Compost aerator and monitor

A compost aerator and monitor which has a cylindrical helical screw, preferably with a sharpened first end. The diameter of the cylindrical helix and the tightness of the windings are selected so as, when the screw is inserted into a compost pile, to create a core of compost material that is sufficiently large to be cohesive and representative but not so large that the weight of the core will cause the core to fall from the screw when such screw is withdrawn from the compost pile. Attached to the second end of the screw is a handle with sufficient leverage to enable the screw to be turned rapidly and, consequently, rapidly introduced into a compost pile and to preclude the screw from rotating as the screw is withdrawn from the pile, thereby retaining the core of compost material. Optionally, either a traditional brace or a traditional power drill can replace the simple handle; and a shaft can be inserted between the screw and the handle or the brace. The handle or brace may be either permanently or removably attached to the screw or the shaft, while the power drill is removably connected to the screw or the shaft.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to a device and method for aerating and monitoring 
the status of a compost pile. 
2. Description of the Related Art 
With increasing environmental awareness, more individuals and neighborhood 
associations are establishing compost piles as a responsible way to 
dispose of yard debris while creating organic fertilizer for gardening. 
The desired biological changes in organic matter within a compost pile can 
be facilitated by the addition of more oxygen through aeration. 
Consequently, this is one purpose for the present invention. And 
decomposition will be even further accelerated by the increased 
penetration of moisture into the compost pile as a result of such 
aeration. 
It can, furthermore, be helpful to know what is in the compost pile. Even 
if a single individual is responsible for the pile, that person may have a 
lapse of memory. When the pile is a communal effort, it becomes even more 
difficult to know the contents. Thus, an additional purpose for the 
present invention is to extract a core sample from the pile for 
examination. The stage of decomposition at the tested location can readily 
be observed; and tests can be conducted upon the sample to determine the 
ratio of carbon to nitrogen, acidity, bacterial count, etc. Additionally, 
by comparing samples extracted at different times, the rate of 
decomposition can be established. 
Traditionally, aeration of a compost pile is accomplished with a pitchfork, 
spade, or the like. This process consists essentially of turning the 
material in the compost pile to mix air into such material. Because new 
material is generally added to the top of the compost pile, this technique 
has the disadvantage of contaminating the deeper, more thoroughly 
decomposed material with higher--and, therefore, less decomposed-material. 
The entire quantity of disturbed material must then be allowed to remain a 
sufficient length of time to permit adequate decomposition of the more 
recent material. 
Moreover, utilizing a pitchfork, spade, or the like to extract a core 
sample for analysis is too laborious and imprecise. Again, even with 
reasonable care, material from different levels--and, therefore, different 
states of decay--will often be unintentionally mixed. And to minimize the 
likelihood of such mixing, considerable time and effort would have to be 
expended. 
No device appears to have been patented for the aeration and monitoring of 
compost piles. 
Six devices intended for entirely different purposes do, however, resemble 
the present invention. 
U.S. Pat. No. 168,890 and U.S. Pat. No. 200,489 both describe and claim a 
picket-pin, i.e., a device which can be screwed into the ground securely 
to retain the rope from a tethered animal, such as a horse. The picket-pin 
of each patent consists of a handle attached to a spiral shaft. U.S. Pat. 
No. 168,890 merely asserts that the "shank . . . is bent in spiral form . 
. . ." U.S. Pat. No. 200,489 describes ". . . a spiral or screw having the 
general form of a corkscrew, which is made of a flat bar of steel or 
wrought-iron, having its greatest diameter at right angles to the axis of 
the screw. The bar is tapering, being thickest at the upper end of the 
screw, and gradually diminishing in thickness toward the lower end, upon 
which there is a chisel-edge. The object in tapering the bar is to cause 
it to wedge as it enters the earth, so as to form a solid bearing." 
Not only is the function for the devices of these two patents to retain 
each device within the earth, but their claims and disclosures fail to 
provide the critical details of construction which would enable these 
devices to serve as compost aerators and monitors. An essential feature of 
the "spiral or screw" for a compost aerator and monitor is that it be 
wound in such a fashion as to create the shape of a hollow cylinder within 
the windings, i.e., the "spiral or screw" must be wound as a cylindrical 
helix, in order to create a space in which the compost will collect for 
subsequent withdrawal. Neither of these two prior patents, however, 
describes the dimensions of the central cylindrical cavity which exists 
between the windings. In fact, both such patents fail even to state that a 
central cylindrical cavity exists. And the related drawings seem to show 
that either there is no such cavity or that its diameter is so minimal as 
to preclude the collection of enough compost to create a cohesive, 
representative mass. 
