Screed Plate Assembly and Method of Fabrication

Description

TECHNICAL FIELD

This patent disclosure relates generally to mobile paving machines for conducting a paving operation and, more particularly, to a screed plate for attachment to a floating screed assembly to distribute and compact the paving material to produce a paving mat.

BACKGROUND

Mobile paving machines, referred to as road pavers, are used during a paving operation to apply, spread, and compact paving material into a paving mat over the ground or road bed to produce a smooth, hard surface such as a roadway, parking lot or other paved area for cars, trucks, and other vehicles to travel upon. A typical example of paving material to produce a paved surface is a hot asphalt mix of hard aggregates like rocks, finer materials like sand, and a bitumen mixer or binder, and possibly other additives and modifiers. The paving material is initially in a loose, almost fluid, state to facilitate spreading and distribution over the work surface and to cover the desired areas.

To distribute the paving material, the mobile paver may be operatively associated with a floating screed assembly that is attached to and towed along the travel direction of the paver. The screed assembly includes one or more flat metal screed plates attached to the underside of a screed frame. The mobile paver delivers the paving material to the work surface in front of the forward leading edge of the screed plate, which is moved over the distributed material by the forward travel of the mobile paver. The floating screed assembly may be self-leveling and attached to the mobile paver to freely float over the distributed paving material, and the weight of the screed assembly and the flatness of the screed plates spreads and compacts the paving material to form a paving mat. In possible variations, the screed assembly may be configured to vibrate to improve compaction of the paving material and the screed plate can be heated to prevent the paving material from adhering thereto.

It is typically desirable to distribute the paving material as evenly and homogenously as possible to produce a paving mat with sufficient density and smoothness to serve as a roadway or similar paved surface subjected to the repeated passing of vehicles and changing weather conditions. To improve the homogenous and even distribution of aggregates and fines within the asphalt mix, U.S. Pat. No. 10,156,050 (“the '050 patent”) describes a screed assembly having screed plates with a textured surface thereon. The textured surface may include corrugations arranged parallel or perpendicular to the direction of travel of the mobile paver. The '050 patent describes that texturing of the underside of the screed plate produces a more homogenous sorting and distribution of aggregates in the paving material and thus a more durable paved surface.

SUMMARY

The disclosure describes, in one aspect, a screed plate for a screed assembly configured to be towed by a mobile paver. The screed plate can be assembled from a support plate that has a forward leading edge and a rearward trailing edge. The support plate also has an upper attachment surface extending between the forward leading edge and the rearward trailing edge and a lower material contacting surface that is adapted to compact and compress paving material sliding underneath the screed plate. The screed plate assembly also has a plurality of geometric texturing bosses that are mountable to the support plate. Each of the plurality of geometric texturing bosses includes a mounting base adapted for adjacent placement to the support plate and a protruding body adapted to project from the lower material contacting surface. To join the plurality of geometric texturing bosses to the support plate, the screed plate also include a plurality of structural joints.

In another aspect, the disclosure describes a method of assembling a screed plate from a support plate and a plurality of geometric texturing bosses. The method involves manufacturing a support plate having a forward leading edge, a rearward trailing edge, an upper attachment surface, and lower material contacting surface opposite the upper attachment surface. The method also includes manufacturing a plurality of geometric texturing bosses, each including a mounting base mountable to the support plate and a protruding body adapted to project from the lower material contacting surface. The method next assembles the plurality of geometric texturing bosses into a texturing pattern on the lower material contacting surface of the support plate. The method then joins the plurality of geometric texturing bosses to the support plate in a fixed relation within the texturing pattern.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view of a mobile paver with a floating screed assembly moving in a travel direction to produce a homogenous paving mat over a work surface.

FIG. 2 is a forward perspective view of the screed assembly configured with screed extenders laterally extended from the screed frame and a plurality of textured screed plate assemblies attached to the underside of the screed frame.

FIG. 3 is a perspective view of the underside of a textured screed plate assembly having a plurality of protruding geometric texturing bosses joined to and projecting from a flat lower material contacting surface in accordance with the disclosure.

FIG. 4 is perspective view of an example of a polyhedron texturing boss adapted for joinder to the flat lower material contacting surface to produce a textured screed plate assembly.

FIG. 5 is a perspective view of an example of a triangular or deltahedron texturing boss adapted for joinder to the flat lower material contacting surface.

FIG. 6 is a perspective view of an example of a pentahedron texturing boss adapted for joinder to the flat lower material contacting surface.

FIG. 7 is a perspective view of an example of a rhombic texturing boss adapted for joinder to the flat lower material contacting surface.

FIG. 8 is a perspective view of a protruding geometric texturing boss in the geometric shape of a truncated cone.

FIG. 9 is a perspective view of a protruding geometric texturing boss in the geometric shape of a globular teardrop.

FIG. 10 is a perspective view of a protruding geometric texturing boss in the geometric shape of a polyhedron pyramid.

FIG. 11 is a perspective view of a protruding geometric texturing boss in the geometric shape of a conical pyramid

FIG. 12 is flow diagram of a method of producing a screed plate having a texturing pattern by joining a plurality of geometric texturing bosses to the flat lower underside of the support plate.

