US3075588A

US3075588A - Soil sampler

Info

Publication number: US3075588A
Application number: US50787A
Authority: US
Inventors: Robert E Mitchell
Original assignee: Individual
Current assignee: Individual
Priority date: 1960-08-19
Filing date: 1960-08-19
Publication date: 1963-01-29
Anticipated expiration: 1980-01-29

Description

Jan. 29, 1963 R. E. MITCHELL 3,075,583

SOIL SAMPLER Filed Aug. 19, 1960 IN VEN TOR.

AM, {Juan by jerking upwardly on the tube.

3,975,588 SOIL QAMPLER Robert E. Mitchell, 302 N. Main St, Lodi, Wis. Filed Aug. 19, 1968, Ser. No. 50,787 '7 Claims. (Cl. 175-420) This invention relates to an improved soil sampler.

It is conventional in the construction industry to take samples of subsurface soil before the erection of a building thereover. Commercially available apparatus for this purpose typically consists of a hollow tube which is driven into the ground in sections to the desired depth. A soil sample is then admitted into the tube and the tube is then drawn up to the surface for analysis of the entrapped sample. In all such prior art devices known to me, the sample is admitted into the tube by withdrawing inwardly the point of the tube by manipulating a rod or the like which is attached to the point and which extends through the entire length of the tube for manipulation by an operator at ground level. Where the tube is made in sections the rod must also be made of sections.

In the soil sampling head of the present invention, however, all of the mechanism for admitting the sample into the tube is disposed within the head itself. Nothing need extend through the tube. Accordingly, the soil sampler of the present invention is simpler and less costly than such prior art devices and the procedures necessary to drive the tube to the desired depth and take the sample are speeded up.

In devices embodying the present invention a pointed end plug of the head is subject to withdrawal inwardly under the bias of a spring. A latch between the pointed plug and the head and engaged with a shouldered stern on the plug holds the pointed plug in place, against the bias of the spring, while the head is forced through the soil to the desired depth. The latch is then released The inertia of the relatively heavy plug and stem is such that when the tube is jerked upwardly the inertia of the plug, and stem, will hold the same against movement, thus to cause axial separation between the latch and stem shoulder. The latch is biased to retract laterally when released from engagement with the stem shoulder to a position Where it will not obstruct subsequent retracting movement of the plug and stem under bias of the spring which will withdraw the plug to a position where sufficient space will be left in the end portion of the head to admit the soil sample.

Accordingly, there need be no operating mechanism between the latch and the operator at ground-level. The latch is triggered simply by jerking upwardly on the tube as aforesaid. The inertia of the plug and stem is relied on for unlatching the plug.

The soil sampler head of the present invention can thus be attached to conventional soil sampling tube sections without requiring any modification whatever therein. completely any need for extraneous control mechanism between the soil sampling head and the operator.

Other objects, features and advantages of the invention will appear from the following disclosure in which:

FIGS. 1 and 2 are diagrammatic illustrations of soil sampling tubes equipped with a sampler head according to the present invention and showing relative positions of the parts in the course of taking the sample.

FIG. 3 is a greatly enlarged fragmentary axial section of a soil sampling head embodying the present invention.

FIG. 4 is a similar axial cross section showing the latch in its released position.

FIG. 5 is a transverse cross section taken along the line 5-5 of FIG. 3.

ttes sent Moreover, the present invention eliminates,

FIG. 6 is a transverse cross section taken along the line d-6 of FIG. 3.

As best shown in FIG. 1, soil sampling apparatus conventionally comprises a series or string of axially jointed tubular sections lti which may be coupled on mating threads 11 (FIG. 3) so that as many sections 10 may be added to the string as are needed to reach the depth of the subsurface test region. The sampling head of the present invention consists of a similarly elongated hollow tube 12 having a threaded coupling 11 at its upper end. At its lowermost end head 12 is provided with a terminal hardened steel collar 13 capable of withstanding shocks incident to driving it through the soil.

As is conventional in this art, collar 13 is provided with an end opening 14.. A pointed plug 15 is provided which is held in its position shown in FIG. 3 as the sampling tube is driven into the soil and which will be retracted to its position shown in FIG. 4 for the purpose of admitting into the hollow space at the end of the head 12 the core sample 16 of soil which is to be analyzed.

