Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
20~08~8
Technical Field
The present invention relates g~nerally to a machine for
trimming an earthen canal prior to the canal being lined with a
water-impervious layer of material to enable a concrete layer to
be placed thereupon.
5 Backaround of the Invention
Many of the older irrigation canals are prone to leakage
since they are formed with a compacted silt bottom and sloped
sides. In some locations, a canal may run through extremely
porous material resulting in serious leakage problems of yet
10 greater concern.
One method for repairing such leaking canals is to
install an impermeable lining in the canal. Heretofore this was
not possible while water continued to flow in the canal. Thus
the water would have to be diverted or retained while the lining
I s was installed which meant that some areas would be without water
during the 1 ining process .
In the application entitled nMethod and Apparatus for
Lining a Canal", Serial No. 395,811 filed August 18, 1989, a
method and apparatus for lining a canal is described. In the
20 device of the above-identif ied application, a method and means
is described for lining and paving the irrigation canal while
water was f lowing therein . The apparatus of the
above-identified application comprises an elongated frame means
which extends transversely across the canal and which has
25 propelling track members at the opposite end~3 thereof to propel
the f rame means along the length of the canal . A concrete
laying mechanism or concrete paver is supported on the frame
means and is designed to lay concrete on at least a portion of
one of the sides of the canal and on at least a portion of the
3~ 1
~ ~ 4 ~
5 ~ b ttom Of the canal as the frame means is moved along the leng~h~
¦ of the canal. Prior to the concrete being placed in the canal,
¦ a flexible sheet material is positioned on the bottom and sides
¦ of the canal with the concrete being placed thereon.
¦ In the method and means of the above-identified
lo ¦ application, ik is necessary for the bottom and the sides of the
¦ canal to be trimmed and/or filled to enable the flexible sheet
¦ material and concrete to be placed on a substantially smooth
¦ surface at the desired grade. In other words, the sheet laying
¦ apparatus and the concrete paver are designed to lay the sheet
¦ material and concrete on a relatively even surface having a
¦ predetermined grade. Inasmuch as water is flowing in the canal
¦ during the trimming operation, it is difficult to monitor the
¦ trimming apparatus since the trimming apparatus is normally
¦ operating beneath the water making it difficult to achieve the
¦ desired grade for the bottom and the sides of the canal.
¦ A canal paving machine is described in U.S. Patent No.
¦ 4,360,293 which is designed to trim the bottom and sides of the
¦ canal and to place a layer of concrete thereon. However, the
¦ machine of U.S. Patent No. 4,360,293 employs a trimming
¦apparatus which iB of a fixed configuration which must be
¦ replaced when canals of different sizes and grades are being
trimmed. Further, the trimming apparatus of U.S. Patent No.
4,360,293 is designed to trim a canal wherein water is not
flowing therein. Additionally, the machine of U.S. Patent No.
'"I ~
204~85~
¦ 4,360,293 does not include any means for fillin~ low spots in
¦ the canal bottom or sides.
¦ It is therefore a principal object of the invention to
¦ provide a machine ~or trimming a canal.
¦ Still another object of the invention is to provide a
~o ¦ machine for trimming a canal wherein the trimming operation is
conducted while water is flowing in the canal.
¦ Still another object of the invention is to provide a
¦ canal trimming machine which includes means for filling low
¦spots in the canal.
IS ¦ Still another object of the invention is to provide a
¦ canal trimming machine which includes guidance means for the
¦trimmer so that the canal will be trimmed to a precise grade.
Yet another object of the invention i8 to provide a canal
trimming machine including a guidance means which may be
modified to conform to different canal grades.
Still another object of the invention is to provide a
canal trimming machine including a guidance means which
automatically compensates for downward deflection of the
supporting structure as the trimmer moves longitudinally
thereon.
Still another object of the invention is to provide a
canal trimming machine including means for quickly and easily
raising the trimmer with respect to the canal to enable the
trimmer to be returned to its starting position.
