Note: Descriptions are shown in the official language in which they were submitted.
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LINKAGE APPARATUS HAVING A MECHANISM
FOR DANPENING VIBRATIONS
Field of the_Invention
The present invention relates to a linkage
apparatus for connecting a use device, mos~ preferably a
vibrating cable plow apparatus, to a ground-engaging
vehi~le, wherein the linkage app~ratus includes a mechanism
for dampening vibrations.
Backqround of the Invention
Cable plows of the type disclosed herein have been
utilized for many years to lay many types~o~ cables,
flexible pipes, conduits, etc. The cable or pipe has been
passed into a trench, dug by a plow-blade, through a chute,
or some other mechani~m for guiding the cable or pipe,
which trails the leading edge of the plow-blade. In either
case, the cable generally passes into an opening in the
ground created by the blade from a spool mounted on the
vehicle which pulls the plow apparatus. Because the plow
must be pulled through very rough and, at times, heavily
packed terrain, the ground-engaging vehicle which pulls the
plow apparatus has had to be a very large and powerul
tractor.
Vehicles pulling cable plows have generally been
required to travel at relatively slow speeds, laying cable
at a rate in a range of inches per minute. In $his regard,
it has been found that vibration, or reciprocating movement
of the plow-blade, is effective to work the soil and reduce
the tractive pulling force required to pull the blade
through the ground. Where such vibration or reciprocating
movement of the blade was employed, it was found that
smaller tractors possessing less tractive pulling power
could be used to lay cable. This ability to use smaller
tractors offered several advantages including less ground
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disturbance, more maneuverabiliky, faster cable laying,
greater mobility, etc.
Following the development of vibratory cabling
laying plows, however, it became apparent that the
vibrations from the plow had a negative effect on the
operators of such machinery, and upon the working parts of
the vehicle pulling the plow. It pxoved to be very
stressful for operators to be sub~ected to constant
vibrations for long periods of time each day. In addition,
the parts of the vehicle ~ended to come apart and need
repeated tightening. The vehicles also seem to wear
faster.
Therefore, efforts were made to dampen the
vibrations emanating from the plow apparatus. For example,
U.S. Patent No. 3,618,237 discloses a frame support for a
cable laying plow apparatus having torque cushioning
elements which absorb some of the reciprocable motion of
the support in an attempt to isolate the frame from the
supporting structure. A four point support apparatus is
also provided to cooperate to define a parallelogram-type
linkage apparatus.
U.S. Patent No. 3,561,539 discloses a vibratory
cable plow having a sharpened plow point at an unspecified
angle and a plurality of resilient pads designed to enhance
vibratory movement and dampen the transfer of vibratory
movemenk from the elongated plow-blade to the mounting
frame. Unfortunately, none of these dampening means
adequately dampens vibrations from the vibration ox
reci~rocating device.
The vibratory plow apparatus of U.S. Patent No.
3,561,539 also discloses a parallelogram-type apparatus for
raising and lowering the plow while maintaining the plow-
blade in a substantially vertical orientation. V.S. Patent
No. 3,684,030 also discloses a parallelogram-type support
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structure for a plow-blade including a number o~ digger
teeth which project forwardly-and downwardly frqm the plow-
blade. Notive mechanisms are also disclosed for swinging
the linkage mechanism on a vertical axis with respec~ to
the vehicle, and for lifting the lower arm of the linkage
mechanism and hence the plow-blade.
One of the advantages of the parallelogram-type
linkage mechanism is that the plow may he raised without
changing the vertical orientation of the plow to the soil.
As compared to three point linkage mechanisms, this enables
the cable plow to continue laying cable at the lowest
possible depth when the plow must be raised to travexse
over immovable objects such as pipes or large rocks which
may be buried in the soil. When a three point lift
mechanism is employed, the plow is generally raised such
that the plow is angled backwards and away from the
vehicle. The backside of the plow-blade where the cable
guide outlet mechanism is generally located, is thereby
raised to a greater degree than the leading edge of the
plow-blade which mus~ traverse across the buried ob~ect.
Since the backside of the plow-blade angles upward from the
leading edge of the plow-blade, the cable can come out o
the guide mechanism as much as a foot higher than the
leading edge of the plow-blade. The parallelogram-type
linkage mechanism allows the plow to be raised vertically
without creating this angle, thereby allowing the cable to
be laid at the greatest depth possible when traversing over
immovable buried objects.