FIG. 13 is a perspective assembly view of the underside of the support plate and a geometric texturing boss having a cooperative alignment feature.

FIG. 14 is a perspective view of a geometric texturing boss adapted to be fastened by a plurality of fasteners to the lower material contacting surface.

DETAILED DESCRIPTION

Now referring to the drawings, wherein whenever possible like reference numbers will refer to like elements, there is illustrated in FIG. 1 an example of a mobile paving machine or paver 100 for laying down paving material 102 on the ground, roadbed, or another work surface 104 to produce a paving mat 106 that paves over and covers the work surface resulting in a paved surface. The finished paved surface may be intended as a roadway, highway, structural foundation or other surface having hardness, flatness and durability characteristics to sustain repeated vehicular traffic and endure changing weather conditions, including temperature changes and precipitation. To distribute the paving material 102 over the work surface 104, the mobile paver 100 can be self-propelled and operated to travel in a travel direction 108 that is aligned with the longitudinal axis or orientation of the paver. As used herein, the terms “forward” or “leading” may refer to the forward direction of the mobile paver 100 when traveling in the travel direction 108, and the terms “aft,” “rearward” or “trailing” may refer to the direction rearward of the mobile paver.

To accommodate and carry paving material 102 prior to distribution on the work surface 104, the mobile paver 100 can include a hopper 110 that is supported on a machine frame or chassis 112 that is the loadbearing structural support and framework of the paver. The hopper 110 can be an opened box-like structure or bin including upward extending sidewalls 114 that are laterally opposed and that contain the paving material 102 deposited therein. The hopper 110 can be located at the forward end of the mobile paver 100 and can receive paving material 102 from above via a transport vehicle such as a dump truck. As the paving material is distributed from the mobile paver 100, the hopper 110 can be regularly replenished with fresh paving material delivered from an asphalt plant or facility.

To direct the loose, granular paving material rearward from the hopper 110, the mobile paver 100 includes a conveyor system 116 that extends through and is supported by the chassis 112. The conveyor system 116 may include one or more conveyor belts that translate about rotating pulleys or drums to move the paving material 102 rearward and discharge the material from the mobile paver 100 to the work surface 104.

To propel the mobile paver 100 over the work surface 104 during a paving operation, the chassis 112 can be supported on a plurality of ground engaging elements 118 that direct and transfer traction and propulsion forces to the work surface 104. An example of the ground engaging element 118 can be continuous tracks that are looped as a belt around a plurality of drive sprockets that can rotate with respect to the chassis 112. The continuous tracks translate with respect to the chassis 112 to move the mobile paver 100 over the work surface 104. Another example of ground engaging elements 118 can be rotatable wheels journalled to the chassis 112.

To generate motive power and drive the ground engaging elements 118, the mobile paver 110 can include an engine 120 supported on the chassis 112. The engine 120 can be a conventional internal combustion engine that combusts a hydrocarbon-based fuel to convert the lateral chemical energy therein to motive power for propulsion and other work. The engine 120 can also be associated with a generator 122 to generate electricity for powering the electrical system of the mobile paver 100. In other possible configurations, the mobile paver 100 can include an electrical powertrain and can be operatively driven by a plurality of electrical storage batteries or fuel cells.

To accommodate an operator for steering and controlling the mobile paver 100, an operator station 124 or operator cab can be situated on top of the chassis 112 in a location providing visibility over the work surface 104. Located in the operator station 124 can be various controls and input control devices 126 such as a steering wheel to alter the travel direction 108 of the mobile paver 100, accelerator and brake pedals, gear and direction shifters, and the like. To visually interface with the operator, the operator station can include an instrument console 128 having various dials, readouts, display screens and the like. Moreover, the input control devices 126 and the instrument console 128 can be associated with an electronic controller configured or programmed to receive and process data and information to assist in operation of the mobile paver 100.

To more evenly distribute the paving material 104, a screed assembly 130 can be coupled to the rear end of the chassis 112 that can be moved over the deposited paving material 102 by the forward travel of the mobile paver 100 in the travel direction 108. The screed assembly 130 can be associated with an auger 132 located rearward and below the conveyor system 116 and arranged to direct and move the loose paving material 114 discharged therefrom laterally towards the sides of the chassis 112. The auger 132 is arranged in a lateral direction 134 or axis that is perpendicular to the forward and rearward travel directions 108 and at right angles to the longitudinal axis of the chassis 112. Moreover, the auger 132 is vertically adjacent to the work surface 104 and establishes a vertical direction 135 normal to both the travel direction 108 and the lateral direction 134. The auger 132 can be an elongated rotating structure with oppositely directed spiral or helical flights that push the paving material 104 laterally outward when rotated.

To compress and smooth the granular paving material 102 laterally distributed by the auger 132, the screed assembly 130 includes one or more screed plates 136 that are attached to the underside of a screed frame 138. The screed plates 136 are metal plates adapted to contact and slide over the paving material 102 deposited on the work surface 104, and the weight and load of the screed frame 138 compresses the loose paving material 102 into the denser, harder paving mat 106. By way of example, the material of the screed plates 136 can be cast nickel or hardened steel.

