Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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Excavation machinery such as "power shovels", "backhoes" and
"ditch diggers" are well known and widely used. A typical power shovel
provides
a tractor supporting an articulated arm carrying a "bucket", which typically
provides a cutting edge having a plurality of teeth. Such machinery greatly
lessens the time required to excavate large quantities of material. However,
as will
be shown, the structure of the tool supported by the articulated arm may lead
an
operator to severely damage buried utility lines, often with great resulting
injury,
damage and expense.
Frequently it is necessary to excavate both above and below a buried
utility line, such as a gas or oil pipeline. this work may be required to make
repairs in a first utility line, or to install an additional utility line that
will cross under
existing utility lines. Such excavation is usually quite hazardous, since
errors by
the machinery operator could result in considerable damage to the pipe being
excavated .
Unfortunately, the operator of a typical backhoe or power shovel is
frequently unable to see the exact location of the blade portion of the bucket
carried by the end of the articulated arm. This is because the backhoe arm
typically reaches out over the pipeline, and the open side of the bucket, with
its
lower edge blade or teeth, is hidden behind the pipeline as the operator
removes
material from beneath the pipeline. The "prior art" figure of the drawings
(Fig. 1)
illustrates this typical situation, where the pipeline blocks the operator's
view of the
bucket. Attempting to use the bucket on the same side of the pipe as the
tractor
unit of the backhoe would fail, since the open side and the cutting teeth of
the
bucket face the tractor. In effect, the design of the typical tool attached to
the
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articulated arm of a backhoe is useful only for removing dirt that is between
the
tractor and the tool attached to the end of the arm. As a result, the operator
would
be unable to remove material located under the pipe unless the arm reaches
over
the pipe. Therefore, in practice, the operator reaches over the pipe with the
articulated arm, and relies on experience and guess-work to tell him where the
bucket is in relation to the pipe.
It is therefore the case that there is an urgent need for an attachment
tool that is suited for operation with all types of power shovels that allows
the
operator to clearly see both the attachment tool and the pipeline at the same
time.
The attachment tool must allow the operator to excavate on the near side of
the
pipe, i.e. on the same side of the pipe as the tractor unit is on. Such an
attachment tool would speed work by allowing the operator to see what he was
doing, because the pipe would not be located between the operator and the
attachment tool, where the pipe would block the operator's view, as is the
case in
the prior art. Such an attachment tool would substantially reduce the risk of
damage to the pipeline of explosion and of injury.
The present invention is directed to an apparatus that satisfies the
above needs. A novel tool for utilization with a power shovel of the type
having a
tractor unit having an articulated arm is provided. The tool attaches to the
articulated arm and is operated in a manner that allows an operator to see the
tool
and entire arm during use, and to excavate material from beneath a utility
line
without having to move the tool into the blind-spot behind the utility line.
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The tool of the present invention provides:
(a) A forwardly directed blade. The forwardly directed blade of
the tool of the invention allows the machine operator to
excavate material from beneath a utility line, with known types
of excavation machinery, while keeping all parts of the tool on
the same side of the utility line as the operator. The blade of a
preferred version of the invention is planar in configuration and
is a slightly elongated rectangle in shape, having a bottom
plate and a smaller, reinforcing top plate. The cutting edge of
the blade is directed forwardly, away from the tractor unit of
the excavation machinery it is attached to, unlike the buckets
typically used in excavation, which provide a cutting surface
with teeth pointing toward the tractor. Because the blade is
forwardly directed, the entire tool may therefore be seen during
use.
(b) Connection means to attach the tool to known types of power
shovels. In the preferred embodiment of the invention, the
connection means includes left and right ears. Each ear is
attached to the blade and has a forward and a rearward pin
hole. The ears are shaped and the pin holes positioned to
allow convenient attachment to a known power shovel of any
type, including a backhoe or larger shovel having an
articulated arm that is suited for excavation purposes. A collar
frames each pin hole and provides strength and reinforcement.
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(c) Brace means to reinforce the connection between the
forwardly directed blade and the connection means. In the
preferred embodiment of the invention, the brace means
includes a forward and a rearward brace on each ear. The
braces add strength to the ears and prevent bending. In the
preferred embodiment, each brace is generally triangular and
has one side attached to an ear and one side attached to the
blade.
It is therefore a primary advantage of the present invention to provide
a novel attachment tool for an excavation machine, such as a power shovel or
backhoe, having a forward-facing blade that will allow an operator to observe
the
movement of the blade when in use, and that will not require the operator to
position the blade behind the utility line being excavated to remove material
from
beneath the utility line.
Another advantage of the present invention is to provide a novel
attachment tool for an excavation machine that will allow excavation from
under a
utility line without the need for men to enter a trench and risk injury while
excavating with hand tools.
Another advantage of the present invention is to provide a novel
attachment tool for an excavation machine that will allow excavation from
under a
utility line in a more rapid and cost-effective manner.
A still further advantage of the present invention is to provide a novel
attachment tool for an excavation machine that will greatly reduce the risk of
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piercing the pipe, and thereby reduce the risk of explosion, injury and
environmental damage.
