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TREE TREATMENT CAPSOLE WITH
RADIAhLY EBPANDING SHANK PORTION
BACKGROUND OF THE INVENTION
The present invention relates to a tree treatment
capsule for feeding a chemical agent into plants and,
more particularly, to a capsule for delivering a chemical
agent to the phloem layer of a tree. The chemical agent
may be either a herbicide or any other tree destroying
agent if the treatment is designed to kill the tree, or
a fertilizer, fungicide or other medicant or nutrient if
the treatment is designed to cure the tree from a disease
or a nutrient deficiency.
Heretofore, tree treatment capsules consisting of a
generally cylindrical hollow container and a plug for
insertion into a predrilled hole in a tree to be treated
have been known. Such tree treatment capsules have
typically been made of a frangible material, or of a
hard, brittle, breakable and non-elastic material, such
as fiberglass, wood or wood fiber. However, the hollow
containers of these known capsules tend to be breakable
before they are assembled or even after assembly upon
inadvertent application of an external imnact_
A
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Tree treatment capsules made of a brittle, breakable
plastic material are also known. However, although it is
difficult to break such capsules before usage, it is also
difficult to break them when they are in use.
Consequently, a great deal of force must be applied to
provide a large enough impact to cause the capsule to
break.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention
to provide a tree treatment capsule which is difficult to
accidentally break before usage, and yet which is easily
breakable when an axial impact force is applied.
It is also an object of the present invention to
provide a capsule which releases a treating chemical more
precisely into the phloem layer of a tree, and to provide
an improved connection between capsule parts.
According to the present invention, a tree treatment
capsule is adapted for insertion into a bore of a tree to
be treated and includes a plastic container and a plastic
plug to sealingly close the container. The plastic
container has a cylindrical shank having an internal
cavity formed with an end opening for containing therein
a chemical agent, and a head integrally formed with the
shank remote from the end opening.
According to one embodiment of the invention, a
plastic plug is tapered from an outer diameter larger
than the diameter of the end opening to a diameter just
slightly smaller than the diameter of the end opening
such that the plug is only partially insertable into the
end opening in order to obtain a tight fit between the
plug and the end opening of the cavity.
The shank has a plurality of recessed scorings which
are formed in the exterior surface thereof at
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circumferentially equal spacings. The scorings extend
from the end opening to the head. The recessed scorings
allow the shank to be broken so that as an impact force
applied to the head moves the shank towards the plastic
plug, the plastic plug expands the end opening and breaks
the shank along the recessed scorings into a plurality of
tongues, thereby providing slits between the separated
tongues through which the chemical agent is allowed to
pass from the internal cavity of the capsule. The
chemical agent passed from the capsule through the slits
then mixes with sap of the tree.
According to another embodiment of the invention, a
plastic plug is partially insertable into the end opening
and includes a circumferential ridge thereon receivable
in a corresponding recess formed in the shank in order to
obtain a tight fit between the plug and the end opening
of the cavity.
The shank has a plurality of recessed slots which
are formed in the exterior surface thereof at
circumferentially equal spacings. The scorings extend
longitudinally along a central portion of the shank. The
recessed scorings allow the shank to be broken so that as
an impact force applied to the head moves the head
towards the plastic plug, the plastic plug expands the
central portion of the shank and breaks the shank along
the recessed slots into a plurality of strips, thereby
providing passages between the separated strips through
which the chemical, agent is allowed to pass from the
internal cavity of the capsule. The chemical agent
passed from the capsule through the passages then mixes
with sap of the tree.