One disadvantage of the parallelogram-type linkage
mechanism is that although it enables one to lay cable at
; the lowest depth possible when traversing over immovable
buried objects, it is not possible to maintain the blade at
a desired orientation to the ground when traveling through
irregular terrain. In irregulax terrain, when the vehicle
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and the plow-blade may simultaneously engage ground at
different pitches or slopes, the angle of the plow-blade
will depend on the slope of the ground to which the vehicle
is engaged. This slope may be entirely different from the
slope of the ground in which the plow-blade is engaged. In
such a situa~ion, the plow-blade will not be perpendicular
to the ground. This can result in the backside of the
plow-blade heing at a differen~ depth than the leading edge
of the plow-~lade. If the backside is higher than the
leading edge, the cable emerging from the backside can be
laid at inconsistent depths in irregular terrain.
It will be appreciated from the foreqoing that
prior art devices present problems which are in need of
solutions. The present invention provides solu~ions for
~hese and other problems.
.
Summary of the Invention
The present invention is directed to a linkaye
apparatus for connecting a use device, most preferably a
vibrating cable laying plow apparatus, to a ground-engaging
vehicle. The linkage apparatus includes: a flrst arm
member having first and second ends and a first mechanism
for connecting the first end to the vehicle; a second arm
member having firs~ and second ends and a second mechanism
for connecting the second end to the use device; a third
mechanism for pivotally connecting the first and second arm
members; and a mechanism for dampening vibrations between
the first and second arm members. The dampening mechanism
preferably includes a resilient member which dampens
vibrations, preferably an air cushion bag. More
preferably, the dampening mechanism includes a resilient
member on each side of the third pivotal connectin~
mechanism. The third pivotal connecting mechanism
preferably includes a substankially horizontal axis about
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1 31 6357
which ~he first and second arm members pivot. More
,preferably, the.linkage, ~pparat~s.a-lso includes an upper ,
mechanism,for linking,,the use device to the vehicl,e which
is located above the first and second arm members and has
first an,d second ends., The linkage apparatus preferably
:in¢Ludes a~:f,ourt~:mechanism.for pivotally connecting the
first end,of the u-pp~er,linking mechanism,to the vehicle,
.a~d a fifth,mqchanism for pivotally,connecting.the second
.e,nd of.the upper linkin~ mechanism-.and the second
.connecting m.echanism are preferably mecha~isms for
pivotally-connecting.. The upper-linking mechanism,
preferably-cooperates with the first a~d second arm members
to,substantially ~orm,.a fo,ur point.linkage. having four
pivotal connection points in a~,roughly quadrilateral
:orientation, and a fifth.pivotal connection linking the
first and second arms. . ..
- , Preferably, the invention includes a.mechanism for
lifting,the first arm member wherein.the pivotal,connecting
mechanisms of the first and second ends of the upper
,20 linking mechanism, the first end.,of the first.arm member,
and *he second,end of the second,arm member, have
substant-ially,horizontal.,axes such th,a,t when the first arm
member,is lifted,,the first arm member and the upper
,linking mechanism pivot substantially horizontallY about
their first,end pivotal connecting mechanisms. The upper
linking mechanism preferably includes an upper linkage
member and a mechanism for adjusting the length of the
upper linkage member, such that the angle of alignment of
the use device may be adjusted by adjusting the length of
the upper linkage member.
The present invention offers many advantages over
the prior art, some of which are discussed below~ The
arrangement of the first and second arm members, the third
pivotal connectLng mechanism and the dampening mechanism
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1 31 6357
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~llow,the..use,of larger Yibrating units:which will direct
more vibration to the .use-device,.while minimizing the
vibrations:transferred from the u~e device ~o the vehicle.
During operation, the vibrating cable plow of the presen~
invention dir.ects most of the force, or torque, created by,
the ground,as,it resists~the plow-blade which i,s being
pulled through the ground, to the second connecting
~e~hanism between the lower-lin~ing mechanism.,and the plow-
blade. This:,is because this mechanism is the closest pivot
point with respect to the ~orce vector which resists
movement of the lower end of the plow-blade-through the
ground. Because the bulk of the force resisting the
tractive pulling force of the vehicle is therefore directed
to the second connecting mechanism~.the bulk of the
vibrations from the plow-blade are directed along the lower
linking mechanism, and particularly, along the second arm
member which is pivotally attached to the first arm member.
Rather than transferring the vibrations along the lower
linking mechanism are directed to the dampening mechanism,
interp,osed b.etween elements of the first-and seco~d arm
members. , .
