Road-cutting apparatus

Information

  • Patent Grant
  • 6402252
  • Patent Number
    6,402,252
  • Date Filed
    Friday, December 10, 1999
    25 years ago
  • Date Issued
    Tuesday, June 11, 2002
    22 years ago
Abstract
A road-cutting apparatus for creating grooves or impressions in a road surface. The apparatus comprises a tool carrier with a rotatable cutter positioned adjacent thereto. A positioning control arm is hydraulically actuated to place the cutter in an operating position just above the road surface, and an operating control arm is hydraulically actuated to move the cutter into and out of cutting engagement with the road surface. The cutting is automatically carried out in response to a signal generated as a result of the distance traveled along the road surface by the apparatus. The road-cutting apparatus also comprises a transport wheel which can be placed into engagement with the road surface such that the cutter is spaced therefrom for transport of the apparatus to a desired location for cutting the grooves or impressions and raised above the road surface for the cutting operation.
Description




BACKGROUND OF THE INVENTION




1. Field of the Invention




This invention relates to machines used for scarifying, abrading and generally treating the surface of roadways, and more particularly, to a road-cutting apparatus which can be intermittently actuated automatically, as the apparatus moves along the road surface, to create spaced impressions or grooves in the roadway surface while allowing manual compensation for cutter wear.




2. Description of the Prior Art




On the shoulders along roadways, it is frequently a desired option to cut impressions or grooves extending laterally across the shoulder-to act as a warning for drivers that they have moved off the main roadway. When the tires of the vehicle contact the grooves, a noise is heard and vibration is felt which alerts the driver that the tires are in contact with the shoulder. Alternatively, ridges may be laid along the shoulder. In either case, the warning effect is the same, and such devices are frequently referred to as “rumble strips.”




The spacing of these grooves varies depending upon the locale. For example, some states may use a different spacing than others. Also, in some areas, it is desired to use a larger spacing between groups of grooves. For example, there may be a group of a specific number of grooves which have a relatively small spacing therebetween and then a much larger space between the next set of grooves of that specific number. Generally, this type of spacing is referred to as intermittent cutting.




One prior art device utilizes a cam-like wheel which engages the surface, and as the device moves along the roadway, the cam rotates. This causes a cutter wheel to be alternately lowered into cutting contact with the road surface and raised out of contact. By moving this device along the road surface, a plurality of spaced grooves may be formed. This device has the disadvantage of not easily accommodating intermittent cutting. Also with the cam device, the spacing between adjacent grooves can only be controlled by changing the cam. There is no quick adjustment available. The present invention solves this problem by providing an apparatus which uses a microprocessor to control the spacing between adjacent grooves, and the microprocessor can also be programmed to provide a preset, larger spacing between sets of grooves to allow automatic intermittent cutting.




Another prior art device uses a hydraulic cylinder which raises and lowers the cutter into contact with the road surface. Such a device is disclosed in U.S. Pat. No. 5,415,495. This device has the disadvantage of requiring a highly specialized vehicle of which the cutting apparatus is an integral part. It is not adapted for use with common vehicles, such as farm tractors. The present invention solves this problem by providing a self-contained apparatus which can easily be pulled behind any number of known vehicles, such as farm tractors.




A cutter drum assembly for cutting grooves or impressions in a road surface is disclosed in U.S. Pat. Nos. 5,046,890; 5,129,755; 5,236,278; and 5,378,080. This, or other types of rotary cutters, may be utilized in the apparatus of the present invention.




The present invention also provides an apparatus which can be conveniently moved along a road surface when not in operation but can be quickly and easily placed into an operating position when desired, while at the same time providing automatic cutting of the grooves and also providing control of the cutter to compensate for wear thereon.




SUMMARY OF THE INVENTION




The present invention is an apparatus for cutting impressions or grooves in a road surface. The apparatus generally comprises a tool carrier adapted for moving along the road surface, a rotatable cutter positioned adjacent to the tool carrier, a cutter positioning means for positioning the cutter between a raised position spaced from the road surface and an operating position adjacent to the road surface, and a cutter operating means for alternately moving the cutter into and out of cutting engagement with the road surface after the cutter is in the operating position thereof A transport wheel is attached to the tool carrier and has a transport position engaging the road surface and a retracted or raised position spaced from the road surface. A wheel actuation means is used for moving the transport wheel between the transport and retracted positions thereof.