These and other features, aspects, and advantages of the present
invention will become better understood with regard to the following
description,
appended claims, and accompanying drawings where:
Figure 1 is a side view of a power shovel in accordance with the prior
art;
Figure 2 is a side view of an attachment tool in accordance with the
present invention attached to a power shovel;
Figure 3 is a perspective view of a version of the attachment tool of
the invention;
Figure 4 is a side orthographic view of the tool of Fig. 3;
Figure 5 is a top orthographic view of the tool of Fig. 3;
Figure 6 is a front orthographic view of the tool of Fig. 3; and
Figure 7 is a front orthographic view of a second species of the
attachment tool of the invention, having a modified form of brace structure.
Referring to Fig. 1, a tool 10 is disclosed for utilization with a power
shovel or backhoe of the type used for excavation providing a tractor unit
having
an articulated arm. The tool 10 attaches to the articulated arm and has a
structure
that allows a user to operate the tool in plain view during use, and to
excavate
material from beneath a utility line 500 without having to move the tool into
the
blind spot behind the utility line. The tool provides a forwardly directed
blade 100
having a bottom plate 20 that is reinforced by a top plate 30. Connecting
means,
including left and right ears 40 carried by the top plate 30, allow the tool
10 to be
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attached to a known type of power shovel 200. Each ear provides an upper pin
hole 60 and a lower pin hole 70 which facilitates rotation and movement of the
tool
by the power shovel. A forward brace 80 and a rearward brace 90 reinforce each
ear.
Referring in particular to Fig. 3, a tool constructed in accordance with
the principles of the invention is seen. The forwardly directed blade 100 is
constructed of a top plate 30 and a bottom plate 20. As seen in Fig. 2, the
blade
is directed forwardly when in use. In contrast, the bucket attached to the arm
201
of the power shovel in Fig. 1 illustrates a bucket 202 having teeth 203 that
are
directed backwardly at the tractor 204 of the power shovel 200.
The bottom plate 20 is formed of a planar sheet of steel plate, and
has an upper surface 21 and a lower surface 22. As seen in Figs 4 - 6, a
forward
end edge 23 is somewhat shorter than the rearward end edge 28, because the
front corners of the blade have been cut off forming a left forward angled
edge 24
and a right forward angled edge 25. Removal of the corners gives the blade 100
a
blunt front end. A left side edge 26 and a similar right side edge 27 are
roughly
twice the length of the forward edge 23 and rearward edge 28.
In the preferred embodiment, the side edges 26, 27 of the bottom
plate 20 are seventy-one inches long. The overall length of the bottom plate
is
seventy-four inches and its thickness is one inch. The rearward end edge 28 is
thirty-six inches in length, while the forward end edge 23 is approximately
thirty
inches long.
A top plate 30 is formed of a planar sheet of steel plate and is
attached, typically by welding, to the bottom plate 20, as seen in Fig. 3. The
top
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w plate reinforces the tool 10, substantially increasing its strength. The top
plate is
rectangular in shape, having a lower surface 32 that is welded to the bottom
plate
20, and an upper surface 31, as seen in Figs. 3 and 5. A forward end edge 33
and a rearward end edge 34 are typically equal in length. A left side edge 35
and
a right side edge 36 are also generally equal in length, and typically
approximately
twice as long as end edges 33, 34.
In the preferred embodiment, the side edges 35, 36 of top plate 30
are forty-eight inches in length, while the end edges 33, 34 are twenty-four
inches
long. The top plate is one inch thick and is made of steel.
As seen in Figs. 3 - 6, mirror image left and right ears 40, together
with upper and lower pin holes 60, 70 provide the connecting means by which
the
tool 10 is attached to the arm of a power shovel. Each ear 40 provides a lower
base edge 41 having a front portion 42 and a rear portion 43. The base edge 41
is attached, typically by welding, to the upper surface 31 of the top plate
30. A
sloping front edge 44 having an upper portion 45 and a lower portion 46 is
adjacent to the front portion 42 of the base edge 41, as seen in Fig. 3. The
sloping front edge 44 is typically at an approximately 45 degree angle to the
top
plate 30. A sloping rear edge 47 having an upper portion 48 and a lower
portion
49 is adjacent to the rear portion 43 of the base edge 41, as seen in Fig. 3.
The
sloping rear edge 47 is typically at an approximately 60 degree angle to the
top
plate 30. A rounded top edge 50 is best seen in Figs. 3 and 4. The top edge is
adjacent to the upper portion 45 of the sloping front edge 44 and to the upper
portion 48 of the sloping rear edge 47. As seen in Fig. 6, an inner surface 51
is
directed to the arm 201 and an outer surface 52 is oppositely directed.
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In the preferred embodiment, the left and right ears are constructed
of one inch thick steel plate. The base edge 41 is approximately thirty-two
inches
in length. The front sloping edge 44 is approximately thirty-eight inches in
length.
The rear sloping edge 47 is approximately fourteen inches in length. The
outside
circumference of each ear is approximately ninety-four inches.