To increase the compressive forces applied to the paving mat 106, the screed frame 138 can include internal eccentric weights that generate vibrating forces in the vertical direction 135 that vibrate the screed plates 136 contacting the paving material 102. To prevent the paving material 102 from cooling and adhering to the screed plates 136, the screed assembly 130 can be associated with inductive heaters located in the screed frame 138.

To adjust the thickness of the paving mat 106, the screed assembly 130 can be pivotally connected to the chassis 112 by one or more tow arms 140. The tow arms 140 are pivotally so that the screed frame 138 can be pivotally tilted with respect to the chassis 112 to adjust the angle of attack, or the angle that the screed plates 136 encounter and come into contact with the paving material 102 exiting the conveyor system 116 onto the work surface 104. Adjusting the angle of attach enables the screed plates 136 to move and slide over the paving material 102 allowing the screed assembly 130 to float with respect to the work surface 104. To raise and lower the screed assembly 130 in the vertical direction 135 to contact and disengage from the work surface 104, one or more extendable and retractable hydraulic lift cylinders 141 can also be connected between the chassis 112 and the screed frame 138.

Referring to FIG. 2, the screed assembly 130 can be extendable in the lateral direction 134 to adjust the lateral width of the screed frame 138. For example, the screed frame 138 can include a main screed section 142 and first and second extender screed sections 144 located toward the opposite lateral ends of the screed assembly 130. The extender screed sections 144 can be located behind the main screed section 142 and the structures can be slidingly connected together, for example, by a sliding dovetail rail. In another configuration, the extender screed sections 144 can be mounted toward the front of the screed frame 138 with respect to the travel direction 108.

The screed assembly 130 can also include hydraulically actuated extender cylinders 146 that operatively connect the main screed section 142 with the first and second extender screed sections 144. Actuation of the extender cylinders 146 moves the first and second extender screed sections 144 in the lateral direction 134 with respect to the main screed section 142. To retain the lateral distribution of the paving material 104, the first and second extender screed sections 144 can each include a lateral flange 148 or blades parallel to and aligned in the travel direction 108.

The screed plates 136 can be removably attached to the underside of main screed section 142 and the first and second extender screed sections 144. A plurality of screed plates 136 can extend across the lateral width of the screed frame 138 to produce a continuously smooth flat paving mat 106 across the lateral direction 134 and extending rearward of the screed assembly 130 in the travel direction 108.

The front of the screed frame 138 may also include a forward panel that extends upward from the intersection with the screed plates 136 that may be configured as a solid planar panel extending in the lateral direction 134. The front of the screed frame 138 pushes excess paving material 102 discharged from the conveyor system forward in the travel direction 108 until the material flows under and is compressed by the screed plates 136. The screed assembly 130 may also include a tamper bar adjacent to the front of the screed frame 138 that can be rapidly and repeatedly moved upward and downward in the vertical direction 135 to tamper and compact the paving material flowing underneath the screed plates 136.

Referring to FIG. 3, in an aspect of the disclosure, the screed plate 136 can be assembly from components that are arranged to improve compaction of the paving material and formation of the paving mat. For example, to function as a structural framework and support, the screed plate 136 can include a support plate 150 that is flat and planar in shape and that may have a rectangular outline or perimeter. The support plate 150 can be manufactured by a casting process in which molten metal is poured into a mold of a desired shape and cooled to harden. Examples of suitable metals include high carbon steel, nickel alloys, and chromium carbide steel, cast iron, hardened aluminum—zinc alloys, and other materials having sufficient hardness and strengths for prolonged physical contact and interaction with the paving material. Other possible materials for the support plate may include ceramics and plastics.

To conform to the flat planar shape, the support plate 150 can have a lower material contacting surface 152 and an upper attachment surface 154 opposite the lowered material contacting surface. When the screed plates 136 are attached to the screed frame, the lower material contacting surface 152 is oriented to interface with the paving material that moves thereunder and the upper attachment surface 154 is in abutting contact with the screed frame. The lower material contacting surface 152 can be flat and planar as shown, although in possible variations, the lower material contacting surface may include structural features for enhancing interaction with the paving material. The upper attachment surface 154 can be flat and planar, although in some configurations, the upper attachment surface 154 can include mounting and attachment features to secure the screed plate 136 to the screed frame.

The lower material contacting surface 152 and the upper attachment surface 154 can extend between a forward leading edge 156 and a rearward trailing edge 158 of the rectangular outline of the plate casting 150. The terms forward leading edge 156 and a rearward trailing edge 158 are in reference to the travel direction 108 of the mobile paver and reflect movement of the screed plate 136 with respect to the work surface.

The forward leading edge 156 and a rearward trailing edge 158 may be linear and parallel to each other in the lateral direction 134. The distance between the forward leading edge 156 and a rearward trailing edge 158 corresponds to the longitudinal length of the screed plate 136 and may be coextensive with the length of the screed frame in the travel direction 108. To assist directing the paving material underneath the screed plate 136, the forward leading edge 156 may be slightly turned up in the vertical direction 135.

The rectangular outline or perimeter of the plate casting 150 can also include parallel first and second side edges 160, 162 that extend between the forward leading edge 156 and the rearward trailing edge 158. The distance between the first and second side edges 160, 162 corresponds to the width of the screen plate 136 in the lateral direction 134. The first and second side edges 160, 162 can be linear and flat to abut seamlessly against the side edges of adjacent screed plates 136 when attached to the screed frame.

