Abstract:
A soil sampling apparatus comprising a motorized vehicle may be used to remove soil samples at intervals over a field of interest. The apparatus comprises a sampling assembly that rotates and extends downwardly into the soil to collect a sample. The probe assembly is raised to dump the sample into a collection assembly, which transfers the sample to a bagging assembly, where the sample may be bagged for later analysis.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. provisional patent application Ser. No. 61/321,425, filed on Apr. 6, 2010, and entitled “Vehicle-Mounted Soil Sampling Apparatus.” Such application is incorporated herein by reference in its entirety. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable. 
     BACKGROUND OF THE INVENTION 
     The present invention relates to soil sampling devices, and in particular to soil sampling devices that may be mounted on a truck, utility vehicle, or the like. 
     In order to optimize the production capacity of any agricultural land, the grower must provide in each plot of soil the amount of fertilizers and other nutrients and additives that will render each plot ideal for the crop that is to be sewn and harvested. The grower cannot know how much fertilizer or other additives should be placed at a plot of soil, however, without knowing the current level of nutrients and important minerals that are already present in each plot. The quantity of these various materials present will vary greatly depending upon such factors as the soil type, the history of crops grown, and additives that have been previously applied to the field. It is thus a common practice for growers to periodically remove soil samples from various regions on their agricultural lands, which are then analyzed to determine the level of various important nutrients and minerals that they contain. It would also be highly desirable to know the level of compaction of soil in various regions, in order to properly gauge the steps necessary to arrive at the proper level of soil compaction for a particular crop to be grown in each region, although this testing is not commonly performed today. 
     Soil sampling has historically been a process performed by hand. Various hand tools have been developed to somewhat ease the burden of this task, but any manual operation to perform soil sampling is necessary tiresome and time-consuming because of the expanse of land that must be covered when soil sampling is performed as part of a large-scale commercial farming enterprise. Typically, a worker drives a truck over the area in question, stopping at each designated point and exiting the vehicle to perform the sampling process. Because of the arduous nature of this task, growers typically take only one sample in a field of interest, or at most a few samples across a field or area of interest and then average the results. The farmer will then apply fertilizers and other nutrients to the soil as if the soil&#39;s level of nutrients were uniform across the field, which is in fact not generally the case. The result is a poor approximation of the optimal nutrient level for each plot of soil, since some plots will likely be under fertilized and others will be over fertilized. Under fertilized plots will produce poor yields, and over fertilized plots may both produce poorer than optimum yields and also result in a waste of fertilizers. The wasted fertilizer not only is an added expense for the grower, but also exacerbates environmental issues that may arise from the later run-off of the excessive fertilizer due to rain or wind. 
     With the wide availability of global positioning system (GPS) satellite receivers today, the use of GPS information in soil sampling is rapidly increasing. GPS receivers have in fact become a staple of modern commercial farming equipment. The use of GPS in conjunction with manual soil sampling, however, only provides modest improvements in accuracy and efficiency. Although the grower now has precise information about where each sample is taken, manual sampling procedures still require a worker to travel to each identified point in the field of interest, remove a sample by hand, and then label and transport that sample for analysis. Thus it would be highly desirable to develop a soil sampling system that would allow for the collection of a periodic sample the soil across a field, while automatically keeping track of where samples were removed using GPS information. 
     The related art includes several attempts to develop soil sampling mechanisms that periodically sample soil over an area. U.S. Pat. No. 3,224,512 to Alexander teaches a soil sampler that is mounted on a trailer and powered by a hydraulic system. The device is intended to be pulled by a tractor around a field, and the motion of one of the vehicle wheels activates a piston and cam-drive arrangement in communication with the soil sampler&#39;s hydraulics. Since the sampling periodicity is driven by the motion of one of the wheels on the trailer, the device automatically samples soil at regular intervals, regardless of the speed of the tractor pulling the trailer. The device uses a sampling tube that is forced into the ground for sample collection. Since the device does not stop in order for samples to be taken, the sampling tube is designed to pivot upon entry into the ground. The sampling tube is returned to its original insertion position (angled toward the front of the trailer) by means of a spring. 