The claims and disclosures for these two patents, furthermore, do not 
appear to describe a head which would provide sufficient leverage 
conveniently to permit the rapid introduction of the devices into 
well-compacted compost or to preclude the devices from rotating as they 
are withdrawn, which would allow the escape of any compost that may have 
collected between the windings. 
Similarly, the function of the guy anchor described and claimed in U.S. 
Pat. No. 728,609 is to retain the guy anchor within the earth; and the 
claims and disclosures of this patent fail to provide the critical details 
of construction which would enable the guy anchor to serve as a compost 
aerator and monitor. The guy anchor is intended to be screwed into the 
ground using a removable bar (or key). The relevant disclosure simply 
states, "The lower end of said body portion . . . consists of a piece of 
rounded metal . . . , which is formed into a screw, sic! and by turning 
the upper body portion . . . the screw will force itself into the ground 
similar sic! to that of a corkscrew." Again, this patent does not 
describe the dimensions of the central cylindrical cavity which exists 
between the windings and even fails to state that a central cylindrical 
cavity exists. The drawings do appear to show such a central cylindrical 
cavity, but such cavity seems to be so large and the windings appear to be 
so far apart that the weight of the compost material within the cavity 
would combine with a significant lack of structural support from the 
windings to cause such compost material to fall from the windings as the 
guy anchor is withdrawn from a compost pile. 
Moreover, the removable design of the bar would cause it to slide and, 
therefore, be inconvenient for use in preventing rotation of the helical 
screw as the guy anchor is withdrawn from the compost. Additionally, the 
bar could easily be lost. 
Another spirally shaped device is one element within the hay boring 
apparatus of U.S. Pat. No. 601,124. The hay boring apparatus has knives at 
a lower end of a tube, which knives move in a circle to cut into a pile of 
hay. This permits the tube to descend into the pile as the cut hay is 
removed by being transported upward through the tube as a result of the 
rotation of the spirally shaped device, termed a "wormer." Once again, no 
dimensions are given for the size of the central cylindrical cavity or the 
tightness of the windings. The drawings, however, appear to depict a 
cavity with such large dimensions and windings so far apart from one 
another that inadequate structural support would be provided to a central 
core of compost material to permit such core to be withdrawn without 
collapsing and thereby preventing the hay boring apparatus from 
successfully either aerating or monitoring a compost pile. 
The ice boring device of U.S. Pat. No. 2,666,623 basically utilizes a 
cutting edge at the lower end of a helix. As the ice boring device is 
turned, the cutting edge goes deeper into the ice; and an annular ring of 
ice is forced up the helix, leaving a central core of uncut ice. The 
helix, thus, provides essentially no structural support for the central 
core. With ice this is unimportant; but were the ice boring device to be 
used in a compost pile, the core of compost material would collapse, 
precluding either aeration or monitoring of the compost pile. 
Unlike the devices of the preceding patents, the auger included within the 
Apparatus for Batch Composting of Waste Material disclosed within U.S. 
Pat. No. 5,405,780 can aerate compost material; this auger cannot, 
however, monitor the material within a compost pile. Aeration is 
accomplished by rotation of the auger to raise materials from lower in the 
pile to the top and would, consequently, have the disadvantage of 
requiring the entire pile to be unavailable for use until the most 
recently added material had had sufficient time to reach the desired state 
of decomposition. Monitoring would be impossible because the disclosed 
auger has a shaft running longitudinally through the central cylindrical 
cavity formed by the windings of the auger, which shaft would preclude a 
core of compost material from accumulating within the cavity. 
One apparently unpatented anchor--which is imported and marketed by 
Wal-Mart Stores, Inc. in the United States; which is made in Taiwan by the 
Yau Feng Chain Company; and which has no designation other than a Spiral 
Stake--does appear, however inadvertently, to have a screw of the 
appropriate shape and size to create the desired core of compost material. 
But this Spiral Stake does not have a head which would provide sufficient 
leverage conveniently to permit the rapid introduction of the device into 
well-compacted compost or to preclude the device from rotating as it is 
withdrawn. The compost which had collected between the windings after 
insertion into the compost pile would, therefore, be allowed to escape 
during the process of withdrawal from the compost pile. 
