United States Patent [19]
`
`Jakob et a1.
`
`[11]
`
`[45]
`
`4,139,318
`
`Feb. 13, 1979
`
`[54] METHOD AND APPARATUS FOR PLANING
`A PAVED ROADWAY
`
`3,874,735
`3,893,780
`
`4/1975 Delli-Gatti ......................... 299/87 X
`7/1975 Gutman ................................. 404/91
`
`[75]
`
`Inventors: Herbert E. Jakob, Oklahoma City;
`Richard A. Silbernagel, Del City,
`both of Okla.
`
`Primary Examiner—Nile C. Byers, Jr.
`Attorney, Agent, or Firm—Dunlap, Codding &
`McCarthy
`
`[73] Assignee: CMI Corporation, Oklahoma City,
`Okla.
`
`[21] Appl. No.: 672,326
`
`[22] Filed:
`
`Mar. 31, 1976
`
`Int. 0.2 .............................................. E010 23/08
`[51]
`[52] US. Cl. ........................................ 404/90; 404/84;
`299/39; 37/43 E; 198/300; 172/540; 172/118;
`172/119
`[58] Field of Search ....................... 404/90, 83, 84, 75,
`404/96; 198/213; 299/39, 91, 87, 79; 172/540,
`118; 37/13, 43 E, 43 C
`
`[56]
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`1,255,275
`1,269,098
`1,938,755
`3,398,989
`3,407,005
`3,414,327
`3,598,027
`3,606,468
`3,767,264
`3,779,661
`3,829,161
`
`2/1918 Barnett ............................ 36/43 E X
`6/1918
`Latta ................
`37/43 E X
`12/1933
`Swearingen ............... 404/91
`8/1968 .Christensen ............ 299/39
`10/1968
`Simms ................ 299/39
`12/1968 Austin ......
`299/39 X
`8/1971
`Swisher
`...... 404/90
`9/1971 Walker
`299/39
`10/1973
`Eckey ......
`. 299/39
`12/1973 Godberson ..
`. 404/98 X
`8/1974 Wirtgen ................................. 299/39
`
`
`
`[57]
`
`ABSTRACT
`
`A method and apparatus for planing a paved roadway
`wherein a main frame is drivingly supported by track
`assemblies and a planer assembly is disposed in cutting
`engagement with a top portion of the paved roadway to
`produce a new roadway surface. An elevation position-
`ing assembly is provided for raising and lowering the
`main frame in response to an external control reference
`a such as a string line, and a cross slope positioning assem-
`bly is provided for raising and lowering one side of the
`main frame relative to the other side thereof for main-
`
`taining a selected cross slope. The planet assembly com-
`prises a planing cutter that is partially surrounded by a
`hood that forms a material directing compartment, and
`spray nozzles produce a vapor mist within the compart-
`ment. A floating moldboard is yieldingly forced into
`contact with the roadway to the rear of the planer as-
`sembly and cooperates with a reclaimer assembly to
`receive and transport the removed pavement material
`to a selected depository. In one embodiment, a road
`sweeper is pulled behind the main frame to remove any
`loose material that may remain on the new roadway
`surface.
`
`12 Claims, 11 Drawing Figures
`
`
`
`Page 1 of 17
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`CATERPILLAR EXHIBIT 1 1 1 6
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`Page 1 of 17
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`CATERPILLAR EXHIBIT 1116
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`US. Patent
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`Feb. 13, 1979
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`Sheet 1 of 4
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`4,139,318
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`US. Patent
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`Feb. 13, 1979
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`Sheet 2 of4
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`US. Patent
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`Feb. 13, 1979
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`Sheet 3 of4
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`4,139,318
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`US. Patent
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`Feb. 13, 1979
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`Sheet4 0f4
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`4,139,318
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`1
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`4,139,318
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`METHOD AND APPARATUS FOR PLANING A
`PAVED ROADWAY
`
`BACKGROUND OF THE INVENTION .
`1. Field of the Invention
`The present invention relates generally to field con-
`struction apparatus, and more particularly but not by
`way of limitation, to a method and planer type road
`construction apparatus that affords precision planing of
`existing paved roadways.