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2~408~8
5 ~ till another o~ject of the invention is to provide
¦ canal trimming machine which includes means for trimming "high"
spots in the canal and means for filling low spots in the canal.
These and other objects will be apparent to those skilled
¦ in the art.
lo ¦ Brief Descri~tion of the Drawinqs
¦ Figure 1 is a perspective view illustrating the trimmer
¦of this invention positioned over a canal:
¦ Figure 2 is a top view of the trimmer of this invention: :
¦ Figure 3 is a partial side view of the trimmer of this
¦ invention as seen from the left side of Figure 1:
¦ Figure 4 is a partial side view as seen from the left of
¦ Figure 1:
¦ Figure 5 i~ a partial side view similar to Figure 3
¦ except that the trimmer head has been lowered into engagement
t~ ¦with the canal:
Figure 6 is a front perspective view of the trimmer head
with some of the related structure:
Figure 7 is a side elevational view of the trimmer head:
Figure 8 is a perspective view of one of the string
sensored radius assemblies:
Figure 9 is an end view of the structure of Figure 8 as
seen from the right of Figure 8:
. Figure 10 is a partial rear sectional view illustrating
~o the trimmer means mounted on its supporting carriage:
2~4~8~8
5 ¦ Figure 11 ~s ~ perspective vle~ of the means for moving~
the trimmer on the frame:
Figure 12 is an end view of the invention:
Figure 13 is a partial perspective view illustrating the
manner in which rock material is diverted from the conveyor into
lo the hoppers:
Figure 14 is a partial rear perspective view of the
machine illustrating the rock spreader means and some of the
associated structure:
Figure 15 is a partial sectional view illustrating the
relationship of the rotary trimmer and the other trimmers which
shape the upper portion of one of the sides of the canal as well
as a horizontal portion at the upper end of the canal; and
Figure 16 1~ a partial side sectional view illustrating
the mean~ by which the trimmer bGom arms are pivotally connected
to the trimming apparatus.
Summary of the Invention
~ canal trimming machine is described and includes an
elongated frame which extends transversely across the canal to
be trimmed and which has opposite ends, a forward end and a
rearward end. Propelling track members are provided at the
opposite ends of the elongated frame for propelling the frame
along the length of the canal. The propelling track members are
guided by a conventional guidance means so that the machine is
properly p elled along the length of the canal at the proper
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grade. A canal trimming apparatus is longitudinally movably
mounted on the frame and includes a rotary trimmer having its
rotational axis disposed parallel to the longitudinal axis of
the canal. The trimming apparatus is moved back and forth along
a substantial portion of the length of the frame to trim at
o least a portion of the bottom of the canal and at least a
portion of one side of the canal. The machine also includes a
rock spreader means which follows the trimmer as the machine is
moved along the length of the canal for filling low spots in the
canal with rock material.
I5 A pair of trimmers are also attached to the frame
adjacent one end thereof for trimming the upper portion of one
of the side walls of the canal and for trimming a horizontal
portion at that end of the frame upon which concrete will be
positioned when the canal i8 subsequently paved. The machine
Z~) includes a guidance means which controls the vertical
displacement of the rotary trimmer so that the desired grade is
formed in the bottom of the canal and at least a portion of one
side of the canal. The guidance means also includes means
enabling the machine to compensate for downward deflection in
the frame a8 the trimming apparatus moves thereon to ensure that
the canal is trimmed to the proper grade.
When the machine reaches a siphon location along the
canal, the machine is turned 180- and then moved back along the
length of the canal just traversed so that the remainder of the
20~08~8
b~ttom and thej other side wall of the canal may be trimmed
and/or filled. The material trimmed from the rotary trimmer is
pumped to a location outwardly of the canal so that the trimmed
material is not reintroduced into the canal.