The plastic container and plastic plug are
preferably made of different plastic materials in order
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to permit the shank element to be easily broken when an
impact force is applied to the head element and moves the
shank element towards the plastic plug.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is an exploded plan view, partly in
cross-section, of a tree treatment capsule in accordance
with a preferred embodiment of the present invention:
Figure 2 is an end view of a container of the tree
treatment capsule of Figure 1;
Figure 3 is a top view of a plug of the tree
treatment capsule of Figure 1:
Figure 4 is a longitudinal plan view of an assembled
tree treatment capsule of Figure 1 shown in a first stage
of insertion in a bore in a tree:
Figure 5 is a longitudinal plan view of an assembled
tree treatment capsule of Figure 1 shown in a second
stage of insertion in a bore in a tree;
Figure 6 is a cross-sectional view taken along line
VI-VI of Figure 5;
Figure 7 is an exploded view of a tree treatment
capsule in accordance with a second preferred embodiment
of the present invention:
Figure 8 is a side sectional view of a container of
the tree treatment capsule of Figure 7;
Figure 9 is an end of the container of Figure 8 as
it appears when viewed in the direction of arrow IX;
Figure 10 is an end view, partly in section, of the
container of Figure 8 as seen along section line X-X;
Figure 11 is a side sectional view of a plug of the
tree treatment capsule of Figure 7:
Figure 12 is an end view of the plug of Figure ll~as
it appears when viewed in the direction of arrow XII; and
Figures 13 and 14 are views illustrating how the
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capsule of the second preferred embodiment of the present
invention is used.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings and, in particular, to
5 Figure 1, the present invention is embodied in a tree
treatment capsule 1 adapted for insertion into a
pre-drilled bore in the trunk of a tree to be treated.
The capsule 1 comprises a generally cylindrical plastic
container 10 and a generally cylindrical, hollow plastic
l0 plug 30. The container 10 and plug 30 are separate from
each other. The cylindrical container 10 includes a
cylindrical, hollow shank portion 11 having a
cylindrical, hollow head element 12 rigidly joined
thereto by a tapered, solid transition portion 13. The
head element 12 has an outer diameter larger than an
outer diameter of the shank portion 11.
The shank portion 11 is formed as a wall enclosing
an internal cavity 14 with one open end 15 of the cavity
defined by an opening 16 for containing a tree treating
chemical agent 2 therein. The head element 12 also forms
an open ended internal cavity 17 , in which ribs 18 are
integrally formed with the head element 12 and extend
crosswise in order to provide a strong, reinforced
structure of the hollow head element 12, as is shown in
Figure 2. Internal cavities 14 and 17 are separated by
a partition 19. The shank portion 11 has a series of,
for example six, equally circumferentially spaced slots
or recessed scorings 20 formed in the exterior surface
thereof. These recessed scorings 20, longitudinally
extending substantially completely from the one end 15 of
. cavity 14 to the bottom of the shank portion 11, are
sufficiently deep so as to make the shank portion easily
breakable when the open end 15 of the shank portion 11 is
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expanded.
The plug 30 is formed with an internal cavity 34
with one end 35 defined by an opening 36. The plug
includes two cylindrical portions, 31 and 32. The
cylindrical portion 31 has substantially the same outer
diameter as the outer diameter of the shank portion 11,
whereas the cylindrical portion 32 has an outer diameter
just smaller than the diameter of the opening 16 of the
end 15. As will become clear, because portion 32 has an
outer diameter just smaller than the internal diameter of
opening 16, portion 32 will be tightly engaged in opening
32 when the capsule is assembled. The cylindrical
portions 31 and 32 are joined with each other by a
tapered transitional.portion 33. The plug 30 also has a
series of, for example four, ribs 37 integrally formed
with and on the circumferentially internal surface of the
cavity 34. Ribs 37 are preferably arranged at equal
circumferential spacings, as is shown in Figure 3. These
ribs 37 extend longitudinally from the open end 35 of the
plug 30 along the radially inner surfaces of cylindrical
portion 31 and tapered transitional portion 33. Ribs 37
terminate at the junction between transitional portion 33
and cylindrical portion 32. The taper of the
transitional portion 13 and 33 of the container 10 and
plug 30, respectively, may be either straight or curved.
All portions of the capsule 1 are made of brittle
plastic materials by, for example, injection molding or
extrusion molding., It is specifically preferred to make
the container 10 of polystyrene or polycarbonate arid the
plug 30 of polyethylene. Making the container 10 and
plug 30 of these different plastic materials enables the
container 10 to be broken more easily than plug 30.
Alternatively, the container 10 and/or plug 30 may be
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produced from a water soluble polymer such as
polyvinylalcohol.
In assembling the capsule 1, the chemical agent 2 is
introduced into the cavity 14 of the container 10 and the
plug 30 is inserted into opening 16 of the container 10.