To improve mixing of the paving material passing underneath the screed plate 136, a three-dimensional texturing pattern 164 can be included on the lower material contacting surface 152 of the support plate 150. The three dimensional topology of the texturing pattern 164 has structural variation with respect to the vertical direction 135. The structural unevenness and topographic variability of the texturing pattern 164 may displace larger aggregates within the paving material. The movement and shifting of the paving material caused by the structure of the texturing pattern 164 may further embed the aggregates within the fines and binders, resulting in a denser and harder paving mat. Further, the additional mixing caused by the texturing pattern 164 may result in a more homogenous consistency of the aggregates and fines within the paving material 102, also resulting in improvement in the characteristics of the produced paving mat 106.

To produce the structure of the texturing pattern 164, a plurality of geometric texturing bosses 166 can be mounted to the otherwise planar lower material contacting surface 154 of the support plate 150. The plurality of geometric texturing bosses 166 can be arranged in a random or organized pattern and can be spaced apart from each other to produce a corresponding plurality of channeling grooves 168 located between the geometric texturing bosses. The arrangement of the protruding elements 166 and channeling grooves 168 results in a variably elevation with respect to the vertical direction 135. For example, the geometric texturing bosses 166 can each have a three dimensional structural shape projecting from the lower material contacting surface 154 including in a spatial extension with respect to the vertical direction 135.

For example, each of the plurality of geometric texturing bosses 166 can have a mounting base 170 adapted to attach with the lower material contacting surface 152 and a protruding body 172 that extends from the mounting base 170. The protruding body 172 may extend to a projected pinnacle 174 that is spaced apart from the mounting base 170 with respect to the vertical direction 135. The distance between the mounting base 170 and the projected pinnacle 174 can define the body height 176 of the geometric texturing boss 166 in the vertical direction 135. The geometric texturing bosses 166 can be formed distinctly from the support plate 150, for example, by casting metallic material, and the mounting base 170 can be joined to the lower material contacting surface 152 by an assembly process.

To join the geometric texturing bosses 166 adjacently to the support plate 150, the mounting base 170 can be operative associated with a structural joint 178. The structural joint 178 can function to securely fix and maintain the texturing bosses 166 in defined locations within the texturing pattern 164 on the support plate. For example, in the embodiments where the support plate 150 and the geometric texturing bosses 166 are cast metallic materials, the structural joint 178 can be a welding bead or brazing bead respectively formed by a welding or brazing process. The structural joint 178 can extend around the perimeter of the mounting base 170 at the intersection with the lower material contacting surface 156 such that the materials of the support plate 150 and the geometric texturing bosses 166 are integrally joined or formed together. The structural joint 178 joining the geometric texturing bosses 166 to the support plate 150 can be created by the application of thermal heat, laser welding, or chemical processes. In another example, the structural joint 178 can be formed by a strong adhesive or bonding cement located between the geometric texturing bosses 166 and the lower material contacting surface 152 of the support plate 150.

In possible variations, the structural joint 178 may be removable to allow for detachment of the geometric texturing bosses 166 from the screed plate, such as threaded fasteners. In another example, the fasteners may be more permanent such as rivets.

The mounting base 170 functions as a foundation or footprint and the protruding body 172 corresponding in shape to the outline or periphery of the mounting base 170. The mounting base 170 can be smooth and flat to adjacently contact and abut the correspondingly smooth and planar lower material contacting surface 152 of the screed plate 150. The protruding body 172 can be dimensioned and adapted to project and extend from the lower material contacting surface 152 in the vertical direction 135 when the mounting base 170 is attached to the support plate 150. The geometric texturing bosses 166 can have any suitable three dimensional shape for interacting with the paving material. Moreover, each of the plurality of geometric texturing bosses 166 can have identical shapes, as shown in the texturing pattern 164 in FIG. 3, or may have different geometric shapes. For example, referring to FIG. 4, the geometric texturing bosses 166 can be three-dimensional polyhedrons having a plurality of flat faces interacting along straight edges and along sharp vertices.

In an example, the polyhedron boss 180 can be shaped as a diamond or rhombus including a four-sided rhombic base 182 having four intersecting edges 184. Associated with and extending from each edge 184 of the four-sided rhombic base 182 is a two-dimensional side face 186 that is flat and planar. The side faces 186 may intersect with the rhombic base 182 at an inward angle and can taper toward a flat, planar pinnacle face 188. The pinnacle face 188 can be parallel to and can correspond in shape to the four-sided rhombic base 182 such that the rhombic boss 180 is geometrically configured as a prism.

