Abstract:
A soil sampler provides samples for on site disposition in forty and twenty milliliter vials for subsequent off site volatile organic analysis. A split sleeve contains a plunger positioned within the sleeve on a shaft to obtain a desired volume of soil when the sampler is thrust into the soil. An outer shell contains the split sleeve and a set screw device fixes the shaft and plunger in desired position within the sleeve. Metering marks on the shaft provide predetermined sample size indication.

Description:
SUMMARY OF THE INVENTION 
     The invention described herein relates to apparatus for obtaining soil samples for reliable detection of volatile organics and hydrocarbon analysis. An external housing has a proximal end, a distal end, an exterior surface and an interior surface. A split sleeve has an outside surface configured for a sliding fit with the external housing interior surface and also has an inside surface. A shaft extends axially through and is spaced from the split sleeve inside surface and further has a proximal end and a distal end. A plunger is connected to the distal end of the shaft and is configured for a sliding fit with the split sleeve inside surface. Means is provided on the shaft proximal end for accessing and moving the shaft in axial position within the split sleeve. Means is also provided for adjustably fixing the shaft in axial position within the split sleeve. 
     In another aspect of the invention, apparatus is described for obtaining soil samples, which includes an external tubular housing having a housing passage therethrough, a distal end and a proximal end. A sleeve is configured to lie within the housing passage and has a distal end and a proximal end. The sleeve further has a sleeve passage therethrough. A flange is formed on the sleeve proximal end adjacent the external tubular housing proximal end. A shaft extends through the sleeve passage and has a shaft distal end and a shaft proximal end. A plunger is attached to the shaft distal end for axial movement and sliding fit within the sleeve passage. Means is provided for fixing the shaft in a plurality of axial positions within the sleeve. 
     In yet another aspect of the invention, soil-sampling apparatus is disclosed for obtaining samples for use in detection of volatile organic and hydrocarbon compounds. An exterior tubular housing has an open sampling end and a housing passage therethrough. A split sleeve is disposed in fixed position within the housing passage and has an open sampling end and a sleeve passage therethrough. A split flange is formed on the split sleeve abutting the exterior tubular housing at an end thereon opposing the open sampling end. A shaft extends through the sleeve passage and the split flange and is disposed for axial movement therein. A plunger is attached to the shaft and has a surface disposed for sliding fit within the sleeve passage from positions spaced from to positions proximate to the split sleeve open sampling end. Further, means is provided for adjustably fixing the shaft in axial position within the sleeve passage. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective of an assembly of the present invention. 
     FIG. 2 is an exploded perspective of a split sleeve utilized in the present invention. 
     FIG. 3 is an exploded perspective of a shaft and plunger assembly utilized in the present invention. 
     FIG. 4 is a section along the line  4 — 4  of FIG.  1 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Investigations have shown that it is difficult if not impossible to get reliable soil samples for volatile organics and hydrocarbons analysis from a conventional brass ring preserved soil sample. Such a soil sample is obtained through the use of the device shown in U.S. Pat. No. 5,343,771, Turriff et al. Soil samplers to provide reliable samples at the site of the sampling should be configured to extract a known volume of sample from the soil being analyzed and afford easy transfer of the soil sample to a secure container for transfer to the analysis laboratory. Ideally, the sampler should provide no contamination and admit no contamination to the sample, should be rugged in construction for on site use and should be easy to clean between samples. Further, the sampler should be able to readily transfer the soil sample to a forty milliliter or twenty milliliter vial at the site of the sampling so that the vials may be transferred to a laboratory for performance of purge and trap sampling. Volatiles should not be lost in the transfer step or inaccurate data will result. 
     Certain EPA testing protocols have recently been implemented which require sample collecting of a specific volume of soil followed by deposit of the soil sample into specified sizes of storage vials for transfer to laboratories for analysis. The invention disclosed herein relates to acquisition of soil samples for on site transfer to 40 milliliter and 20 milliliter vials which are sealed and then transferred to the laboratories. FIG. 1 shows the soil sampler  10  in assembled condition having an exterior housing  11  with a shoulder  12  located about midway along the axial length of the exterior housing. The exterior housing has a distal end  13  with a chisel-like edge  14  at the distal end. A thin groove  16  has a thin cable  17  wrapped therearound and secured with a crimped bushing  18 . The opposing end of the thin cable  17  is wrapped around a screw  19  and secured to the screw with another crimped bushing  21 . The screw  19  engages threads formed in the top of a knurled set screw  22  which has a threaded shank  23  configured to engage threads in a threaded hole  24  which is axially oriented in the external housing  11 . 