The wheel actuation means comprises a transport control arm pivotally connecting the transport wheel to the tool carrier and a transport cylinder connect to the tool carrier and the transport control arm, whereby the transport control arm and the transport wheel may be pivoted with respect to the tool carrier.




The cutter positioning means comprises a positioning control arm pivotally attached to the tool carrier and a positioning cylinder interconnecting the positioning control arm and the cutter whereby the cutter may be pivoted between the raised and operating pistons thereof The cutter positioning means may be used for pivoting the cutter with respect to the tool carrier for compensating for wear on cutting elements on the cutter.




The cutter operating means comprises an operating control arm attached to the cutter and an operating cylinder interconnecting the positioning control arm and the operating control arm whereby the cutter may be engaged and disengaged with the road surface. The cutter operating means is adapted for pivoting the cutter with respect to the tool carrier when moving the cutter between cutting engagement with the road surface and disengagement therefrom.




The apparatus further comprises an elevating wheel connected to the cutter for supporting the cutter on the road surface when the cutter is in the operating position thereof and when the cutter is cuttingly engaged with the road surface. The elevating wheel is connected to the positioning control arm and pivotable therewith.




Preferably, the apparatus further comprises a means for measuring a distance the tool carrier is moved along the road surface and generating a signal in response thereto and a logic controller actuating the cutter operating means in response to the signal. This may be used to control the width and depths of the grooves or impressions and also the spacing therebetween. It may also be used to control the longer spacing between groups of grooves or impressions during intermittent cutting.




Numerous objects and advantages of the invention will become apparent as the following detailed description of the preferred embodiment is read in conjunction with the drawings which illustrate such embodiment.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

shows the road-treating apparatus of the present invention in a transport position for movement along a road surface prior to treatment thereof.





FIG. 2

shows the road-treating apparatus in an operating position in which the cutter is adjacent to the road surface.





FIG. 3

illustrates the road-cutting apparatus of the present invention in a cutting position for providing spaced grooves along the road surface.





FIG. 4

is a schematic of the logic control circuit used in the apparatus.











DESCRIPTION OF THE PREFERRED EMBODIMENT




Referring now to the drawings, and more particularly to

FIG. 1

, the road-cutting apparatus of the present invention is shown and generally designated by the numeral


10


. Apparatus


10


comprises a frame or tool carrier


12


which in the illustrated embodiment is adapted for connection to a vehicle


14


by a trailer hitch


16


of a kind known in the art at a forward end


18


of the tool carrier. An advantage of apparatus


10


is that vehicle


14


can be almost anything, for example, a farm tractor. A specialized vehicle


14


is not required. Alternatively, apparatus


10


can be a self-contained vehicle with its own power source (not shown) on board.




A transport wheel


20


is positioned adjacent to a rearward end


22


of tool carrier


12


. In the preferred embodiment, a pair of transport wheels


20


are utilized and positioned at generally opposite lateral sides of the apparatus. Wheel


20


is of a kind generally known in the art and preferably has a tire


24


thereon and is rotated about an axle


26


. Axle


26


is connected to a rear portion


28


of a first control arm


30


. First control arm


30


may also be referred to as transport control arm


30


. An intermediate portion


32


of transport control arm


30


is connected to rear end


22


of tool carrier


12


by a pivot


34


.




Transport control arm


30


also has a forward portion


36


. A first hydraulic cylinder


38


, also referred to as a transport cylinder


38


, has one end thereof attached to forward portion


36


of transport control arm


30


at a pivot


40


. The other end of transport cylinder


38


is connected to a cylinder bracket


42


by another pivot


44


. Cylinder bracket


42


is fixedly attached to tool carrier


12


.




A control arm bracket


46


is fixedly attached to tool carrier


12


. A second control arm


44


is attached to control arm bracket


46


by a lower pivot


50


. Second control arm


48


may also be referred to as a positioning control arm.




A second hydraulic cylinder


52


has one end attached to positioning control arm


48


by an upper pivot


54


. Second hydraulic cylinder


52


may be referred to as positioning cylinder


52


. The other end of positioning cylinder


52


is attached to a cylinder bracket


55


by a pivot


56


. Cylinder bracket


55


is fixedly attached to tool carrier


12


.




A third hydraulic cylinder


58


is attached to positioning control arm


48


by an intermediate pivot


60


. Third hydraulic cylinder


58


may also be referred to as an operating cylinder


58


. The other end of operating cylinder


58


is connected to an upper portion


62


of a third control arm


64


by a pivot


66


. Third control arm


64


may also be referred to as an operating control arm


64


. The maximum extension and retraction of operating cylinder


58


may be controlled as further described herein.