`2. Description of the Prior Art
`The planing of roadways or the like involves the use
`of heavy duty cutting devices that remove a selected
`top portion of a concrete or bituminous surface. Planing
`provides an alternative to the usual practice of contin-
`ued buildup of bituminous layers over a roadway in a
`resurfacing program of maintenance and repair. As is
`well known in the art, when a roadway has received a
`number of resurfacing bituminous layers, there comes a
`time that the roadway can no longer be simply resur-
`faced, and the accumulation of layers of bituminous
`material must be torn out and the roadway is in essence
`constructed anew. This buildup of bituminous layers is
`prevented if the to surface of the old roadway is par-
`tially removed so that the freshly laid bituminous sur-
`face is applied over a recessed surface.
`Prior art planers used in the road construction indus-
`try have generally consisted of a planing cutter sus-
`pended from the undercarriage of grading equipment or
`the like. Such prior art planers have found limited usage
`in a road building program for the reason that the plan-
`ing process performed thereby was generally inaccurate
`and relatively slow. In an attempt to increase the rate of
`planing bituminous surfaces, several prior art devices
`have used heaters to heat the bituminous roadway just
`in front of the planer’s travel to reduce the force re-
`quired of the planing cutter. The heaters used in the
`technique known as hot planing usually were fueled by
`a petroleum product, and were consequently expensive
`to operate as well as being objectionable due to the
`production of hydrocarbon vapors and the products of
`combustion. Also, the roadway serves as a heat sink
`during hot planing, and it was quickly discovered that
`an attempt to heat a frozen or very cold bituminous
`roadway was largely an exercise in futility, leading to
`the necessity of scheduling hot planing during the
`warmer seasons of the year. Cold planing, although
`requiring more cutting power, did not have seasonal
`limitations.
`Furthermore, material removed by the cutting action
`of prior art planers created considerable problems in
`cleaning the planed surface, as a large amount of debris
`was generated and left in the wake of the planar. In cold
`planing. the planing process literally created a cloud of
`dust and cuttings, and the whole process was generally
`very dirty, bothersome and time-consuming.
`Perhaps all of the above conditions would have been
`tolerable and planing would have achieved wider ac-
`ceptance if accurate surface removal could have been
`effected, but the results achieved in planing a particular
`roadway in the past depended very largely upon the
`skill of the operator. It was also apparent that the
`greater the depth of cut taken by a pass of a planing
`cutter, the greater the problem of obtaining a uniform
`and accurately cut substrate for the next layer of bitumi-
`nous material. Therefore, it was often necessary to take
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`2
`multiple cutting passes, or to restrict the use of the
`planing process to those applications which required
`only shallow cuts.
`It is clear from the above that the practice of planing,
`as applied to the road construction art, has had very
`limited application. There has not been a way to
`achieve precision planing for the removal of a selected
`portion of a roadway to provide a new roadway surface
`having a predetermined grade and cross Slope as is
`presented by the present invention.
`SUMMARY OF THE INVENTION
`
`The present invention provides a method and appara-
`tus for removing the top surface of an existing paved
`roadway and producing a planed surface having a pre-
`determined grade and cross slope. A planing cutter is
`passed over the existing roadway surface to remove a
`selected portion thereof, the planing cutter being con-
`trollably supported so that the newly created surface
`has a predetermined grade and cross slope.
`‘
`Accordingly, it is an object of the present invention
`to provide a method and apparatus for removing the top
`surface of an existing paved roadway to produce a new
`surface having a predetermined grade and cross slope.
`Another object of the present invention is to provide
`a method and‘ apparatus to achieve the above stated
`object while at the same time clearing the removed
`material from thenew surface.
`Another object‘of the present invention is to provide
`a method and apparatus to achieve the'above stated
`objects while minimizing dust and other particulate
`matter in the surrounding air.
`‘
`Another object of the present invention is to provide
`a method and apparatus to achieve the above stated
`objects in a manner that permits year round operation,
`independent to most Weather considerations.
`Another object of the present invention is to provide
`a method and apparatus to achieve the above stated
`objects in an efficient and economical manner.
`Other objectsandadvantages of the invention will be
`evident from the following detailed description when
`read in conjunction with the accompanying drawings
`which illustrate various embodiments of the invention.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIG. 1 is a diagramma‘tical representation of a cross
`section of a typical paved roadway tht hasbeen resur-
`faced.