As seen in Fig. 4, left and right ears each provide a similar upper pin
hole 60 and a lower pin hole 70, differing primarily in location only. The pin
holes
allow the tool 10 to be attached to the arm of a power shovel by known and
standardized bolts. An open pin hole passageway 61 goes through the inner and
outer surfaces 51, 52 of ear 40. A collar 62, welded to the ear 40, provides
an
annular end surface 63, outside cylindrical surface 64 and inside cylindrical
surface
65. The function of the collar 62 is to reinforce the pin hole and to reduce
stress
on any pin inserted into the pin hole by providing a larger inside cylindrical
surface
65 in contact with the pin.
In the preferred embodiment, the distance from the center of the
upper pin hole 60 to the center of the lower pin hole 70 is twenty-one inches.
Each pin hole is three and one-half inches in diameter. The radial measurement
of
the annular end surface 63 of each collar 62 is two inches. In the preferred
embodiment, each pin hole collar provides a unitary structure that includes a
short,
one inch thick pipe that is inserted into open pin passageway 61. The pipe has
a
one inch flange that is attached to the outer surface 52 of the ear 40.
Therefore,
prior to installation of the collar, the two holes in each ear 40 are five and
one-half
inches in diameter. The collar reduces the diameter of the opening to three
and
one-half inches.
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Optionally, each ear 40 may provide an upper safety bolt hole 53 and
a lower safety bolt hole 54. The safety bolt holes provide a means to attached
safety bolts which are a back-up means of connecting the blade 100 to the arm
201 of a power shovel.
As seen in Fig. 3 - 6, a front brace 80 and a similar rear brace 90
hold the forwardly directed blade 100 and the ears 40 in a rigid relationship.
Each
brace is constructed of steel and is planar in configuration. Each brace
provides a
sloping outside edge 81 adjacent to a horizontal bottom edge 83 and a vertical
edge 82. The bottom edge 83 is welded to the top plate 30 and to the bottom
plate 20. The bottom edge 83 may be notched, as seen in Fig. 6, so that it
fits
precisely against the top and bottom plates. The vertical edge 82 is welded to
the
ear 40. As seen in Fig. 5, each brace 80, 90 has a forward surface 84 and a
rearward surface 85.
In the preferred embodiment, all four braces are constructed of one-
half inch thick sheet steel, and have an eight inch bottom edge, a six and one-
half
inch vertical edge, and an eleven inch sloping outside edge. The distance
between the pair of braces on each side of the tool is nine and one-half
inches.
A second species brace 180 is seen in Fig. 7. The species is similar
to braces 80, 90, but provides a vertical outside edge 181 and bottom edge 183
is
attached only to top plate 30, and is not attached to bottom plate 20.
To use the tool 10 of the invention, an operator would first use
conventional means to dig a trench parallel and adjacent to a buried utility
pipeline. Frequently, the operator would first dig such trenches on both sides
of
the pipeline. To excavate material from beneath the pipeline, the operator
would
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then attach the tool 10 of the invention to a power shovel. As seen in Fig. 2,
the
forwardly directed blade 100 is inserted into the ground beneath the pipeline.
Importantly, the operator, tractor 204, arm 201 and attached tool 10 all
remain on
one side of the pipeline. In this manner, the operator is able to see the
forwardly
directed blade 100 at all times. After insertion, the blade may be rotated
slightly,
so that the forward end edge 23 of the bottom plate 20 is lowered, and the
rearward end edge 28 raised. The blade is then withdrawn, causing material to
be
removed form underneath the pipeline. Where a trench has been dug on both
sides of a pipeline, the tool 10 may also push material from underneath the
pipeline to the trench on the opposite side of the pipeline. These actions are
repeated, as necessary, until the area under the pipeline is sufficiently
excavated.
If needed, the material excavated by the tool 100 may be removed from the
trench
by conventional excavating machinery.
The previously described versions of the present invention have many
advantages, including that of having a forward-facing blade that will allow an
operator to observe the movement of the blade, and what will not require the
operator to position the blade in the blind spot behind the utility line being
excavated to remove material from beneath the utility line.
Another advantage of the present invention is to provide a novel
attachment tool for an excavation machine that will allow excavation from
under a
utility line without the need for men to enter the trench and risk injury
while
excavating with hand tools.
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Another advantage of the present invention is to provide a novel
attachment tool for an excavation machine that will allow excavation from
under a
utility line in a more rapid and cost-effective manner.
A still further advantage of the present invention is to provide a novel
attachment tool for an excavation machine that will greatly reduce the risk of
piercing the pipe, and thereby reduce the risk of explosion, injury and
environmental damage.
Although the present invention has been described in considerable
detail and with reference to certain preferred versions, other versions are
possible.
For example, the exact dimensions of the components of the tool 10 are
somewhat
variable, as long as the teachings of the invention are followed. Also, while
the
use of a top plate and a bottom plate to form the blade is preferred, a blade
constructed of a single plate might in some cases be substituted. Moreover,
while
two braces per ear are preferred, a greater rf lesser number might be
substituted.
Therefore, the spirit and scope of the appended claims should not be limited
to
the description of the preferred version disclosed here.
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