Descri~tion of the Preferred Embodiment
o Referring now to the drawings, especially Figure 1, in
which similar or corresponding parts are identified with the
same reference numeral, the canal trimming machine of the
present invention is generally designated at lo, and includes an
elongated frame means 12 extending tranversely across a canal 14
having water flowing therein, and having driven tracks 18 and
18' at one end t~ereof and driven tracks 20 and 20' at the other
end thereof for moving frame means 12 along the canal 14.
conventlonal hydraulic cylinders interconnect the frame means 12
and the tracks 18, 18' and 20, 20' to permit frame means 12 to
2() be raised and lowered with respect to the tracks. The machine
i9 powered by conventional power means such as a diesel engine
22 or the like located at operator's station 24. A second
operator's station 26 is also provided on the frame means 12.
For purposes o~ description, canal 14 will be described
as comprising a bottom 28 and opposite sides 30 and 32. Prior
to the trimming operation, a large excavation machine will be
utilized to create paths 34 and 36 at opposite sides of the
canal to permit the tracks to move thereupon. A conventional
grade line and sensing mechanism 38 is employed along each of
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2 ~
s ~ th paths 34 and 36 for guiding the tracks along the paths 34
and 36 respectively at the proper grade.
¦ A plurality of rock hoppers 40 are positioned
¦longitudinally on the frame means 12 adjacent the upper end
¦thereof. A substantially horizontally disposed conveyor 42
lo ¦extends across the top of the hoppers 40 and includ~s an upper
¦belt portion 44. The numeral 46 refers to an angled strike-off
¦plate which is longitudinally movably mounted with respect to
¦the conveyor 42 and which is adapted to engage the rock material
¦movinq on the upper belt portion 44 to deflect or divert the
¦rock material into a particular individual hopper 40 as desired.
¦A chain means 48 is operatively connected to the strike-off
¦plate 46 for selectively moving the plate 46 to the desired
¦location. A second conveyor 50 supplies the rock material to
¦the conveyor 42.
2(~ ¦ At least one tube 52 extends from each of the hoppers 40
¦downwardly to compartment~ 54 in a spreader means 56 which
¦includes a substantially horizontally disposed portion 58 and an .
inclined portion 60 hingedly secured thereto about a horizontal
axis which extend5 upwardly ~rom the outer end of horizontal
25 portion 58 at the same angle as the side wall 30 or 32. The
lower ends of the compartments S4 in the spreader means 56 are
positioned closely adjacent the bottom or side of the canal and
are designed to fill low spots in the trimmed canal with rock
material with the rock material having a consistency such that
it will not wash prior to the canal beinq lined and paved.
' 30
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204~8~8
A plurality of veltically disposed hydraulic cylinders 62
connect the rearward end of spreader means 56 with frame means
12 to enable the rearward end of the spreader means 56 to be
vertically positioned as desired. Similarly, a plurality of
hydraulic cylinders 62' connect the forward end of spreader
lo means 56 to frame 12 to enable the forward end of spreader means
56 to be vertically positioned as required. A plurality of
angularly disposed cylinders 64 extend upwardly and forwardly
from the forward end of spreader means 56 to the frame means 12
to stabilize the spreader means 56 as the machine is moved along
the length of the canal.
Cable 66 is secured to the frame means 12 adjacent the
opposite ends thereof and extends along the length of the frame
means 12 as seen in the drawings. A plurality of sensor
assemblies 68 are mounted as shown in Figure 14 to control the
operation of one or more cylinders 62. Cable 69 also extends
between the ends of the frame means forwardly of cable 66 as
seen in the drawings. A plurality of sensor assemblies 70 are
mounted as seen in Figure 14 to control the operation of one or
more cylinders 62'. Sensor assemblies 68 and 70 ensure that the
spreader means 56 will be maintained at the proper grade.
The numeral 72 refers to a trimming apparatus which is
longitudinally movably mounted on frame means 12. Trimming
apparatus 72 is basically a dredger sold under the trademark
~MUDCATn by Ellicott Corporation. Trimming apparatus includes a
il~ -10-
20~0~8
5 ~ pa r of pontoons 74 and 76 which would norrally permit the
¦MUDCAT to float in water. In the machine of this invention, the
¦pontoons 74 and 76 only serve to provide a mounting means to
¦secure the apparatus to its supporting structure. The trimming
¦apparatus 72 i5 mounted on a carriage 77 which rolls along a
1() ¦pair of I-beams extending along the length of the frame means 12
¦which will be discussed in more detail hereinafter.
