Sample collection apparatus

Sample collection apparatus is disclosed wherein the preferred and illustrated embodiment includes a cylinder enclosing a piston which defines a storage chamber below the piston. The storage chamber is provided with an inlet in a cylinder head at the lower end of the cylinder. The storage chamber is maintained under pressure by pressurizing the opposite side of the piston. A stirring disc is located in the storage chamber. The stirring disc is in the form of a plate, and it is agitated by a rod connected to it. This stirs the sample to prevent separation into strata of different ingredients. The rod connected to the stirring disc passes through the head at one end of the cylinder and extends from it. In one embodiment, the rod is attached to a small piston which is pressurized in a cylinder to be driven in one direction or the other to stir the sample. In another embodiment, the rod extends downwardly in a surrounding tubular wall and is aligned therewith, and supports a foot operated treadle which can be pumped by the user to stir the sample.

BACKGROUND OF THE DISCLOSURE 
The present inventor devised U.S. Pat. No. 4,172,670 as a sample collection 
apparatus. That structure has functioned quite well. It is particularly 
valuable in collection of small samples, typically in the range of one or 
two liters. When the sample must be larger, perhaps five or ten liters, 
the apparatus becomes somewhat tall, perhaps objectionably so. As will be 
appreciated, scaling the structure up is no problem in terms of 
manufacture but it is sometimes a problem in installation. It is generally 
undesirable to have an apparatus which stands taller than about eight feet 
because it is difficult to install under low ceilings. Moreover, some hand 
strength is required to grip the handle and stir the accumulated sample. 
In light of the scale limitations which are noted above, it has been 
determined that an alternate sample collection apparatus be provided. This 
structure, actually having the form of alternate embodiments, overcomes 
the difficulties mentioned above. First of all, it provides a structure 
which is substantially shorter. It is not merely a matter of changing the 
scale so that the storage chamber is greater in diameter; as the diameter 
of the stirring disc increases, the strength required to reciprocate it 
likewise increases. It is very easy to stir a small diameter sample 
container while it requires more strength to do this with a larger 
diameter disc. Accordingly, to provide a five or ten liter sample 
collection apparatus, this disclosure sets forth a shorter collection 
apparatus which will fit beneath a low ceiling so that structural or 
building modifications are not required for its installation. It also 
provides a means whereby the stirring disc in the sample collection 
chamber can be reciprocated. 
On the latter point, this disclosure sets forth alternate means. The first 
is obtained through the use of a double acting piston appended to the 
sample collection apparatus. The piston is received within the chamber and 
is acted on by pressure fluid on both faces thereby yielding a double 
acting arrangement. The piston in turn is connected to a rod which joins 
to the stirring disc. In the other embodiment, foot power of the operator 
is used. The rod which extends from the stirring disc downwardly is 
centralized within a hollow upstanding pipe which has a window cut in one 
side. The rod connects to a stirrup which can be foot actuated. A window 
is cut to enable the user to insert his foot into the stirrup to force the 
stirring disc upwardly and downwardly. This permits the user to stir 
manually through the use of his body weight as opposed to hand stirring. 
Moreover, this structure is also relatively short so that it can fit 
beneath conventional ceiling heights. 
Through the use of the structure disclosed herein, large samples can be 
collected. Even should the sample stratify in the sample collection 
chamber, it can be stirred with a great deal of turbulence to adequately 
mix the sample. 
BRIEF DESCRIPTION OF THE APATUS 
This apparatus discloses a cylinder surrounding a piston. The piston is 
enclosed between facing cylinder heads. The lower side of the piston 
defines a sample storage chamber. The upper side defines a pressurization 
chamber to provide adequate back pressure bearing against the sample. The 
back pressure forces the piston against the sample so that the sample is 
maintained in a liquid state to avoid partial vaporization of the sample. 
Moreover, the piston is steadily forced upwardly against back pressure as 
the sample accumulates. As the piston is moved upwardly with increases in 
sample size, the sample is eventually accumulated to capacity of the 
storage device. At this juncture, it is desirable to remove the sample. 
