U.S. patent application number 10/179454 was filed with the patent office on 2003-01-23 for gripping and cutting apparatus.
Invention is credited to Moon, Thomas A., Riha, Gary D..
Application Number | 20030015251 10/179454 |
Document ID | / |
Family ID | 24196372 |
Filed Date | 2003-01-23 |
United States Patent
Application |
20030015251 |
Kind Code |
A1 |
Moon, Thomas A. ; et
al. |
January 23, 2003 |
Gripping and cutting apparatus
Abstract
Apparatus (10) having special application for gripping and
cutting tree limbs around utility lines includes a tubular insert
(18) slideably received in the free end of a tubular boom (12). A
plate (28) is pivoted about a first pivot axis relative to the
insert (18). by a linearly extendable actuator (36) mounted within
the insert (18) and mounts a first rotary actuator (38). A second
rotary actuator (58) is mounted to a U-shaped mount (48) which is
pivoted about a second pivot axis to the first rotary actuator (38)
and rotates a working head (96) 360.degree. about a third pivot
axis. Gripping arms (78) are fixed to shafts (74) rotatably mounted
in the working head (96) about axes perpendicular to the third
axis, with the shafts (74) being rotated by a single linearly
extendable actuator (82) extending between crank arms (80) fixed to
the shafts (74). The crank arms (80) abut with an abutment (84) to
prevent only one set of gripping arms (78) from moving. An
untethered remote control unit (112) is provided to prevent the
creation of an electrical path to ground through the operator. A
solar and battery-powered transmitter (144) mounted on the head
(96) sends an electromagnetic signal to prevent actuation of the
valves (101-103) controlling the operation of the boom assembly
(14) when the saw bar (88) is not in its home position.
Inventors: |
Moon, Thomas A.; (Lena,
WI) ; Riha, Gary D.; (Green Bay, WI) |
Correspondence
Address: |
Alan D. Kamrath
Rider, Bennett, Egan & Arundel, LLP
Suite 2000
333 South Seventh Street
Minneapolis
MN
55402
US
|
Family ID: |
24196372 |
Appl. No.: |
10/179454 |
Filed: |
June 25, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10179454 |
Jun 25, 2002 |
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09550256 |
Apr 14, 2000 |
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6408906 |
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Current U.S.
Class: |
144/24.13 |
Current CPC
Class: |
A01G 23/091 20130101;
A01G 3/08 20130101 |
Class at
Publication: |
144/24.13 |
International
Class: |
B27M 003/00; A01G
023/095 |
Claims
1. Assembly for insertion in a free end of a tubular boom having
annular cross sections comprising, in combination: a tubular insert
having first and second ends and an outer surface having annular
cross sections of a size corresponding to and for a tight slideable
fit within the free end of the tubular boom, with the outer surface
of the tubular insert being adapted to be glued or similarly
adhered within the tubular boom; first pivot ears formed on the
first end of the tubular insert; first actuator ears secured in the
tubular insert spaced from the first end; a mount having second
pivot ears pivotably mounted to the first pivot ears about a first
pivot axis, with the mount having second actuator ears; and an
extendable actuator having a first end pivotably mounted to the
first actuator ears about a second pivot axis spaced from and
parallel to the first pivot axis and having a second end pivotably
mounted to the second actuator ears about a third pivot axis spaced
from and parallel to the first and second pivot axes and extending
within the interior of the tubular insert.
2. The assembly of claim 1 further comprising, in combination: an
end plate secured to the second end of the tubular insert, with the
first actuator ears extending from the end plate.
3. Gripping assembly comprising, in combination: first and second
shafts rotatable about first and second, spaced, parallel pivot
axes; a first crank arm extending radially from the first shaft; a
second crank arm extending radially from the second shaft; an
extendable actuator having a first end pivotably mounted to the
first crank arm about a third pivot axis and having a second end
pivotably mounted to the second crank arm about a fourth pivot axis
spaced from and parallel to the first, second, and third pivot
axes; at least a first gripping arm extending radially from the
first shaft; at least a second gripping arm extending radially from
the second shaft; and an abutment located equidistant between but
in a plane parallel to but spaced from a plane extending between
the first and second pivot axes to limit travel of the crank arms
and rotational movement of the first and second shafts.
4. The gripping assembly of claim 3 further comprising, in
combination: an end plate, with the first and second shafts
extending through and being rotatably mounted in apertures formed
in the end plate, with the abutment being secured to the end
plate.
5. The gripping assembly of claim 4 further comprising, in
combination: a support extending perpendicularly from the end
plate, with the support being parallel to and intermediate the
first and second shafts; and first and second pivot brackets
extending from the support spaced from the end plate, with the
first shaft being pivotably mounted by the end plate and the first
pivot bracket, with the second shaft being pivotably mounted by the
end plate and the second pivot bracket, with the end plate located
intermediate the crank arms and the gripping arms.
6. The gripping assembly of claim 5 further comprising, in
combination: means for rotationally mounting the support about an
axis extending generally perpendicular to the plane extending
between the first and second pivot axes.
7. The gripping assembly of claim G wherein the mounting means
comprises a rotary hydraulic actuator.
8. Apparatus for gripping and cutting attachable to a free end of a
boom of a boom assembly, comprising, in combination: a gripping and
cutting assembly; and means for mounting the gripping and cutting
assembly to the free end of the boom of the boom assembly for
pivotable movement about a first axis, a second axis substantially
perpendicular to the first axis, and a third axis substantially
perpendicular to the first and second axes.
9. The apparatus of claim 8 wherein the mounting means provides
pivotable movement 360.degree. about one of the first, second, and
third axes.
10. The apparatus of claim 8 wherein the mounting means comprises,
in combination: a leveler mount; a first rotary actuator for
rotating the leveler mount about the first axis; a head mount; and
a second rotary actuator for rotating the head mount relative to
the leveler mount about the second axis.