According to the present invention plug 15 is connec'ted. to a stem 19 in any convenient manner, for example by means of a dowel 2d and set screw 21 as shown in FIG. 3. At its end remote from the plug 15 the stem 19 is provided with a cap 22 which has an axially extending apertured ear 23 providing an anchorage for one end of a tension spring 24 which has its other end fastened to a transverse pin 25 spanning the head tube 12 near its upper end. With the plug 15 in its position shown in FIG. 3, spring 24 is tensioned and biases the plug upwardly towards a retracted position.

Retraction of the plug is normally prevented by a latch member or arm as which, as best shown in FIGS. 3 and 4, desirably comprises an axially extending laterally biased leaf spring having an upper end portion fastened to the inner wall of the tube 12 by set screws 27. The bias of the spring 26 is such as to tend to move it to its position shown in FIG. 4 (and in broken lines in FIG. 3) in which the leaf spring 26 lies closely adjacent the wall of the tube 12. However, for the purpose of holding the plug 15 in its FIG. 3 position while the head is being driven into the soil, the leaf spring 26 functions as a latch and is cocked laterally against its own resilient bias and its free end engages over the shoulder 36 on the stem 19.

To receive the free end portion of latch 2-6, the stern 3.9 is notched out at 31. While the shoulder 3d could be formed integrally with the stem 19', it desirably consists of a wear plate 32 releasably fastened by the screws 33 to the side of the stem 19 below the notch 31 so that as the shoulder 3i)? wears, it may be periodically replaced. The free end of the latch 26 is desirably notched at 34 to fit over the shoulder.

When the latch is engaged with the shoulder 36! as shown in FIG. 3, plug 15 will be held against retraction upwardly, notwithstanding the bias of the spring 24 which tends to draw the plug into the head. Driving force imposed on the tube string is transmitted to the plug 15 thnough the latch 26.

To take a sample of soil in the subsurface test region indicated diagrammatically by reference character 35 in FIGS. 1 and 2, the string of tubes it is driven downwardly until head 12 reaches the desired depth, which may be predetermined from previous tests. When the head 12 is at the desired depth, a handle section 36 may be threaded to the top of the uppermost tube section it and a sharp blow with a hammer or the like delivered upwardly against the handle bar 37. Accordingly, the string of tubes It? will be jerked abruptly upwardly. The inertia of the plug 15 and stem 19- is such, however, that these parts will tend to remain at rest while the latch 3,- 3 26 which is attached to the head 12 will be jerked abruptly upwardly along with the tube sections In practice the string of tubes is jerked upwardly a distance of approximately M2 or /3 inch, this being suificient to axially displace the body 12 with respect to the plug 15 and disengage the notched end 34 of the latch 26 from the shoulder B ll on the stem 19 and to permit the lateral bias of the latch spring as to snap it to its dotted line position shown in PEG. 3 and its full line position of FIG. 4. Tie inertia of the plug 15 and stem its"? will hold these parts in their HG. 3 position only momentarily, but for a time s fficient to permit disengagement of the latch as aforesai Thereafter, spring will be free to draw the stem and plug upwardly to their position shown in HG. 4, thus to withdraw the plug 15 from the opening lid at the lower end of the head 12;. The parts are relatively dimensioned substantially as shown in the drawing to permit the stem to slide past the retracted latch 26.

Now the string of tubes llll is driven downwardly for an additional dist-a as, typically about one foot, as diagrammatically shown in FIG. 2, thus to fill the space within the head l2 and between the plug 15 and collar 3 with a specimen 16 of test region soil. Thereupon the entire string of tubes is drawn upwardly to carry with it the sample 16 to the surface, where it is removed from the head 1?, for analysis. As the string of tubes is being withdrawn, it will ordinarily be disassembled at the joints 11.

Cup 22 is desirably notched at ed, as shown in PEG. 5, so as to it about the fixed end portion of the latch 21%. Accordingly, such fixed portion of the latch will guide cap 22 for axial movement within the tubular head 12 without rotation. The sliding engagement of the notched cap 212 with the latch 25 will key the stem 15 to face its side with the notch 31 and shoulder toward the latch 25.