The cylindrical portion 32 tightly fits in the opening 16
and the tapered transitional portion 33 tightly engages
against the circumferential edge of the open end 15 to
completely seal off the open end 15. Although a tight
fit is obtained between the tapered transitional portion
33 of the plug 30 and the top end 15 of the shank portion
11, it is preferred to adhesively secure the cylindrical
portion 32 in the opening 16 in order to provide a
superior seal.
The chemical agent 2 may be of any kind of, for
example, a herbicide or a fungicide, and in any form of,
for example, a tablet, a powder, a jelly-like material,
a pasty material, or a liquid.
The chemical agent containing capsule 1 is inserted
into a pre-drilled bore 4 in the trunk of a tree 3 to be
treated. As is seen in Figure 4, the bore 4 is
dimensioned to extend through the bark 7 and into the
phloem layer 8 of the tree 3. The bore 4 is further
dimensioned to have an internal diameter between the
external diameters of the shank portion 11 and head
element 12, respectively, and a depth slightly greater
than the length of the shank portion 11, including the
plug 30. The capsule 1 is inserted into the bore 4 of
the tree 3 until the plug 30 abuts against a wall, for
instance the bottom wall 4A of the bore 4, as is shown in
Figure 4. This brings the tapered transitional portion
13 of the container 10 into contact with the
circumferential edge 6 of the bore 4.
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Impact force is applied to the head element 12 by,
for example, hammering, in the direction shown by arrow
9, causing the head element 12 and the shank portion 11
of the container 10 to move toward the plug 30 such that
the shank portion 11 climbs up along the tapered portion
33 of the plug 30. The plug 30, in particular the
tapered portion 33 thereof, expands the open end 15 of
the shank portion 11 and breaks the shank portion 11
along the scorings 18 into tongues 11A, as is shown in
Figures 5 and 6. The tongues 11A form therebetween
passages 11B to permit the chemical agent 2, if it is in
a jelly-like or liquid form, to be released and mix with
the sap of the tree 3, or to permit the sap of the tree
3, if the chemical agent is in the form of a tablet or a
powder, to permeate and mix with the chemical agent 2.
Since the outer diameter of the head element 12 of
the capsule 1 is larger than the inner diameter 6 of the
originally pre-drilled bore 4, a very tight fit will be
obtained between the head element 12 of the capsule 1 and
the opening of the bore of the tree 3 after the impact
force has been applied. This causes the capsule 1 to be
held very firmly in the tree 3. The tongues 11A formed
in the shank portion 11 will also be pressed against the
internal surface of the bore 4 and be frictionally
engaged with the internal surface, so as to contribute to
retention of the capsule 1 firmly in bore 4 of tree 3.
Referring now to the drawing figures illustrating
the second embodiment of the invention and, in
particular, to Figure 7, the present invention is again
embodied in a tree treatment capsule adapted for
insertion into a pre-drilled bore in the trunk of a tree
to be treated. In Figures 7-14, the same reference
numbers have been used to indicate parts of the capsule
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which are similar to corresponding parts of the capsule
shown in Figures 1-6. The: capsule 1 comprises a
generally cylindrical plastic container l0 and a
generally cylindrical, hollow plastic plug 30. Container
10 and plug 30 are initially formed separate from each
other, but when capsule 1 is assembled, container 10 and
plug 30 are secured togetrier and share a common
longitudinal axis A.
Referring now to Figures 8-10, it may be seen that
l0 the cylindrical container 10 includes a cylindrical,
hollow shank portion 11 having a cylindrical, hollow head
element 12 rigidly joined thereto by a conically tapered,
solid transition portion 13. 'The head element 12 has an
outer diameter larger than an outer diameter of the shank
portion 11.
The shank portion 11 is formed as a circumferential
wall having radially inner and outer surfaces. Shank
portion 11 encircles an internal cavity 14 and has a
first, open end 15 defining an end opening to the cavity,
into which a tree treating chemical agent (not shown) is
placed. The head element 12 also forms an open ended
internal cavity 17, in which ribs 18 are integrally
formed with the head element 12. Ribs 18 extend
crosswise in cavity 17 in order to provide a lightweight
and yet strongly reinforced structure to the hollow head
element 12. As is apparent from Figure 8, the axially
outer surface 18s of each rib 18 is angled at about 45°
relative to longitudinal axis A. Internal cavities 14
and 17 are separated by a partition 19. Partition 19
thus closes a second end of the shank portion opposite
the first, open end 15.