11. The apparatus of claim 10 wherein the leveler mount is
generally U-shaped and includes a central plate and first and
second end plates extending generally perpendicular from the
central plate, with the first rotary actuator received between the
end plates and the first axis extending through the end plates; and
wherein the second rotary actuator is mounted between the head
mount and the central plate; and wherein the head mount is directly
secured to the gripping and cutting assembly.
12. The apparatus of claim 11 wherein the head mount is pivotable
360.degree. about the second axis.
13. The apparatus of claim 11 wherein the mounting means further
comprises, in combination: a rotator mount, with the first rotary
actuator being mounted to the rotator mount; and means for
pivotally mounting the rotator mount to the free end of the boom of
the boom assembly for pivotable movement about the third pivot
axis.
14. The apparatus of claim 13 wherein the boom of the boom assembly
is tubular; and wherein the means for pivotally mounting the
rotator mount comprises, in combination: a tubular insert having
first and second ends and an outer surface having annular cross
sections of a size corresponding to and for a tight slideable fit
within the free end of the tubular boom, with the outer surface of
the tubular insert being adapted to be glued or similarly adhered
within the tubular boom; first pivot ears formed on the first end
of the tubular insert; first actuator ears secured in the tubular
insert spaced from the first end, with the rotator mount having
second pivot ears pivotably mounted to the first pivot ears about
the third axis, with the rotator mount having second actuator ears;
and an extendable actuator having a first end pivotably mounted to
the first actuator ears about a fourth pivot axis spaced from and
parallel to the third axis and having a second end pivotably
mounted to the second actuator ears about a fifth pivot axis spaced
from and parallel to the third and fourth axes and extending within
the interior of the tubular insert.
15. The apparatus of claim 11 wherein the gripping and cutting
assembly comprises, in combination: a saw system of the chain saw
type including a bar pivotable about an axis perpendicular to the
second axis and in a plane parallel to the second axis.
16. The apparatus of claim 15 wherein the gripping and cutting
assembly comprises, in combination: first and second shafts
rotatable about spaced, parallel pivot axes; a first crank arm
extending radially from the first shaft; a second crank arm
extending radially from the second shaft; an extendable actuator
having a first end pivotably mounted to the first crank arm about a
pivot axis and having a second end pivotably mounted to the second
crank arm about a pivot axis spaced from and parallel to the pivot
axes of the first and second shafts and of the first end of the
extendable actuator; at least a first gripping arm extending
radially from the first shaft; at least a second gripping arm
extending radially from the second shaft; and an abutment located
equidistant between but in a plane parallel to but spaced from a
plane extending between the pivot axes of the first and second
shafts to limit travel of the crank arms and rotational movement of
the first and second shafts.
17. Device for gripping and cutting comprising, in combination: a
moveable boom assembly mounted on a vehicle; a gripping and cutting
apparatus mounted to the boom assembly, with the gripping and
cutting apparatus being pivotably moveable about at least a first
pivot axis relative to the vehicle, with the gripping and cutting
apparatus including pivotable gripping arms and a saw system; means
carried by the vehicle for controlling the operation of the boom
assembly, the pivotable movement of the gripping and cutting
apparatus, the pivoting of the gripping arms, and the operation of
the saw system; a remotely operated control operating the
controlling means and which is untethered to the vehicle during
operation, with the remotely operated control including a first
transmitter, and the controlling means including a first receiver
for receiving control transmissions from the first transmitter.
18. The gripping and cutting device of claim 17 wherein the saw
system includes a sensor for detecting an operational mode of the
saw system, with the controlling means including an interlock for
preventing operation of the boom assembly when the operational mode
of the saw system is detected by the sensor.
19. The gripping and cutting device of claim 18 further comprising,
in combination: a second transmitter carried by the saw system for
providing a signal when the operational mode is detected; and a
second receiver for receiving the signal provided by the second
transmitter for controlling the interlock.
20. Device for cutting comprising, in combination: a moveable boom
assembly mounted on a vehicle; a cutting apparatus mounted to the
boom assembly, with the cutting apparatus including a sensor for
detecting an operational mode of the cutting apparatus; and means
for controlling the operation of the boom assembly and the
operation of the cutting apparatus, with the controlling means
including an interlock for preventing operation of the boom
assembly when the operational mode of the cutting apparatus is
detected by the sensor.
21. Method of cutting comprising: moving a boom assembly; moving a
saw system relative to the boom assembly between a home position
and outside the home position; sensing whether the saw assembly is
in the home position or outside the home position; and preventing
moving of the boom assembly when the saw assembly is sensed outside
the home position.
22. Method of cutting tree limbs from around electrical lines
comprising; moving a boom assembly including a saw system for
cutting the tree limbs and means for controlling the movement of
the boom assembly; and manipulating a control operating the
controlling means and which is not connected to the boom assembly
in a manner which creates an electrical path from the electrical
lines to ground.
23. The method of claim 22 wherein manipulating the control
comprises manipulating the control which is untethered to the boom
assembly during operation.
Description
BACKGROUND
[0001] The present invention generally relates to apparatus for
gripping and cutting wood in the form of trees or poles,
particularly relates to gripping and cutting apparatus for mounting
on the end of a boom of a boom assembly, and specifically relates
to gripping and cutting apparatus for mounting on the end of a
fiberglass boom of a boom assembly.
[0002] In the utility industry, it is necessary to trim tree limbs
which have a possibility of interference with utility lines.