-. - .The pivo,tal movement o~ the-first and second arm
member,s with respec.t to one another, cooperate with the '~
pulling force e~erted,on the plow blade, the pivotal
connecting mechanisms which allow other pivotal movement,
and the tooth of the plow-blade, to urge the lower end
portion of the plow blade, specifically the toath of the
plow-blade, to follow an elliptical path. The upper
surface of the tooth, and particularly the specific angel
of the upper surface of the tooth with respect to a line
perpendicular to the front edge of the plow-bla,de, is very
important in creating this pattern of elliptical movement.
: The elements described above cooperate to effectively
utilize the tractive pulling force of the vehicle and the
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1 31 6357
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vibra~ory energy directed along the lower linking mechanism
to provide ~he elliptical motion of the tooth which works
the ground, thereby making it easier to pull the plow-
blade.
S The cycle of elliptical motion s~arts with the
first and second arm members in a substantially parallel
relationship such that the straight line length is
maximized between the distal ends of the lower linking
mechanism, meaning the first end of ~he first arm member
and the second end of the second arm member where the first
and second connecting mechanisms are respectively located.
When the arm members pivot such that the distance between
their distal ends is shortened, since the radius of the
pivot about the third connecting mechanism is shorter than
the radius of the pivot about the fourth connecting
mechanism, the lower end of the plow-blade is drawn closer
to the vehicle. At the same time as the lowex end is drawn
closer, the angle of the upper surface of the tooth meets
the ground at such an angle that it acts to force the pIow-
blade initially downwardO The movement of the lower end ofthe plow-blade is, therefore~ initially downward and toward
the vehicle. As the plow-blade pivots, and as the angle of
the surface of the tooth changes with respect to the vector
of the tractive pulling force being exerted on the plow-
blade, the lower end of the plow-blade and the tooth
gradually turn upward and the tooth passes throuyh the
bottom~of its elliptical cycle, and comes to the top of the
pattern. Throughout that pattern of movement, the tooth
works the ground. Once the angle of the surface of the
tooth no longer forces the plow-blade downward, the
distance between the distal ends of the two arm members
begin to lengthen. As this distance lengthens, the angle
of the plow-blade and the angle of the surface of the tooth
with respect to the vector of the pulling force being
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exerted on the plow-blade change, returning to the original
angles. When the angles return to the criginal angles, and
when the length between the ends of the lower linking
mechanism is maximized, the tooth pulls the blade downward
again and the distance between the distal ends of the two
arm members shortens again, and the elliptical cycle begins
a second path downward and toward the vehicle. It is this
elliptical pattern of movement which works the soil and
reduces the requirement for tractive pulling forceO For
this reason, the present invention requires much less
tractive pulling power than the prior art devices, and
therefore, does not require tractors as large as those
generally sued with the prior art devices. It is
understood that other patterns of motion are possible with
other configurations of the elements discussed herein.
A further advantage of the present invention is
the m~chanism for adjusting the length of the upper linking
member which allows the angle of the plow-blade with
respect to the ground to be adjusted when ~he plow-blade is
traversing irregular terrain. The ability to manipulate
the angle of the plow-blade with respect to the ground
allows the operator to go over a ridge and through a ditch
while at the same time maintaining th~ plow-blade at a
perpendicular angle to the ground. This allows the
operator to prevent the rear part of the lower end of the
plow-blade, where the cable guide means generally release
the cable into the ground, from angling toward the surface
with respect to the position of the front edge of the lower
end of the plow-blade. This manipulation allows operators
to lay all the cable, even that laid in irregular terrain,
at a consistent depth.