     A split sleeve shown generally at  26  in FIG. 2 has two half sleeves  26   a  and  26   b,  the distal ends  25   a  and  25   b  of which are shown extending from the distal end  13  of the external housing  11  in FIG. 1. A knob or handle  27  is shown in FIG. 1 at the proximal end of the sampler  10  which is attached by means of a shaft  28  (FIG. 3) to a plunger  29  (FIGS.  1  and  3 ). The shaft  28  extends through a passage  43  within the half sleeves  26   a  and  26   b  and has a threaded distal end  31  which mates with a threaded hole  32  in the proximal end of the plunger  29 . The distal end of the plunger  29  is shown extending from the distal ends  25   a  and  25   b  of the split sleeve  26  in FIG. 1. A thin teflon disc  30  is shown in FIG. 3, which is placed against the distal end of plunger  29  when the plunger is withdrawn axially into the split sleeve  26  preparatory to obtaining a predetermined volume of soil for a sample as hereinafter described. The thin disc  30  has a diameter that fits snugly within the inside diameter of the assembled split sleeve  26 . The thin disc prevents grit from becoming embedded in the end of the plunger  29  and further inhibits migration of grit or other foreign matter between the outside diameter of the plunger and the inside diameter of the split sleeve. This prevents scoring of both parts and prevents contamination of the plunger distal end and analyte carryover. 
     The split sleeve  26  (FIG. 2) has a split flange shown at  33   a  and  33   b  which is fixed, as by brazing, to the proximal ends of the split sleeve portions  26   a  and  26   b,  respectively. The split sleeve portions have adjacent edges  34   a  and  34   b  (FIG. 2) when assembled. A hole is formed through the edges  34   a  and  34   b  of the split sleeve having hole halves  36   a  and  36   b  as also seen in FIG.  2 . The hole halves  36   a  and  36   b  form a through hole in the side of the assembled split sleeves  26   a  and  26   b  allowing passage of the tip of the threaded portion  23  on set screw  22 , so that the tip of the threaded portion  23  may contact the surface of the shaft  28 . Shaft  28  has a narrow groove  37  formed in the periphery thereof which is spaced from a wider groove  38  around the periphery of the shaft. The split flange  33   a  and  33   b  has a flat surface thereon shown at  39   a  and  39   b.  When the shaft  28  is positioned axially within the split sleeve assembly  26   a  and  26   b  so that the groove  37  is aligned with the flat surface formed by  39   a  and  39   b,  the wide groove  38  is positioned directly beneath the tip of the threaded portion  23  on the set screw  22 . In this fashion, the plunger  29  is drawn a predetermined distance from the distal end of the split sleeve assembly and fixed in this position by the set screw  22 . This predetermined distance provides for a volume between the distal end of the plunger  29  and the distal ends  25   a  and  25   b  of the split sleeve assembly  26 . Thus, a predetermined volume is obtained which will fit into a vial, thereby providing a defined sample size. 
     As described hereinbefore for thin groove  37  and wider groove  38 , another thin groove  41  is shown in the periphery of the shaft  28  spaced a predetermined distance from another wide groove  42  in the periphery of the shaft. When the handle  27  is drawn away from the distal end of the sampler  10  until the narrow groove  41  appears aligned with the flat surfaces  39   a  and  39   b,  the wide groove  42  is disposed directly underneath the tip of the threaded portion  23  on the set screw  22 . Therefore, when the set screw  22  is advanced to contact the surface of the groove  42  the shaft  28  is locked axially in place. The plunger  29  is thus withdrawn from the distal end of the sampler  10  to provide a volume between the distal end  25   a  and  25   b  of the split sleeve assembly and the distal end of the plunger  29  which is sufficient to be deposited within a predetermined size sample vial. 