Typically, trimming is performed by a person located in a bucket
hoisted adjacent to the tree limbs and using a severing means to
trim the desired limbs. In order to trim such tree limbs, the
operator in the bucket must get into close proximity with the
utility lines, which presents electrocution risks in the case of
high power lines. To reduce the risk of electrocution in the event
of accidental contact with power lines, at least one of the booms
of the boom assembly is formed of fiberglass which is a poor
electrical conductor compared to metal but which has a reduced load
carrying capability than booms formed of metal. In addition, the
limbs are often not in a position to be dropped to the ground after
severance because of interference with the lines. Especially for
bucket trucks having fiberglass booms having limited load carrying
capabilities, as the operator's weight is carried by the fiberglass
boom, the operator is not allowed to rest or otherwise support the
severed limb on the bucket as the boom assembly is not designed for
this type of load. Thus, the operator often has to tie off the limb
to a higher limb using a series of ropes and to then lower the limb
to the ground. This is a time-consuming process and puts the
operator in danger around power lines.
[0003] Boom carried tree pruning apparatus are known in the art,
but mostly in the commercial tree growing industry and not in the
utility industries. In particular, most prior, commercially
available tree pruning apparatus are of a size and weight required
to be carried by massive boom assemblies and vehicles and in
particular are not of a design capable of being attached to and/or
carried by boom assemblies formed of fiberglass. Thus, the expense
of and limited versatility of the vehicles and boom assemblies
prevented the market acceptance of such apparatus in the utility
industries. Further, because of their relatively large mass and/or
their inability to be attached to fiberglass booms, prior tree
pruning apparatus were attached on metal boom assemblies which are
electrically conductive. This significantly increased the risk of
electrocution of the operator and people nearby. Furthermore, the
controls for the boom carried tree pruning apparatus were mounted
to the vehicle such that the operator often created an electrical
path to ground which increased the risk of electrocution. Also, as
tree limbs are at varying angles, viewing movement and operation of
the boom carried tree pruning apparatus was often obstructed to the
operator of the controls. Additionally, although many attempts have
been made to solve the need for tree pruning apparatus for the
utility industries, such prior attempts have suffered from various
deficiencies which are believed to have prevented their market
viability.
[0004] Thus, a need continues to exist for apparatus for gripping
and cutting wood which is advantageous, especially when used in the
utilities industries, and which overcomes the deficiencies and
shortcomings of prior apparatus.
SUMMARY
[0005] The present invention solves this need and other problems in
the field of gripping and cutting apparatus by providing, in the
preferred form, a gripping assembly including an extendable
actuator having opposite ends pivotally mounted to crank arms
extending radially from first and second shafts each having at
least one gripping arm extending radially therefrom. The travel of
the crank arms is limited by abutting with an abutment so that
movement of the gripping arms is centered on the gripping head.
[0006] In other aspects of the present invention, the opposite ends
of an extendable actuator are pivotably mounted to actuator ears
within a tubular insert and to actuator ears of a mount pivotally
mounted to the tubular insert, with the tubular insert being glued
or similarly adhered within the tubular boom of a boom assembly.
Thus, the insert provides a rigid mounting surface for the actuator
when utilized for booms formed of fiberglass or other material
which provides an inadequate medium for mounting the actuator as
well as provides a cleaner, more compact package having a reduced
tendency to catch on tree limbs, utility wires, and the like.
[0007] In further aspects of the present invention, the gripping
and cutting assembly is mounted to the free end of a boom of a boom
assembly for pivotable movement about a first axis, a second axis
substantially perpendicular to the first axis, and a third axis
substantially perpendicular to the first and second axes. In most
preferred aspects of the present invention, the gripping and
cutting assembly is rotated by a first rotary actuator received
between the end plates of a U-shaped leveler mount and by a second
rotary actuator mounted between the central plate of the U-shaped
leveler mount and a head mount, with the gripping and cutting
assembly being rotatable 360.degree. about the second rotary
actuator.
[0008] In still further aspects of the present invention, the
operation of a gripping and cutting apparatus mounted to a boom
assembly is controlled utilizing a remotely operated control unit
which is not connected to the vehicle to which the boom assembly is
mounted in a manner which creates an electrical path and in the
most preferred form is untethered to maximize the possibilities of
potential operator positions and to minimize the risk of
electrocution.
[0009] In additional aspects of the present invention, operation of
the boom assembly is prevented when the saw bar is not in a home
position and is thus most prone to damage. In the most preferred
form of the present invention, a proximity switch on the cutting
apparatus actuates a transmitter which provides an electromagnetic
signal to a receiver at the base of the boom assembly for
interlocking valve actuation of the boom assembly when the saw bar
is not in its home position.
[0010] It is thus an object of the present invention to provide a
novel apparatus for gripping and cutting wood.
[0011] It is further an object of the present invention to provide
such a novel gripping and cutting apparatus especially adapted for
fiberglass boom assemblies.
[0012] It is further an object of the present invention to provide
such a novel gripping and cutting apparatus including an insert for
receipt within a tubular boom and for providing an inside rigid
mounting surface for an extendable actuator.
[0013] It is further an object of the present invention to provide
such a novel gripping and cutting apparatus which does not create
an electrical path to the remote control unit.
[0014] It is further an object of the present invention to provide
such a novel gripping and cutting apparatus including an untethered
remote control unit.
[0015] It is further an object of the present invention to provide
such a novel gripping and cutting apparatus including a mechanical
abutment to center the travel of the gripping arms in a gripping
head.
[0016] It is further an object of the present invention to provide
such a novel gripping and cutting apparatus providing pivotal
movement of the gripping head about three perpendicular pivotable
movement axes.
[0017] It is further an object of the present invention to provide
such a novel gripping and cutting apparatus which locks out boom
operation when the saw bar is not in its home position.
[0018] These and further objects and advantages of the present
invention will become clearer in light of the following detailed
description of an illustrative embodiment of this invention
described in connection with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The illustrative embodiment may best be described by
reference to the accompanying drawings where:
[0020] FIG. 1 shows a perspective view of a gripping and cutting
apparatus fabricated in accordance with the preferred teachings of
the present invention mounted on the end of a boom assembly mounted
on a powered vehicle.
