Abstract:
A containment cartridge for extracting and preserving a soil sample comprises a cylindrical sampling barrel for insertion into the soil for collecting a soil sample.

Description:
CROSS-REFERENCE 
     This application claims benefits from provisional Patent Application Ser. No. 60/342,991 filed on Dec. 21, 2001, entitled “Tool and Method for Soil Sampling.” 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates generally to instruments for measuring and testing, and more particularly, to instruments for sampling soil composition. 
     Soil sampling tools and devices are used for a variety of purposes, e.g., to obtain samples for soil moisture content or to detect and analyze the composition of the soil. Usually, for various reasons, when a soil sample is required for certain testing, the result of the testing depends in large part upon the availability of high quality test instruments and the ability to preserve the integrity of the obtained soil sample. Preservation of the integrity of the soil sample thus involves (among other factors) preventing evaporation of various volatile elements in the soil sample. 
     In the conventional art in the industry, various problems exist with respect to soil sampling tools. For example, many sampling tools are made of metal, preferably stainless steel, and tend to be unnecessarily complicated in design. As a consequence, the users have to pay extraordinary cost to acquire such tools. 
     U.S. Pat. No. 5,505,098 to Turriff et al. (hereinafter “Turriff”) proposes a soil sample containment cartridge. However, in practice, this soil sample containment cartridge must be used in connection with two metal handles, one for taking the sample at sites, and another for extracting the sample out in a lab environment. Typically, the metal handle for taking the sample is structurally different from the metal handle for extracting the sample, and they are not functionally interchangeable. It is thus cumbersome to require two different handle tools to complete the sample taking and extracting process. 
     An improved soil sampling tool which addresses and overcomes disadvantages of prior art tools is greatly desired. 
     SUMMARY OF THE INVENTION 
     An improved containment cartridge is disclosed for extracting and preserving a soil sample. The cartridge comprises a cylindrical sampling barrel for insertion into soil for collecting a soil sample wherein the sampling barrel has a holder at the end of the sampling barrel. The holder has a bigger diameter than that of the sampling barrel. The sampling barrel has a rod-like ejector with a disk-like plunger to push the soil sample out from the sampling barrel. The containment cartridge has a first lid securable to a first threaded connection on the sampling barrel at a first side of the holder. The first lid having a concentrically located nipple component with a hole in the center with a predetermined depth. And the nipple component further has a locking slot for further locking a detachable handle tool onto the first lid. The containment cartridge has a second lid securable to a second threaded connection on the sampling barrel at a second side of the holder to seal the soil sample in the sampling barrel after it is collected. The second lid has a sealing septum which isolates the soil sample from the air as the second lid is secured to the sampling barrel. The containment cartridge is used in the field for collection and sealing a soil sample therein and transporting the same to a lab environment. In the lab environment, after the second lid is detached from the sampling barrel, the first lid is detached and reversed to put the ejector in the hole of the first lid so that a force can be applied onto a rim of the first lid to push the ejector downwards, thereby retrieving the collected soil sample from the sampling barrel without securing any handle to the cartridge. 
     The present invention as described above thus provides an improved soil sampling instrument. The present invention has new features facilitating sample preservation, storage, transportation and identification. For instance, after the soil sample is extracted, there is no need to affix a handle on the entire cartridge to retrieve the soil sample. Since the amount of soil sample in the sampling barrel is relatively small, the top lid serves as a handle for a user to extract the soil sample out, and therefore significantly eases the lab use of the sampling instrument. Moreover, the entire sampling instrument can be made out plastic so that the cost of the instrument can be significantly less expensive than the conventional stainless steel set. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 illustrates a soil sampling instrument including two detachable components: an extended handle module and a containment cartridge according to one example of the present invention. 
     FIG. 2 illustrates three detachable components of the containment cartridge of FIG.  1 . 
     FIG. 3 is a representative sectional view showing the interior of a sampling barrel of the containment cartridge of FIG.  2 . 
     FIG. 4 is a top view of the containment cartridge of FIG.  1 . 
     FIG. 5 is a front view of using a top lid of the containment cartridge to assist retrieving the soil sample in the containment cartridge. 
     FIG. 6 is a front view of a soil sampling instrument including an interior view of half of the instrument according to another example of the present invention. 
     FIG. 7 is a sectional view of the top lid of the instrument. 
     FIG. 8 is a sectional view of the sampling barrel and the guiding passage of the instrument. 
     FIG. 9 is a sectional view of the bottom lid of the instrument. 