Operating control arm


64


is connected to a cutter frame


68


by a pivot


70


. Cutter frame


68


is connected to, or forms a portion of, a cutter housing


72


. A cutter drum assembly


74


is disposed in cutter housing


72


and rotatably mounted on cutter frame


68


by a cutter shaft


76


. Cutter shaft


76


, and thus cutter drum assembly


74


, may be rotated by a prime mover


78


. Prime mover


78


may be of any kind known in the art, such as a hydraulic motor, an internal combustion engine, an electric motor, etc.




Cutter drum assembly


74


itself is a prior art device comprises a cutter drum


80


with a plurality of cutter elements


82


attached to the outer surface thereof. Cutter elements


82


may be of any kind known in the art and are preferably replaceable and interchangeable with other cutter elements so that they may be easily replaced as desired.




A lower portion


84


of operating control arm


64


extends downwardly and forwardly from pivot


70


. An elevation wheel


86


is rotatably connected to lower portion


84


of operating control arm


64


by an axle or shaft


88


. Preferably, there are two laterally spaced elevations wheels


86


generally aligned with the ends of cutter drum assembly


74


.




A measuring wheel


100


is rotatably mounted on a shaft or axle


102


and attached to tool carrier


12


, such as by bracket


104


. A distance counter wheel


106


is also mounted on shaft


102


and is rotatable with measuring wheel


100


which is always engaged with road surface


90


. Distance counter wheel


106


is part of a logic control circuit


108


which includes electronic and hydraulic components.




Referring now to

FIG. 4

, the details of logic control circuit


108


are shown. A magnetic proximity switch


110


is positioned adjacent to distance counter wheel


106


, and is adapted to detect the movement of cogs


112


on the distance counter wheel as they move past the proximity switch. Magnetic proximity switch


110


is connected to a distance logic controller


114


by wires


116


.




A first cylinder proximity switch


116


is connected to controller


114


by wires


118


, and a second cylinder proximity switch


120


is connected to controller


114


by wires


122


. As will be further described herein, first cylinder proximity switch


116


and second cylinder proximity switch


122


are adapted to sense the presence of rod end


124


of operating cylinder


58


when positioned thereto. The longitudinal positioning of first cylinder proximity switch


116


and second cylinder proximity switch


120


may be adjusted longitudinally with respect to operating cylinder


58


, and as will be further described herein, this allows control of the stroke of operating cylinder


58


and thus the cutting position of cutter drum assembly


74


.




A three-position electric solenoid hydraulic valve


126


is connected to controller


114


by wires


128


and


130


. Hydraulic valve


126


is hydraulically connected to operating cylinder


58


by hydraulic lines


132


and


134


. Hydraulic valve


126


is connected to a hydraulic pump


136


by a line


138


. Hydraulic pump


136


is hydraulically connected to a hydraulic reservoir


140


by a line


142


. A hydraulic suction filter


144


may be used with line


142


. Hydraulic pump


136


may also be referred to as operating hydraulic pump


136


.




A hydraulic return line


146


extends from hydraulic valve


126


to reservoir


140


.




Another hydraulic pump


148


which may be referred to as transport hydraulic pump


148


is connected to reservoir


140


by a line


50


and a hydraulic suction filter


152


. Hydraulic pump


148


is connected to a transport control valve


154


by a line


146


. Transport control valve


154


is hydraulically connected to transport cylinder


38


by lines


158


and


160


. A hydraulic return line


162


extends from transport control valve


154


to reservoir


140


. Transport control valve


154


is illustrated as a manual or hand valve, but could also be an electronic solenoid valve.




A further hydraulic pump


164


, which may also be referred to as positioning hydraulic pump


164


, is connected to reservoir


140


by a line


166


and another hydraulic suction filter


168


. Positioning hydraulic pump


164


is connected to a positioning control valve


170


by a line


172


. Positioning control valve


170


is hydraulically connected to positioning cylinder


52


by lines


174


and


176


. A hydraulic return line


178


extends from positioning control valve


170


to reservoir


140


. Positioning control valve


170


is illustrated as a manual or hand valve, but could also be an electronic solenoid valve.