[0021] FIG. 2 shows an exploded, perspective view of the gripping
and cutting apparatus of FIG. 1.
[0022] FIG. 3 shows a side view of the gripping and cutting
apparatus of FIG. 1, with portions shown in cross section to show
internal detail.
[0023] FIG. 4 shows a top plan view of the remote control unit of
the gripping and cutting apparatus of FIG. 1.
[0024] FIG. 5 shows a diagrammatic view of the control system of
the gripping and cutting apparatus of FIG. 1.
[0025] All figures are drawn for ease of explanation of the basic
teachings of the present invention only; the extensions of the
Figures with respect to number, position, relationship, and
dimensions of the parts to form the preferred embodiment will be
explained or will be within the skill of the art after the
following teachings of the present invention have been read and
understood. Further, the exact dimensions and dimensional
proportions to conform to specific force, weight, strength, and
similar requirements will likewise be within the skill of the art
after the following teachings of the present invention have been
read and understood.
[0026] Where used in the various figures of the drawings, the same
numerals designate the same or similar parts. Furthermore, when the
terms "top", "bottom", "first", "second", "side", "end", "inner",
"outer", "inside", "outside", "upper", "lower", and similar terms
are used herein, it should be understood that these terms have
reference only to the structure shown in the drawings as it would
appear to a person viewing the drawings and are utilized only to
facilitate describing the preferred embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0027] Gripping and cutting apparatus according to the preferred
teachings of the present invention is shown in the drawing and
generally designated 10. In the most preferred form, apparatus 10
is mounted on the free end of an upper boom 12 of a boom assembly
14 mounted on a powered vehicle 16, with boom 12 being tubular and
having annular cross sections. In the most preferred form, boom
assembly 14 includes a lower boom 13 having its upper end pivotally
attached about a horizontal axis to the lower end of boom 12 and
its lower end pivotally attached about a horizontal axis to a
turntable 15 rotatable about a vertical axis. A hydraulic actuator
12a having its opposite ends pivotally connected to booms 12 and 13
pivots boom 12 relative to boom 13. A hydraulic actuator 13a having
its opposite ends pivotally connected to boom 13 and turntable 15
pivots boom 13 relative to turntable 15. A hydraulic motor 15a is
mounted to turntable 15 to rotate turntable 15 relative to vehicle
16. In the most preferred form, vehicle 16 and boom assembly 14 are
of a conventional design referred to in the trade as a bucket truck
utilized extensively in the utilities industry. In its most
preferred aspect, at least boom 12 is formed of fiberglass to
reduce the risk of electrocution in the event of contact with
electrical lines. In particular, boom 12 is in the form of a
fiberglass tube. It should be appreciated that the use of
fiberglass in boom assembly 14 in addition to the reduction of
electrocution risk has advantages including being of reduced weight
and expense, but has limitations including strength and
specifically in load carrying capacity.
[0028] Apparatus 10 in the preferred form includes a boom insert 18
in the form of a tube having an outer surface having annular cross
sectional sizes corresponding to and for a tight slideable fit
within the free end of boom 12. In the most preferred form, the
outer surface of insert 18 is glued such as by epoxy glue or
similarly adhered in boom 12. Insert 18 includes an end plate 20
secured to and closing an end of insert 18, with actuator ears 22
secured in insert 18 by extending from end plate 20 inside of
insert 18 and spaced from the outer end of insert 18. The outer end
of insert 18 forms and terminates in pivot ears 24 located outside
of boom 12. In the most preferred form, the hydraulic fittings for
apparatus 10 are carried by boom insert 18 outside of boom 12.
[0029] Apparatus 10 in the most preferred form further includes a
rotator mount 26 having a plate 28 from which pivot ears 30 extend
perpendicularly from a face thereof intermediate its upper and
lower edges. Mount 26 is pivotably mounted to insert 18 by a pivot
pin 32 extending through pivot ears 24 and 30. Mount 26 further
includes actuator ears 34 extending parallel to pivot ears 30. In
the most preferred form, mount 26 is pivoted relative to insert 18
and thus boom 12 by a linearly extendable hydraulic actuator 36
extending within the interior of insert 18 and having its opposite
ends pivotably mounted to ears 22 and 34 about pivot axes spaced
from and parallel to each other and the pivot axis defined by pivot
pin 32. Thus, extension and retraction of actuator 36 results in
pivotable movement about a first pivot axis defined by pivot pin 32
relative to boom assembly 14.
[0030] Apparatus 10 further includes a rotary hydraulic actuator 38
in the most preferred form having a cylindrical body 40 suitably
mounted to mount 26 such as by tangential legs 42 fixed to body 40
and suitably removably secured to plate 28 on the opposite face
than ears 30. Rotary actuator 38 includes a circular plate output
44, with an axial opening extending through output 44 and body
40.
[0031] Apparatus 10 further includes a leveler mount 48 of a
generally U-shape. Specifically, mount 48 includes a central plate
50 and first and second end plates 52 extending generally
perpendicularly from the opposite ends of plate 50. The spacing
between end plates 52 is generally equal to and for slideably
receiving actuator 38. Actuator 38 in the preferred form is
rotatably mounted between plates 52 by an elongated pin 54
extending through apertures formed in end plates 52 and through the
axial opening extending through output 44 and body 40. Output 44 is
suitably secured to leveler mount 48 such as by bolts 56 extending
through end plate 52 adjacent to output 44 and threadably received
in output 44. Thus, rotation of output 44 relative to body 40, legs
42, and mount 26 results in rotation of mount 48 about a second
pivot axis defined by pin 54 relative to body 40, legs 42, mount 26
and boom assembly 14. It should be appreciated that the second
pivot axis defined by pin 54 is perpendicular to the first pivot
axis defined by pivot pin 32.