In an embodiment, the shape of the polyhedron boss 180 can establish a major diagonal 190 of the rhombic base 182 that extends between two opposing vertices. The rhombic base 182 can also include a minor diagonal 192 that perpendicularly intersects the major diagonal 190. The major diagonal 190 is longer than the minor diagonal 192 so that the rhombic base 182 has an oblong length greater than the width. Moreover, the opposing vertices associated with the major diagonals 190 can be angularly smaller than the corresponding vertices associated with the minor diagonal 192

The polyhedron boss 180 can include a leading boss edge 194 and a trailing boss edge 196 that extends between the rhombic base 182 and the pinnacle face 188 and that is formed by the intersection of two of the side faces 184. The leading boss edge 194 can be aligned with the major diagonal 190. When the polyhedron boss 180 is attached to the lower material contacting surface 152, the leading boss edge 194 is oriented toward the forward leading edge 156 of the support plate 150 and the trailing boss edge 196 toward the rearward trailing edge 158 of the support plate 150. Moreover, the leading boss edges 194 and the trailing boss edges 196 can extend at smaller or shallower angles with respect to the rhombic base 182, and thus have an overall longer dimension, than the side boss edges 198 that may be associatively aligned with the shorter minor diagonal 192 of the rhombic base 182.

Referring to FIG. 5, in an example, the polyhedron boss can be delta shaped or triangular boss, referred to herein as a deltahedron boss 200, having three-sided triangular base 202 with three edges 204 and three side faces 206 extending therefrom. The three side faces 206 can extend to and intersect with a pinnacle face 208 that is parallel to and that corresponds in shape with the triangular base 202 such that the deltahedron boss 200 is a geometric prism. Moreover, the three side faces 206 can angle inwardly with respect to the triangular base 202 and converge toward the pinnacle face 208 so that the deltahedron boss 200 has a tapered configuration.

In an example, the deltahedron boss 200 can be a geometric isosceles triangle and can have a longer leading boss edge 210 that is formed along two intersecting side faces 206 and that is orthogonal to a shorter trailing boss base 212. When joined to the lower material contacting surface 152 of the screed plate 136, the leading boss edge 210 can be oriented toward the forward leading edge 156 of the support plate 150 and the trailing boss base 212 can be oriented toward the rearward trailing edge 158.

Referring to FIG. 6, in an example, the polyhedron boss can be a pentahedron boss 220 having a five sided pentagonal base 222 including five edges 224 from each of which extends one of five side faces 226. The five side faces 226 can extend to and intersect a flat planar pinnacle face 228 that is parallel to and that corresponds in shape to the pentagonal base 222. The five side faces 226 can also be angulated inwardly with respect to the pentagonal base 222 so that the pentahedron polyhedron 220 is generally tapered.

The pentagonal boss 220 can include five boss edges 230 that extend between the pentagon base 222 and the pinnacle face 228. In an example, the pentagonal boss 220 can have a regular pentagon base 222 such that each of the boss edges 230 have the same length, and any of the five symmetrically similar boss edges 230 can be oriented toward the forward leading edge 156 when the pentagonal boss is joined to the support plate 150. In other examples, the pentagonal base 222 can be irregular and asymmetrical in shape and the five boss edges 230 can have different lengths. The asymmetrical pentahedron bosses can be mounted to the lower material contacting surface 152 of the support plate 150 in a suitable orientation to reduce friction and resistance and facilitate sliding interaction with the paving material.

Referring to FIG. 7, in an example, the polygonal boss can be a trapezoidal boss 240 having a four sided trapezoid base 242 with four edges 244, two of which may be parallel and two of which are not parallel. Extending from each of the four edges 244 can be a trapezoid shaped side face 246 that collectively intersects a flat planar pinnacle face 248 corresponding in shape and parallel to the trapezoid base 242. The four side faces 246 are oriented at an inward angle with respect to the trapezoid base 242 so that the trapezoidal boss 240 is a tapered prism.

Because of the non-parallel edges 244, the trapezoidal boss 240 can include a leading face 250 and an oppositely situated trailing face 252. The leading face 250 can be shorter in dimension than the trailing face 252. When the trapezoidal boss 240 is joined to the support plate 150, the leading face 250 can be oriented toward the forward leading edge 156 so as to encounter the paving material first. The shorter width provided by the leading face 250 may result in the trapezoidal boss 240 encountering less resistance in operation as the structure moves through and displaces the paving material

Referring to FIG. 8, in an example, the geometric texturing boss can have a circular, rounded, or curvilinear shape rather than be geometrically configured as a polygonal structure. For example, a curvilinear boss 260 can have circular base 262 circumscribed by a circumferential edge 264. The circumferential edge 264 may be an enclosed curved lines extending 360° and intersecting itself as a circle. Extending from the circumferential edge 264 can be a cylindrical or conical sidewall 266 that intersects and terminates at a flat planar pinnacle face 268. The pinnacle face 268 can be parallel to and can correspond in circular shape to the circular base 362 so that that curvilinear boss 260 is geometrically configured as a prism. To tapper the curvilinear boss 260, the conical sidewall 266 converges radially inward with respect to the circular base 262 and can be truncated by the pinnacle face 268.

The circular or rounded shape of the curvilinear boss 260 results in symmetrical geometry that allows the curvilinear boss 260 to be attached at any orientation with respect to the forward leading and rearward trailing edges 156, 158 of the support plate 150. In other examples, the curvilinear boss 260 may have an oval or elliptical mounting base and a corresponding geometry. The asymmetrical curvilinear bosses can be mounted to the lower material contacting surface 152 of the support plate 150 in a suitable orientation to reduce friction and resistance and facilitate sliding interaction with the paving material.