The above de~cribed features and advantages along
with various other advantages and features of novelty are
; pointed out with particularity in the claims of the present
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1 31 6357
application. However, for a better understanding of the -
invention-, its advantages, and.objects attained by its use,
reference should be made to.the drawings which form a
further part hereof and to the accompanying descriptive
matter in which prefarred.embodiments of the invention are
described and-illustrated. . - - -,
- Brief-Description-~of the Drawinqs
-:. ~ FI~; l-is an elevational perspective vie~,of the
linkage appàratus of the present i.nvention connecting a
cable plow apparatus to-~.ground-engaging vehicle and shown
in its environment pulling the plow through the ground;
- . FIG. 2-is a side.view of:..the linkage apparatus of
the present invention connected to a cable plow apparatus,
wherein the-lower linking mechanism'is shown in partial
cross section; ' '
FIG. 3 is a side view similar to FIG. 2 wherein
the first arm has been"raised;
.. ~ , FIG. 4 is a top view of the linkage apparatus
connected to a vibrating cable plow apparatus; -
. . -FI~.-5 is a.top.v.iew similar.to Figure 4 wherein
the linkage apparatus.,-is swung-to one side of the vehicle
and the plow-blade is angled in the opposite direction with
respect to the linkage apparatus;
. FIG. 6 is a top view of the lower linking
mechanism showing a pivotal connection between the first
and second arms and air cushion bags in phantom;
FIG. 7 is a side view of the linkage apparatus
connected to a cable plow apparatus, wherein the length of
the upper linking mechanism is substantially the same as
the length of the lower linking mechanism;
FIG. 8 is a side view similar to Figure 7 wherein
the distance between the first end of the first arm and the
second end of the second arm is shortened;
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. FIG. 9 is a side view similar to ~igure 7 wherein
the upper linking mechanism is longer;
. FIG. 10 is a side view similar to Figure 7 wherein
the length of the upper linking mechanism is.shorter;
- FIG. ll is a cross-sectional vie~ th.rough line ll-
ll ~.FIG. 2; . ..
FIG. 12 is a side view of ~he lower por~ion of the
cable plow; and . ..
-i: ^ ..FIG. 13 is.a perspective view of the lower portion
of:the cable plow showing the upper surface of the tooth
and khe edge of the plow-blad
. . . ~ .
: Detailed DescriPtion of khe Preferred
. Embodiment of the Invention
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Referring to the drawings, FIG. 1 shows a
preferred embodiment of a linkage apparatus 100- for
connecting a use device, preferably a vibrating cable plow
apparatus 200 as shown, ko a ground-engaging vehicle,
preferably a.tractor I0. The tractor lO.can carry a la.rge
spool 12 from which a continuous cable 14 is dispensed.
The cable 14.passes between kwo cable guide posts 205,...into
a.cable guide chu~e.210 having a cable entrance 212 and a
cable outlet 214.
The use device of the present invention may be any
apparatus which causes vibrations. It may be any ground
working device including a plow, preferably a cable plow,
and most preferably a vibrating cable plow for laying cable
in the ground or subsurface.
The ground-engaging vehicle of the present
invention can be a tractor of virtually any size having any
type of traction devices. Since the preferred embodiment
of the present invention is capable of dampening vibrations
from a very large vibrator, thereby allowing khe cable plow
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1 31 635-,'
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to use a large vibrator, the tractor may be much smaller
and provide much less tractive pulling force than would
otherwise be required for laying cable in occasionally
heavily packed ground. For this reason, the tractor may
have wheels, preferably rubber wheels which might not
otherwise providP the required tractive pulling power to
pull a cable plow through heavily packed ground.
Embodiments of the present invention may lay many
types of cable, flexible pipe, conduit, tubing, and the
like. Electrical cable is commonly laid by such a device.
Recently, devices ~hich can lay cable without jarring the
cable have been needed to lay fiber-optic cable which has
small fiberglass filaments int he center of a heavily
insulated cable. Any violent shaking or pounding of the
fiber-optic cable may damage it such that it is less
effective in carrying transmissions. Therefore, a device
which minimizes any violent concussion of the cable would
be a desirable apparatus for use in connection with laying
such a cable.
Referring now to FIGS. 1 and 2, the linkage
apparatus 100 in accordance with principals of the present
invention, has an-upper linkage mechanism 138 and a lower
linkage mechanism 108 which are pivotally connected such
that the linkage apparatus 100 has a four-point linkage.
The upper linkage mechanism 138 includes an upper linking
member 140 which includes two parallel upper linking arm
members 142 which are adjustable in length. Each upper
linking arm membex 142 includes a sleeve 143 and a sliding
arm 144 which slides inside of the sleeve 143 ~o allow
adjustment in length of the upper arm members 142. The
upper linking mechanism 138 also includes a hydraulic
cylinder 146. Referring also to FIG. 3, 4 and 5, the
hydraulic cylinder 146 is located between the upper arm
members 142 and is connected thereto. The hydraulic
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1 31 6357
cylinder 146 includes a sleeve 148 and a piston 149 in a
typical hydraulic cylinder, sleeve and piston arrangement.
