Screed plate with non-linear profile

Abstract

A screed plate that includes a first surface configured to engage a screed system of a paver; and a second surface opposite the first surface, the second surface configured to contact a paving material, and wherein the second surface has a non-linear profile in a direction from a front end to a back end of the screed plate.

Description

SCREED PLATE WITH NON-LINEAR PROFILE, INCLUDING AT LEAST ONE CURVED PLATE SECTION AND / OR TWO OR MORE SEGMENTED PLATE SECTIONSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 496,551, filed April 17, 2023, and U.S. Provisional Patent Application No. 63 / 579,278, filed August 28, 2023, and hereby incorporates by reference herein the contents of these applications.TECHNICAL FIELD

[0001] Aspects of the disclosure are directed to screed plates having a non-linear profile. In some aspects, the screed plates may have a curved profile. In some aspects, the screed plate can be used with a road paver.BACKGROUND

[0002] Road pavers are used to apply a paving material, such as hot mix asphalt or concrete, to surfaces at sites such as highways, airports, roads, and construction sites. The paving material is typically loaded in front of a tractor of the road paver, typically in a hopper, and conveyed to the rear by a set of flight feeders (conveyor belts), where the paving material is spread to a desired width by a set of augers in the road paver, and then leveled and compacted by a screed system. The screed system is typically towed behind the tractor of the paver. The screed system typically includes a screed plate. The screed plate is typically heated so as to effectively spread, level, and compress the paving material across the surface being paved.SUMMARY

[0003] The following presents a simplified summary of one or more aspects of the disclosure in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects of the disclosure in a simplified form as a prelude to the more detailed description that is presented later.

[0004] According to some aspects, the present disclosure is directed to a screed plate including a first surface configured to engage a screed system of a paver and a second surface oppositethe first surface. The second surface is configured to contact a paving material. The second surface has a non-linear profile in a direction from a front end to a back end of the screed plate.

[0005] To the accomplishment of the foregoing and related ends, the one or more aspects of the disclosure comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail include certain illustrative features of the one or more aspects. These features are indicative, however, of but a few of the various ways in which the principles of various aspects can be employed, and this description is intended to include all such aspects and their equivalents.BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The novel features believed to be characteristic of aspects described herein are set forth in the appended claims. In the descriptions that follow, like parts are marked throughout the specification and drawings with the same numerals, respectively. The drawing figures are not necessarily drawn to scale and certain figures can be shown in exaggerated or generalized form in the interest of clarity and conciseness. The disclosure itself, however, as well as a preferred mode of use, further objects and advances thereof, will be best understood by reference to the following detailed description of illustrative embodiments when read in conjunction with the accompanying drawings, wherein:

[0007] FIG. 1 illustrates a side view of a road paver according to an aspect of the disclosure;

[0008] FIG. 1A illustrates a detail view of a screed system of the road paver of claim 1 according to an aspect of the disclosure;

[0009] FIG. 2 illustrates a side view of a screed plate according to an aspect of the disclosure;

[0010] FIG. 3 illustrates a side view of another screed plate according to an aspect of the disclosure;

[0011] FIG. 4 illustrates a side view of another screed plate according to an aspect of the disclosure;

[0012] FIG. 5 illustrates a side view yet another screed plate according to an aspect of the disclosure; and

[0013] FIG. 6 illustrates a side view of yet another screed plate according to an aspect of the disclosure.

[0014] FIG. 7 illustrates a plot of percent compaction of the paving material versus gyration according to an aspect of the disclosure.DETAILED DESCRIPTION

[0015] The detailed description set forth below in connection with the appended drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein can be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of various concepts. However, it will be apparent to those skilled in the art that these concepts can be practiced without these specific details. In some instances, well known structures and components are shown in block diagram form in order to avoid obscuring such concepts.

[0016] FIG. 1 illustrates a road paver 100 according to an aspect of the present disclosure. The road paver 100 includes a tractor 104 and a screed system 108. The tractor 104 may include a hopper, a conveyor system, and an operator cabin 112. Although the figures and following description are in relation to a rear-mount screed system, the invention described herein is also useable in front-mount screed systems as well.

[0017] During paving, the paving material 128 is fed from the hopper via the conveyor system in a direction shown by arrow 134 and deposited in front of a front end 138 of the screed system 108. The screed plate 316 of the screed system is configured to spread and compact the paving material along the surface to be paved. For example, the screed plate 316 may be configured to engage the paving material 128 dispensed from the road paver 100 so as to spread and level the paving material 128 along the surface to be paved. In some aspects of the disclosure, the bottom surface (e.g., the surface configured to contact the paving material) may include a pattern or a texture, such as a repetitive wave form pattern, a repetitive v-shaped pattern, a repetitive diamond-shaped pattern, a repetitive block shaped pattern, a pattern of undulations, or a variably shaped wave pattern.