The shank portion il has a series of, for example
six, equally circumferentially spaced, recessed slots 20
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formed in the exterior, radially outer surface thereof.
These recessed slots 20 longitudinally extend along the
shank portion 11 from the junction between transition
portion 13 and head element 12 towards open end 15 of the
5 shank portion. As illustrated, recessed slots 20 extend
longitudinally along the exterior of shank portion 11
over approximately 80% of the length of the shank
portion. As is apparent from Figure 10, each of the
recessed slots is formed by a pair of side walls 21 which
10 diverge from each other at an angle of approximately 90°.
Additionally, longitudinally opposite ends 20A and 20B of
each slot 20 are each angled at approximately 45°
relative to the longitudinal axis A. Recessed slots 20
are sufficiently deep so as to make the shank portion
easily breakable along the slots, as will be described.
Shank portion 11 is additionally provided with a
plurality of ribs 22. As is apparent from Figures 8 and
10 of the drawings, ribs 22 are. integrally formed with
the rest of the shank portion 11 and extend radially
inwardly into cavity 14 from the inner surface of the
shank portion. Each rib extends longitudinally along the
radially inner surface of shank portion 11 so as to be
substantially coextensive with, or equal in length to,
recessed slots 20. Referring to Figure 10, it can be
seen that each rib 22 is provided at a circumferential
location which is midway between adjacent recessed slots
20. It should be noted, however, that it is not
necessary to provide a rib 22 midway between every pair
of adjacent recessed slots 20. As illustrated, three
ribs 22 are provided on the radially inner surface of the
shank portion at 120° intervals, and at locations between
every other pair of adjacent slots 20. Each rib 22 is
also provided with an inclined end surface 24 which is
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oriented at approximately 30° relative to the
longitudinal central axis A of the capsule 1. The shank
portion 11 additionally includes a circumferential recess
25 provided in the radially inner surface of shank
portion 11 at a location which, in the direction of
longitudinal axis A of capsule 1, is intermediate the
ends of slots 20 and ribs 22 and the first, open end 15
of shank portion 11. This location, which is generally
designated by reference number 26 in Figure 8, is
substantially more rigid than the remainder of the
portion 11, due to the absence: in the location of slots
20.
Referring to Figures 11 and 12, it is apparent that
the plug 30 is formed with an internal cavity 34 having
a first, open end, generally designated 35 and a second,
closed end, generally designated 36. The plug 30
includes a cylindrical portion 31 and a tapered or
inclined portion 32. As illustrated, portion 32 is
substantially conical. The cylindrical portion 31 has
nearly the same outer diameter as the inner diameter of
the shank portion 11 so that end part 31A of the
cylindrical portion 31 is snugly received within cavity
14 when the capsule 1 is fully assembled. At its first
longitudinal end, the cylindrical portion is integrally
connected to the conical portion 32. At its second
longitudinal end, cylindrical portion 31 is provided with
an annular flange 38 projecting radially outwardly from
the cylindrical portion.
Conical portion 32 of plug 30 has an outer surface
which is angled, relative to central axis A, at
approximately 30°. As will become clear, because the
outer surface of conical portion 32 has the same angle
relative to longitudinal axis. A as end surfaces 24 of
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ribs 22, conical portion 32 tightly engages inclined end
surfaces 24 of ribs 22 when the capsule 1 is fully
assembled. A circumferentially protruding ridge 33 is
provided on the outer surface of cylindrical portion 31
at a location adjacent the first longitudinal end of the
plug. As will become clear, when capsule 1 is assembled,
ridge 33 of plug 30 interlocks with recess 25 in the
radially inner surface of shank portion 11 to secure plug
30 in open end 15 of the shank portion. The plug 30 also
has a series of, for example four, reinforcing ribs 37
integrally formed with and on the circumferentially
internal surface of the cylindrical portion 31 to provide
a strong plug structure. Ribs 37 are preferably arranged
at equal circumferential spacings, as is shown in Figure
9. These ribs 37 extend longitudinally from the open end
35 of the plug 30 along the radially inner surfaces of
cylindrical portion 31 and conical portion 32. Ribs 37
terminate at the junction between conical portion 32 and
a front end wall 33 of the plug. In the embodiment
illustrated in Figures 7-14, the cooperating inclined
surfaces 24 of the ribs 22 and of the conical portion 32
of plug 30 are shown as being straight; however, surface
24 and portion 32 could be curved if desired.