Hydraulic cable lines 145 are connected to a hydraulic
control mechanism 18 in the vehicle 10 which supplies
hydraulic power to drive the cylinder 146 in a conventional
fashion known to those of skill in the art. The upper
linking arm member 142 and the piston 149 are pivotally
- connected to an outer support member 170. At the opposite
end the upper linking arm members 142 are pivotally
connected to a vertical support member 156.
The lower linking mechanism 108 includes a first
arm membar 110 and a second arm member 120 which are
pivotally connected. The distal ends of the lower linking
mechanism,away from the pivo~al connection 125 which joins
the arm membars 100 and 120, are pivotally connected ~o a
vertical support member 156 and an outer linking mechanism
170. The first and second arm members 110 and 120 are
pivotally connected ahout a pivotal connection 125,
including bushings 126 in the first and second arm members
110 and 120, and a pin 128 forming a substantially
horizontal axis. Still referring to FIGS. 1-5, along with
FIG. 6, the first arm member 110 includes two parallel
support members 112 which are connected by a first plate
member 113 and a second plate member 114 which are
connected to the parallel support members 112. A first end
llOa of the first arm member 110 is pivotally connected to
the vertical support member 156. A pin 111 forming a
horizontal axis passes through the first end llOa of the
first arm member 110, thereby passing through both of the
parallel support members 112.
The second end 120b of the second arm member 120
also have a pivotal connection 123. The second end 120b of
the second arm member 120 is preferably bifurcated into two
second arm end members 122 which are joined to a second arm
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1 31 6357
body.mQmber 124 which is connected to the second arm end
members 122 to form a single integral second arm member
120. The second arm body membex 124 is a flat metal,
preferably steel ally, body plate 127 supported by a number
of horizontal beams 129. The body plate 127 is
substantially horizontal and is suppor~ed by four
horizontal beams 129 which are connected to the bottom
surface of the body plate 127 and orientated.
perpendicularly to the.plane of the body plate 127.
Bushings 126..extend through a receiving portion 127a of the
body plate 127 and receive the pin 128 which forms.an axis
about which the second arm member 120 pivots in relation to
the first arm member 110. The pin 128 also passes through
bushings 126 in the first.arm member 110 to pivotally
connect the first and second arm members 110 and 120 about
the pivotal connection 125.
Interposed between the.first plate member 113 and
the second plate member 114 of the first arm member 110 and
the body plate 127 of the second arm body member 124 of the
~0 second arm member 120, are air cushion bags 130 and 132.
These air cushion bags 130 and 132 are attached, preferably
using fasteners, preferably bolts, to.the first and second
plate members, 113 and 114 respectively, of the first arm
member 110 and to the body plate 127 of the second arm body
member 124. Additional air cushion bags can be added, but
are not necessary.
The mechanism for dampening vibrations between the
first and second arm members may include any mechanism for
cushioning an impact. Resilient members of the present
invention may include hydraulic cushioning mechanisms, gas
cushioning mechanisms such as gas pack struts or shock
absorbers, resilient springs of various types, including
metal coils and other metal spring devices generally known
in the art,~ hard or soft rubber or polymer cushions or
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pucks, or the air cushion bags or the pre~erred embodiment.
- The air cushion.bags are similar to air bags used-to
cushion semi-truck trailers:. ThesP air bags are used in
the place of struts or shock absorbers and accomplish the
same task. Such air bags are generally made of vulcanized
rubber or other materials similar to the materials used to
construct rubber road tires. The air cushion bags may have
intertubes or may be.tubeless. Preferably, they hold air.
and the air.-may.be increased.or decreased using appropriate
mechanism. Dur~ng operation,-the.air cushion bags 130 and
132 cushion, or absor~, the vibrations between the first
and second arm members 110 and 120, thereby dampeniny the
vibrations and reducing the transfer of.vibrations to.the
vehicle.
The first end llOa of the first.arm member 110 is
pivotally connected to vertical support member 156 which is
pivotally connected to vehicle frame 107. The first end
140a of ~he upper linking mechanism 140 is.also pi~otally
connected to.the vertical support member 156 which is
pivotally connected to the vehicle frame 107. The pivotal
: connect~ions-105 and 109 between the vertical support member
156 and the frame 107 have substantially vertical axes
which allow the linkage apparatus 100 to swing horizontally
left and right with respect to the vehicle.. In the
preferred embodiment, this motion is driven by hydraulic
cylinders 150 and 152 located on either side of the linkage
apparatus 100 and pivotally connected to the frame 107 and
the vertical support member 156.
