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.