     U.S. Pat. No. 3,625,296 to Mabry et al. teaches another soil sampling device that is mounted on a trailer, and which is intended to periodically sample soil over which the trailer passes. A digger foot is used to collect the soil sample, the foot being mounted at the end of a lever that includes a cam follower at its opposite end. By means of the cam follower, a cam on one of the tractor&#39;s wheels forces the digger foot into the ground as the trailer travels, thereby scooping a soil sample. As the cam rolls forward, the digger foot is released and a spring biases the digger foot upward, where it strikes a bumper block and deposits the soil sample into a collection container. Like the Alexander device, the Mabry et al. device automatically samples soil at regular intervals, since its sampling periodicity is driven by the distance traveled by the cam-equipped tractor wheel. 
     U.S. Pat. No. 5,741,983 to Skotnikov et al. teaches a third trailer-mounted automatic soil sampling device. In this case, an odometer is used to monitor the distance of travel of the trailer, which drives the sampling period of the device. The device utilizes a shaft-drive and linkage arrangement to control the period of the sampling action based upon the rotation of one of the trailer&#39;s wheels. A complex linkage arrangement allows the sampling tube to be raised into a position to eject and deposit a sample during each sampling cycle. The device further includes a bagging mechanism, whereby each of the samples that are drawn from the ground may be automatically bagged and labeled for later laboratory analysis. 
     The sampling mechanisms described above suffer from important disadvantages that have limited their adoption in large commercial farming operations. Mechanisms that simply scoop a sample of material from the top of the ground are undesirable, since such a sample may not be representative of the lower levels of the soil in the area that is sampled. The most relevant section of the soil is that section that will be in greatest contact with the roots of the crop to be planted, which in the case of almost all commercial crops will be soil that lies at some distance below the surface. Further, in many applications the most desirable sample will be one that spans a section of the soil, from the surface to a pre-determined depth beneath the surface. A scooping mechanism will likely be unable to probe deeply enough to produce a sufficient sample to meet this need. 
     Although sampling mechanisms that insert a tube into the ground to collect a sample are superior to scoop mechanisms in many applications, the tube-type sampling mechanisms known in the art also suffer from important disadvantages. The process of inserting and removing a tube from a moving vehicle presents a number of difficulties. In one case these difficulties have been addressed by the use of a tube that pivots, thereby allowing the tube to be inserted into the ground at a forward-sloped angle, while it pivots rearwardly until the tube is removed. Depending upon the hardness of the soil, however, this may create a great deal of stress upon the tube. The pivoting action causes the tube to push backward against soil that is rearward of the tube at its distal end, and push forward against soil that is forward of the tube at its proximal end. While this may be a workable solution in very loose, highly compressible soil, this will likely lead to bending, excessive wear, or other damage to the tube in more firmly packed soil, such as many clay-based soils, or soil that may contain rocks or other hard obstacles. 
     Another solution to the problem of vehicle motion while the tube is inserted in the ground is a complex linkage arrangement that allows the structure immediately supporting the sampling tube to “follow” the tube during the portion of the sampling cycle when the tube is inserted into the ground. While this arrangement may avoid the problems presented by tube rotation, the structure and linkages necessary for this functionality are complex, and would likely be expensive to manufacture and difficult to maintain. 
     U.S. Pat. No. 7,255,016 to the inventor hereof teaches an automated machine that automatically takes soil samples as it is directed across a field of interest. A track is used with a probe that rotates as the track moves in contact with the ground. The machine automatically inserts the probe in the ground, withdraws the probe, and empties soil from the probe during reach revolution. This device solves many of the problems presented with the prior art devices, in that sampling may be continuously performed over an area of interest, and a great number of samples may thus be collected providing a high degree of resolution for the resulting soil analysis on a particular plot. The device is expensive, however, and while its use will likely prove to be cost-effective for larger farms, it is not clear that it will be cost-effective for small farms, where a more simple sampling scheme with fewer samples collected may suffice. 