For example, referring to FIG. 9, there is illustrated a geometric texturing boss having an asymmetrically curved geometry in the configuration of a teardrop or globular shaped boss 270. The teardrop boss 270 can have a flat, planar mounting base 272 that is outlined by a curvilinear edge 274 that is geometrically shaped as a teardrop. Extending from the curvilinear edge 274 is a corresponding curvilinear face or sidewall 276 that intersects with a flat planar pinnacle face 278. The pinnacle face 278 is parallel to and corresponds in shape with the mounting base 272 such that the teardrop boss 270 is a three-dimensional prismatic structure.

The teardrop boss 270 can include a forward or leading boss edge 280 corresponding to the intersection of the curvilinear sidewall 276 upon itself. The leading boss edge 280 can be situated at an angle with respect to the mounting base 272 such that the forwardly directed portions of the curvilinear sidewall 276 proximate to the leading boss edge 280 tapers between the curvilinear edge 274 and the pinnacle face 278. When the teardrop boss 270 is attached to the lower material contacting surface 152, the leading boss edge 280 is directed toward the forward leading edge 156 of the support plate 150 to penetrate and reduce sliding resistance with respect to the paving material. To complete the teardrop shape, the teardrop boss 270 can also include a curved or U-shaped trailing face 282 opposite the leading boss edge 280 that extends between the mounting base 272 and the pinnacle face 278.

In addition to being geometrically shaped as a prism, in which the pinnacle face 176 is generally parallel and corresponds in shape to the mounting base 170, the geometric texturing bosses 166 can be configured as geometric pyramids. A pyramid boss can be characterized as having a mounting base of a particular surface area and one or more side faces that converge to a common point or pinnacle apex.

For example, referring to FIG. 10, there is illustrated a geometric texturing boss in the configuration of a pyramid boss 290 having a polygonal base 292 adapted for mounting to the screed plate and a pinnacle apex 294, embodied as a singular point, that is spaced apart from the polygonal base 292. Extending between the polygonal base 292 and the pinnacle apex 294 can be a plurality of side faces 296 which may be triangular in shape. The plurality of side faces 296 angular converge toward the pinnacle apex 294 from the mounting base 292 so that the pyramid boss 290 has a tapered geometry. The polygonal base 292 can have any suitable shape and the flat side faces 296 can be provide in any suitable number so that the pyramid boss 290 can have various different geometric configurations.

Referring to FIG. 11, there is illustrated a geometric texturing boss geometrically corresponding to a curved or rounded pyramid such as, for example, a conical boss 300. The conical boss 300 can include a circular mounting base 302 of a given surface area and a pinnacle apex 304 spaced apart from the circular base 302. Extending between the circular base 302 and the pinnacle apex 304 can be continuous conical side face 306. The conical side faces converges radially inward between the circular base 302 and the pinnacle apex 304 such that the conical boss 300 is conically shaped.

The geometric texturing bosses 166 described herein are exemplary, and the geometric texturing bosses can have other suitable shape and configuration sufficient to interact with the paving material to produce a homogenous and dense paving mat. The shape and configuration of the geometric texturing bosses 166 can be selectively designed and adapted for specific paving operations. For example, geometric configuration of the texturing boss 166 can be adapted to interface with particular compositions of paving materials such as based upon aggregate size and binder viscosity. As another example, the body height 176 of the geometric texturing boss 166 can be set adapted to correspond to the depth of the paving mat being produced.

The texturing pattern 164 can be characterized structurally by arranging the geometric texturing bosses 166 in successive lateral boss rows 310 that are aligned parallel to the forward leading and rearward trailing edges 156, 158, in the lateral direction 134. For example, as shown in FIG. 3, the successive lateral element rows 310 can extend generally between the parallel first and second side edge 160, 162 over the lateral width of the support plate 150. In a particular example, the texturing pattern 164 may include a plurality of successive lateral boss rows 310 including a first boss element row 312 that extends adjacent and parallel to the forward leading edge 156 of the support screed plate 150 and a second lateral boss row 314 that is situated rearward of the first lateral boss row 312 with respect to the travel direction 108. A third lateral boss row 316 can be situated rearward of the second lateral boss row 314 so that the texturing pattern 164 extends toward the rearward trailing edge 158 of the support plate 150.

The geometric texturing elements 166 in each of the successive lateral boss rows 310 can be laterally spaced apart from each other in the lateral direction 134 resulting in a dimensional boss pitch 318. The lateral spacing associated with the boss pitch 318 may produce the channel groove 168 delineated between the plurality of geometric texturing bosses 166. The channeling grooves 168 direct the paving material to pass between the adjacent protruding elements 166 as the lower textured surface 152 moves with respect to the work surface. The channeling grooves 168 may extend generally along the travel direction 108 across the length of the lower textured surface 152.