`,
`i
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`FIG. 2 is a side elevational view of a planar type road
`construction apparatus constructed in accordance with
`the present invention.
`FIG. 3 is a top plan view of the planar apparatus
`shown in FIG. 2.
`
`FIG. 4 is a block diagram depiction of the steering,
`elevation and cross slope control mechanisms of the
`planar apparatus of FIG. 2.
`FIG. 5 is a front elevational view in partial detail Of
`the planing cutter of the planer apparatus of FIG. 2.
`FIG. 6 is a view of the planar cutter taken at 613 6 in
`FIG. 5.
`
`FIG. 7 is a view of one of the cutting heads used on
`the planing cutter shown in FIG. 5.
`FIG. 8 is a side elevtional view showing the hood and
`one of the end shield members. FIG. 9 is a side eleva-
`tional view in partial cutaway depiction of the floating
`moldboard of the planer apparatus shown in FIG. 2.
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`Page 6 of 17
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`3
`FIG. 10 is a partial plan view showing the attachment
`of the base elevator to the floating moldboard in the
`planer apparatus of FIG. 2.
`FIG. 11 is a side elevational view of a planer appara-
`tus of the type shown in FIG. 2 and having a sweeper
`assembly attached thereto.
`
`DESCRIPTION OF THE PREFERRED
`EMBODIMENT
`
`In the discussion that is to follow, it will be well to
`begin with a somewhat more detailed description of the
`different approach to road maintenance that is herein
`presented. Referring to FIG. 1, shown therein is a dia-
`grammatical representation of a cross section of a typi-
`cal paved roadway 10 that has been resurfaced.
`The paved roadway 10 has an original base layer of
`bituminous asphalt 12 thus developed through traffic
`usage, a very rough top surface 14 that has highs and
`lows therein, a peak 16 and a valley 18 being typical. Of
`course, a typical top surface of a well worn paved road-
`way can have a variety of swells and pockets, and in
`general, surface damage of many varieties. Therefore, it
`will be understood that the present invention is not
`limited to the conditions depicted by FIG. 1; rather, the
`undulating top surface 14 as shown in FIG. 1 has been
`drawn in a manner to demonstrate the present inven-
`tion.
`
`A typical repair of the paved roadway 10 depicted in
`FIG. 1 would be to overlay the base layer 12 with a
`bituminous layer 20, a technique that is well known and
`practiced widely throughout
`the road construction
`industry. The layer 20 (also referred to herein as the old
`technique layer) would normally be compacted with a
`bituminous paving roller to obtain a smooth upper sur-
`face 22. Of course, it will be appreciated that the layer
`20 must have sufficient thickness 24 over the peak 16 to
`give a strong resurfacing job, and further, that the layer
`20 must havea thickness at the valley 18 to give the
`smooth upper surface 22.
`It is well known that the wear of a bituminous layer
`will be greatly influenced by the uniformity of its sub-
`strate. That is, a bituminous layer that is laid over a
`uniformly even substrate surface will hold up very well
`in traffic usage. One of the reasons for this is that the
`layer is capable of receiving uniform compaction in the
`final rolling operation commonly practiced in the road-
`building art. On the other hand, when a bituminous
`layer is laid over a surface like the one depicted by the
`top surface 14 in FIG. 1, experience has shown that the
`amount of compaction achieved is not uniform, and that
`less compaction will occur over the valley 18 than over
`the peak 16. As the new layer 20 is subjected to traffic,
`it will be further compacted by the traffic and the
`smooth upper surface 20 will be shifted and redistrib-
`uted. As wear forces continue, the roadway once again
`will come into a state of disrepair.
`The present invention contemplates the use of preci-
`sion planing wherein a portion of the base layer 12 will
`be removed prior to the resurfacing of a paving road-
`way. Referring once again to FIG. 1, the present inven-
`tion teaches a method and apparatus for selectively
`removing material from the roadway down to a new
`roadway surface 28 as indicated by the dashed line. It
`should be noted that the new roadway surface 28 is
`shown in a location just below the valley 18, which is a
`plane of recession. selected so as to have some material
`removed at all points of the old top surface 14. While
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`this is not essential, it is desirable as a more uniformly
`even new roadway surface is thereby obtained.