¦ Tranversely extending pipe 78 is rotatably mounted in
¦brackets 79 (not shown) and 79' which are secured to pontoons 74
¦and 76 respectively. Pipe 78 has a pair of horizontally spaced
¦uprights 80 (not shown) and 82 secured thereto and extending
¦upwardly therefrom. Brace 84 is secured to and extends between
uprights 80 and 82 below the upper ends thereof as seen in the
¦drawings. A pair of braces 86 (not shown) and 88 are welded to
l brace 84 and extend downwardly and forwardly therefrom to arms
¦9o and 92 respectively which have their rearward ends secured to
pipe 78. Links 94 (not shown) and 96 are pivotally secured at
¦their upper ends to the forward ends of arms 90 and 92
respectively and are pivotally secured at their lower ends to
¦boom arms 98 and 100 respectively. The rearward ends of boom
25 l arms 98 and 100 are pivotally secured to pontoons 74 and 76
respectively. In the conventional MUDCAT structure, a hydraulic
cylinder would be pivotally connected to the upper end of each
of the uprights 80 and 82 and pivotally connected to the
l associated pontoon. However, in this apparatus, such clinders
3o l are not required.
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I
204~8~8
Trimmer head 106 is secured to the rorward ends of boom~
¦arms 98 and loO and includes a transversely disposed trimming
¦ auger 108 which has its rotational axis disposed parallel to the
¦length of the canal. Shield or cover 110 extends partially
¦around the forward end of auger 108 and is pivotally mounted on
lo ¦the head 106. ~ydraulic cylinders 112 and 114 are operativ~ly
¦ connected to cover 110 for pivotally moving cover 110 with
¦ respect to head 106 and auger 108 at times.
¦ Frame members 116 and 118 extend horizontally forwardly
¦ from carriage 77 and have a pair of uprights 120 and 122
¦extending upwardly therefrom rearwardly of the forward ends
¦thereof. Boom arms 124 and 126 are pivotally secured at their
¦ rearward ends to the upper ends of uprights 120 and 122 and are
¦ pivotally moved with respect thereto by a pair of hydraulic
¦ cylinders 126 and 128.
20 ¦ Arms 130 and 132 are pivotally connected at their upper
ends to the forward ends of boom arms 124 and 126 and extend
¦downwardly therefrom. The lower ends of arms 130 and 132 are
pivotally secured to shafts 134 and 136 which extend
horizontally outwardly from opposite sides of head 106.
Hydraulic cylinders 138 and 140 are operatively pivotally
secured to frame members 116 and 118 and have their rods 142 and
144 pivotally secured to opposite ends of head 106.
Trimmer head 106 includes a cowling or housing 146 in
which is positioned a dredge pump 148 having its intake 150
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5 ~ p sitioned ~dja~ent the ~uger 108 as seen in the drawings. ~he~
¦ inta3ce of pump 148 is covered with a grill 152 to prevent rocks
¦ from en~ering the pump 148. Exhaust or discharge pipe 154
¦ extends from pump 148 and is operatively connected to a
discharge nozzle or means located laterally of the canal so tha
lO mud and water taken into pump 148 is discharged outwardly of the
¦ canal.
¦ The numerals 158 and 158' refer to a sensor mounting
¦ assemblies which are mounted on arms 130 and 132 respectively as
will now be described. Inasmuch as assemblies 158 and 158' are
l5 identical, only assembly 158 will be described in detail with
¦ " "' indicating identical structure on assembly 158'. Assembly
¦ 158 include5 a frame mean9 160 which is secured to arm 130 and
which has a hydraulic cylinder 162 secured thereto. One end of
the cylinder 162 is connected to slide 164 whiCh is vertically
20movably mounted on guide5 166 and 168. Slide 164 has a shaft or
rod 170 extending upwardly therefrom through guide 171 which has
¦ a 8en50r 172 mounted on the upper end thereof including a sensor
arm 174 whiCh is adapted to engage the underside of cable 176
¦ which extends from one end of the frame means 12 to the other
25end thereof. Cable 176' extend5 from one end of the frame means
¦ 12 to the other end thereof Which iS sensed by assembly 158'.