The head E2 is desirably jointed at 41 opposite the latch 2'6. Accordingly, to reset the latch 26, the head joint 41 is opened, the stem 1% drawn axially against the bias of spring 2d, the latch 25 set against its shoulder 3t} and the joint it recoupled.

I claim:

1. Soil sampling apparatus comprising a tube adapted to extend from ground surface level to a subsurface soil test region, a soil sampling head at the subsurface end of the tube, said head comprising a hollow body having an end opening, plug means normally closing said opening and mounted for longitudinal movement in said body, spring means for biasing and plug means to a retracted position away from said opening, latch means comprising cooperating means on said body and said plug means for holding said plug means in said opening against the bias of said spring means, said latch means being responsive to axial displacement of said body with respect to said plug means to release the plug means for projection by the spring means to a retracted position mess in which a soil sample may be admitted into said body.

2. The device of claim 1 in which said plug means includes a stem with a latch receiving shoulder, said latch means comprising a latch mm, means for mounting the arm on the head with a portion thereof in abutment with the stem shoulder, said arm resiliently biased laterally whereupon said latch arm will be removed from abutment with the shoulder on such axial displacement.

3. The device of claim 1 in which said plug means includes a stem with a latch receiving shoulder, said latch means comprising a leaf spring and means for mounting said spring with one end fixed with respect to the head and its other end biased into endwise abutment against said shoulder by said spring means, said leaf spring being biased by its own resilience to withdraw laterally from said shoulder on relative axial displacement of the body with respect to said plug means and consequent separation of the leaf spring from the shoulder to release the stem for retraction of the plug means by I said spring means from said openin 4. The device of claim 3 in which said stem is provided with a cap having a notched margin in which said leaf spring is keyed "to face the stem shoulder toward the latch.

'5. The device of claim 3 in which said stem is provided I with a latch retainer behind which a notch is formed in with an end opening, plug means normally closing said opening and mounted for longitudinal movement in said body, spring means for biasing said plug means to a retracted position away from said opening, latch means comprising cooperating means on said body and said plug means for holding said plug means in said opening against the bias of said spring means, said latch means being responsive to axial displacement of said body with respect to said plug means to release the plug means for projection by the spring means to a retracted position in which a soil sample may be admitted into said body.

7. The device of claim 6 in which said plug means includes a stem with a latch receiving shoulder, said latch means comprising a resiliently biased arm, means for mounting said arm on the head for movement between one position in which it is biased into abutment against said shoulder by said spring means, and anotherposition in which it is withdrawn laterally from said shoulder to release the stem for retraction of the plug by said spring means from said opening.

Refierences Cited in the file of this patent UNlTED STATES PATENTS UNITED STATES PATENT OFFICE CERTIFICATE, OF CORRECTION Patent Noe 3,075,588 January 29- 1963 Robert E, Mitchell It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 3, line 50, for "and" read said O Signed and sealed this 27th day of August 1963,

(SEAL) Attest:

ERNEST w. SWIDER AVID L- LADD Attesting Officer Commissioner of Patents

Claims

1. SOIL SAMPLING APPARATUS COMPRISING A TUBE ADAPTED TO EXTEND FROM GROUND SURFACE LEVEL TO A SUBSURFACE SOIL TEST REGION, A SOIL SAMPLING HEAD AT THE SUBSURFACE END OF THE TUBE, SAID HEAD COMPRISING A HOLLOW BODY HAVING AN END OPENING, PLUG MEANS NORMALLY CLOSING SAID OPENING AND MOUNTED FOR LONGITUDINAL MOVEMENT IN SAID BODY, SPRING MEANS FOR BIASING AND PLUG MEANS TO A RETRACTED POSITION AWAY FROM SAID OPENING, LATCH MEANS COMPRISING COOPERATING MEANS ON SAID BODY AND SAID PLUG MEANS FOR HOLDING SAID PLUG MEANS IN SAID OPENING AGAINST THE BIAS OF SAID SPRING MEANS, SAID LATCH MEANS BEING RESPONSIVE TO AXIAL DISPLACEMENT OF SAID BODY WITH RESPECT TO SAID PLUG MEANS TO RELEASE THE PLUG MEANS FOR PROJECTION BY THE SPRING MEANS TO A RETRACTED POSITION IN WHICH A SOIL SAMPLE MAY BE ADMITTED INTO SAID BODY.