The vertical support member 156 is pivotally
connected to a substantially upright hydraulic cylinder
158. The hydraulic cylinder 158 has a typical hydraulic
cylinder, piston and sleeve arrangement. The piston 160 is
pivotally connected to the first arm member 110 at a
pivotal connection point 162. All o the hydraulic
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1 31 G357
cylinders are linked to a hydraulic control mechanism 18 in
the vehicle 10, ~he upright cylinder 158 being so linked by
hydraulic cables 163 and 164.
When the first arm member 110 is lifted by th0
S hydraulic cylinder 158, the first arm member 110 pivots
with respect to the second arm member 120 on the horizontal
axis of the pivotal connection 125, as well as with respect
to the vertical support member 156. Referring also to FIG.
7 and 8, if the pivotal connection 125 lies on a straight
line between the pivotal connections 111 and 123 of the
first end llOa of the first arm member 110 and ~he second
end 120b of the second arm member 120 when the first arm
member 110 is lifted by the hydraulic cylinder 158, then,
when the first arm member 110 pivots with respect to the
second arm member 120 on the horizontal axis of the pivotal
connection 125, the pivotal connection 111 will be drawn
closer to the pivotal connection 123. In addition, when
the second arm member pivots on the horizontal axis of the
pivotal connection 125, the lower end 220 of the plow-blade
215 will be drawn closer to the vehicle 10. This is
because the second arm member 120 will pivot on a shorter
radius than the upper linking member 140 pivots, thereby
drawing the lower end 220 of the plow~blade 215 closer to
the vehicle 10.
The outer linking mechanism 169 includes an outer
support member 170 which is pivotally connected to the
second arm member 120 at the pivotal connection 123 located
at the second end 120b of the second arm member 120. The
outer support member 170 is also pivotally connected to the
upper linking mechanism 140 at a pivotal connection 172 at
the second end 140b of the upper linking mechanism 140.
Referring also to FIG. 9 and 10, the linkage
apparatus of the preferred embodiment of the present
invention forms a four-point linkage which exists as a
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1 31 635-7
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parallelogram-type linkage when the upper linking mechanism
138 has the same length as the lower linking mechanism 108.
Since the upper linking mechanism 138 includes a mechanism
for adjusting the length of the upper linking member 142,
and since the straight line length of the lower linkage
mechanism 108 may also be varied, the four-point linkage of
the present invention need not exist at all times as a
parallelogram-type linkage. The upper linking member 142
may be shortened or lengthened with respect to the lower
linking mechanism 108 thereby changing the angle of the
plow~blade 215 with respect to the linkage apparatus 160
and the vehicle 10. Such adjustments of the upper linking
mechanism 138, may be used to vary the angle of the plow-
blade 215 with respect to the ground, thereby obtaining a
desired angle with respect to the ground when the plow-
blade 215 traverses through irregular terrain.
The plow apparatus of the present invention
includes a plow-blade housing 200 having a mechanism ~or
receiving an upper end 235 of the plow-blade 215, wherein
the housing 200 is pivotally attached to the outer support
member 170. The housing 200 includes a bolt 260, which
passes through an opening in the plow~blade 215, and
through openings in two vertical plates 261 which extend
identically down and along both sides of the upper portion
235 of the plow-blade 215, such that the bolt 260 will pass
through the openings in the vertical plates 261 of the
housing 200 and the opening in the plow-blade 215 to
connect to the plow-blade 215 to the housing 200. The
receiving mechanism includes a box 240 receiving the upper
end 235 of the plow-blade 215. The box 240 is connected to
vibration mechanism, preferably an eccentric hydraulic
vibrator 250. The hydraulic vibrator 250 is connected to a
hydraulic control mechanism 18 by hydraulic ca~les 251 and
252 and is controlled in a conventional fashion as known to
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1 31 6357
~17-
those skilled in the art. Any vibrating mechanism
generally known in the art may be used:with the ca~le
laying plow apparatus of the present invention. Referring
also to FIG. 11, the box 240 includes rubber.strips 270 and
metal strips 271 and 273 which are packed around the plow-
blade 215 such that the movement of.the upper end 235 of
the plow-blade 215 is.restricted to movement within the box
~40. . ;.. . . ..