The successive lateral boss rows 310 of the texturing pattern 164 can be staggered and offset with respect to each other. For example, the geometric texturing bosses 166 of the second lateral boss row 314 can be laterally shifted and offset in the lateral direction 134 with respect to the plurality of geometric texturing bosses 166 in the first lateral boss row 312. The geometric texturing bosses 166 of the second lateral boss row 314 are located in the boss pitch 318 of the first lateral boss row 312 therefore interspersed between the respective geometric texturing bosses 166 of the first lateral boss rows 312. The geometric texturing bosses 166 of the third lateral boss row 316 may align with the geometric texturing bosses 166 in the first lateral boss row 312 with respect to the travel direction 108.

As a result of the lateral staggering of the successive lateral boss rows 310 of the texturing pattern 164, the channeling grooves 168 may assume a crooked or zigzag pattern across the lower textured surface 152 as the channeling grooves extend from the forward leading edge 156 toward the rearward trailing edge 158. The crooked or laterally shifting pattern of the channeling groove 168 assists in physically manipulating and mixing the paving material moving there through.

In an embodiment, to assist in smoothing the produced paving mat, the screed plate 136 may include a lateral leveling band 320 that is located adjacent to the rearward trailing edge 158 of the lower textured surface 152. The lateral leveling band 320 may be located rearward of the texturing pattern 164 in travel direction 108. The lateral leveling band 312 can be characterized by the absence of any protruding elements 166 and channeling grooves 168 of the texturing pattern 164, and thus has a flat planar configuration. The lateral leveling band 320 can occupy the remaining 15% to 33%, and particularly the remaining 20%, of the length of the lowered textured surface 152 in the travel direction 108 of the screed plate 136. The vertical flatness of the lateral leveling band 320 may function to further compact and smooth out the paving material moving underneath the screed plate 136

To attach the screed plate 136 to the screed frame, the support plate 150 can include one or more attachment devices 322, 324 located on the upper attachment surface 154. The attachment devices 322 can be configured as opposing claws extending in the lateral direction 134 across the upper attachment surface 154 with a first attachment device 322 adjacent to the forward leading edge 156 and the second attachment device 324 located proximate to the rearward trailing edge 158. The attachment devices 322, 324 can engage and release with corresponding structures on the screed frame to releasably attach the screed plate 136. In addition to the claw-like configuration, the attachment devices 322, 324 can utilize different connection techniques and structures to attach the screed plate and screed frame.

INDUSTRIAL APPLICABILITY

Referring to FIG. 12, with continued reference to the proceeding figures, there is illustrated an exemplary flow diagram of a method and process of fabricating a screed plate 136 with a texturing pattern 164 for physically manipulating aggregate paving material during a paving operation. Aspects of the illustrated fabrication process 400 may be conducted at a manufacturing facility or industrial plant to produce screed plates 136 at large volumes on an industrial scale. Aspects of the fabrication process 400 can also be conducted in the field to adapted and retrofit existing screed plates 136 with flat, planar, lower material contacting surfaces 154 to incorporate a texturing pattern 164 as described herein. Additionally, aspects of the fabrication process 400 can be conducted to repair and refurbish screed plates 136 in which the three-dimensional texturing pattern 164 has become worn or damaged, for example, during prolonged interaction with abrasive paving materials. Repair or refitting kits that include a plurality of geometric texturing bosses 166 and related hardware can be provided for these purposes.

To produce the structural components, the fabrication process 400 can include a plate manufacturing step 402 in which the support plate 150 is produced. For example, the support plate 150 can be cast by introducing molten metal to a correspondingly shaped mold that is allowed to harden. In another example, the support plate 150 can be machined from existing stock material during the plate manufacturing step 402. Possible other materials suitable for the support plate may include ceramics and plastics. The support plate 150 can also be produced from different material and processes. The support plate 150 may be manufactured with the lower material contacting surface 152 having a flat, planar shape.

The fabrication process 400 can also include a boss manufacturing step 404 in which a plurality of geometric texturing bosses 166 are produced. In various examples, the boss manufacturing step 404 can produce the geometric texturing bosses 166 by casting steel or metallic alloys or may involve machining with conventional machine tools. Possible other materials suitable for the geometric texturing bosses may include ceramics and plastics. In some examples, the geometric texturing bosses 166 themselves may be assembled from one or more subcomponents.

The fabrication process 400 can next involve an assembly step 408 in which the support plate 150 and the plurality of geometric texturing bosses 166 are assembled together to produce the texturing pattern 164 located on the lower material contacting surface 152. The texturing pattern 164 may arrange and organize the plurality of geometric texturing bosses 166 in sequential rows between the leading edge 156 and the trailing edge 158 of the screed plate 136 as shown in FIG. 3. The organized texturing pattern 164 can produce the staggered and laterally shifting arrangement of the channeling grooves 168 formed between the geometric texturing bosses 166. In other configurations, for example, when the screed plate 136 is assembled in the field in a refitting operation, the locations of the geometric texturing bosses 166 in the texturing pattern 164 can be random. The assembly step 408 can involve placing the mounting bosses 170 of the plurality of geometric texturing bosses 166 adjacent to the flat, planar lower material contacting surface 152 of the support plate so that the protruding body 172 projects from the lower material contacting surface 152 and the projected pinnacle 174 is vertically spaced therefrom in the vertical direction 135. Indicia may be provided or included on the lower material contracting surface 152 to assist in placing the plurality of geometric texturing bosses 166 in the texturing pattern 164.