`Once the new roadway surface 28 has been created
`by planing the old top surface 14, a uniform layer 29 of
`bituminous material can be laid to a level indicated by a
`broken line 30 having a thickness 32 that may be the
`same as, or less than, the thickness 24 that was needed
`over the peak 16 by the old paving technique. It is obvi»
`ous that far less bituminous material will be necessary
`for the layer 29 (also referred to as the new technique
`layer) as compared to the amount of material for the old
`technique layer 20 for the reason that it is no longer
`necessary to fill the valley 18 in order to cover the peak
`6. In fact, the new technique layer 29 can be made sig-
`nificantly thinner than the minimum thickness required
`of the old technique layer 20. The reason for this is that
`the thickness 24 of the old technique layer 20 must be
`adequate to withstand lateral tearing forces incurred
`with the shifting of the material in the layer 20 during
`traffic wearing as mentioned above. Since lateral move-
`ment is less of a consideration in the new technique
`layer 29 laid over the uniform new roadway surface 28,
`the thickness 32 can be reduced to between approxi-
`mately § to approximately I of previously used resur-
`facing layers, with the actual thickness used being de-
`pendent upon the traffic requirements of a particular
`location.
`An added benefit of a precision planing operation
`prior to resurfacing is the lack of buildup of the paved
`roadway that occurs in the old method of adding suc-
`cessive resurfacing layers. This buildup has become so
`great in many areas that the pavement has overrun the
`original curbing, gutters and manhold skirts, leading to
`the necessity in many such cases of having to extend
`these items to reach the increased pavement elevation.
`In the practice of the present invention, this buildup is
`avoided as the surface of the new layer can be main-
`tained with a grade and cross slope approximately equal
`to that of the original pavement, and this can be
`achieved for each subsequent resurfacing layer laid on a
`paved roadway throughout the life of the roadway.
`Further, the resultant planed surface 28 that is cre-
`ated by the method and apparatus taught herein is a
`very clear surface, being free of oil and other road films.
`The planed surface 28 is a generally smooth, yet tex-
`‘tured, surface which provides a very good bonding
`surface for overlay with concrete, latex concrete‘ or
`asphalt. In fact, there are many applications in which
`the planed surface 28 can be used without an overlay, as .
`for example when removing the top portion of a road-
`way that has received several bituminous layers. Such
`roads can possibly be planed several times in a repair
`program designed to . lessen the overall thickness of
`paved material while using the new roadway surface 28
`as an intermediate roadway.
`While a bituminous roadway has been shown in FIG.
`1 to illustrate the present invention, it is not limited to
`the planing of bituminous material. The invention
`teaches precision planing, and it relates as well to other
`types of pavement, such as concrete or the like, as will
`become clear in the following discussion. When bitumi-
`nous material is removed by the invention, the removed
`pavement material can be recycled by heating the re-
`moved pavement material and adding it in controlled
`measure to new bituminous pavement material. Re-
`moved concrete, or other such pavement materials, may
`also find recycle use as aggregate fill material.
`
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`5
`Turning now to the description of the preferred em-
`bodiment for practicing the present invention, attention
`is directed to FIGS. 2 and 3 wherein is shown a planer
`type road construction apparatus 40 constructed in
`accordance with the present invention. The planer ap-
`paratus 40 includes a main frame 42 having a forward
`end 44, a rearward end 46, a left side 48 and a right side
`50. The main frame 42 is supported via a rear drive
`assembly 52 and a front track assembly 54, the rear
`drive assembly 52 being drivingly connected to a power
`drive unit 56 for drivingly moving the main frame 42
`during the operation of the planer type road construc-
`tion apparatus 40. The power drive unit 56 may be of a
`conventional design such as, for example, a diesel pow-
`ered engine, and the construction and operation of such
`a power unit, and the various interconnecting compo-
`nents and operation thereof to drivingly connect the
`power drive unit 56 to the endless track members, are
`well known in the art and a detailed description thereof
`will not be required herein. The major portion of the
`various manually operated and control actuating ele-
`ments, which are utilized by an operator to contrOl and
`operate the planer type road construction apparatus 40,
`is, in a preferred form, supported in a control console
`58. The control console 58 is supported on the main
`frame 42, generally near the forward end 44 thereof,
`and a guard-rail type of structure 60 is connected to the
`main frame 42, as shown in FIGS. 2 and 3.