While control circuit


108


has been illustrated as mounted on apparatus


10


, it could also be mounted on vehicle


10


or at any other location which would be convenient for the operator of the apparatus. Also, while three different hydraulic pumps


136


,


148


and


164


have been shown, it will be seen by those skilled in the art that one or more of these could be combined and still provide the appropriate hydraulic pressure to actuate any or all of cylinders


38


,


52


and


58


.




In an alternate embodiment, transport wheel


20


and trailer hitch


16


can be mounted on opposite ends so that transport wheels


20


are adjacent to elevation wheels


86


. The invention is not intended to be limited to the specific configuration shown in the drawings.




OPERATION OF THE INVENTION




Referring again to

FIGS. 1 and 4

, transport cylinder


38


is shown in an extended position such that transport wheels


20


are in their lowermost position so that road-cutting apparatus


10


may be pulled or driven along a road surface


90


with elevation wheels


86


and cutter drum assembly


74


spaced above the road surface. When apparatus


10


is at the desired location, pumps


136


,


148


and


164


are turned on. Then, transport control valve


154


is operated to actuate transport cylinder


38


to a retracted position as shown in FIG.


2


. This pulls on forward portion


36


of transport control arm


30


which rotates rear portion


28


of transport control arm


30


and wheels


20


about pivot


34


in a counterclockwise direction as seen in the drawings. As transport wheels


20


are raised, the rest of apparatus


10


is correspondingly lowered until elevation wheels


86


and measuring wheel


100


contact ground surface


90


. Further actuation of transport cylinder


38


will raise transport wheels


20


above road surface


90


as shown in FIG.


2


. Thus, apparatus


10


has a transport wheel actuation means for moving transport wheels


20


between the transport and retracted positions thereof.




The exact position of cutter drum assembly


74


with respect to road surface


90


is controlled by actuation of positioning cylinder


52


by operating positioning control valve


170


. Actuation of positioning cylinder


52


will cause positioning control arm


48


to be pivoted about lower pivot


50


. Because operating cylinder


58


and operating control arm


64


are connected to positioning control arm


48


, and because cutter frame


68


is connected to operating control arm


64


, it will be seen that actuation of positioning cylinder


52


will cause cutter drum assembly


74


to be raised and lowered with respect to road surface


90


. That is, cutter drum assembly


74


is thus pivoted about axle


88


. Preferably, cutter drum assembly


74


is positioned so that cutter elements


82


on cutter drum


80


are just above road surface


90


and not in contact therewith initially. Thus, a cutter positioning means is provided in apparatus


10


.




Cutter elements


82


on cutter drum


80


may be brought into cutting engagement with road surface


90


by actuation of operating cylinder


58


to an extended position (see

FIG. 3

) and disengaged by further actuation of the operating cylinder to a retracted position (see FIG.


2


). That is, extension of operating cylinder


58


will cause operating control arm


64


to be rotated clockwise about pivot


70


which lowers cutter drum assembly


74


toward road surface


90


such that cutter elements


82


will cut a groove or impression


92


therein. See FIG.


3


. Retraction of operating cylinder


58


will rotate operating control arm


64


counterclockwise about pivot


70


, raising cutter drum assembly


74


again to the disengaged position. Referring again to

FIG. 3

, it will be seen that by alternately extending and retracting operating cylinder


58


as apparatus


10


is moved along road surface


90


, a series of spaced grooves


92


may be cut along the road surface leaving an uncut portion


94


between each adjacent pairs of grooves. In this way, apparatus


10


comprises a cutter operating means.




Prior to the cutting operation, first proximity switch


116


and second proximity switch


120


are positioned as desired adjacent to operating cylinder


58


and located there such as by clamping on a support member (not shown) or any other known means. The distance between proximity switches


116


and


120


will determine the total working stroke of operating cylinder


58


and thus the total movement of rod end


124


thereof.