     With reference now to FIG. 4, an amplifying description of the relative positions of the various parts of the soil sampler  10  will be undertaken. The shaft  28  is seen to be centrally located within the passage  43  extending axially along the length of the split sleeve assembly presented by the split sleeve half  26   a.  The shaft threaded portion  31  is configured to engage threads in hole  32  in plunger  29 . The shaft also has a threaded portion  44  on the proximal end thereof which is configured to engage threads  46  in knob or handle  27 . Plunger  29  can thus be manipulated axially within the through passage  43  to occupy any desired position therealong. The plunger  29  is seen in both FIGS. 1 and 4 extended as far as possible toward the distal end of the soil sampler  10 . As described hereinbefore in conjunction with FIG. 3, the handle  27  may be drawn upwardly in FIG. 4 to align the thin groove  27  with the upper surface  39   a  so that the wide groove  38  is positioned directly beneath the tip of the threaded portion  23  of the set screw  22 . The thin disc  30  may then be placed within the split sleeve  26  in position to overly the distal end of the plunger  29 . As a result, the plunger  29  is drawn upwardly in FIG. 4 a predetermined distance from the distal end of the soil sampler and fixed there in position so that the aforementioned predetermined volume of soil sample is obtained when the distal end of the soil sampler is forced into the ground at the sampling site. The volume of the soil sample obtained in this manner may be appropriate for insertion into a twenty milliliter sample vial, for example. A shoulder  47   a  in FIG. 4 ( 47   a  and  47   b  in FIG. 2) is formed near the distal ends  25   a  and  25   b  of the two split sleeve halves  26   a  and  26   b.  The twenty milliliter vial for receiving the soil sample has an upper opening with a lip surrounding the opening. The shoulder  47   a  (and  47   b ) is sized to contact the lip of the twenty milliliter vial and prevent insertion of the soil sampler  10  further into the interior of the vial. Consequently, the soil is freely deposited into the vial by pushing the handle  27  downwardly to eject the sample. In similar fashion, when the narrow groove  41  is aligned with the surface  39   a  (FIG. 4) the wide groove  42  is disposed beneath the tip of the threaded portion  23  of the set screw  22  and the shaft is fixed in position by the set screw when the threaded portion is advanced to seat against the periphery of the groove  42 . The result is that the distal end of the plunger  29  is positioned within the passage  43  farther from the distal end of the split sleeve assembly so that a larger soil sample is obtained within the passage  43  when the distal end of the soil sampler  10  is thrust into the soil surface at the sampling site. When the soil sampler is withdrawn from the soil surface with the sample contained inside the passage  43 , the sampler&#39;s distal end is inserted into an upper opening in a larger vial, i.e., a forty milliliter vial, having a surrounding lip at the opening. The sampler entry into the vial is limited by contact between the vial lip and the shoulder  12  on the external housing  11 . The sample is deposited within the vial by pushing the handle  27  down to expel the soil sample from the distal end of the passage  43 . It should be noted that the shaft  28  is held centrally located within the passage  43  by the plunger  29  and a hole  48   a  (and  48   b  as seen in FIG. 2) in the flange halves  33   a  and  33   b,  respectively. It should also be noted that the sampler is designed to be held in one hand while pushing handle  27  with fingers on the same hand to expel the sample. The receiving vial may be held by the other hand. This facilitates sample taking, sample isolation and sample containment at the sampling site. 
     When a sample is taken, it is desirable to clean the sampler to avoid contamination of subsequent samples. The set screw  22  is backed out of the threaded hole  24  in the external housing  11  and is therefore removed from the half holes  36   a  and  36   b  in the split sleeve  26 . The split sleeve and shaft assembly is removable through the upper portion of the external housing  11  as seen in FIG.  4  and the split sleeve portions are separated from the shaft and plunger. The thin disc  30  is deposited in the vial with the sample and is replaced with a new disc when the soil sampler is used to obtain a subsequent sample. All surfaces on all other parts of the sampler assembly are thereby readily accessible for thorough cleaning prior to reassembly for subsequent sample taking. 
     In addition, it should be noted that plunger  29  has an outer surface  49  which has a low static and dynamic friction coefficient characteristic. This feature may be obtained through the use of Teflon material for the plunger  29  or through the use of a Teflon coated plunger in the best mode of the invention. It is envisioned, however, that other means, materials and configurations may be utilized to obtain the low friction coefficient on the outer surface  49  of the plunger  29 . The low coefficient of friction characteristic between the outer surface  49  of the plunger and the surface of the passageway  43  is desirable because a sliding fit is necessary between these two surfaces. If debris was allowed to migrate between the surfaces  49  and  43 , binding between the plunger and the split sleeve assembly would occur causing rapid degradation of the soil sampler  10  and possible loss of volatiles from the sample. It should also be noted that in the best mode of the invention a relatively close fit is desirable between the outer surface of the split sleeve assembly  26  and the inner surface  51  (FIG. 4) of the external housing  11 . Although these surfaces are not required to move relative to one another during operation of the soil sampler, it is still desirable to prevent migration of debris between them as much as possible. Cleansing of the parts following the taking of a sample and disassembly will remove any debris that has been able to intervene between these two surfaces. 
     A soil sampler is disclosed herein which quickly and consistently produces uniform soil samples and which is operable with one hand to deposit the samples immediately into appropriate sample containers on the site of the sampling without contaminating the sample or losing analytes. 
     Although the best mode contemplated for carrying out the present invention has been shown and described herein, it will be understood that modification and variation may be made without departing from what is regarded to be the subject matter of the invention.