Cables 176 and 176' include horizontally di6posed
portions 178 and 178', arcuate portions 180 and 180' and
oinclined portions 182 and 182 ;; Hydraulic cylinders 162 and
.3
20~08~8
s ¦162' are designed to raise or lower the sensor arms 174 and 174'
¦a distance of approximately two feet when cylinders 162 and 162'
¦are activated as will be described in more detail hereinafter.
¦Sensors 172 and 172' are operatively connected to hydraulic
¦cylinders 138 and 140 to control the operation thereof in
¦response to the position of the sensors relative to the cables
¦176 and 176' respectively.
¦ The numerals 184 and 184' refer to sensored string line
¦radius assemblies which are positioned on the frame means 12 and
¦which are normally in engagement with the cables 176 and 176' to
¦create a radius therein which will generally correspond to the
¦juncture of the bottom of the canal with one side of the canal.
¦Inasmuch as assemblies 184 and 184' are identical, only assembly
¦184 will be described in detail with ~'~ indicating like
¦structure on assembly 184'. Frame members 186 and 188 are
horizontally adjustably mounted on frame members 190 and 192
which are selectively vertically mounted on suitable supports S
and S' on the frame means 12. Frame member 193 is secured to
and extends between the frame members 186 and 188 and has the
base end of hydraulic cylinder 194 pivotally secured thereto.
The rod 196 of cylinder 194 is pivotally connected to ear 198
which iR welded to crankshaft 200 which is rotatably secured to
and which extends between frame members 186 and 188. Ears or
brackets 202 and 204 are welded to crankshaft 200 and extend
therefrom as seen in the drawings. Connect links 206 and 208
-14-
, 20408~8
are pivotally connected at their upper ends to ears 202 and 204
respectively and are pivotally connected at their lower ends to
radius 210. Shafts 212 and 214 are welded to radius 210 at the
opposite ends thereof and extend upwardly therefrom and are
slidably received by guides 216 and 218 welded to the lower ends
lo of frame members 186 and 188 respectively.
Radius weldment 220 is welded to the lower end of radius
210 and has the cable 176 secured thereto by suitable clamps or
the like. Arm 222 is bolted to radius 210 and extends upwardly
therefrom and is selectively vertically movably received in tube
224. Arm 222 may be selectively vertically positioned in tube
224 by means of the crank 226. A set screw or the like may be
used to maintain the relative position between members 222 and
224 when the desired relationship has been established.
Horizontally extending arm 228 is secured to the upper end of
2~) tube 224 and has a sensor 230 mounted thereon including sensor
arm 232 which is normally in engagement with the string line
cable 234 which is secured to and which extends between the
supporting frame structure of the tracks 18, 18' and 20, 20' and
is not connected to the frame means 12.
Carriage 77 is longitudinally movably mounted on I-beams
236 and 238 o~ frame means 12 by means of hanger assemblies 240.
Carriage 77 is moved along the beams 236 and 238 by means of a
double wrapped winch 242 controlled by a reVersible hydraulic
motor 244. Cable 246 is wrapped around winch 242 and has its
~:
20~08~8
s op ~site ends secured to ~pposite ends of the frame means 12 or~
the supporting frame structure for the tracks lB, 18' and 20,
¦20~. Limit switches 248 are operatively mounted on opposite
¦ends of carriage 72 and are designed to be engaged and activated
¦by actuators clamped onto the cable 246 to cause the carriage 77
¦to be stopped at a predetermined position when advancing in its
¦trimming mode and to be stopped at a predetermined position when
¦moving in its return mode.