Referring also to-FIG. 12 and 13, the plow-blade
215 has a front edge 217, two vertically extending side
surfaces 216 and a tooth 225. The tooth 225 extends
downwardly and outwardly-from the front edge 217,.and
outwardly from.the front edge 217, and outwardly from the
side surfaces 216 of the plow-blade 215. Preferably, the
upper surface 227 of the tooth 215 is aligned at an angle
of about 37-43 with respect to a line which i5
perpendicular to the front edge 217 of the.plow-blade 215.
The plow-blade preferably has a single opening
through which a pin/ preferably the bolt 260 is inserted to
hold the plow-blade in place with respect to the housing
200. The bolt 260 passes through openings in two vertical
plates 261 which extend identically down and along on both
sides 216 of the plow-blade 215. The plow-blade 215 is
substantially prevented from pivoting on bolt 260 by the
box 240 receiving the upper end 235 of the plow-blade 215.
The upper end of the plow-blade 235 is tapered or truncated
to ~it into a slot in the bottom of the box 240. The plow-
blade 215 does not come into direct contact with any
portion of the box 240. The upper end 235 of the plow-
blade 215 received by the box 240 is packed in a series of
rubber strips 270 which cooperate with two metal strips 271
and 273 which cooperate to prevent substantial movement of
the upper end 235 ot the plow-bLade 215 in the oox 240.
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The metal plates 271 and 273 do not come into contact with
the box 240, but instead, only with the.rubber strips 270.
In other embodiments, the rubber strips 270 may be made of
any resilient material known in the art. It is possible to
5 interpose re~ilient material or packings between the upper
portion 235 of the plow-blade 215 and the metal strips 271
and 273. The metal strips 271 and 273 prevent the plow-
blade from damaging.the rubber strips 270. The box also
has a plate 241 on one side which may.be removed to access
10 the rubber strips 270 and the metal strips 271 and 273.
The plate 241 is attached to the box with fasteners,
preferably bolts, which fasten the plate to a lip 243 on
the edge of the adjacent side oiE the box 240.
The front edge 217 of the plow-blade 215 widens as
15 it angles back to two parallel sides 216 on either side of
the plow-blade 215. The sides of the plow-blade 216 have
weldings 218 which form cross-hatchings ~o protect the
plow-blade from wear. On the lower end 220 of the plow-
blade 215, the tooth.225 extends downwardly and outwardly
20 from the plow-blade 215 with respect to the front edye 217
of the plow-blade 215, and outwardly from the sides 216 of
the plow-blade 215. The tooth 2w25 has an upper surface
227. The plane of the upper surface 227 of the tooth 225
lies at an angle of about 37-43 with respect to a line
25 which is perpendicular to the front edge 217 of the plow-
blade 215. This edge 217 is a substantially straight line
oriented vertically with respect to the plow-blade 215.
The angle of the tooth is preferably about 38-42, more
preferably about 39-41. The preferred embodiment has a
30 tooth angle of about 41.
The angle of the upper surface 227 of the tooth
225 with respect to the perpendicular line to the front
edge 217 of the plow-blade 215 critical to minimize the
amount of drag which is experienced when pulling the plow-
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blade through the soil. If the angle is too great, for
instance more than 43, the plow-blade 215 will have much
greater resistance and will require much gre~ter tractive
pulling force. However, if the angle is too little, the
elliptical motion of the tooth 225 during operation of the
vibrator 250 and the tractor 10 will be minimizedO
The upper surface 227 of the tooth 225 is also
very important to the elliptical movement of the plow-blade
215, wherein the tooth 225 pulls the lower portion 220 of
the plow-blade 215 downward as the lower portion 220 of the
plow-blade 215 moves-toward the tractor when the second arm
member 120 pivots about ~he pivotal connection 125 to
shorten the distance between the distal ends of the lower
linking mechanism 108. 110. The tooth 225 prevents the
plow-blade 215 from riding up because the tooth 225 must
work the soil which meets the upper surface 227 of the
tooth 225. It will be appreciated that other
configurations with respect to the distance between the
ends of the various linking mechanisms and members will
vary the critical angle for optimum elliptical motion, and
that other motions, therefore, will also be possible. .
In the préferred embodiment, a cable guide chute
210 is pivotally attached to the rear edge 219 of the plow-
: blade 215. The rear edge 219 is flat having a plane which
is roughly at right angles to the planes o~ the twovertical sides 216 of the plow-blade 215. The guide chute
210 has four pivotal connections 209 which pivotally
connect the chute 210 to the plow-blade 215. The pivotal
connections 209 allow the chute 210 to pivot with respect
to the plow-blade 215 on a vertical axis. The chute 210
has a cable entrance 212 which receives the cable 14 and a
cable outlet 214 which guides the cable 14 into an opening
or a trench in the ground created by the plow-blade 215.