[0032] Apparatus 10 further includes a rotary hydraulic actuator 58
in the most preferred form having a cylindrical body 60 suitably
mounted to central plate 50 of mount 48 such as by bolts 62 passing
through plate 50 and threaded into body 60 and having a rotatable
central core 64. A head mount 66 is suitably secured to core 64
such as by bolts 65 extending through mount 66 and threadably
received in core 64. Thus, rotation of core 64 relative to body 60
results in rotation of mount 66 about a third pivot axis defined by
core 64 relative to body 60, mount 48 and boom assembly 14. It
should be appreciated that the third pivot axis defined by core 64
is perpendicular to the first and second axes pivot defined by pins
32 and 54, respectively.
[0033] Apparatus 10 further includes a gripping arm assembly 68
having a main support 70 including a mount 71 which can suitably be
secured to head mount 66 such as by bolts. An end plate 72 is
suitably secured to one end of support 70 such as by countersunk
cap screws, with support 70 extending perpendicularly from plate
72. First and second shafts 74 extend through apertures formed in
plate 72 and are rotatably mounted thereby about pivot axes which
are spaced and parallel to each other and on opposite sides of and
parallel to support 70 between plate 72 and lower pivot brackets 76
suitably fixed relative to support 70 such as by welding to support
70. Each of the shafts 74 include first and second gripping arms 78
fixed thereto for rotation therewith. In the most preferred form,
arms 78 of the first shaft 74 are located axially between arms 78
of the second shaft 74 such that the first shaft 74 can be axially
shorter than the second shaft 74. Shafts 74 and arms 78 are spaced
axially inwardly from the end of support 70 opposite to plate 72.
It can then be appreciated that the third pivot axis defined by
core 64 extends generally perpendicular to the plane extending
between the pivot axes of first and second shafts 74.
[0034] For purposes of pivoting shafts 74 and gripping arms 78, the
free ends of shafts 74 extending through plate 72 each include a
crank arm 80 extending radially from shafts 74. Thus, plate 72 is
located intermediate arms 78 and 80. A single, linearly extendable
hydraulic actuator 82 has its opposite ends pivotably mounted to
crank arms 80 about pivot axes which are spaced and parallel to
each other and to the pivot axes of shafts 74. An abutment 84 is
suitably secured to plate 72 equidistant between but in a plane
parallel to but spaced from a plane extending between the pivot
axes of shafts 74, with abutment 84 abutting with both crank arms
80 when actuator 82 is in its retracted position to limit travel of
crank arms 80 and rotational movement of shafts 74. Arms 78 are
located and shaped in such a way to give a range of motion by a
single actuator 82 to grab limbs effectively from a 12 inch (30 cm)
maximum diameter down to a 0.75 inch (1.9 cm) minimum diameter.
[0035] Apparatus 10 further includes a saw system 86 which can be
of a variety of conventional types. In the preferred form shown,
saw system 86 is of the chain saw type including a bar 88 pivotable
relative to a housing 89 which in the most preferred form is formed
of plastic due to weight considerations. In the most preferred
form, bar 88 is pivotable about an axis parallel to the axes
defined by shafts 74 and perpendicular to the third pivot axes
defined by core 64 and is pivotable in a plane parallel to the
third pivot axis defined by core 64. In the preferred form, bar 88
is pivoted by a linearly extendable hydraulic actuator 90. Bar 88
carries an endless cutting chain 92, with chain 92 being moved
around bar 88 by a hydraulic rotary motor 94. Saw system 86 is
suitably secured to the end of support 70 opposite to plate 72.
Arms 78 of assembly 68 as shown are designed in such a way that
allow them to fold and overlap each other, rendering them out of
the way so that saw system 86 can be used independent of arms
78.
[0036] Now that the basic construction of apparatus 10 according to
the preferred teachings of the present invention has been
explained, the preferred mode of operation and some of the
advantages thereof can be set forth. Specifically, as is
conventional, apparatus 10 can be moved to the general area by
pivoting and rotation of boom assembly 14. Assembly 68 and system
86 forming the working head 96 of apparatus 10 can then be moved
relative to boom 12 to be aligned with the particular limb to be
severed by movement about 3 independent axes. Specifically, head 96
can be pivoted about the horizontal pivot axis defined by pivot pin
32 by extending or retracting actuator 36.
[0037] It should then be appreciated that insert 18 according to
the preferred teachings of the present invention is advantageous
for several reasons. First, the use of extendable actuator 36
offers the greatest amount of torque in a compact and lightweight
package. Further, boom insert 18 provides a rigid mounting surface
for actuator 36 rather than attempting attachment to boom 12.
Specifically, fiberglass provides an inadequate medium for mounting
actuator 36. Thus, as actuator 36 is mounted to insert 18, the
stress of mounting and operation of actuator 36 is not directly
placed upon the fiberglass forming boom 12 in the most preferred
form. Furthermore, especially with insert 18 slid within boom 12,
actuator 36 can be positioned inside of insert 18 such that the
operative length of apparatus 10 can be minimized as actuator 36 is
positioned within the extent of boom 12 and specifically, it is not
necessary for the entire length of actuator 36 to be located beyond
the free end of boom 12. Additionally, locating actuator 36 inside
of boom 12 maximizes the amount of rotation of plate 28 in
comparison to which would be allowed if actuator 36 were located
outside of boom 12. Specifically, in the most preferred form, plate
28 of mount 26 can be rotated along an arc which in the preferred
form is in the order of 110.degree. and most preferably is in the
order of 180.degree. about pivot pin 32. Further, actuator 36
located within insert 18 is protected from the environment as well
as allows for a cleaner, more compact package. This is especially
important in the pruning of trees around utility wires as actuator
36 positioned outside of boom 12 could have a tendency to catch on
adjacent tree limbs, utility wires, and the like.
