BACKGROUND OF THE INVENTION
The present invention relates to the field of driven cutter devices for use in roadway surface milling, earthworking, mining, or other in situ disintegration of hard materials. More particularly, the present invention is directed to cutter devices of various geometries and groupings of such cutter devices.
Roadway surfaces may become damaged over time thus requiring periodic maintenance. Milling may be performed to degrade a layer of the roadway surface to recondition it for travel or prepare it for resurfacing. It may be desirable to leave the roadway surface as smooth as possible after milling to ease travel or optimize adhesion of resurfacing materials. For example, U.S. Pat. No. 5,639,180 to Sulosky, et al., which is incorporated herein for all that it contains, describes a drum assembly for the milling of a roadway substrate to a fine texture. The design of the drum assembly permits the spacing between adjacent points of impingement to be 0.100 inches, and even less than 0.100 inches. The result is a substantially smooth roadway surface with little road noise.
U.S. Pat. No. 3,325,219 to Guillon, et al., which is incorporated herein for all that it contains, describes how adjacent picks on known cutting machines may follow each other at such relatively great distances that the stresses developed in the material by one of the picks has no influence on the conditions of working of the following picks. To overcome this issue, Guillon discloses distributing picks such that the tracks left by the picks are sufficiently close, such that a ridge becomes sufficiently fragile to be broken-up by the passage of the pick making the next adjacent cut, to provide in the vicinity a substantially plane surface.
U.S. Pat. No. 4,621,871 to Salani, which is incorporated herein for all that it contains, also describes how, when surface finish is important in road planning, more cutting teeth having a smaller spacing are desired.
Thus, increases in the smoothness produced by roadway surface milling operations and other in situ disintegration procedures are desired.
BRIEF SUMMARY OF THE INVENTION
A movable base, such as a rotatable drum, continuous chain or other such driven mass known in the art, may be disposed on a translatable vehicle such as a road milling, mining, or trenching machine for the in situ degradation of a hard surface. The movable base may comprise a plurality of cutting elements disposed thereon. The cutting elements may be detachable from the movable base. The cutting elements may also be interchangeable with other cutting elements.
Groupings of the plurality of cutting elements may comprise unique cutting surface geometries. For example, a first grouping of cutting elements may comprise conical, cylindrical or dome shaped cutting surface geometries while a second grouping of cutting elements may comprise flat shaped cutting surface geometries. The flat shaped cutting surface geometries may be formed as semicircular cylinders.
In some embodiments, cutting elements from the first grouping may be alternated with cutting elements from the second grouping when viewed tangentially. This arrangement may be accomplished by alternating cutting elements from the first grouping with cutting elements from the second grouping in a series or disposing cutting elements from the first grouping in a series parallel to a series of cutting elements from the second grouping. Either way, the cutting elements of each grouping may be arranged such that at least two of the cutting elements from the first grouping precede a cutting element from the second grouping in a direction of motion of the movable base. Additionally, the first grouping may be disposed at a greater distance from the movable base than the second grouping.
Such an arrangement may form a degradable surface comprising a cross-sectional topography resembling a waveform comprising truncated peaks. In various embodiments, the waveform may be triangular or sinusoidal. The waveform may also be uniform or comprise valleys with varied spacing there between.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an orthogonal view of an embodiment of a road milling machine.
FIG. 2 is a cross-sectional view of an embodiment of a degradation platform disposed on a road milling machine.
FIG. 3 is an orthogonal view of an embodiment of a rotatable drum comprising cutting elements with conical and flat cutting surface geometries disposed thereon.
FIG. 4 is an orthogonal view of another embodiment of a rotatable drum comprising cutting elements with conical and flat cutting surface geometries disposed thereon.
FIGS. 5
a, 5b and 5c are perspective views of embodiments of arrangements of cutting elements comprising various cutting surface geometries.
FIG. 6 is a perspective view of an embodiment of a cutting element comprising a flat cutting surface geometry.
FIGS. 7
a, 7b and 7c are perspective graphical representations of progressive embodiments of a surface being degraded.
FIGS. 8
a and 8b are perspective graphical representations of surfaces comprising cross-sectional topographies with truncated peaks and valleys.
FIG. 9 is an orthogonal view of an embodiment of a trenching machine.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the figures, FIG. 1 discloses an embodiment of a milling machine 100 traveling over a degradable surface 101. The degradable surface 101 may be a man-made roadway such as those comprising pavement, concrete, or asphalt or it may be a naturally occurring earthen formation. A degradation platform 102 may be attached to the milling machine 100 such that it may degrade the degradable surface 101. The degradation platform 102 may comprise a rotatable drum or continuous chain as are known to those of skill in the art. In the embodiment shown, the degradation platform 102 comprises a rotatable drum which may be driven by the milling machine 100.
FIG. 2 discloses an embodiment of a degradation platform 202 comprising a plurality of cutting elements 220 disposed on a rotatable drum 203. The rotatable drum 203 may be driven such that the cutting elements 220 engage and degrade a degradable surface 201.
FIG. 3 discloses an embodiment of a rotatable drum 303 with a plurality of cutting elements 320 disposed thereon. Groupings of the plurality of cutting elements 320 may comprise unique cutting surface geometries. For example, cutting elements may comprise conical, flat, cylindrical or dome shaped cutting surface geometries. In the embodiment shown, a first grouping 329 of cutting elements 320 comprises conical shaped cutting surface geometries 330 and a second grouping 332 of cutting elements 320 comprises flat shaped cutting surface geometries 333.