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ThP housing 200 is pivotally connecting to the
outer linking mechanism 169. This mechanism includes a
hydraulic cylinder 280 having a typical hydraulic cylinder,
piston and sleeve arrangement to pivot the plow-blade 215
with respect to the outer linking mechanism 169 and the
linkage apparatus 100. The hydraulic cyllnder 290 is
pivotally connected to the housing 200 and pivotally
connected to the outer linking support member 170. The
hydraulic cylinder 280 is connectecl to the hydraulic
control mechanism 18 by hydraulic cables 281 and 282. FIG.
5 presents a top view of a linkage apparatus 100 connected
to a housing 200, wherein the linkage apparatus 100 is
swung to one side with respect to the vehicle 10 and the
plow-blade 215 and the housing 200 are swung in the
opposite direction with respect to the outer linking
mechanism 169 and the linkage apparatus 100.
FIG. 7 shows the four-point linkage of the linkage
apparatus 100. The upper linking mechanism 138 is
substantially equal in length to the lowex linking
mechanism 108, thereby allowing the four-point linkage to
effect a parallelogram-type linkage. In FIG. B, however,
the first arm member 110 has bee li~ted by the hydraulic
cylinder 158 such that the second arm member 120 has
pivoted at the pivotal connection 125 with respect to the
first arm member 110, thereby bringing the pivotal
connection 111 of the first end llOa of the first arm
member 110 closer to the pivotal connection 123 of the
second end 12Ob of the second arm member 120, and thereby
changing the configuration so that there is no longer a
parallelogram-type linkage. The lifting of the first arm
member 110 has drawn the lower portion 220 of the plow-
blade 215 closer to the vehicle 10.
In FIG. i, the length of the upper linking ::~
mechanism 138 h~s been adjusted such that the upper linking
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mechanism 138 is longer than--the lower.linking mechanism
108. The lower end 220 of the plow-blade 215:is drawn
closer to the vehicle 10 as the upper linking mechanism 138
is lengthened. In FIG. 10, the length of ~he upper linking
mechanism 138 has been adjusted so that the upper linking
mechanism 138 is shor~er than the.lower linking mechanism
llO. As the upper linking mechanism 138 is shortened, the
lower end 220 of the plow-blade.215 is mo~ed further away
from the-vehicle 10. Because.the sleeve 1543 is longer
than the distance between the pivotal connections 125 and
123 of the second arm-member 120,:the radius of the pivot
of the upper linking mechanism 138 will always be longer
than the radius of the pivot of the.second arm member 120
a~out the pivotal connection 125 which links the first and
second arm members 110 and 120.
The adjustable length upper linking member 140,
allows the plow-blade 215 to.be maintained at a desirable
angle with respect to the ground such that ~he cable outlet
~: 214 is not angled backward and raised about the depth of a
leading corner 229 of the plow-blade 215,.as it would have
to be at times when attached prior art devices which do not
have adjustable length upper linking members. The ability
to manipulate the angle of the plow blade 215 with respect
to the ground surface allows the operator to go over a
ridge and through a ditch, while at the same time
maintaining the plow at a perpendicular angle to the
surface. This allows the operator to prevent the cable
outlet 214 at the back of the lower end 220 of the plow-
blade 215, from angling toward the surface with respect to
the position of the leading corner 229 of the lower end 220
of the plow-blade 215. This enables the operator to lay
cable in irregular terrain while maintaining a
substantially consistent cable depth. This is desirable
.since the cable may be damaged if it is exposed on the
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surface of the ground. The deeper the cable, the safer it
is considered to be. This is especially true in ditches or
gullies which may be subject -to erosion at later points in
time, th~reby increasing the likelihood that the cable may
be exposed on the surface of^the ground~
All o~ the hydraulic cylinders shown in the
drawings of the preferred embodiment of the present
in~ention are-connected to a hydraulic control mechanism 18
in the.vehicle.lO by hydraulic cables,-some of which are
bundled together in a cable bundle 162, which connects to
the control mechanism 18. The.hydraulic cylinders are
controlled in conventional fashion as known to those
skilled in the art.
While certain representa~ive embodiments of the
present invention have been described herein, for purposes
of illustration, it will be ~pparen~ to those skilled in
the art that modifications therein may be made without
departing from the spirit and scope of the present
invention.
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