¦ If it has been determined that a particular earthen
¦irrigation canal must be lined and paved, the machine of this
¦invention will be,utilized to prepare the canal bottom and sides
¦for lining and paving. In preparation for the trimming
¦operation, a large excavator or the like i8 used to create the
¦paths 34 and 36 as previously described. The machine 10 is then
¦positioned on the paths 34 and 36 with conventional grade and
¦direction sensing devices being utilized along the paths 34 and
¦36 80 that the machine 10 is properly guided at the proper
grade.
Assumin~ that the machine 10 has been positioned on the
paths 34 and 36 a~ viewed in the perspective view of Figure 1,
the spreader means 56 is lowered downwardly into the water by
means of the hydraulic cylinders 62 and 62'. The individual
hoppers 40 are filled with rock material by means of the
conveyor 42 and the strike-off plate 46. The sensor assemblies
68 and 70 for the hydraulic cylinders 62 and 62' are adjusted so
.
1 -16- l
2~4~8~8
5 ~ t t the spreader means 56 will be located at the proper grade.
The sensor assembly 68 will sense the relative position of the
rear end of the spreader means ~6 with respect to the cable 66
and will actuate the hydraulic cylinders 62 to raise or lower
the rearward end of the spreader means 56 to the desired grade.
lo Similarly, sensor assembly 70 senses the relative position of
the forward end of the spreader assembly 56 with respect to the
cable 69 to actuate the hydraulic cylinders 62' to raise or
lower the forward end of the spreader means 56 to the proper
grade. As the spreader means 56 is moved along that portion of
the trlmmed bottom and side of the canal, rock material will
pass from the bottom of the spreader means 56, when a low spot
in the canal is encountered, to fill the low spots that are
present in the bottom of the canal or in the side of the canal.
As the machine 10 is advanced along the length of the
canal, trimmer 250 trlms and levels that portion of the path 34
immediately in front of the track 20 and augers the trimmed
material downwardly onto the upper portion of the side 30 of the
canal. Trimmer 250 creates a horizontal surface upon which
concrete will be positioned during the lining and paving of the
canal. Trimmer 252 is disposed at an angle corresponding to the
desired grade of the side 30 and augers the trimmed material
downwardly therefrom so that the trimming auger 108 may auger
the same into the dredge pump 148 so that the mud or trimmed
` .3~) -17-
,
2 ~
m terial m~y be pumped to a lo~ation laterally ~f the ~nal such~
¦as illustrated in the drawings.
¦ Trimmer 250 may be selectively raised or lowered by
¦hydraulic cylinders 251 while trimmer 252 may be selectively
¦raised or lowered by hydraulic cylinders 253.
¦ The trimming apparatus 72 is ini~ially located towards
¦side 32 of the canal so that the trimming auger 108 may trim at
¦least a majority of the side 32 of the canal 14 and at least
¦one-half of the bottom 28 during its trimming mode.
¦ The sensor mounting assemblies 158 and 158' are initially
¦adjusted to achieve th,e desired grade. Inasmuch as assemblies
¦158 and 158' operate identically, only the operation of assembly
¦158 will be described in detail. Assuming that the trimming
~auger 108 is in its proper grade position and is in its
¦outermost end of travel, the carriage 77 i6 moved longitudinally
¦on the frame means 12 by means of the winch 242 so that the
¦trimmer head 106 trims side 32 of the canal and then the bottom
¦of the canal corresponding to the grade as determined by the
¦inclined portion 182 of cable 176 and then the horizontally
¦disposed portion of the cable 176 to control the actuation of
¦hydraulic cyllnder 140 to ensure that the canal will be properly
¦trimmmed. As the carriage 77 moves away from side 32 of the
canal, the sensor arm 174 moves along the underside of the
inclined portion 182 of cable until the radius assembly 210 is
reached. As the sensor arm 174 leaves the inclined portion 182
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20~0~8
s ¦ o cable 176, the sensor arm 174 will sense the fact that it is
¦moving into engagement with the arcuate portion 180 and will
¦cause the hydraulic cylinder 138 to be lowe~ed so that the
¦trimmer head 106 will create the radius between the side and the
¦bottom of the canal. As the carriage 77 continues in its
¦trimming mode, the sensor arm 174 senses the underside of the
¦arcuate portion 180 of the cable so that cylinder 138 is
¦continued to be extended and then maintained in position so that
¦the trimmer head 106 will trim the bottom of the canal at the
¦proper grade as determined by the horizontal portion 178 of the
IS ¦cable 176.
