Soil sampler lay flat sheet liner system

Abstract

A liner assembly for use in a soil sampling system comprises a thin sheet of flexible plastic that can be laid flat for shipping and rolled into a cylindrical shape with overlapping edges for use as a liner. The rolled sheet can be inserted into a soil sample tube to line the sample tube during soil sampling operations. A wedge assembly comprising a split holding ring and a wedge ring holds the liner in place at the bottom of the soil sample tube. After the soil sampling system is advanced into the subsurface to collect a soil sample, the soil sample is removed by removing the cutting shoe from the sample tube and sliding the rolled liner sheet out the bottom end of the sample tube. The liner sheet can be unrolled to access and remove the soil sample. The liner sheet can be reused after removing the soil sample.

Claims

1. A liner assembly for a soil sampling system, comprising: a thin sheet of flexible plastic having a first configuration in which the sheet lays flat for shipping and for permitting soil access, and a second configuration in which the sheet is rolled into a cylindrical shaped liner with overlapping edges for lining an inside of a soil sample tube, said sheet being changeable from said first configuration to said second configuration for lining the inside of the sample tube and back to said first configuration for permitting access and removal of soil without cutting or tearing said sheet, thereby allowing said sheet to be used and reused multiple times; and a means for holding the cylindrical shaped liner in place at a bottom end of the soil sample tube without permanently attaching the overlapping edges together, wherein said means for holding comprises a wedge assembly that fits inside the cylindrical shaped liner without being permanently attached to the liner and presses radially outward to compress a lower end of the cylindrical shaped liner against the inside of the soil sample tube to maintain the cylindrical shaped liner in a cylindrical shape within said soil sample tube while collecting soil, and wherein said wedge assembly is removable from the cylindrical shaped liner after collecting soil to allow the sheet to be removed from the soil sample tube and changed from said second configuration back to said first configuration.

2. The liner assembly according to claim 1, wherein said flexible plastic is polyethylene.

3. The liner assembly according to claim 2, wherein said polyethylene is a material selected from the group consisting of: high density polyethylene, low density polyethylene, and ultra high molecular weight polyethylene.

4. The liner assembly according to claim 1, wherein said wedge assembly comprises a split holding ring having a gap in a circumference of the ring that allows an outer diameter of the ring to be expanded to press against the inside of the cylindrical shaped liner, and a wedge ring that fits inside the split holding ring to press the split holding ring radially outward against the inside of the cylindrical shaped liner.

5. The liner assembly according to claim 1, wherein said sheet has a flat rectangular shape in said first configuration.

6. A soil sampling system comprising: a cylindrical soil sample tube; a cutting shoe coupled to a bottom end of said soil sample tube; a liner assembly comprising a sheet of flexible material having a first configuration in which the sheet lays flat for shipping and for permitting soil access, and a second configuration in which the sheet is rolled into a cylindrical shaped liner with overlapping edges and positioned inside of said soil sample tube, said sheet being changeable from said first configuration to said second configuration for lining the inside of the sample tube and back to said first configuration for permitting access and removal of soil without cutting or tearing said sheet, thereby allowing said sheet to be used and reused multiple times; and a means for holding the cylindrical shaped liner in place at the bottom end of the soil sample tube without permanently attaching the overlapping edges together, wherein said means for holding comprises a wedge assembly that fits inside the cylindrical shaped liner without being permanently attached to the liner and presses radially outward to compress a lower end of the cylindrical shaped liner against an inside surface of the soil sample tube to maintain the cylindrical shaped liner in a cylindrical shape within said soil sample tube while collecting soil, and wherein said wedge assembly is removable from the cylindrical shaped liner after collecting soil to allow the sheet to be removed from the soil sample tube and changed from said second configuration back to said first configuration.

7. The soil sampling system according to claim 6, wherein said wedge assembly comprises a split holding ring having a gap in a circumference of the ring that allows an outer diameter of the ring to be expanded to press against the inside of the cylindrical shaped liner, and a wedge ring that fits inside the split holding ring to press the split holding ring radially outward against the inside of the cylindrical shaped liner.

8. The soil sampling system according to claim 7, wherein said split holding ring comprises a ribbed outer surface that presses against the cylindrical shaped liner.

9. The soil sampling system according to claim 6, wherein said sheet has a flat rectangular shape in said first configuration.

10. The soil sampling system according to claim 6, further comprising a drive head coupled to an upper end of the soil sample tube.