To secure and fix the plurality of geometric texturing bosses 166 arranged on the support plate 150, the assembly step 408 can include a mounting and joining operation 410 or sub-step. The mounting and joining operation 410 can utilize various different techniques. For example, in a bonding operation 412, the geometric texturing bosses 166 can be physically bonded to the lower material contacting surface 152 of the support plate 152. In a particular example, the bonding operation 412 can utilize a welding or a brazing operation in which the metallic geometric texturing bosses 166 are structurally joined to the material of the support plate 150, with or without a filler material per convention. The bonding operation 412 can produce the structural joint 178 between the geometric texturing boss 166 and the support plate 150 shown in FIG. 3. In another example, the bonding operation 412 can utilize adhesive or cement to join the geometric texturing boss 166 and support plate 150.

In another example, the mounting and joining step 410 can utilize alignment features to align the geometric texturing bosses 166 with respect to the texturing pattern 164 and to assist in joining them to the support plate 150. Alignment of the geometric texturing bosses 166 can be accomplished by an alignment operation 414. The alignment operation 414 can assist in producing texturing patterns 164 have an organized arrangement of the plurality of geometric texturing bosses 166 such as successive rows.

Referring to FIG. 13, in an example, to create the alignment features 416, the support plate 150 can include a plurality of alignment recesses 418 that are disposed into the lower material contacting surface 152. The alignment recesses 418 can be empty spaces cast or machined into the support plate 150, accessible from the lower material contacting surface 152, and that correspond in shape to the geometric texturing bosses 166. For example, if the geometric texturing bosses 166 are rhombic or configured as polyhedrons, the plurality of alignment recesses 418 can each be shaped as diamonds or polygons of similar shapes and sizes that protruded into the lower material contacting surface 152 of the support plate 150.

To utilize the alignment features 416, each geometric texturing boss 166 is oriented toward the respective alignment recess 418 with the mounting base 170 facing the lower material contacting surface 152. The outline of the mounting base 170 may correspond to the shape of the alignment recess 418 such that the geometric texturing boss 166 can be inserted and form sliding fit therein. The depth of the alignment recess 418 may be dimensioned to accommodate the mounting base 170 with the protruding body 172 projecting beyond the lower material contacting surface 152. The geometric texturing boss 166 accommodated in the alignment recess 418 can be structurally joined to the support plate 150, for example, by the bonding operation 412.

An advantage of the alignment features 416 may be maintenance of the orientation of the plurality of geometric texturing bosses 166 within the texturing pattern 164. For example, where the geometric texturing bosses 166 include leading boss edges and trailing boss edges, those feature may be correctly oriented and aligned with respect to the forward leading edge 156 and the rearward trailing edge 158 of the support plate 150. The alignment features 166 can also maintain the desired spacing of the plurality of geometric texturing bosses 166 within the texturing pattern 164 to produce the desired shape and arrangement of the channeling grooves 168. The alignment features 416 thus facilitates assembly of the screed plate 136.

In another example, the geometric texturing bosses 166 can be removable from the support plate 150. For example, if the protruding body 172 of an individual geometric texturing boss 166 becomes worn or damaged, the component can be removed and replaced as part of a fastening operation 420. To facilitate removable attachment, referring to FIG. 14, the geometric texturing bosses can include one or more fastener apertures 422 disposed into the structure of the mounting base 170. The fastener aperture 422 can be cylindrical holes or bores configured to receive a threaded fastener 424 that can engage with a corresponding threaded bore disposed into the lower material contacting surface 152 of the support plate 150. In the fastening operation 420, the threaded bolts 424 can secure the geometric texturing bosses 166 to the support plate 150 in the texturing pattern 164 and can be unthreaded to remove the geometric texturing bosses 166 when desired.

In an embodiment, the mounting base 170 may include a peripheral rim 426 or flange that projects laterally with respect to the protruding body 172. The fastener apertures 422 can be situated in the peripheral rim 426 for accessibility. In another embodiment, the fastener apertures 422 can be disposed into the structure of the protruding body 172. The fastener apertures 422 can include counterbores to accommodate the fastener heads and avoid interference with and disruption of the paving material during sliding contact. The use of fasteners 424 to join the geometric texturing bosses 166 to the support plate 150 may facilitate refitting existing screed plates 136 in service.

It will be appreciated that the foregoing description provides examples of the disclosed system and technique. However, it is contemplated that other implementations of the disclosure may differ in detail from the foregoing examples. All references to the disclosure or examples thereof are intended to reference the particular example being discussed at that point and are not intended to imply any limitation as to the scope of the disclosure more generally. All language of distinction and disparagement with respect to certain features is intended to indicate a lack of preference for those features, but not to exclude such from the scope of the disclosure entirely unless otherwise indicated.

Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context.

The use of the terms “a” and “an” and “the” and “at least one” or the term “one or more,” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The use of the term “at least one” followed by a list of one or more items (for example, “at least one of A and B” or one or more of A and B”) is to be construed to mean one item selected from the listed items (A or B) or any combination of two or more of the listed items (A and B), unless otherwise indicated herein or clearly contradicted by context.

Accordingly, this disclosure includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the disclosure unless otherwise indicated herein or otherwise clearly contradicted by context.