¦ When the carriage 77 i5 at the end of its trimming mode,
¦the movement of the carriage will be stopped by a limit switch
¦248 thereby discontinuing the operation of the hydraulic motor
1244 and winch 242. In order to prevent damage to the trimmer
¦assembly during its return mode, the sensor assemblies 158 and
158' are actuated to lower the sensor arms 174 and 174' with
respect to cables 176 and 176' when sensor arms 174 and 174'
move out of engagement with the cables 176 and 176', the sensors
172 and 174 actuated hydraulic cylinders to retract the same so
that the trimmer head 106 is raised with respect to the canal
bottom approximately two feet.
When the trimmer head 106 has been so raised, carriage 77
is moved towards the end of frame means 12 by the double wrapped
3~ ~winch 242 til the limit switch 24~ is actuated to stop the
20~8S8
5 r turn mode of 'che carriage. When the carriage 77 has reached
¦ the end of its return mode, the operator actuates the switch
¦ controlling the cylinders 1~2 and 162' to raise switch arms 174
¦ and 174' relative to arms 130 and 132 thereby causing the
¦ cylinders 162 and 162' to be extended until slides 164 and 164'
lo ¦ engage the underside of guides 171 and 171' respectively. The
¦ switch arms 174 and 174' engage the cables 176 and 176' and
¦ actuate hydraulic cylinders 138 and 140 to e~tend the same
¦ thereby lowering trimmer head 106 to the proper grade. During
¦ the raising and lowering of trimmer head 106, cylinders 126 and
l5 ¦ 128 act as dampener cylinders to "smooth out" the operation of
¦ cylinders 138 and 140.
¦ It has been ~ound that the weight of the carriage means
77 tends to cause the frame means 12 to deflect downwardly as
¦ the carriage 77 moves therealong. Since the downward deflection
2() ¦ of the frame means 12 will also cause the downward deflection of
¦ the cables 176 and 176', the sensor string line radius
¦ assemblies 184 and 184' will also be lowered which would cause
the trimmer head 106 to be vertically moved downwardly
corresponding thereto since the sensor arms 174 and 114 ' would
25 be sensing the lowered deflected portion of the cable.
To correct for the deflection of the frame means 12,
sensor string line radius assemblies 184 and 184 ' are provided.
Inasmuch as assemblie6 184 and 184 ' are identical, only assembly
3~ ¦ 1~4 will b described in detail. As assembly 1~4 moves ¦
,
20~0~a8
do nwardly due to the deElection of the frame means 12, ssnsor
¦ arm 232 moves out of engagement with the cable 234 which causes
the actuation of cylinder 194 to retract the same so that
crankshaft 200 rotates thereby vertically moving connect links
¦206 and 208 upwardly which causes the radius to tend to be moved
lo ¦upwardly and the switch arm 232 until the switch arm 232 again
¦senses the location of cable 234 at which time cylinder 194 is
¦deactivated. The radius assembly functions in an opposite
¦manner when frame means 12 moves upwardly when the carriage
¦means 77 is not causing the downward deflection of the frame
¦means 12. Thus it can be seen that a novel radius assembly has
¦been provided which not only permits the string line cables to
¦be radiused into the proper configuration but which also
¦automatically compensates for any deflection of the frame means
¦12 as the carriage moves longitudinally thereon.
¦ When at least one-half of the canal bottom and one side
¦thereof have been trimmed, the machina is reversed 180- at a
siphon location and moved back along the length of the canal to
trim side 30 and the remainder of the bottom of the canal.