     What is desired then is an automatic soil sampling mechanism that facilitates the sampling of soil across an area of interest, while also being inexpensive to manufacture and simple to operate and maintain. The limitations of the prior art are overcome by the present invention as described below. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a soil sampling apparatus that comprises a truck or other vehicle carrying a sampling assembly that is capable of quickly and efficiently removing a sample from the soil when the vehicle stops. It is not required for the driver to exit the vehicle in order to collect a sample. The sample may be dropped from the sampling tube as it passes around the top portion of the mechanism. In various embodiments, soil compaction within the sampling tube may be avoided by tapering of the interior of the tube itself. 
     Soil cores dropped from the sampling tube fall into a collection trough, which in certain embodiments may include an auger system to direct soil. A pneumatic delivery system may be used in certain embodiments to move collected samples from the collection tray to sample storage bags, which for ease of access may be located adjacent to the operator of the vehicle. In one embodiment, a rotating carousel with multiple bag holders may be employed in order to collect samples. A computer-based GPS mapping system may be used in conjunction with the present invention in order to coordinate the mapping of a field of interest and collection of samples at appropriate locations, as well as guiding the pull vehicle. 
     It is therefore an object of the present invention to provide for a soil sampling mechanism that may collect soil samples over an area of interest without requiring a driver to exit the vehicle to which the sampling mechanism is attached. 
     It is also an object of the present invention to provide for a soil sampling mechanism that is inexpensive to produce and easy to maintain. 
     It is also an object of the present invention to provide for a soil sampling mechanism that allows for the pneumatic movement of collected samples from a collection tray to a location more convenient to an operator. 
     It is also an object of the present invention to provide for a soil sampling mechanism that allows the collection of a number of soil samples in a plurality of separate bags for later analysis. 
     It is also an object of the present invention to provide for a soil sampling mechanism that allows for the use of a computer-based mapping system in order to map an area of interest and collect samples from the appropriate portions of the area of interest. 
     These and other features, objects and advantages of the present invention will become better understood from a consideration of the following detailed description of the preferred embodiments and appended claims in conjunction with the drawings as described following: 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a top plan view of a vehicle including a preferred embodiment of the present invention. 
         FIG. 2  is a side plan view, in partial cut-away, of a vehicle including a preferred embodiment of the present invention. 
         FIG. 3A  is a side elevational view of a sampler assembly in the drive position according to a preferred embodiment of the present invention. 
         FIG. 3B  is a side elevational view of a sampler assembly in the collection position according to a preferred embodiment of the present invention. 
         FIG. 4  is a top plan view of the sampling and collection assemblies according to a preferred embodiment of the present invention. 
         FIG. 5  is a detail, side elevational view, in partial cut-away, of the collection assembly according to a preferred embodiment of the present invention. 
         FIG. 6  is a side elevational view, in partial cut-away, of the bagging assembly according to a preferred embodiment of the present invention. 
         FIG. 7  is a side elevational view, in partial cut-away, of the probe according to a preferred embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference to  FIGS. 1 and 2 , a general description of the preferred embodiment of the present invention may be described. Vehicle  10  may be a truck or any of the sorts of utility vehicles that are commonly used in farming applications. Preferably, vehicle  10  has a bed  12 . Sampling assembly  14  and collection assembly  16 , the individual components of which will be described in more detail below, are mounted at bed  12 , and a portion of collection assembly  16  extends into cab  18  of vehicle  10 . Bagging assembly  20  is preferably mounted in cab  18  in order to provide convenient access to collected soil samples for the driver of vehicle  10 . Sampling assembly  14  is powered by hydraulic cylinders  22 , of which there are two in the preferred embodiment. 