11. A soil sampling system comprising: a cylindrical soil sample tube; a cutting shoe coupled to a bottom end of said soil sample tube; a liner assembly comprising a sheet of flexible material having a first configuration in which the sheet lays flat for shipping and for permitting soil access, and a second configuration in which the sheet is rolled into a cylindrical shaped liner with overlapping edges and positioned inside of said soil sample tube; and a means for holding the cylindrical shaped liner in place at the bottom end of the soil sample tube, wherein said means for holding comprises a wedge assembly that fits inside the cylindrical shaped liner and presses radially outward to compress the cylindrical shaped liner against an inside surface of the soil sample tube; wherein said wedge assembly comprises a split holding ring that presses against the cylindrical shaped liner, and a wedge ring that fits inside the split holding ring to press the split holding ring radially outward; and wherein said wedge ring is separate from said cutting shoe, and wherein said cutting shoe comprises an internal ledge arranged to engage a bottom edge of said wedge ring to press said wedge ring into engagement with said split holding ring when the cutting shoe is coupled to said soil sample tube.

12. A method of using a soil sampling system, comprising: providing a cylindrical sample tube and a lay flat liner sheet; rolling said liner sheet into a cylindrical shape with overlapping edges that are not permanently attached together; inserting the rolled liner sheet into said sample tube to line said sample tube; and holding the rolled liner sheet in place at a bottom end of the sample tube using a device that fits inside the rolled liner sheet without being permanently attached to said rolled liner sheet and presses radially outward to compress a lower portion of the rolled liner sheet against the inside of said sample tube; attaching a cutting shoe to the bottom end of the sample tube after the rolled liner sheet is inserted into the sample tube; and advancing the soil sampling system into the subsurface; extracting the sampling system from the subsurface; and removing a first soil sample from the sampling system by removing the cutting shoe from the sample tube, sliding the rolled liner sheet out an end of the sample tube, and unrolling the rolled liner sheet into a flat configuration to access the first soil sample contained therewithin.

13. The method according to claim 12, further comprising reusing the liner sheet to collect a second soil sample after removing the first soil sample, said reusing comprising: rolling the same liner sheet into a cylindrical shape with overlapping edges that are not permanently attached together, inserting the rolled liner sheet into said sample tube to line said sample tube, holding the rolled liner sheet in place at the bottom end of the sample tube, advancing the soil sampling system into the subsurface, extracting the sampling system from the subsurface, and removing the second soil sample from the sampling system by unrolling the rolled liner sheet into a flat configuration to access the second soil sample contained therewithin.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present invention will become more clearly appreciated as the disclosure of the invention is made with reference to the accompanying drawings. In the drawings:

(2) FIG. 1 is a perspective view of a soil sampling system with a conventional liner.

(3) FIGS. 2(a) to 2(d) illustrate a typical soil sampling operation using the conventional soil sampling system shown in FIG. 1.

(4) FIG. 3 is a perspective view of a soil sampling system with a lay flat liner assembly of the present invention.

(5) FIGS. 4A and 4B are perspective views of the liner in a flat configuration and a rolled cylindrical configuration, respectively.

(6) FIG. 5 is an exploded elevation view of the lower end of the soil sampling system with a wedge assembly for holding the liner within the soil sample tube.

(7) FIG. 6 is a perspective view of the two piece wedge assembly for holding the liner within the soil sample tube.

(8) FIG. 7 is a cross section view of the lower end of the soil sampling system.

(9) FIG. 8 is a detail cross section view of a portion of the soil sampling system labeled D8 in FIG. 7.

DETAILED DESCRIPTION OF THE INVENTION

(10) A soil sampling system 20 with an improved liner according to the present invention will now be described in detail with reference to FIGS. 3 to 8 of the accompanying drawings.

(11) The basic components of the soil sampling system 20 of the present invention are shown in FIG. 3. The soil sampling system 20 includes a cylindrical soil sample tube 21, a drive head 22 attached to the upper end of the sample tube 21, a drive shoe or cutting shoe 23 attached to the bottom end of the sample tube 21, and a liner assembly 24 positioned inside of the sample tube 21. The sampling system 20 can be used in vibratory, percussion, and rotary applications. Other features, such as discreet points and core catchers, can also be used with the sampling system 20.

(12) The liner assembly 24 includes a thin sheet 25 of readily recyclable flexible plastic, such as polyethylene. The polyethylene can be, for example, high density polyethylene, low density polyethylene, or ultra high molecular weight polyethylene. The thin plastic sheet 25 has a first flat configuration, as shown in FIG. 4A, and a second rolled configuration, as shown in FIG. 4B. In the first configuration (FIG. 4A), the sheet 25 lays flat for shipping and for permitting access to soil collected by the sampling system 20. The sheet 15 has a generally flat rectangular shape in the first configuration.

(13) In the second configuration (FIG. 4B), the sheet 25 is rolled into a cylindrical shaped liner with overlapping edges 26, 27 for lining the inside of the soil sample tube 21, as shown in FIG. 3. The overlapping edges 26, 27 of the liner 25 allow the liner 25 to be easily opened for access to the soil sample without the use of any tools. Since no cutting or tearing of the liner 25 is required, no sharp material edges are exposed (only factory manufactured edges), thereby improving safety.