`A steering assembly 62 is connected to the main
`frame 42 and to a portion of the front track assembly 54
`for steering the planer type road construction apparatus
`40. More particularly, the steering assembly 62 is con-
`structed to automatically steer the front track assembly
`54in a steering direction 64 and a steering direction 66,
`as shown in FIG. 3, to steeringly maintain the alignment
`of the planer type road construction apparatus 40 rela-
`tive to a control reference, commonly a “string-line”, in
`one aspect of the operation of the planer type road
`construction apparatus 40.
`A planer assembly 68 is supported on the main frame
`42, generally near the forward end 44 thereof, and a
`floating moldboard 70 is also connected to the main
`frame 42, generally near the planer assembly 68.
`, A reclaimer assembly 80, which generally includes a
`base conveyor 82 and an elevated conveyor 84, is sup-
`ported on the main frame 42 for receiving the removed
`pavement material removed by the planer assembly 68
`and for depositing same in a predetermined, controlled,
`remote location or selected depository. The reclaimer
`assembly 80 is of the type taught in US Pat. No.
`3,946,506, entitled “Conveyor and Control Apparatus
`for Road Construction Apparatus or the Like”, as-
`signed to the assignee of the present invention. There-
`fore, a detailed description of the various components,
`and the cooperation of those components, of the re-
`claimer assembly 80 will not be required herein. Rather,
`it will be sufficient to state that the base conveyor 82 is
`supported generally between the left side 48 and the
`right side 50, and extends angularly downwardly from
`near the rearward end 46 of the main frame 42 to the
`floating moldboard 70.
`As will become clear below, the base conveyor 82
`receives removed pavement material at a material re-
`ceiving end 90 and moves the material toward a mate-
`rial delivery end 92 which is disposed near the rearward
`end 46 of the planer type road construction apparatus
`40. The elevated conveyor 84 has a material receiving
`end 96 disposed in material receiving relationship to the
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`material delivery end 92 of the base conveyor 82, and
`the material received therefrom is moved via an endless
`belt to a material delivery end 98 for depositing the
`material in a selected position behind the planer type
`road construction apparatus 40. The general construc-
`tion details of the base conveyor 82 and the elevated
`conveyor 84 are provided in US. Pat. No. 3,946,506,
`mentioned above, and the further details are not neces-
`sary herein, with the exception that the material receiv-
`ing end 90 of the base conveyor 82 is supported by the
`floating moldboard 70 as described below.
`The front track assembly 54 and the rear drive assem-
`bly 52 are of the type described in US. Pat. No.
`3,802,525, entitled “Trimmer Type Road Construction
`Apparatus or the Like”, and assigned to the assignee of
`the present invention. Therefore, it will not be neces-
`sary to fully describe the construction details of the
`front track assembly 54 in the present disclosure. The
`rear drive assembly 52 comprises a left track assembly
`110 connected to the left side 48 of the main frame 42
`and a right track assembly 112 connected to the right
`side 50 of the main frame 42.
`The planer type road construction apparatus 40 as
`illustrated herein comprises a planer assembly 68
`mounted on a frame that is supported and driven by a
`three track drive assembly. This illustration is exem-
`plary only, as the present invention is not limited to the
`drive assemblies 52, 54 described herein for purposes of
`this disclosure, an important consideration being that
`when the planer assembly 68 is rigidly fixed to the frame
`of the propelling machine, which is the preferred em-
`bodiment, the frame must be supported in such a man-
`ner that the frame may be precisely controlled as to
`grade and cross slope while the planer assembly 68 is
`operating.
