Abstract:
An improved rotary soil probe is provided with a frame pivotally mounted on the rear of a truck or vehicle for movement about a horizontal axis between raised and lowered positions. A rotatable wheel is pivotally mounted to the frame for movement about an upwardly angled axis between an extended use position and a folded transport position. The wheel includes probes extending radially outwardly from the perimeter of the wheel. The probes are adapted to receive soil samples as the wheel is rolled along the ground. Plunger assemblies automatically discharge the soil samples on each rotation of the wheel so that the samples can be continuously collected, without the need to stop to clean out the soil samples.

Description:
BACKGROUND OF THE INVENTION 
     Soil probes are well known in the art for collecting soil samples. These prior art soil samplers take a variety of forms, including a rotary wheel with a soil probe extending radially outwardly from the perimeter of the wheel. Such rotary probes are typically pulled behind a vehicle such that the probe penetrates the soil near the six o&#39;clock position and then is withdrawn from the soil as the rotation of the wheel continues. Thus, the soil sample is received in the open outer end of the probe. The soil sample then is discharged through the inner end of the probe and deposited in a container positioned within the perimeter of the wheel. 
     Such prior art rotary soil probes have several shortcomings. For example, the soil samples occasionally become compacted in the probes and do not discharge through the inner end into the compartment. Also, the samples cannot be easily removed from the compartment without stopping the wheel. Also, the wheel is relatively large in diameter such that its size presents a hazard when transporting the wheel down a roadway, since the wheel extends substantially behind the rear of the vehicle upon which it is mounted. 
     Also, conventional rotary soil probes are relatively slow. For example, one known rotary probe covers approximately 80 acres per hour. 
     Therefore, a primary objective of the present invention is the provision of an improved rotary soil probe. 
     Another objective of the present invention is the provision of a rotary soil probe wheel having a plurality of probes with open outer ends through which the soil sample is collected and discharged. 
     A further objective of the present invention is the provision of an improved rotary soil probe which can be raised and lowered between operative and inoperative positions, and which can be folded between a use and transport position. 
     Another objective of the present invention is the provision of a rotary soil probe having plunger assemblies for discharging the soil samples from the probes. 
     A further objective of the present invention is the provision of an improved rotary soil probe which is fast and easy to use, and which may cover several hundred acres per hour. 
     Still another objective of the present invention is the provision of a rotary soil probe which is economical to manufacture and durable in use. 
     These and other objectives will become apparent from the following description of the invention. 
     BRIEF SUMMARY OF THE INVENTION 
     The soil probe of the present invention includes a frame mounted to the rear of a vehicle, such as a pickup truck. The frame has a first section which is pivotal about a horizontal axis, and a second section which is pivotal about a vertical axis. A wheel is rotatably mounted on the second frame section and has a perimeter with a plurality of soil probes extending radially outwardly therefrom. The pivotal connections of the frame sections allows the wheel to be raised and lowered and to be folded between a longitudinally extended use position and a laterally extending transport position. A plunger assembly is associated with each probe, with each assembly including an arm pivotally mounted on the wheel and a rod pivotally mounted on the arm. A cam surface engages the arm as the wheel turns to move the rod from an retracted to an extended position with respect to the probe. As the rod is extended into the probe, the soil sample received in the outer end of the probe is discharged through the outer end for collection. Thus, the rotary soil probe of the present invention can be operated continuously without stopping to collect the soil samples. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a rear perspective view of the rotary soil probe of the present invention mounted on the back of a pickup truck. 
     FIG. 2 is a side elevation view from one side of the soil probe. 
     FIG. 3 is a side elevation view from the opposite side of the soil probe. 
     FIG. 4 is a perspective view showing the soil probe folded to the transport position. 
     FIG. 5 is a perspective view showing the inside of the wheel, the plunger assembly and an anti-reverse mechanism. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The rotary soil probe of the present invention is generally designated by the reference numeral  10  in the drawings. The probe  10  includes a frame  12  adapted to be mounted on the back of a vehicle, such as a pickup truck  14 , and a wheel  16  rotatably mounted on the frame  12 . The wheel  16  includes a plurality of probes  18  adapted to pull soil samples from the soil as the truck moves forwardly to rotate the wheel over the soil. The probes each have a beveled outer end and at least one axially extending slot  19  to facilitate collection and discharge of soil to and from the probe  18 . 