     Turning now to  FIGS. 3A and 3B , the probe components of sampling assembly  14  may be described in greater detail. It may be noted that the components shown in  FIGS. 3A and 3B  are repeated on each side of bed  12  of vehicle  10  in the preferred embodiment, although in alternative embodiments only one probe mechanism may be employed. Arm guide plate  24 , which preferably is formed in an “L” shape, is mounted to vehicle  12  by means of guide plate axle  28 . Guide plate  24  may turn freely about the axis of guide plate axle  28 , a roller bearing (not shown) preferably being employed in a known manner to reduce friction. Probe arm  30  is fitted to guide plate  24  and held in place by guide plate rollers  28 . Guide plate rollers  28  allow probe shaft  30  to move longitudinally with respect to guide plate  24 , the purpose of which will be described below. In the preferred embodiment, there are a total of six guide plate rollers  28  on each guide plate  24 , with two of the rollers being forward of probe shaft  30 , two being rearward of probe arm  30 , and two being to the outside of probe shaft  30 . Since guide plate  24  itself fits against probe arm  30  on its fourth side, it may be seen that probe shaft  30  is effectively “trapped” against guide plate  24  in this manner. Probe shaft  30  may thus move longitudinally with respect to guide plate  24 , with the various guide plate rollers  28  turning as it does so, but may not move laterally with respect to guide plate  24 . Probe  31  is attached at the distal end of probe shaft  30 , its design being described in more detail below 
     Probe arm  32  is rotatably connected to probe shaft  30  at a point between the connection of probe shaft  30  and guide plate axle  28  and the connection of probe shaft  30  with probe  31 . Probe arm  32  is preferably formed in hinged sections, with probe arm  32  being formed in three sections, two being hinged together, in the preferred embodiment. Probe arm  32  is connected at probe arm axle  34  in a rotatable manner, and linked to hydraulic cylinder  22 . It may be seen that in this manner, the extension of hydraulic cylinder  22  causes an extension of probe arm  32  forwardly, which in turn causes probe arm  32  to rotate counterclockwise about guide plate axle  28 . Simultaneously, probe arm  32  extends outwardly, causing an extension of probe arm  32  into the soil. As a result, probe  31  is turned to point downwardly into the soil in order to collect a soil sample, as shown in  FIG. 3B . Retraction of hydraulic cylinder  22  results in a reversal of this operation, such that probe  31  returns to the rest position, pointed upwardly, as shown in  FIG. 3A . 
     Turning now to  FIG. 7 , the structure of probe  31  may be described in more detail. Probe  31  comprises a hollow tube  36  designed to receive soil upon its insertion into the ground during sampling operation. Probe  31  may be constructed of any sufficiently rigid and durable material, such as steel. Probe tip  38  is attached at the distal end of probe  31 . In alternative embodiments, probe tube  36  and probe tip  38  may be constructed as a single part, although it is preferred that they are separate so that probe tip  38  may be easily replaced as it wears or is damaged during sampling operations. It will be noted that the interior of probe tip  38  in the preferred embodiment is sloped such that the inner diameter increases as soil pushes into tip  38 . Because soil is dumped from the proximal end of tube  36  during the collection process as described below, it will be seen that this design serves to prevent soil compaction as the soil is being moved from an area of more restricted diameter to an area of greater diameter during removal. 
     Turning now to  FIGS. 4 and 5 , the process of collecting soil from probe  31  into sampling assembly  14  may be described. It may be seen that the longitudinal axis of probe  31  is set towards the centerline of the apparatus relative to the centerline of probe shaft  30 . As a result, there is no impediment to soil that is collected in tube  36  of probe  31  to simply fall from probe  31  as probe  31  is returned to the position shown in  FIG. 3A  due simply to gravity. In the preferred embodiment, a stop  40  (shown in  FIG. 2 ) may be employed to halt the clockwise rotation of probe shaft  30  as it returns to the position shown in  FIG. 3A , and to provide a “bump” that helps to dislodge soil from tube  36  of probe  31 . It may be seen in  FIG. 4  that when probe  31  reaches the position shown in  FIG. 3A , soil falling from probe  31  will drop into transverse auger tray  42 . The rotation of transverse auger  44  within transverse auger tray  42  will cause the soil to be drawn towards the centerline of the apparatus, where it will drop down through an opening in the center of transverse auger tray  42 . 