`In the preferred form of the present invention, the
`planer type road construction apparatus 40 is automati-
`cally actuated in an actuated position thereof in re-
`sponse to an output signal of a track steering sensor that
`senses the location of an external reference line such as
`a string-line. Also, the elevation of the main frame 42
`relative to the front track assembly 54 and the rear drive
`assembly 52 is automatically actuated and controlled in
`an actuated position thereof in response to an elevation
`sensor that senses the location of an external reference
`line such as a string—line. A track steering sensor 100 and
`an elevation sensor 192 are each supportedly connected
`to the left side 48 of the main frame 42 generally near
`the forward end 44 thereof. The construction of such
`sensors and the utilization of sensors such as the track
`steering sensor 100 and the elevation sensor 102 to pro-
`vide an output signal responsive to a control reference
`are well known in the art, such sensors for example
`being described in U.S. Pat. No. 3,423,859, entitled
`“Road Construction Methods and Apparatus”, assigned
`to the assignee of the present invention. Furthermore,
`the application of such sensors and the supporting hy-
`draulic and electrical circuitry to steeringly control the
`main frame 42 and to raise and lower the main frame 42
`relative to the drive assembly (the track assemblies 54,
`110 and 112) in an actuated position thereof is described
`in US. Pat. No. 3,802,525, entitled “Trimmer Type
`Road Construction: Apparatus or the Like”, assigned to
`the assignee of the present invention. Therefore, further
`details of the construction and operation such sensors
`are not necessary for purposes of the present disclosure.
`Further, in the manner of that described in US. Pat.
`No. 3,802,525, the elevation of one side of the main
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`frame 42 is set in a predetermined elevation setting and
`the elevation of the other side thereof is automatically
`controlled via an automatic slope sensor and control
`apparatus to position the main frame 42 in a predeter-
`mined grade and slope position during the operation
`thereof. Automatic control equipment to establish a
`predetermined grade and slope of the main frame 42 is
`also taught in US. Pat. No. 3,423,859, cited above.
`Therefore, a detailed description of such equipment and
`the cooperation of the components necessary to provide
`such control is not required herein.
`As stated above, construction details of the control of
`the steering, elevation and cross slope of the main frame
`42 are not required herein as this may be readily ob-
`tained from the cited patents. However, it is believed
`useful to include a discussion of the operation of such
`equipment by reference to a block diagram as shown in
`FIG. 4. As shown therein, a double acting front eleva-
`tion cylinder 120 is shown connected to a front eleva-
`tion control apparatus 122. Also, a double acting, left
`rear elevation cylinder 124 is also connected to a rear
`elevation control apparatus 125. As described in the
`patents cited above, the front elevation cylinder 120 is
`connected to the forward end 44 of the main frame 42
`and to the front track assembly 54 for the purpose of
`raising or lowering the forward end 44 when the front
`elevation cylinder 120 is actuated. In like manner, the
`left rear elevation cylinder 124 is connected to the left
`side 48 of the main frame 42 and to the left rear track
`assembly 110 for the purpose of raising or lowering the
`left side 48 when the left rear elevation cylinder 124 is
`actuated. In operation, an external reference line 126
`(which may be a string-line or the like) is followed by
`the elevation sensor 102 and an appropriate control
`signal
`is sent thereby to the front elevation control
`apparatus 122 that in turn sends pressure fluid to extend
`or retract the cylinder 120 to establish the elevation of
`the main frame 42 at the forward end 44 at a predeter-
`mined elevation.
`The left rear elevation cylinder 124 can be extended
`and established in a setting corresponding to a predeter-
`mined grade (known as locked to grade), or the left rear
`elevation cylinder 124 can be controlled via a rear ele-
`vation control apparatus 125. The operation of the rear
`elevation control apparatus 125 is identical
`to that
`which is described above for the front elevation control
`apparatus 122. That is, an elevation sensor 127 (not
`shown in FIGS. 2 and 3) follows the external reference
`line 126 and an appropriate control signal is sent thereby
`to the rear elevation control apparatus 125 that in turn
`sends pressure fluid to extend or retract the cylinder 124
`to establish the elevation of the left side 48 of the main
`frame 42 at a predetermined elevation.
`The right side 50 of the main frame 42 is controlled
`by a double acting, right rear elevation cylinder 128 that
`is connected to the right side 50 of the main frame 42
`and to the right track assembly 112 for the purpose of
`raising or lowering the right side 50 when the right rear
`elevation cylinder 128 is actuated. A cross slope sensor
`and control apparatus 130 senses the cross slope of the
`main frame 42, compares the cross slope of the main
`frame 42 to a predetermined cross slope value, and
`actuates the right rear elevation cylinder 128 to main-
`tain the cross slope of the main frame 42 at the predeter—
`mined cross slope value.