(14) The liner assembly 24 also includes a means for holding the liner 25 in place at the bottom end 28 of the soil sample tube 21. The holding means may not be required in every application, but will be useful in some soil formations because the lay flat sheet liner 25 of the present invention has a very low buckling strength (due to the overlapping seam) and will buckle in the presence of too much side friction. The holding means includes a wedge assembly 29, 30 that fits inside the cylindrical shaped liner 25 and presses radially outward to compress the liner 25 against the inside of the soil sample tube 21. The wedge assembly 29, 30 has a split holding ring 29 that presses against the inside of the cylindrical shaped liner 21, and a wedge ring 30 that fits inside the holding ring 29 to press the holding ring 29 radially outward.

(15) The holding ring 29 has a ribbed outer surface 31 that presses against the liner 25. The split 32 in the holding ring 29 facilitates expansion of the holding ring 29 when the wedge ring 30 is forced into engagement with the holding ring 29. An outer lip 33 is formed at the bottom edge of the holding ring 29 for limiting the insertion distance into the cylindrical sample tube 21.

(16) The wedge ring 30 has a tapered outer surface 34 that engages the inside surface of the holding ring 29 to cause the holding ring 29 to expand when the two rings 29, 30 are pressed together. An outer lip 35 is provided at the bottom edge of the wedge ring 30 for limiting the insertion distance into the holding ring 29. The bottom edge of the wedge ring 30 is arranged to engage an internal ledge 36 of the cutting shoe 23.

(17) The cutting shoe 23 is coupled to the soil sample tube 21 by mating the female threads on the cutting shoe 23 with the male threads on the soil sample tube 21. As the cutting shoe 23 is threaded onto the soil sample tube 21, the internal ledge 36 of the cutting shoe 23 engages the bottom edge of the wedge ring 30 to press the wedge ring 30 into engagement with the holding ring 29. The outer lips 33, 35 on the holding ring 29 and the wedge ring 30, respectively, prevent the rings 29, 30 from being inserted too far into the sample tube 21.

(18) In use, the soil sampler assembly 20 is assembled by rolling a flat plastic sheet 25 into a cylindrical shape with overlapping edges, and inserting the rolled plastic sheet 25 into the soil sample tube 21 to line the sample tube 21. The rolled liner sheet 25 is held in place at the bottom end of the sample tube 21 by the wedge assembly 29, 30, which fits inside the rolled liner sheet 25 and presses radially outward to compress the liner 25 against the inside of the sample tube 21. The cutting shoe 23 is then threaded onto the bottom end of the soil sample tube 21.

(19) The soil sampler assembly 20 with the rolled liner sheet 25 contained therein is then advanced into the subsurface through a soil sample interval to collect a soil sample. The assembly 20 is then retracted out of the borehole B and brought to the surface where it can be disassembled. Disassembly of the soil sampler assembly 20 is accomplished by removing the cutting shoe 23 and the wedge assembly 29, 30 from the bottom end of the soil sample tube 21. The rolled liner sheet 25 with the soil sample contained therein can then be slid out the bottom end of the sample tube 21. The liner sheet 25 can be unrolled and laid flat to access and remove the soil sample. Once the soil sample has been removed from the liner sheet 25, the liner sheet 25 can be reused by rolling it into its cylindrical configuration with overlapping side edges 26, 27 and reinserting the rolled sheet 25 into the soil sample tube 21 for use in collecting the next soil sample.

(20) The soil sample liner 25 of the present invention is more efficient than the conventional rigid thin walled cylindrical liner. The liner 25 of the present invention is rolled into a cylindrical shape to line the sampler, but when not in use it lays flat. The flat shape is easier to manufacture, and the liners 25 can be densely stacked to increase storage, shipping and handling efficiency, which contributes to cost reduction.

(21) The overlapping edges 26, 27 form a seam that allows easy soil access and also allows for easy soil removal. Since soil can be easily removed, the lay flat liner 25 can be reused multiple times. This reduces sampling costs compared to conventional plastic liners, which are not reusable.

(22) It will be appreciated that certain features of the present invention described above can be changed without departing from the scope of the invention. For example, the liner assembly 24 described herein can be used with a wide range of soil sampler diameters and lengths. For another example, the sample tube 21 can be either a solid cylindrical tube (as illustrated herein), or it can be a split sample tube, as disclosed in Applicant's Application No. 61/780,100 titled Split Tube Soil Sampling System. For another example, the inner surface of the holding ring 29 can be tapered and the outer surface of the wedge ring 30 can be straight to provide a wedge action when the rings 29, 30 are pressed together. Other means for holding the liner 25 in place at the bottom of the soil sample tube 21 can also be used, such as adhesive, retaining ring, and so forth.

(23) While the invention has been specifically described in connection with specific embodiments thereof, it is to be understood that this is by way of illustration and not of limitation, and the scope of the appended claims should be construed as broadly as the prior art will permit.