[0038] Rotary actuator 38 according to the teachings of the present
invention allows rotative movement of head 96 to either side of
boom 12. In particular, actuator 38 allows pivotable movement of
head 96 about a second pivot axis defined by pivot pin 54 which is
perpendicular to the first pivot axis defined by pivot pin 32. In
the most preferred form, actuator 38 provides pivotable movement in
the range of 180.degree.. It should then be appreciated that use of
rotary actuator 38 maximizes pivotal movement in a compact space
and in particular the operative extent of apparatus 10 allowing
movement about the second pivot axis defined by pivot pin 54 is
generally equal to the diameter of rotary actuator 38 which is
considerably shorter than the operative length of a linearly
extendable hydraulic actuator. Additionally, the use of pivot pin
54, in the most preferred form, passing through end plates 52 of
mount 48 and through the opening of actuator 38 provides additional
strength to assembly 10.
[0039] Rotary actuator 58 according to the teachings of the present
invention allows rotative movement of head 96 about an axis
generally perpendicular to the axes defined by shafts 74 of
gripping arm assembly 68 and relative to boom assembly 14. In
particular, rotary actuator 58 allows pivotable movement of head 96
about a third pivot axis defined by core 64 which is perpendicular
to the first pivot axis defined by pivot pin 32 and perpendicular
to the second pivot axis defined by pivot pin 54. In the most
preferred form, actuator 58 provides pivotable movement in the
range of 360.degree.. It should then be appreciated that the use of
rotary actuator 58 maximizes pivotal movement in a compact space
and in particular the operative extent of apparatus 10 allowing
movement abut the third pivot axis defined by core 64 is generally
equal to the axial length of rotary actuator 58 which is
considerably shorter than the operative length of a linearly
extendable hydraulic actuator which would also not be able to
provide 360.degree. pivotable movement as does rotary actuator
58.
[0040] It should then be appreciated that in one mode of operation,
apparatus 10 can be generally positioned by pivoting of turntable
15 and booms 12 and 13 to be within the general vicinity of a limb
to be cut. With gripping arms 78 in an open condition, apparatus 10
can be positioned such that main support 70 is generally parallel
to and abutting with the limb or other piece of wood desired to be
cut. At that time, cylinder 82 can be actuated to pivot gripping
arms 78 to their closed condition to grip the limb or other piece
of wood in assembly 68. It should be appreciated that abutment 84
prevents gripping arms 78 on one of the shafts 74 from moving
without having movement of gripping arms 78 on the other of the
shafts 74. The ability of gripping arms 78 to close separate and
independent of each other allows the limb to be grasped and held
without forcing the limb to the center of head 96. This is
important to reduce the stress on head 96 and the limb and to
create better conditions to severing the limb. The use of a single
actuator 82 and abutment 84 reduces the complexity of assembly 68
according to the teachings of the present invention, which is
important in the ease and expense of manufacture as well as in
minimizing the weight of apparatus 10.
[0041] After gripping in assembly 68, saw system 86 can be actuated
to cut the limb or other piece of wood being gripped. After being
severed, the cut limb or other piece of wood is held in arm
assembly 68 and can be moved to a position away from vehicle 16 by
pivoting of apparatus 10 by actuating actuator 36, 38 and/or 58
and/or by pivoting of turntable 15 and booms 12 and 13. As boom
assembly 14 does not carry the weight of the operator in a bucket
as with conventional bucket trucks, boom assembly 14 even formed of
fiberglass in the most preferred form is able to carry the weight
of apparatus 10 and most severed limbs, with the preferred form of
apparatus 10 minimizing its weight to thereby maximize the
potential payload. Thus, is it not necessary to tie off limbs to
higher limbs as was previously required. It should be appreciated
that suitable provisions can be provided to allow automatic
movement of boom assembly 14 and/or apparatus 10 in the event that
a cut payload gripped in assembly 68 exceeds the load carrying
capability of boom assembly 14 and/or apparatus 10. After the limb
or other piece of wood is moved to or above the desired disposal
position, actuator 82 can be retracted to move gripping arms 78 to
their open condition to release the severed limb or other piece of
wood.
[0042] It should then be appreciated that in addition to movement
provided by boom assembly 14, apparatus 10 according to the
preferred teachings of the present invention provides movement of
head 96 about three perpendicular axes relative to boom assembly
14. This increased dexterity in the movement of head 96 is
especially important so that head 96 can be positioned parallel to
whatever the angle that the limb being severed extends from the
tree. This reduces the tendency of pivotable bar 88 being pinched
in the cut during cutting. Additionally, head 96 can be moved into
the tree around other limbs and utility lines so that trimming of
only the necessary limbs are necessary and without catching on
and/or damaging adjacent limbs or utility lines. Thus, movement
about three independent pivot axes is especially advantageous in
the utilities industries.
[0043] The preferred construction of apparatus 10 according to the
teachings of the present invention is believed to be advantageous
for several reasons. First, the use of rotary actuators 38 and 58
provides a maximum range of motion without the use of complex
mechanisms involving shafts, sprockets, gears, and the like.
Further, the use of insert 18, the arrangement of rotary actuators
38 and 58, and the construction of mounts 26, 48, and 66 minimize
the distance from the end of boom 12 and head 96 which is important
to reduce torque loads on boom 12. In this regard, having the third
axis defined by core 64 being perpendicular to shafts 74 and thus
to actuator 82, creates a more compact design than other
arrangements. Additionally, the compact and light weight of
apparatus 10 allows apparatus 10 to be utilized with fiberglass
booms 12 and still have the ability to hold and carry severed limbs
or similar wood. It is also believed that the arrangement of mounts
26, 48, and 66 and rotary actuators 38 and 58 enhances the range of
motion desired in the applications for which apparatus 10 of the
present invention is intended to be utilized.