     FIG. 10 shows a front view of an ejector of the instrument. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The present invention provides a soil sampling instrument that only requires one type of handle to work with an improved soil sample containment cartridge to extract soil samples in the field, and does not require a handle of any kind to retrieve the collected soil samples in the lab environment. 
     FIG. 1 illustrates a soil sampling instrument  10  including two detachable components: an extended handle module  12  and a containment cartridge  14 . Referring further to FIG. 2 wherein the containment cartridge  14  is further illustrated with three detachable components: a top lid  16 , sampling barrel  18 , and bottom lid  20 . FIG. 3 is a detailed sectional view of the sampling barrel  18 . 
     Referring back to FIG. 2, the top lid  16  has two locking slots  22  situated on the surface of one nipple end  24 , a first part of the locking slot  22  is parallel to the axis of the top lid, and the second part of which is at an angle to the first part. When a protruding element  15  (FIG. 1) such as a small cylindrical notch is inserted into the first part of the locking slot  22 , and turned to fit in the second part of the locking slot, the elongate, tube-like, T-shaped handle module  12  is now concentrically secured to the containment cartridge  14 . It is understood that many other similar connection mechanisms can be implemented to secure the top lid  16  with the extended handle module  12 . For instance, simply designing a threaded area on the upper part of the top lid and matching the threaded area at the bottom of the extended handle will connect the two components together. It is also noted that the nipple end  24  has two functions. One, it is smaller than the diameter of the top lid so that it is easier to insert a rod-like ejector (which will be explained below in FIG. 3) into a contained hole area in the nipple end. Two, it increases the strength of the top lid to server as a “pusher” of the ejector (which is also explained below). Since taking soil samples only requires a vertical force to push the containment cartridge into the soil, applying a force on the extended handle module  12  would not accidentally separate the handle module  12  from the containment cartridge  14 . Even if it requires some minor rotational movements, the connection between the extended handle and the containment cartridge will not be deconstructed. In fact, in this immediate example, a user can even twist the handle clockwise toward the second part of the locking slot while applying the force downward to push the containment cartridge into the soil. 
     At a distal end of the top lid  16 , there are grooves  26  (or threaded interior area) to secure the top lid  16  with matching threads  28  on a connecting end of the sampling barrel  18 . The bottom lid  20  contains a rubber or plastic septum  29  which is designed to seal off the soil sample in the sampling barrel  18  when the sampling barrel is “screwed into” the bottom lid  20 . Because this septum is in a direct contact with the “mouth piece” of the sampling barrel  18 , it does not leave any space for the soil sample to evaporate, thereby achieving the best sealing effect. 
     Referring to FIG. 3, the interior region  30  of the sampling barrel  18  contains a rod-like ejector  32  connecting to a disc-like plunger  34 . The plunger  34  and the ejector  32  are all preferably cylindrical and are actually preferred to be molded as one piece instead of two separate pieces. The sampling barrel has a passage  35  extending along its length for receiving the rod-like ejector  32 . The passage  35  and ejector  32  are all preferably circular in cross-sectional shape. The diameters of the passage  35  and the ejector  32  are cooperatively selected to provide slight clearance therebetween so that the ejector  32  may move freely within the passage  35 . 
     The interior height of the top lid  16  needs to be high enough to accommodate the movement of the ejector  32  because when the cartridge is pushed against a soil level, the soil pushes the plunger  34  back up. In one example, inside the interior portion of the sampling barrel  18 , and centrally situated around the ejector  32  is a stopper  36 , which is formed from the interior wall of the sampling barrel  18 . By designing the protruding length of the stopper  36  appropriately so that the ejector  32  stops at a predetermined location, the cartridge  14  takes in a known amount of soil for sampling every time it is used. The plunger  34  is actually formed by three layers of material. The top and bottom layers ( 38  and  40 ) are made of plastic which is the same piece as the ejector  32 . A rubber ring  42  is positioned between the top and bottom layers ( 38  and  40 ), which have a slightly larger diameter than those of the top and bottom layers. The diameter of the rubber ring  42  is selected so that it is in close contact with the interior wall of the sampling barrel to prevent any leakage of soil to the upper portion of the sampling barrel beyond the rubber ring  42 . Between the interior region  30  and the connecting end of the sampling barrel  18 , there is a ring of grooved holder  44 . The holder  44  is designed to allow the user to hold it and twist open or close either the top lid  16  or the bottom lid  20 . As stated above, the bottom lid  20  is for sealing the soil sample inside the sampling barrel  18  after the soil sample is extracted. The advantage of using the bottom lid is that a sealing and labeling tape can further circle around between the bottom lid  20  and the grooved holder  44 . 