All portions of the capsule b are made of brittle
plastic materials by, for example, injection molding or
extrusion molding. It is specifically preferred to make
the container 10 of polystyrene or polycarbonate and the
plug 30 of polyethylene. Making the container 10 and
plug 30 of these different plastic materials enables the
container 10 to be broken more easily than plug 30.
In assembling the capsule 1, the chemical agent is
introduced into the cavity 14 of the container 10 and the
plug 30 is inserted into open end 15 of the container 10.
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Plug 30 is forced into the open end until ridge 33 snaps
into engagement and is completely received in recess 25.
The end part 31A of cylindrical portion 31 tightly fits
in the open end 15 and the inclined, conical portion 33
tightly engages the inclined end surfaces 24 of ribs 22.
Ridge 33 is completely received in and tightly engaged
with recess 25 to completely seal off the open end 15 of
container 10. An improved connection between capsule
parts, i.e., container 10 and plug 30, is, therefore,
provided. Although a tight fit is obtained between the
plug 30 and the container 10 due to the interengagement
of ridge 33 and recess 25, it i.s possible to additionally
apply an adhesive at the jun<aion between plug 30 and
container 10 to further secure the end part of
cylindrical portion 31 in the: open end 15 in order to
provide a superior seal.
The chemical agent 2 may be of any kind of, for
example, a herbicide or a fungicide, and in any form of,
for example, a tablet, a powder, a jelly-like material,
a pasty material, or a liquid.
The assembled chemical agent containing capsule 1 is
inserted into a pre-drilled bore 4 in the trunk of a tree
3 to be treated. As is seen in Figures 13 and 14 , the
bore 4 is dimensioned to extend through the bark 7 and
into the phloem layer 8 of the tree 3. The bore 4 is
further dimensioned to have an internal diameter between
the external diameters of the shank portion 11 and head
element 12, respectively, and a depth slightly greater
than the length of the shank portion 11, including the
plug 30. The capsule 1 is inserted into the bore 4 of
the tree 3 until the flange 38 of the plug 30 abuts
against a wall, for instance the bottom wall of the bore
4, as is shown in Figure 13. This brings the tapered
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transitional portion 13 of the container 10 into contact
with the circumferential edge 6 of the bore 4.
Impact force is applied to the head element
12 by, for example, hammering, in the direction shown
by arrow 9, causing the head element 12 and the shank
portion 11 of the container 10 to move toward the plug 30
such that the conical or otherwise inclined portion 32
slides along inclined end surfaces 24 of ribs 22. The
inclined portion 32 of plug 30 acts as a cam and forces
the ribs 22 to expand the central part of shank portion
il radially outward and break the shank portion 11 along
the slots 20 into strips 20A, as is shown in Figure 14.
The strips 20A form therebetween passages 20B to permit
the chemical agent 2, if it is in a jelly-like or liquid
form, to be released and mix with the sap of the tree 3,
or to permit the sap of the tree 3, if the chemical agent
is in the form of a tablet or a powder, to permeate and
mix with the chemical agent 2. Because passages 20B are
located in the central part of shank portion 11, they are
more precisely aligned with the phloem layer of tree 3.
The chemical contained in the capsule 1 is, therefore,
more precisely released into this phloem layer.
Since the outer diameter of the head element 12 of
the capsule 1 is larger than the inner diameter 6 of the
originally pre-drilled bore 4, a very tight fit will be
obtained between the head element 12 of the capsule 1 and
the opening of the bore of the tree 3 after the impact
force has been applied. This causes the capsule 1 to be
held very firmly in the tree 3. The central parts of
strips 20A formed from the shank portion 11 will also be
pressed against the internal surface of the bore 4 and~be
frictionally engaged with the internal surface, so as to
contribute to retention of the capsule 1 firmly irr bore
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4 of tree 3.
It is to be understood that although the invention
has been described in detail with respect to a preferred
embodiment, nevertheless, various other embodiments and
5 variants are possible which are within the spirit and
scope of the present invention,, and such embodiments and
variants are intended to be covered by the following
claims.