The device of this disclosure stirs the sample through reciprocation of a 
stirring disc in the sample receiving chamber. This disc extends 
transversely of the cylindrical storage chamber, and flushes the 
accumulated sample about the edges with turbulence to commingle the sample 
and break up strata in the sample. The stirring disc is mounted on a rod 
which reciprocates. Alternate embodiments are disclosed wherein the sample 
stirring rod is either powered by a hydraulic cylinder which is 
bidirectionally powered or in the alternative, it is powered by a foot 
operated stirrup.

DETAILED DESCRIPTION OF PREFERRED AND ILLUSTRATED EMBODIMENTS 
Attention is first directed to FIG. 1 of the drawings where the sample 
storage apparatus is identified generally by the numeral 10. It will be 
described preceding from the base upwardly. It is shown supported on a 
base plate 12 which enables the equipment to be stationed at a convenient 
location standing in the upright position. The base plate is joined to and 
supports an upstanding cylindrical cage 14. A stirring rod 16 is 
concentric with the cage. The cage has a window cut at 18, and the window 
is elongate. The window has a width to receive a user's foot. The length 
of the window is sufficient to enable reciprocating strokes of the user's 
foot in an upward and downward motion. Moreover, the window extends 
substantially to the floor and has a height which is sufficient to prevent 
barking the shin of the user. 
The stirring rod 16 is attached to a spider 20 at its lower end by welding 
or other suitable means. The spider extends outwardly to inverted U-shaped 
clevises 22 which are affixed to a plate 24. The plate 24 is generally 
horizontal so the user can place his foot on it in order to reciprocate 
the stirrup. 
The plate 24 is guided with the surrounding structure by means of rollers 
26 which are mounted on suitable shafts. Ideally, three are used and they 
are spaced at 120 degree intervals around the plate. The window 18 is 
slightly less than 120 degrees in width. This enables the user to insert 
his foot between a pair of the rollers underneath the spider. The spider 
thus defines a position sufficiently large for the user to insert his foot 
onto the plate to force the stirrup downwardly. The plate is guided in 
upward and downward movement by the rollers 26. Needless to say, the 
rollers can be varied from the uniform spacing depicted in FIG. 2. 
The stirrup is foot operated to force the stirring rod 16 downwardly. The 
rod 16 extends upwardly concentric of the cylindrical apparatus and passes 
through a lower cylinder head 28. The head 28 includes a seal mechanism at 
30. This seals around the stirring rod 16. Moreover, the cylinder head 28 
includes an upstanding circular lip and seal at 32 on the interior of a 
cylindrical wall 34. The cylinder 34 extends from the lower cylinder head 
28 to an upper cylinder head 36. The cylinder heads are spaced from one 
another and are similarly constructed. Both are equipped with internal 
seals to define closed chambers within the cylinder 34, and they define 
the limits of travel of a piston 40. The piston 40 reciprocates within the 
cylinder 34 and leakage past the piston is prevented by seal rings. 
Moreover, the lower head 28 is drilled with a tapped hole at 44, and a 
passage 46 extends through the cylinder head into a lower chamber. The 
chamber beneath the piston 40 is identified by the numeral 48 while the 
top chamber is identified by 50. The two chambers are between the cylinder 
heads 28 and 36 on the interior of the cylindrical wall 34. 
FIG. 1 further discloses a stirring disc or plate 52. It is joined to the 
stirring rod 16. Moreover, it is shaped to be received within a facial 
recess 54 on the lower side of the piston 40. It is also joined to and 
aligned with an upstanding rod 56. The rod 56 extends fully through the 
piston 40. The rod telescopes into a hollow sliding sleeve 58. The sleeve 
58 is joined to the piston 40 by threads, and leakage along the rod 56 is 
prevented by the incorporation of suitable seals at 60. The seals 60 
prevent leakage of the sample under pressure along the rod 56. 
The rod 56 telescopes on the interior of a surrounding sleeve 58. The 
sleeve receives air at atmospheric pressure into a chamber 62, there being 
a small passage 64 in cap 66 for pressure relief. The sleeve 58 is closed 
over by a threaded cap 66 which is shown at the top of FIG. 1. The cap 
closes the sleeve to define the chamber 62. This chamber enables the rod 
56 to telescope upwardly so that the stirring disc 52 may be retracted 
into the facial recess 54. When it is against the piston, it is completely 
retracted so that the chamber 48 is not divided by the stirring disc. 