     FIG. 4 is a top view of top lid  16  of the containment cartridge  14 . A receptive hole  46  with a predetermined depth and diameter is made in the nipple end. The receptive hole  46  is used to receive the rod-like ejector  32 , and push out the soil sample contained in the sampling barrel in a lab environment. FIG. 5 illustrates how the top lid  16  is reversed, and put on the ejector so that a user in the lab can push the rim of the top lid  16  to extract the soil sample. This is a significant improvement over the prior art since there is no need to use another handle at all. The containment cartridge  14  delivered to the lab will be self-sufficient for extracting the soil out from the sampling barrel. This containment cartridge does not need additional handles to be used in the lab environment, thus reducing the cost to maintaining the extracting tools in the lab as well as simplifies the soil sample extracting process. 
     By using soil sampling instrument disclosed according to the present invention, a new method for collecting a soil sample  24  is also introduced. When a field user needs to take a soil sample, he only needs to take one extended handle module with him since it can be used with multiple containment cartridges  14 . The containment cartridge  14  has both the top lid  16  and bottom lid  20  secured thereon before the user handles it to ensure that the containment cartridge is not contaminated. The user can simply insert and twist the handle module clockwise into the locking slot  22  on the nipple portion  24  of the containment cartridge  14  to secure the handle module to the cartridge. Then, the user holds on to the handle module and the top lid of the containment cartridge, and unscrew the bottom lid  20  off from the containment cartridge. The mouth piece or open end of the sampling barrel is now ready to be pushed into a soil ground for extracting a soil sample. The soil sample pushes the plunger  34  back until it is stopped by the stopper  36 , and the entire sampling barrel is taken out from the soil, and immediately sealed with the bottom lid being screwed thereon. The user then holds the entire containment cartridge  14  in one hand, and uses the other hand to twist the handle module  12  counterclockwise and pulls it off the cartridge. Now the containment cartridge  14  is back to its initial state except that it now has the soil sample contained therein. A piece of sealing and labeling tape can be put on to further seal off the containment cartridge  14 . This labeled containment cartridge  14  is then shipped to a predetermined lab for retrieving the soil sample. In the lab, a lab user needs no additional tools such as the handle module to retrieve the soil sample. She holds on the holder  44  and unscrews the top lid  16  off first, and does the same to the bottom lid  20  to expose the contained soil sample. She reverses the top lid  16 , puts the rod-like ejector into the receptive hole  46 , and pushes the ejector downward so that the soil are now unloaded from the sampling barrel  18 . 
     FIG. 6 is a front view of a soil sampling instrument  50  including an interior view of half of the instrument according to another example of the present invention. As the soil sampling instrument  10 , the soil sampling instrument  50  includes two detachable components: the extended handle module  52  and a containment cartridge  54  which further containing a top lid  56 , sampling barrel  58 , and bottom lid  60 . Although the top lid  56  is marked differently from the top lid  16  (FIG.  1 ), it is understood that they can be the same design and functionally the same. Similar to the cartridge illustrated in FIG. 1, the containment cartridge  54  has a holder  44  to allow both the top lid  56  and the bottom lid  60  to be secured thereon. The holder  44  may be grooved and is around the periphery of the cartridge. As described along with FIG. 1, the holder allows both the top and bottom lids to be secured thereon, and is typically around the upper end of the sampling barrel. In the upper portion of the containment cartridge  54 , there is a guiding passage  62  extending along the length for receiving an ejector  64  which is in connection with a disc-like plunger  66 . The guiding passage  62 , in one example, is cylindrical in shape to host the ejector for a predetermined distance. As such, the ejector  64  is preferably cylindrical generally, and is actually preferred to be molded as one piece with the plunger. The diameters of the guiding passage  62  and the ejector  64  are close to each other, and are cooperatively selected to provide slight clearance therebetween so that the ejector  64  may move freely within the guiding passage  62 . At a predetermine place on the ejector  64 , a groove  68  is carved out to receive a rubber ring. The ejector  64  equipped with the rubber ring seals off any significant gap between the ejector  64  and the interior wall of the guiding passage  62  while still allowing the ejector moves in and out along the guiding passage. Since the sampling instrument  50  is going to receive soil inside the sampling barrel  58 , and there may be a gap between the plunger  66  and the interior wall of the sampling barrel  58 , by implementing such a sealing mechanism within the guiding passage actually reduces any possibility of leaking volatile elements of the soil. In addition to the sealing mechanism in the guiding passage area, there is an internal taper  70  connecting between the ejector  64  and the plunger  66  which in conjunction with a taped sealing node  72  further prevents any volatile elements to escape through the upper half of the containment cartridge  54 . The design of the sealing node  72  and the taper  70  is such that the harder the plunger is pushed upward, the tighter the conical surface of the taper gets against the sealing node due to the gradual change in diameter of the internal taper, thereby creating another sealing mechanism. In addition, the taped sealing node  72  also serves as a stopper to hold the plunger  66  at the top of the sampling barrel  58 . 