`Also shown in FIG. 4 is a double acting steering
`cylinder 132 that is connected to the forward end 44 of
`the main frame 42 and to the front track assembly 54 for
`
`8
`the purpose of pivoting the front track assembly 54
`relative to the main frame 42. The steering cylinder 132
`is actuated by a steering control apparatus 134. The
`track steering sensor 100 senses the reference line 126
`and signals the steering control apparatus 134 that sends
`pressurized hydraulic fluid to actuate the steering cylin-
`der 132 as required to maintain the desired path of the
`planer type road construction apparatus 40.
`The above comments relative to FIG. 4 are illustra-
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`45
`
`50
`
`55
`
`6O
`
`65
`
`tive only, as it will be understood that the planer type
`road construction apparatus 40 may be equipped for
`other modes of operation as well. That is, the track
`steering sensor 100 and the elevation sensors 102 and
`127 may be supported at the right side 50 of the main
`frame 42, and the reference line 126 disposed along the
`right side of the planer type road construction apparatus
`40. The elevation of the main frame 42 would then be
`achieved by control of the cylinders 120 and 128, while
`the cross slope would be controlled via the left rear
`elevation cylinder 124. Also, it is common to equip road
`construction apparatus such as the planer type road
`construction apparatus 40 with manual steering equip-
`ment and with manual elevation and cross slope actuat-
`ing equipment that are of known construction, and the
`details of such equipement are unnecessary herein.
`In summation then,
`the above described steering,
`elevation and cross slop controls are exemplary only,
`and it is within the contemplation of the present inven-
`tion to provide manula or automatic steering controlled
`from either side of the planer apparatus 40; to provide
`manual or automatic elevation capability on all suspen-
`sion points controlled from either side of the planer
`apparatus 40; and to provide cross slope capability,
`controlling as necessary, either side of the planer appa-
`ratus 40. And although a string reference line 126 is
`shown, it is contemplated that a conventional ski appa-
`ratus can be used to provide a reference line on either
`side of the planer apparatus 40, with such ski apparatus
`being supported to one side of the planer apparatus 40
`to give an elevation of a roadway lane or the like that
`exists alongside of the selected travel of the planer appa-
`ratus 40. In this way, the planer apparatus 40 can con-
`trolled to provide precision planing with reference to
`the grade of an existing surface.
`The planning assembly 68 performs the function of
`planing the top surface of a paved roadway (such as the
`top surface 14 of the roadway 10 before being resur-
`faced) by cutting away a selected portion of the road-
`way, as discussed above. The planning assembly 68 in
`the preferred form comprises a planing cutter 138 that
`comprises a rotary drum 140 as shown in FIG. 5. The
`drum 140 is rotatably supported under the main frame
`42 by way of the trunions 142 and 144 that are journally
`mounted in the support members 146 that extend down-
`wardly from the main frame 42. The drum 140 is rotat-
`able about its longitudinal axis 148 by a conventional
`hydraulic driving assembly (not shown) powered by the
`power drive unit 56.
`Extending about the drum 140 is a spirally winding
`first flight 152 that begins near the end 154 and termi-
`nates near the center portion 156 of the drum 140. An-
`other spirally winding second flight 158 begins near the
`end 160 and terminates near the center portion 156. The
`winding pitches of the flights 152 and 158 are opposite
`to each other and are designed so that the first flight 152
`has apparent motion in the first end-to-center direction
`162, and the second flight 158 has apparent motion in
`the second end to center direction 164 when the drum is
`
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`4,139,318
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`9
`rotated in the rotary direction 166 as viewed in FIG. 6.
`The planing cutter 138 is preferably rotated in the ro-
`tary direction 166 so as to cause the removed portion of
`the paved roadway 10 to be directed forwardly of 'the
`planing cutter 138 and generally moved from the ends
`154, 160 in the apparent directions 162, 164 as the main
`frame 42 is driven in a forward direction 168.
`Attached along each of the flights 152 and 158 at
`approximately equal intervals are a plurality of cutting
`heads 170, a side view of one such cutting head being
`shown in FIG. 7. The cutting head 170 shown in FIG.
`7 comprises a support block 172 which is attached to the
`outer edgeyl74 of the first flight 152. The support block
`172 has an angled support surface 176 to which is at-
`tached a chisel cutter, the chisel cutter 178 having a
`cutting point 180 that is preferably made as an insert of
`tungsten carbide or the like.
`In the preferred form, the planing cutter 138 is dimen-
`sioned such that the cutting points 180 of all of the
`c