     More particularly, the frame  12  of the soil probe  10  includes a first section  20  mounted to the truck for pivotal movement about a horizontal axis, and a second section  22  pivotally connected to the first section  20  for movement about a substantially vertical axis. The first frame section  20  includes an elongated member preferably mounted on the rear bumper of the truck  14  so as to be horizontally disposed, with the longitudinal axis of the member  20  defining the horizontal pivot axis for the first frame section  20 . A leg  20  extends downwardly from the member  24  and is connected to the extensible rod  28  of a hydraulic cylinder  30 . The cylinder  30  is mounted to the frame of the truck  14  and is operatively connected to a hydraulic fluid source (not shown). The controls for the hydraulic cylinder  30  are preferably located in the bed of the truck  14  so that an assistant riding in the back of the truck can operate the cylinder  30 . 
     A yoke  32 , defined by a pair of spaced apart arms, extends rearwardly from the elongated member  24 . The inner end of the second frame section  22  extends between the plates of the yoke  32  and is pivotally connected thereto by a bolt  34 . The bolt  34  defines a substantially vertical or upwardly angled pivot axis about which the second frame section  22  pivots relative to the first frame section  20 , such that the second frame section  22  is moveable between a rearwardly extending use position, shown in FIGS. 1-3, and a laterally extending folded or transport position, shown in FIG.  4 . The inner terminal end of the second frame section  22  includes a hole adapted to receive a lock pin  36  extending through aligned slots  38  in the plates of the yoke  32 . The pin  36  retains the second frame section  22  and the attached wheel  16  in the extended use position, while the slots  38  allow an angle of play, preferably 10°-15°, in the alignment of the first frame section  20  and the yoke  32 , so as to prevent binding of the wheel  16  if the truck  14  deviates slightly from a straight line path. In the folded transport position, the weight of the wheel  16  and the angled axis of bolt  34  keeps the soil probe  10  in the transport position. 
     The outer end of the second frame section  22  includes a hub  40  upon which the wheel  16  is rotatably mounted. The four probes  18  extend radially from the outer perimeter of the wheel  16  and are spaced equally around the wheel at 90° intervals. A plurality of spikes  42  extend radially outwardly from the perimeter of the wheel  16 , and are spaced at 90° intervals around the wheel between the probes  18 . When the wheel  16  is in a ground engaging use position, the probes  16  and spikes  42  penetrate the ground and cause the wheel  16  to rotate as the truck  14  moves forwardly. The probes  18  are hollow tubes, and preferably include a longitudinally extending slot  44 , which facilitates receipt and discharge of soil samples from the probes  18 . 
     A plurality of plunger assemblies  46  are pivotally mounted on the inner face of the wheel  16 , as best seen in FIG.  3 . Each of the plunger assemblies  46  is associated with one of the probes  16 . Each plunger assembly  46  includes an arm  48  having a first end  50  having a tubular collar  52  welded thereto in a transverse relationship to the longitudinal axis of the arm  48 . A bolt  54  extends through the wheel  16 , the collar  52 , and a tab  56  extending inwardly from the perimeter of the wheel  16 . The bolt  54  defines a pivot axis for the outer end  50  of the arm  48 . 