The cutting elements 320 may be disposed around an exterior of the rotatable drum 303 in several series. Each series may comprise a plurality of cutting elements 320 each offset a certain angular rotation and axial distance from an adjacent cutting element such as to form a spiral around the exterior of the rotatable drum 303. In the embodiment shown, the first grouping 329 of cutting elements 320 form a first series 328 that runs parallel to a second series 331 formed by the second grouping 332 of cutting elements 320.
FIG. 4 discloses another embodiment of a rotatable drum 403 comprising a plurality of cutting elements 420 disposed thereon. The rotatable drum 403 is similar to the one shown in FIG. 3 in that it comprises a first grouping 429 of cutting elements 420 comprising conical shaped cutting surface geometries 430 and a second grouping 432 of cutting elements 420 comprising flat shaped cutting surface geometries 433. However, in the embodiment shown in FIG. 4, the cutting elements 420 from the first grouping 429 are alternately disposed with cutting elements 420 from the second grouping 432 in a single series 434.
FIGS. 5
a, 5b and 5c disclose embodiments of arrangements of cutting elements and illustrate how cutting elements comprising unique cutting surface geometries may work in concert to create a smooth degraded surface.
The embodiment shown in FIG. 5a comprises a lead cutting element 535a comprising a conical cutting surface geometry 530a, a subsequent cutting element 536a comprising a conical cutting surface geometry 531a, and a trailing cutting element 537a comprising a flat cutting surface geometry 532a. While degrading a surface, the lead cutting element 535a may engage the surface first, cutting a first valley in the surface. The subsequent cutting element 536a may engage the surface next, cutting a second valley in the surface. The first and second valleys may form a cross-sectional topography in the surface resembling a waveform. In some embodiments, the waveform may be uniform or in other embodiments the waveform may comprise non-uniform spacing. The trailing cutting element 537a may then engage the surface and truncate crests of the waveform thus resulting in a smoother surface.
The embodiments shown in FIGS. 5b and 5c are similar to that of FIG. 5a in that they comprise lead cutting elements 535b, 535c, subsequent cutting elements 536b, 536c, and trailing cutting elements 537b, 537c. However, the lead cutting element 535b and subsequent cutting element 536b of the embodiment shown in FIG. 5b comprise cylindrical shaped cutting surface geometries 530b and 531b respectively. In addition, the lead cutting element 535c and subsequent cutting element 536c of the embodiment shown in FIG. 5c comprise dome shaped cutting surface geometries 530c and 531c respectively. The cylindrical shaped cutting surface geometries 530b, 531b and dome shaped cutting surface geometries 530c, 531c may form a cross-sectional topography in a degraded surface resembling a sinusoidal waveform. The crests of the sinusoidal waveform may then be truncated by flat cutting surface geometries 532b, 532c disposed on the trailing cutting elements 537b and 537c respectively.
FIG. 6 discloses an embodiment of a cutting element 620 comprising a flat cutting surface geometry 625. The flat cutting surface geometry 625 may be constructed by splitting a cylindrical polycrystalline diamond compact of the type known in the art through its axis.
FIGS. 7
a, 7b and 7c disclose graphical representations of progressive embodiments of a surface being degraded. Specifically, FIG. 7a discloses a graphical representation of an embodiment of a surface 750. The surface 750 has been partially degraded by a cutting element comprising a conical cutting surface geometry that has created v-shaped valleys 755 within the surface 750. FIG. 7b shows the surface of FIG. 7a after having been further degraded by a subsequent cutting element comprising a conical cutting surface geometry that has created additional v-shaped valleys 760. The plurality of v-shaped valleys 755 and 760 may form a cross-sectional topography resembling a waveform comprising crests 765 disposed between adjacent v-shaped valleys 755, 760. FIG. 7c shows the surface of FIG. 7b after having been further degraded by a trailing cutting element comprising a flat cutting surface geometry that has truncated the crests 765 to form truncated peaks 770 and a cross-sectional topography resembling a truncated waveform.
FIGS. 8
a and 8b disclose embodiments of surfaces 801a, 801b with cross-sectional topographies comprising truncated peaks 845a, 845b and valleys 844a, 844b. The embodiment shown in FIG. 8a comprises a cross-sectional topography wherein spacing between the valleys 844a may vary. For example, a first spacing 847 may be substantially smaller than a second spacing 848. FIG. 8b shows an embodiment of a surface 801b wherein valleys 844b have been formed by cutting elements with cylindrical or dome shaped cutting surface geometries resulting in a curved shape cutting profile. The cross-sectional topography of the surface 801b may resemble a sinusoidal waveform with truncated peaks.
FIG. 9 discloses an embodiment of a trenching machine 900 traveling over a degradable surface 901. A degradation platform 902 comprising a plurality of cutting elements disposed on a continuous chain 903 may be disposed thereon. The continuous chain 903 may be brought in contact with the degradable surface 901 in order to dig a trench therein.
Whereas the present invention has been described in particular relation to the drawings attached hereto, it should be understood that other and further modifications apart from those shown or suggested herein, may be made within the scope and spirit of the present invention.