When control circuit


108


is operational, movement of apparatus


10


along road surface


90


results in rotation of measuring wheel


100


and distance counter wheel


106


. As each cog


112


on distance counter wheel


106


move past magnetic proximity switch


110


, the magnetic proximity switch sends a signal through wires


116


to logic controller


114


. Logic controller


114


actuates operating hydraulic valve


126


which in turn actuates operating cylinder


58


. That is, logic controller


114


and hydraulic valve


126


determine when operating cylinder


58


is extended and retracted. When operating cylinder


58


is extended, rod end


124


will pass adjacent to first proximity switch


116


which sends a signal to logic controller


114


through wires


118


, stopping actuation. When operating cylinder


58


is retracted, rod end


124


thereof moves adjacent to second proximity switch


120


, and another signal is sent to logic controller


114


through wires


122


to stop actuation in that direction. Logic controller


114


includes a programmable microprocessor which can be programmed to extend operating cylinder


58


after a preselected number of “hits” sensed by magnetic proximity switch


110


as cogs


112


pass thereby and retract operating cylinder


58


after another preselected number of hits. In this way, the width of grooves


92


and the width of the uncut portions


94


therebetween may be easily and accurately determined. Further, if intermittent cutting is desired, the microprocessor in logic controller


114


may be programmed to leave a larger space between a group of grooves


92


of a preselected number. Thus, all that is necessary to vary the width of grooves


92


and the spacing


94


therebetween and any longer spacing between adjacent groups of grooves


92


is to simply reprogram the microprocessor logic controller


114


. It is not necessary to change cutters or cams or other devices as is required in some of the prior art devices.




The positioning of first proximity switch


116


and second proximity switch


120


determines the spacing above road surface


90


when in the disengaged position and the depth of grooves


92


when in the cutting or engaged position. For example, but not by way of limitation, the proximity switches could be set to position cutter drum assembly


74


one-quarter inch above road surface


90


when not cutting and set the depth of grooves


92


to one-half inch when cutting. Other dimensions could also be used as desired.




Throughout the operation of operating cylinder


58


, elevating wheels


86


stay in contact with road surface


90


allowing road-cutting apparatus


10


to be guided along the road surface. Trailer hitch


16


and elevation wheels


86


thus provide a three-point contact for apparatus


10


during operation, the hitch being the front pivoting point and the dual elevating wheels


86


providing a movable rear support. This three-point design allows full “flotation” of apparatus


10


, resulting in a highly consistent cutting action of cutter drum assembly


74


and correspondingly uniform depths, lengths and spacing of grooves


92


.




As cutter elements


82


wear, positioning cylinder


52


may be actuated by operating positioning control valve


170


to compensate so that the cutting edges of cutter elements


82


are maintained in approximately the same position with respect to road surface


90


in the disengaged position shown in FIG.


2


. This is normally done manually as necessary.




When the desired portion of road surface


90


has had grooves


92


cut therein, operating cylinder


58


is retracted to the disengaged position by operating transport control valve


154


shown in FIG.


2


. Transport cylinder


38


is re-extended to pivot transport control arm


30


about pivot


34


, thus lowering transport wheels


20


into engagement with road surface


90


so that apparatus


10


is again in the transport position shown in FIG.


1


. At this point, apparatus


10


may then be transported to another desired location with cutter drum assembly


74


and elevation wheels


86


displaced above the road surface.




It will be seen, therefore, that the road-cutting apparatus of the present invention is well adapted to carry out the ends and advantages mentioned as well as those inherent therein. While a presently preferred embodiment has been described for the purposes of this disclosure, numerous changes in the arrangement and construction of parts may be made by those skilled in the art. All such changes are encompassed within the scope and spirit of the appended claims.