     As shown in  FIG. 5 , soil passing through such opening will enter rotor housing  46 , wherein rotor  48  is located. The purpose of rotor  48  is to regulate the flow of soil into bagging assembly  20 . Rotor  48  is preferably powered by a hydraulic motor (not shown), as are well known in the prior art. In the preferred embodiment, the upper sidewalls of rotor housing  46  are carved out to match a hole in the bottom of transverse auger tray  42 . The blades of rotor  48  extend far enough that they pass into the carved out portion of rotor housing  46 , and thus extend into the interior of transverse auger tray  42 . As a result, soil that passes through transverse auger tray  42  into rotor housing  46  does not simply fall into rotor housing  46  from above, but instead is fed directly into the blades of rotor  48  due to the action of transverse auger  44 . It is believed that this design provides a more reliable, positive feed of soil samples from transverse auger tray  42  through rotor housing  46 . Soil that reaches rotor housing  46  is forced from the top section of rotor housing  46  to the bottom section of rotor housing  46  as a result of the rotation of the blades of rotor  48 . In the preferred embodiment, cleaning brush wheel  50  may be mounted adjacent to rotor  48  such that the rotation of rotor  48  causes the blades of rotor  48  to push against rotor brush wheel  50 . The purpose of rotor brush wheel  50  is to keep the blades of rotor  48  clean of moist soil that might otherwise cling to the blades of rotor  48  and thereby degrade the operation of the apparatus. 
     Soil drawn into rotor housing  46  by rotor  48  is pushed by rotor  48  down through transverse auger tray funnel  51  and into longitudinal auger tray  52 . The soil is then delivered by longitudinal auger  54  towards bagging assembly  20  positioned in cab  18 , as shown in  FIG. 6 . The soil is delivered by longitudinal auger  54  to chopping blade housing  56 . Chopping blades  58  rotate without chopping blade  56 . In the preferred embodiment, chopping blades  58  comprise a series of blades of different lengths for the purpose of cutting any sticks or other organic material that may have been collected with the soil sample and delivered to chopping blade housing  56 . The result of passing the soil through chopping blades  58  will be the reduction of such material to small particles that will not interfere with the analysis of the resulting soil samples. Chopping blade brush wheel  60 , driven by gear mechanism  62  from the rotation of longitudinal auger  54 , serves to keep chopping blades  56  clean in a manner similar to that of rotor  48  as described above. Soil passing through chopping blade housing  56  falls through longitudinal auger funnel  64  and into one of the bags  68  on bagging tray  66 . Preferably, bagging tray  66  rotates to present another bag for collection as soon as the previous bag is filled. The operator or operators may then place empty bags in place of each filled bag during a continuous sampling operation. 
     As used herein, “comprising” is synonymous with “including,” “containing,” or “characterized by,” and is inclusive or open-ended and does not exclude additional, unrecited elements or method steps. As used herein, “consisting of” excludes any element, step, or ingredients not specified in the claim element. As used herein, “consisting essentially of” does not exclude materials or steps that do not materially affect the basic and novel characteristics of the claim. Any recitation herein of the term “comprising”, particularly in a description of components of a composition or in a description of elements of a device, is understood to encompass those compositions and methods consisting essentially of and consisting of the recited components or elements. The invention illustratively described herein suitably may be practiced in the absence of any element or elements, limitation or limitations which is not specifically disclosed herein. 
     When a Markush group or other grouping is used herein, all individual members of the group and all combinations and subcombinations possible of the group are intended to be individually included in the disclosure. 
     The terms and expressions which have been employed are used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the invention claimed. Thus, it should be understood that although the present invention has been specifically disclosed by preferred embodiments and optional features, modification and variation of the concepts herein disclosed may be resorted to by those skilled in the art, and that such modifications and variations are considered to be within the scope of this invention as defined by the appended claims. Thus, additional embodiments are within the scope of the invention and within the following claims. 
     In general the terms and phrases used herein have their art-recognized meaning, which can be found by reference to standard texts, journal references and contexts known to those skilled in the art. The preceding definitions are provided to clarify their specific use in the context of the invention. 
     All patents and publications mentioned in the specification are indicative of the levels of skill of those skilled in the art to which the invention pertains. All references cited herein are hereby incorporated by reference to the extent that there is no inconsistency with the disclosure of this specification. 
     The present invention has been described with reference to certain preferred and alternative embodiments that are intended to be exemplary only and not limiting to the full scope of the present invention as set forth in the appended claims.