     Inside of the lid  60 , there is a polytetrafluroethylene liner  74 , i.e. TEFLON, further seals the soil sample in the sampling barrel  58  after the lid is screwed on the sampling barrel. Due to the non-reactive nature of the Teflon liner  74 , any chemical elements contained in the soil sample will not be contaminated. In another example, the interior wall of the sampling barrel can be coated with prevention materials to reduce the possibility of having any chemical reaction or contamination between the soil and the material of the sampling barrel. Because the sealing mechanisms at the guiding passage part and the tapped joint part, there is no requirement to reduce the space between the plunger and the interior wall of the sampling barrel to seal the soil sample therein. As such, there is no friction created between the plunger and the interior wall of the sampling barrel, and the integrity of the coated interior wall can be maintained. On the other hand, if the sealing mechanism is implemented around the plunger, the protection coating may become ineffective. 
     FIG. 7 is a sectional view of the top lid  56 . The top lid  56  has an internal height  76  high enough to host a protruding ejector while the plunger is pushed all the way up. The top lid  56  also has the receptive hole  46  for receiving the ejector for pushing thereof. 
     FIG. 8 is a sectional view of the sampling barrel  58  and the guiding passage  62 . Also shown in this FIG. 8 is the tapped sealing node  70 . 
     FIG. 9 is a sectional view of the bottom lid  60  wherein the Teflon liner is placed at the tip of the lid. 
     FIG. 10 shows a front view of the ejector  64  with the groove  68  for receiving a rubber ring, the plunger  66 , and the tapped joint  70 . 
     The soil sampling instrument as described above with regard to FIG. 6 can improve the soil sampling process in the field. For example, when the soil sampling instrument is shipped to the user, the plunger  66  has been pushed all the way to the upper portion of the sampling barrel with the top lid covering thereof. In addition, since the rubber ring on the ejector  64  is in close contact with the guiding passage, both sealing mechanisms are securely applied. As such, there is no requirement for the user to push the soil sample tightly against the plunger in order to use the upper surface (or back surface) of the plunger to seal off the gap between the plunger and the guiding passage. However, in order to minimize any possible contamination, the bottom lid  60  is already put on. When the user is ready to take the soil sample, she takes off the lid, the top lid is inserted into a handle module using a locking mechanism (e.g., an insert-and-turn locking mechanism), and the user holding the handle module can push the empty sampling barrel to the ground. Since the intake of the soil sample does not need to push the plunger up, it is a far easier process to get the soil sample comparing to conventional tools which require the soil sample to propel the plunger up. Once the soil sample is in the sampling barrel, the bottom lid  60  is put back on with the Teflon liner covering the open end of the sampling barrel. When the cartridge is shipped to a lab environment, the bottom lid  60  is opened and reversed, and, as described above, pushes the rod-like ejector to extract the soil sample from the sample barrel. 
     The present invention, as described above, thus provides an improved soil sampling instrument. The present invention has new features facilitating sample preservation, storage, transportation and identification. For instance, after the soil sample is extracted, there is no need to affix a handle to retrieve the soil. The top lid serves the function of an extended handle, and thus significantly eases the lab use of the sampling instrument. The septum contained inside the bottom lid isolates the obtained soil sample from the air, thereby maintaining the integrity of the obtained sample during further transportation of the containment cartridge. Moreover, the entire sampling instrument can be made out plastic so that the cost of the instrument can be significantly less expensive than the conventional stainless steel set. 
     The above disclosure provides many different embodiments, or examples, for implementing different features of the invention. Specific examples of components, and processes are described to help clarify the invention. These are, of course, merely examples and are not intended to limit the invention from that described in the claims. 
     While the invention has been particularly shown and described with reference to the preferred embodiment thereof, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention, as set forth in the following claims.