Claims
  • 1. An apparatus for cutting impressions in a road surface, said apparatus comprising:a tool carrier adapted for moving along the road surface; a rotatable cutter positioned adjacent to said tool carrier; a cutter positioning means for positioning said cutter between a raised position spaced from the road surface and an operating position adjacent to the road surface; a cutter operating means for alternately moving said cutter into and out of cutting engagement with a road surface after the cutter is in the operating position thereof; a transport wheel attached to said tool carrier and having a transport position engaging the road surface and a retracted position spaced from the road surface; and wheel actuation means for moving said transport wheel between said transport and retracted positions thereof, said wheel actuation means comprising: a control arm pivotally connecting said transport wheel to said tool carrier; and a cylinder connected to said tool carrier and said control arm whereby said control arm and said transport wheel may be pivoted with respect to said tool carrier.
  • 2. The apparatus of claim 1 further comprising:a transport wheel attached to said tool carrier and having a transport position engaging the road surface and a retracted position spaced from the road surface.
  • 3. The apparatus of claim 2 further comprising wheel actuation means for moving said transport wheel between said transport and retracted positions thereof.
  • 4. The apparatus of claim 1 wherein said cutter positioning means comprises:a positioning control arm pivotally attached to said tool carrier; and a positioning cylinder interconnecting said positioning control arm and said tool carrier whereby said cutter may be pivoted between said raised and operating positions.
  • 5. The apparatus of claim 4 wherein said cutter operating means comprises:an operating control arm attached to said cutter; and an operating cylinder interconnecting said positioning control arm and said operating control arm whereby said cutter may be engaged with, and disengaged from, the road surface.
  • 6. The apparatus of claim 5 further comprising:an elevating wheel connected to said cutter for supporting said cutter on the road surface when said cutter is in the operating position thereof.
  • 7. The apparatus of claim 6 wherein said cutter positioning means is adapted for pivoting said cutter with respect to said tool carrier for compensating for wear on said cutter.
  • 8. The apparatus of claims 6 wherein said elevating wheel is connected to said positioning control arm and pivotable therewith.
  • 9. The apparatus of claim 6 wherein said cutter operating means is adapted for pivoting said cutter with respect to said tool carrier when moving said cutter between cutting engagement with the road surface and disengagement therefrom.
  • 10. The apparatus of claim 1 further comprising:means for measuring a distance said tool carrier is moved along the road surface and generating a signal in response thereto; and a controller for actuating said cutter operating means in response to said signal.
  • 11. The apparatus of claim 10 wherein said means for measuring is characterized by:a distance counter wheel; and a proximity switch adjacent to said distance counter wheel.
  • 12. An apparatus for cutting impressions in a road surface, said apparatus comprising:a tool carrier adapted for moving along the road surface; a positioning control arm pivotally attached to said tool carrier; a positioning cylinder attached to said positioning control arm and said tool carrier; an operating cylinder pivotally attached to said positioning control arm; an operating control arm pivotally attached to said operating cylinder; a transport wheel attached to said tool carrier and having a transport position engaging the road surface and a retracted position spaced from the road surface; wheel actuation means for moving said transport wheel between said transport and retracted positions thereof, said wheel actuation means comprising: a transport control arm pivotally connecting said transport wheel to said tool carrier; and a transport cylinder connected to said tool carrier and said transport control arm whereby said transport control arm and said transport wheel may be pivoted with respect to said tool carrier; and a rotatable cutter mounted on said operating control arm; wherein: actuation of said positioning cylinder moves said cutter between a raised position spaced from the road surface and an operating position adjacent to the road surface; and actuation of said operating cylinder moves said cutter into and out of cutting engagement with the road surface and disengagement from the road surface.
  • 13. The apparatus of claim 12 further comprising:a transport wheel attached to said tool carrier and having a transport position engaging the road surface and a retracted position spaced from the road surface.
  • 14. The apparatus of claim 13 further comprising wheel actuation means for moving said transport wheel between said transport and retracted positions thereof.
  • 15. The apparatus of claim 12 further comprising:an elevating wheel rotatably mounted on said operating control arm for supporting said cutter on the road surface when the cutter is in the operating position thereof.
  • 16. The apparatus of claim 15 wherein said positioning control arm is adapted for pivotally supporting said cutter with respect to said elevating wheel, thereby compensating for wear on said cutter.
  • 17. The apparatus of claim 15 wherein said operating control arm is adapted for pivotally supporting said cutter with respect to said elevating wheel when moving said cutter between said engaged and disengaged positions thereof.
  • 18. The apparatus of claim 12 further comprising:means for measuring a distance said tool carrier is moved along the road surface and generating a signal in response thereto; and a controller for actuating said cutter operating means in response to said signal.
  • 19. The apparatus of claim 18 wherein said means for measuring is characterized by:a distance counter wheel; and a proximity switch adjacent to said distance counter wheel.
US Referenced Citations (16)
Number Name Date Kind
4025819 Lafever et al. May 1977 A
4157877 Lee Jun 1979 A
4463989 Kennedy Aug 1984 A
4832412 Bertrand May 1989 A
4900094 Sergeant Feb 1990 A
5046890 Dickson Sep 1991 A
5054989 Fell Oct 1991 A
5129755 Dickson Jul 1992 A
5236278 Dickson Aug 1993 A
5297894 Yenick Mar 1994 A
5299857 Zanetis Apr 1994 A
5378080 Dickson Jan 1995 A
5391017 Thomas et al. Feb 1995 A
5415495 Johnson May 1995 A
5676490 Nelson Oct 1997 A
6247757 Cochran Jun 2001 B1
Non-Patent Literature Citations (1)
Entry
Melroe Company “Pavement Repair with the Bobcat Planer” May 1997.