SUMMARY OF THE INVENTION 
The present Compost Aerator and Monitor has a cylindrical helical screw, 
preferably with a sharpened first end. The diameter of the cylindrical 
helix and the tightness of the windings are selected so as, when the screw 
is inserted into a compost pile, to create a core of compost material that 
is sufficiently large to be cohesive and representative but not so large 
that the weight of the core will cause the core to fall from the screw 
when such screw is withdrawn from the compost pile. 
Attached to the second end of the screw is a handle with sufficient 
leverage to enable the screw to be turned rapidly and, consequently, 
pushed rapidly into a compost pile and to preclude the screw from rotating 
as the screw is withdrawn from the pile, thereby retaining the core of 
compost material. This core can then be inspected and analyzed to monitor 
the compost pile for, inter alia, the status of decomposition, the rate of 
decomposition, moisture, nature of the compost material, and location of 
any boundary between compost material which has decomposed sufficiently to 
be a final product, i.e., humus, and compost material which has not yet 
attained such a state of adequate decomposition. Removal of the core from 
the compost pile creates a channel for aeration as well as a pathway for 
moisture more rapidly to penetrate into the recesses of the pile. 
As the screw penetrates deeper into the compost, the material from the 
upper layers is pushed from the screw so that there is no mixing from 
different layers and that the core sample is characteristic of the deepest 
layer into which the screw was inserted. 
One may, if desired, remove the core sample from the area of the compost 
pile to preclude the mixing of that sample with the upper layer of the 
compost pile. More often, however, the core will simply be visually 
inspected while retained within the screw and the screw will be inserted 
again into the compost pile for further monitoring or aeration. Such 
re-insertion will then cause the core to be pushed from the screw and 
deposited on the top of the compost pile where the increased number of 
bacteria within the material from the core (because of the more advanced 
decomposition of such material as compared to the more newly added 
material on top of the compost pile) will serve to accelerate the 
decomposition of the more recently added material at the top of the 
compost pile.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
The Compost Aerator and Monitor, as illustrated in FIG. 1, has a screw 1 
shaped as a cylindrical helix, preferably with a sharpened tip 2, and even 
more preferably so sharpened as to have the same shape as the tip of a 
traditional chisel, at the first end 3 of the screw 1. 
The diameter of the central cylindrical cavity formed by the cylindrical 
helix of the screw 1 and the tightness of the windings 4 of the screw 1 
are of such sizes that, when the screw 1 is inserted into the compost 
pile, there is collected within the windings 4 of the screw 1 a core of 
compost material that is sufficiently large to be cohesive and 
representative but not so large that the weight of the core will cause the 
core to fall from the screw 1 when such screw 1 is withdrawn from the 
compost pile. It has been experimentally determined that, preferably, the 
screw 1 is ten inches long, the distance between similar points on 
adjacent windings 4 is two inches, and the diameter of the central 
cylindrical cavity is one inch. 
Although the second end 5 of the screw 1 can be connected directly to a 
traditional brace 6, the second end 5 of the screw 1 is preferably 
connected to a first end 7 of a straight shaft 8. The second end 9 of the 
shaft 8 is attached to the traditional brace 6. 
Preferably, as shown in FIG. 1, the shaft 8 is aligned with the 
circumference of the central cylindrical cavity formed by the cylindrical 
helix of the screw 1. Alternatively, the shaft 8 may be aligned with any 
other point, such as the center of the central cylindrical cavity formed 
by the cylindrical helix of the screw 1, as depicted in FIG. 3. 
Rather than utilizing the traditional brace 6, a simple handle 10 can be 
attached to the second end 9 of the shaft 8, as illustrated in FIG. 5 and 
FIG. 7, where such handle 10 has sufficient leverage to enable the screw 1 
to be turned rapidly and, consequently, pushed rapidly into a compost pile 
and to preclude the screw 1 from rotating as the screw 1 is withdrawn from 
the pile. Likewise, any powered device capable of producing rotary motion 
with sufficient torque to drill into the compost pile and with sufficient 
strength to prevent the screw from rotating during withdrawal from the 
compost pile could be utilized. 