[0044] Now that the basic construction and preferred mode of
operation of apparatus 10 have been set forth, a preferred control
system 100 for apparatus 10 according to the preferred teachings of
the present invention can be explained. Specifically, control
system 100 includes a first remotely controlled valve 101 in fluid
communication with motor 15a, with valve 101 in the most preferred
form being of the proportional type to allow rotation in either
direction at varying speeds. A second remotely controlled valve 102
is in fluid communication with hydraulic actuator 13a, with valve
102 in the preferred form being of the proportional type to allow
pivoting of boom 13 in either direction at varying speeds. A third
remotely controlled valve 103 is in fluid communication with
actuator 12a, with valve 103 in the preferred form being of the
proportional type to allow pivoting of boom 12 in either direction
at varying speeds. A fourth remotely controlled valve 104 is in
fluid communication with actuator 38, with the valve 104 in the
preferred form being of the on/off type to allow pivoting of mount
48 in either direction generally at a constant speed when actuated.
A fifth remotely controlled valve 105 is in fluid communication
with actuator 36, with valve 105 in the preferred form being of the
on/off type to allow pivoting of mount 26 in either direction
generally at a constant speed when actuated. A sixth remotely
controlled valve 106 is in fluid communication with actuator 58,
with valve 106 in the preferred form being of the on/off type to
allow pivoting of mount 66 in either direction generally at a
constant speed when actuated. A seventh remotely controlled valve
107 is in fluid communication with actuator 82, with valve 107 in
the preferred form being of the on/off type to allow actuation of
actuator 82 to move gripping arms 78 in either direction generally
at a constant speed when actuated. An eighth remotely controlled
valve 108 is in fluid communication with hydraulic motor 94, with
valve 108 in the preferred form being of the on/off type to allow
actuation of motor 94 to move saw chain 92 around bar 88 at a
constant speed when actuated. In the most preferred form, valve 108
is a valve section that operates in two positions, one of which
actuates motor 94 and actuator 90 to pivot bar 88 away from the
home position and the other which actuates actuator 90 to pivot bar
88 in the opposite direction towards the home position and without
actuation of motor 94 for moving saw chain 92. Specifically,
although most of the hydraulic oil discharged from motor 94 is
returned to the hydraulic fluid reservoir, the return line includes
a metering valve 110 for metering hydraulic oil to hydraulic
actuator 90 for pivoting bar 88 away from its home position. It can
then be appreciated that saw system 86 is self regulating.
Specifically, if the saw chain 92 slows down from feeding too fast,
motor 94 slows down and consequently slows the feed of oil to
actuator 90 and that slows the pivoting of bar 88 and thus the feed
of bar 88 into the wood. In the most preferred form, an emergency
stop valve 109 is in fluid communication with each of the valves
101-108 to stop flow when valve 109 is actuated. The proportional
control of valves 101-103 provides infinitely variable speed
control which is important in control of boom assembly 14 to
prevent dynamic overloading and also in offering greater control to
the operator to position head 96.
[0045] In the most preferred form, valves 101-109 are located on
turntable 15 for rotatable movement with boom assembly 14 and
relative to vehicle 16 so that only a single rotary joint is
necessary between the hydraulic fluid reservoir and pump and boom
assembly 14 and apparatus 10. It should be noted that the hydraulic
system can operate other accessories of vehicle 16 including but
not limited to outriggers, a dump box, or the like. It should also
be appreciated that suitable electrical connections are similarly
provided between turntable 15 and vehicle 16 allowing relative
rotation between turntable 15 and vehicle 16 but providing
electrical power necessary for control system 100.
[0046] Control system 100 according to the preferred teachings of
the present invention includes a remote control unit 112 which in
the most preferred form is carried on the operator such as by a
belt 113 to allow two hand operation. In particular, unit 112
includes a first joystick type switch 114 for operating valve 106
when moved in one direction such as back and forth and for
operating valve 102 when moved in a perpendicular direction such as
up and down. A second joystick type switch 116 is also provided for
operating valve 104 when moved in one direction such as back and
forth and for operating valve 105 when moved in a perpendicular
direction such as up and down. A third joystick type switch 118 is
further provided for operating valve 101 when moved in one
direction such as back and forth and for operating valve 103 when
moved in a perpendicular direction such as up and down. It should
be appreciated that switches 114, 116 and 118 allow simultaneous
movement in both directions such that two valves can be actuated
simultaneously by each switch 114, 116, and 118, with actuation
being dependent on the amount of movement in the particular
direction in the case of proportional valve types.
[0047] Remote control unit 112 further includes a toggle type
switch 119 for operating valve 107 to open and close grapple arms
78. A push button switch 120 is provided for starting control
system 100. A toggle type switch 122 is provided for controlling
the RPM of the motor and/or the hydraulic system of vehicle 16 and
thereby the amount of hydraulic fluid flow of the hydraulic system.
A push button switch 124 is provided for operating emergency stop
valve 109. A push button switch 126 is provided allowing an
override function which will be described in more detail
hereinafter. A push button switch 128 is provided for controlling
operation of valve 108 controlling saw system 86. Unit 112 further
includes a LED 130 to show that unit 112 is under power.
[0048] In the most preferred form, remote control unit 112
according to the teachings of the present invention is not
connected to vehicle 16, apparatus 10, and/or boom assembly 14 in a
manner which creates an electrical path to ground and in the most
preferred form is untethered. Specifically, in the most preferred
form, remote control unit 112 includes a portable power supply 132,
a control processor 134, and a transmitter 136. Power supply 132 in
the preferred form is one or more batteries of either the
disposable or rechargeable type. Processor 134 receives input from
switches 114, 116, 118, 119, 120, 122, 124, 126 and 128 for
controlling transmitter 136. Transmitter 136 in the most preferred
form transmits radio signals of the desired electromagnetic
frequency according to the input from switches 114, 116, 118, 119,
120, 122, 124, 126 and 128.