     Each plunger assembly also includes a rod  58 . The inner end of the rod  58  is pivotally connected to the inner end  60  of the arm  48 . The inner end of the rod  58  is connected to a transverse collar  57  received within a cut out in the square tubular arm  48  and is pivotally secured in place with a nut and bolt assembly  61 , as best seen in FIG.  5 . The outer end of the rod  58  has an enlarged head  59  and is adapted to slide within the hollow probe  18  so as to discharge the soil sample collected by the probe  18  during each rotation of the wheel  16 . The extension of the rod  58  into the probe  18  is accomplished by a cam wheel  62  which engages the arm  48  after the probe  18  is withdrawn from the soil. As best seen in FIG. 3, the cam wheel  62  engages the arm  48  at approximately a two o&#39;clock position. As the clockwise rotation of the wheel  16  continues, the cam wheel  62  causes the arm  48  to pivot in a clockwise direction (as seen in FIG. 3) about the horizontal axis defined by the bolt  54 , thereby extending the rod  58  into the probe  18  such that the head  59  pushes out the soil sample contained in the probe  18 . After the inner end  60  of the arm  48  moves past the cam wheel  62 , the rod  58  is automatically urged to the retracted position by a spring  64  connected between the wheel  16  and the arm  48 . The cam wheel  62  is adjustably mounted on the second frame section  22  with a mounting bracket  66 . The guide collar  67  is axially aligned with the probe  18  to guide the extension and retraction of the rod  58  relative to the probe  18 . 
     The second frame section  62  also includes an anti-reverse mechanism  68  to prevent the wheel from rotating counterclockwise. More particularly, the anti-reverse mechanism  68  includes a bar  70  mounted on the second frame section  22  and extending upwardly therefrom. An arm  72  is pivotally mounted to the bar  70  and extends laterally or transversely. The arm  72  has one end  74  extending toward the wheel  16  a sufficient distance to engage the tab  56  on the wheel  16 . The opposite end  76  of the arm  72  extends away from the wheel  16 . The bar  70  includes a stop element  78  which prevents the arm  72  from rotating clockwise, as seen in FIG. 5, beyond the transverse position. Upon the normal clockwise rotation of the wheel  16 , the bottom edge of the tab  56  engages the arm  72  and rotates it downwardly against the bias of the spring  80 . After the tab  56  passes beyond the arm  72 , the spring  80  urges the arm  72  back to the transverse position shown in FIG.  5 . If the wheel starts to rotate counterclockwise, which may occur when it is raised from the ground engaging position. The arm  72  will engage the top edge of the tab  56  to prevent further counterclockwise rotation of the wheel. Otherwise, the retracted rod  58  below the cam wheel  62  would hit the cam wheel and be bent or damaged. 
     The soil probe  10  is transported to the field or soil sampling site by the truck  14  with the wheel  16  folded to the transport position, as seen in FIG.  4 . In the transport go position, the wheel has been raised, by the extension of the hydraulic cylinder rod  28 , such that the probes  18  do not engage the ground. The wheel  16  remains in the transport position due to the inclined orientation of the pivot axis defined by the bolt  34  and the weight of the wheel  16 . 
     Upon arrival at the desired location, the lock pin  36  is removed from the yoke  32  and the wheel  16  is manually folded from the transport position to the use position. The hydraulic cylinder  30  is then actuated so as to retract the rod  28 , thereby lowering the wheel so that the probes  18  and spikes  42  will be forced into the ground. The lock pin  36  is reinserted into the yoke  32  and through the aligned hole in the second frame section  22  to limit the lateral movement of the wheel  16  to a relatively small angular range, preferably between 10°-15°. 
     The truck can then be driven forwardly such that the wheel  16  rolls upon the ground, with each probe  18  collecting a soil sample as it is inserted into and withdrawn from the ground. As the rotation of the wheel  16  continues, the cam wheel  62  engages the lever arm  48  to extend the plunger rod  58  into the associated probe  18  to expel the soil sample from the outer end of the probe  18 . Preferably, the probes  18  include a longitudinal slot which facilitates collection and discharge of the soil sample from the probe  18 . An assistant riding in the back of the truck  14  collects the soil samples in any desired container as the sample is expelled from the probe  18  by the extended plunger rod  58 . As the lever arm passes beyond the cam wheel  62 , the spring  64  retracts the rod  58  so that the probe is ready to collect another soil sample. 
     Whereas the invention has been shown and described in connection with the preferred embodiment thereof, it will be understood that any modifications, substitutions, and additions may be made which are within the intended broad scope of the following claims. From the foregoing, it can be seen that the present invention accomplishes at least all of the stated objectives.