The stirring disc 52 has an expanse which covers a substantial portion of 
the cross-sectional area of the storage chamber 48. The clearance between 
the outer lip of the stirring disc and the adjacent cylindrical wall is 
relatively small. This enables the equipment to stir, churn or otherwise 
agitate the specimen stored in the chamber 48. 
The pressure levels of the system should be noted. First of all, the top 
cylinder head 36 includes a tapped port 68 which admits hydraulic fluid 
under pressure. Preferably, the pressure that is maintained is a 
controlled back pressure. It fills the chamber 50 and forces the piston 40 
downwardly. As sample is accumulated in the chamber 48, the sample is 
collected and forces the piston upwardly against back pressure in the 
chamber 50. Assume for instance that the sample is collected from a 
pipeline where the pressure is maintained at 1,000 psi. In these 
circumstances, the chamber 50 might be maintained at an intermediate 
pressure of perhaps 900 psi. This is sufficient to force the piston down 
before sample is accumulated. The sample is admitted at a controlled rate 
dependent on the sample size and duration. Sample is admitted at a rate 
which may require weeks or months to fill the chamber 48. In this 
interval, the ambient temperature may significantly drop, thereby reducing 
the temperature of the sample. Temperature reduction and stagnation 
typically lead to stratification of the sample. As the sample accumulates, 
the piston is forced upwardly. When the sample chamber is full, the piston 
is at the top-most extreme of travel. Moreover, the piston moves to this 
position when full capacity is achieved. 
The two rods connected to the stirring disc 52 should be noted. The 
stirring rod 16 is of relatively small diameter while the rod 56 is 
larger. They are both exposed to the high pressure found in the chamber 
48. Just as important, the ends of the rods are exposed to atmospheric 
pressure because they are protected by seals. There is an area 
differential between the two, and the high pressure in the chamber 48 
forces the disc 52 upwardly into the recess provided for it. The high 
pressure creates a force proportional to the differential area. This force 
secures the disc in the recessed position during sample collection. 
After the sample has been collected, and the chamber 48 has been filled, 
the sample can be selectively churned and mixed. The operator simply 
inserts his foot through the window 18 and places his foot on the plate 24 
and pumps the stirrups downwardly. After the disc 52 is pumped down it 
will be forced back to the top by the pressure acting on the area 
differential as mentioned above. There is some displacement when the disc 
travels downwardly, this displacement of fluid being equal to the 
displacement achieved by sliding the larger rod 56 into the chamber 48. As 
this occurs, the chamber 48 must expand slightly. To this end, the piston 
40 is forced toward the upper limits of its travel, leaving a very small 
chamber 50. Ideally, the chamber 50 is filled with a compressible fluid to 
enable the piston 40 to reciprocate slightly as the pumping occurs. 
Attention is next directed to FIG. 3 of the drawings. FIG. 3 shows a 
structure very similar to the structure of FIG. 1. The differences will be 
first noted. The similar portions of the apparatus shown in FIGS. 1 and 3 
will not be described, and reference is made to the foregoing description. 
To this end, the structure of FIG. 3 is identified by the numeral 100. The 
stirring rod 116 is attached to a piston 124 received within a lower 
cylinder 114. The piston divides the cylinder 114 into upper and lower 
chambers, and fluid ports are provided at 120 at the top and 122 at the 
bottom. The two chambers receive hydraulic oil through the ports 120 and 
122 under pressure to force the piston 124 upwardly or downwardly. A 
stirring motion is thus obtained by forcing the piston 124 in 
reciprocating fashion which in turn transmits movement to the stirring rod 
116. The stirrng disc 152 is reciprocated in this fashion. Moreover the 
disc 152 operates in the same fashion as described for the disc 52. The 
piston 124 provides an alternate source of power to the foot operated 
stirrup shown in FIG. 1. 
In other regards, the structure shown in FIG. 3 is similar to the structure 
shown in FIG. 1. To this end, the detailed description of the structure 
has been abbreviated. 
While the foregoing is directed to the preferred embodiment of the present 
invention, other and further embodiments of the invention may be devised 
without departing from the basic concept thereof, and the scope thereof is 
determined by the claims which follow.