[0049] Control system 100 further includes a receiver 138 for
receiving the radio signals transmitted by transmitter 136 and
controlling the actuation of valves 101-109. In the most preferred
form, receiver 138 is located on turntable 15 for rotatable
movement with boom assembly 14 and relative to vehicle 16.
[0050] It should be appreciated that remote control unit 112
according to the teachings of the present invention produces
several advantages. First, the operator can stand at any position
relative to vehicle 16 within the range of transmitter 136 and
receiver 138. In particular, the operator can stand at a position
at a distance from where apparatus 10 is located such that the
operator is not subject to falling debris including but not limited
to saw dust, broken limbs, or the like. Further, as branches of
trees can extend at different angles, the operator can stand where
viewing of apparatus 10 according to the angle of the particular
limb being severed, according to any visual obstructions such as
but not limited to other limbs, vehicle 16, boom assembly 14, and
the like. However, in addition to increasing the possibilities of
the potential operator positions, an untethered remote control unit
112 has a further advantage of reducing the risk of electrocution.
Specifically, in the event that apparatus 10, boom assembly 14,
vehicle 16, or a severed or unsevered limb captured in head 96
should engage an electrical power line, which can be a significant
risk as a preferred use is for trimming trees around power lines,
the operator should stand at a sufficient distance from vehicle 16
to prevent electric shock from any electrical charge passing
through boom assembly 14 and vehicle 16.
[0051] Because of the decreased risk of electrocution, apparatus 10
according to the teachings of the present invention can be utilized
in unique manners. As an example, a utility pole carrying power
lines can be grasped by head 96 and cut by saw system 86. After
cutting and while still holding the cut portion of the utility
pole, boom assembly 14 and/or turntable 15 can be moved to position
the cut portion and power lines carried thereby horizontally spaced
from and out of the way of the remaining portion of the utility
pole. At that time, the remaining portion of the utility pole can
be removed from the ground and replaced with a new utility pole.
After the new utility pole is in place, the power lines can be
removed from the cut pole portion and attached to the new utility
pole in one of any desired manners. Thus, utility poles can be
replaced without interference with existing power lines and without
the need for loosening or removing the power lines from a series of
utility poles utilizing apparatus 10 according to the teachings of
the present invention.
[0052] Control system 100 according to the preferred teachings of
the present invention further includes provisions for preventing
movement of boom assembly 14 when an operational mode of saw system
86 is detected and specifically when saw bar 88 is not in its home
position. In particular, a proximity switch 142 is located on
housing 89 of saw system 86 to provide an electrical signal
whether. or not saw bar 88 is within the confines of housing 89. In
the most preferred form, switch 142 senses a metal object on saw
bar 88 when it is in its home position within the confines of
housing 89. In the preferred form, switch 142 actuates a
transmitter 144 also mounted upon housing 89. In the most preferred
form, transmitter 144 is battery and solar powered so that a
physical electrical connection is not necessary and transmits radio
signals of the desired electromagnetic frequency. A receiver 146
receives the signals of transmitter 144 and prevents or locks out
actuation of valves 101, 102, and 103 controlling movement of boom
assembly 14 and in the most preferred form does not prevent
actuation of valves 104-109. In the most preferred form, receiver
146 is located on turntable 15 for rotatable movement with boom
assembly 14 and relative to vehicle 16. Thus, the operator is
prevented from moving boom assembly 14 when saw bar 88 is not in
its home position and is especially susceptible to damage. It
should be appreciated that saw bar 88 from time to time can become
pinched or caught on a limb and not fully retract to the home
position inside of housing 89 and thereby leaving it vulnerable.
The operator will still have full use of multiple degrees of
movement provided by apparatus 10 and specifically by actuation of
valves 104-107 to try to release saw bar 88 from its bound
position. If this is not accomplished, the operator may actuate
override switch 126 that will allow actuation of valves 101, 102
and 103 for moving boom assembly 14. When saw bar 88 is in its home
position inside of housing 89, actuation of all valves 101-107 and
109 is permitted.
[0053] It is believed that the use of the transmitter 144 and
receiver 146 according to the preferred teachings of the present
invention is advantageous. Specifically, use of radio signal
transmitter 144 and receiver 146 according to the preferred
teachings eliminates any requirement of a physical communication
connection between saw system 86 and turntable 15 which could form
an electrical path from apparatus 10 down boom assembly 14 to
vehicle 16 and which could be subject to stress fatigue, wear, and
damage as the result of bending or engagement with other
objects.
[0054] Now that the basic teachings of the present invention have
been explained, many extensions and variations will be obvious to
one having ordinary skill in the art. For example, although
apparatus 10 of the most preferred form includes the combination of
several, unique features believed to obtain synergistic results,
apparatus for mounting on the free end of a boom of a boom assembly
could be constructed according to the teachings of the present
invention including such features singly or in other combinations.
As an example, use of an untethered remote control unit 112
according to the teachings of the present invention could be
utilized with other types of heads 96 and/or other manners of
mounting and moving head 96 relative to boom assembly 14.
Similarly, the preferred construction of assembly 68 could be
utilized with other types of saw systems 86, other manners of
mounting and moving head 96 relative to boom assembly 14, and other
types of control systems 100, and the like.
[0055] Thus since the invention disclosed herein may be embodied in
other specific forms without departing from the spirit or general
characteristics thereof, some of which forms have been indicated,
the embodiments described herein are to be considered in all
respects illustrative and not restrictive. The scope of the
invention is to be indicated by the appended claims, rather than by
the foregoing description, and all changes which come within the
meaning and range of equivalency of the claims are intended to be
embraced therein.
* * * * *