing is provided by a spring-loaded retaining pin on said adaptor co-operating with a slot in an adjacent portion of said casing.