An additional option for the Compost Aerator and Monitor is having the 
second end 9 of the shaft 8--or the second end 5 of the screw 1 in an 
embodiment where there is no shaft--removably, rather than permanently, 
attached to either the traditional brace 6 or the simple handle 10. This 
is accomplished by having an adjustable aperture 11 on the brace 6 or 
handle 10, which adjustable aperture 11 is well known in the art, and 
shaping the second end of the shaft 7--as shown in FIG. 2, FIG. 4, FIG. 6, 
and FIG. 8--in the form which is traditionally used for removable 
insertion into the adjustable aperture of a brace. 
In still another embodiment of the Compost Aerator and Monitor, depicted in 
FIG. 9, the traditional brace 6 is replaced with a traditional power drill 
14 into the chuck 15 of which power drill 14 the second end 9 of the shaft 
8--or the second end 5 of the screw 1 in an embodiment where there is no 
shaft--is removably inserted. With the power drill, it is preferable to 
utilize the shaft 8 and to have a guard 16 slidably mounted on such shaft 
8. 
The first end 17 of the guard 16 preferably is generally disc-shaped to 
prevent the guard 16 and, consequently, the chuck 15 of the power drill 14 
from entering the compost. The guard 16 also protects the chuck 15 from 
striking any debris that may be near the surface of the compost pile. 
The second end 18 of the guard 16 preferably has a generally conical shape 
to permit the guard 16 to be removably pulled over the chuck 15 of the 
power drill 14, as illustrated in FIG. 10. 
And between the first end 17 and the second 18 end of the guard 16 is the 
middle section 19 of the guard 16, which preferably has a cross-sectional 
diameter that is conveniently sized for grasping by a hand of a user. 
When utilized with the power drill 14, the shaft 8 preferably has a stop 20 
between the first end 7 and the second end 9 of the shaft 8 to preclude 
the guard 16 from reaching the screw 1. 
Additionally, on the inside 21 of the guard 16 a pliable, high-friction 
insert 22, which is preferably composed of rubber, is placed so that it 
will be in contact with the chuck 15 when the guard 16 is pulled over the 
chuck 15 and against the power drill 14. 
The method of using the Compost Aerator and Monitor is quite simple. 
The handle 10 or brace 6 is merely rotated or the power drill 14 is 
activated to initiate rotation of the chuck 15, i.e., the portion of the 
power drill 14 that is removably connected to the shaft 8, which causes 
the screw 1 and, if rotation is continued long enough, the shaft 8 of the 
Compost Aerator and Monitor to penetrate the compost pile to a desired 
depth, as illustrated in FIG. 11. The Compost Aerator and Monitor is then 
pulled in the direction opposite to the direction in which the screw 
entered the compost pile while the handle 10 or the brace 6 is held or, in 
the embodiment with the power drill 14, the guard 16 is pulled against the 
chuck 15 of the power drill 14 with sufficient force--considering the 
leverage created by the handle 10 or the brace 6 or the friction produced 
by the pliable, high-friction insert 22--that the screw 1 does not rotate. 
This process, as depicted in FIG. 12, creates a cohesive, representative, 
cylindrical core of compost material within the screw 1 which may be 
utilized for analysis and, also, leaves a hole in the compost pile which 
facilitates the introduction of water as well as oxygen into the compost. 
If the core of compost retained within the Compost Aerator and Monitor 
after the preceding process is not removed for analysis, subsequent 
reutilization of the Compost Aerator and Monitor will force the core from 
the device, leaving the material from the core on top of the compost pile 
where it mixes with newer material, which--as observed above--is generally 
located higher on the compost pile, and thereby accelerates the decay of 
such newer material. 
This self-cleaning action also prevents newer material from being pushed 
lower where it would contaminate the underlying material that may have 
already reached the desired state of decomposition. Therefore, unlike the 
situation with traditional methods of mixing and turning the compost, 
higher layers can be scraped away to reveal compost that may then be 
removed and used as an organic fertilizer; after traditional mixing and 
turning, the entire quantity of disturbed material must be allowed to 
remain a sufficient length of time for the decomposition of the newly 
added material. 
The guard 16, in addition to precluding rotation of the screw 1 during 
withdrawal of the screw 1 from a compost pile, preventing compost from 
entering the chuck 15 of the power drill 14, and keeping the chuck 15 from 
striking any debris, serves two other functions. This guard 16 may be 
grasped by the user to stabilize the screw 1 while it enters the compost 
pile; and then the guard 16, also, simultaneously protects the hand 
utilized by the user to stabilize the screw 1, from the rotating chuck 15.