[0018] The tractor 104 may be coupled to the screed system 108 via one or more tow arms 116. A hydraulic cylinder 120 may be engaged with the tow arm 116 at a tow point 130 to adjust a position of the screed system 108 relative to the surface to be paved. For example, the hydraulic cylinder 120 may be used to change an angle of attack A of a screed plate 316. As used herein, the phrase “angle of attack” refers to an angle between the screed plate 316 and the surface to be paved, as shown in FIG. 1 A. A setting pin 124 may be coupled between the tow arm 116 and the screed system 108. The setting pin 124 may be actuated by an operator (e.g., via the handle 126) to further adjust the angle A between the screed plate 316 and thesurface to be paved. The angle of attack A impacts both the density and the grade of the paving material. In a typical linear screed plate, the angle of attack A may be between 2° and 5°.

[0019] As used herein, the phrases “compact” and “compaction” generally refers to the process of increasing the density of the paving material 128 by applying a force to the paving material 128 (e.g., via the screed system 108) to reduce the size of void spaces between particles of paving material 128. As shown schematically at section 128a, the paving material 128 is at its loosest (e.g., least dense, least compact, least level) proximate the front end of the screed system 108. The paving material 128 becomes less loose (e.g., denser, more compact, more level) as the screed system 108 slides over the paving material 128, as shown schematically at 128b. The paving material 128 is most compact proximate a back end 141 of the screed system 108, as shown schematically at 128c. FIG. 7 illustrates a plot 700 of percent compaction of the paving material versus gyration. The plot 700 illustrates data taken from a gyratory compactor, and the term “gyration” refers to the density increase per gyration of the compactor. As shown in FIG. 7, compaction does not occur at a linear rate as the screed system 108 passes over the paving material 128. Instead, compaction occurs at a faster rate toward the front of the screed system 108 (arrow 704), where the paving material 128a is at its loosest. The rate of compaction slows (arrow 708) as the screed system 108 passes over the paving material 128 and the paving material becomes more dense.

[0020] FIG. 2 illustrates an example screed plate 200 according to aspects of the present disclosure. The screed plate 200 includes a body 202 including a first or top surface 204 and a second or bottom surface 208 opposite the first surface 204. The first surface 204 is configured to engage the screed system 108. The second surface 208 is configured to engage the paving material 128. Although the second surface 208 is shown as smooth in the illustrated example, it is contemplated that the second surface 208 may include a pattern or a texture, such as, for example, a repetitive wave form pattern, a repetitive v-shaped pattern, a repetitive diamondshaped pattern, a repetitive block shaped pattern, a pattern of undulations, or a variably shaped wave pattern.

[0021] A profile of the screed plate is shown schematically using the line 212. As used herein, the phrase “profile” is indicative of the cross-sectional shape of the screed plate. As shown in FIG. 2, the shape of the profile 212 changes from a front end 216 of the screed plate to a back end 220 of the screed plate 200. The front end 216 of the screed plate 200 contacts the loosest portion 128a of the paving material 128. The back end 220 of the screed plate 220 contacts the least loose (e.g., the densest) portion 128c of the paving material 128. A first portion 224of the screed plate 200 has non-linear profile 212. For example, in the aspect illustrated in FIG. 2, the first portion 224 of the screed plate 200 has a curved profile 212. For example, in some aspects, the profile 212 of the screed plate 200 may be similar to the shape of a French curve. In other aspects, the 212 profile of the screed plate 200 may include a plurality of linear segments that collectively form a curved profile. The first portion 224 of the screed plate 200 is configured to engage the loosest portion 128a of the paving material 128 and at least some of the portion 128b of the paving material 128a. It may be advantageous to use the curved profile 212 proximate the front end 216 of the screed plate because the rate of compaction of the loosest portion 128a of the paving material is the most non-linear. Further, the curved profile 212 may more evenly distribute the pressure applied to the paving material along the length of the screed plate 200. In conventional screed plates, the pressure is typically concentrated at or near the back of the screed plate (e.g., the portion of the screed plate contacting the densest portion of the paving material). In some aspects, the amount of curvature of the first portion 224 decreases from the front end 216 of the screed plate 200 toward the back end 220 of the screed plate 200 (e.g., the curvature of the first portion 224 decreases as the density of the paving material 128 increases).

[0022] A second portion 228 of the screed plate 200 may have a linear profile or a substantially linear profile. The second portion 228 of the screed plate is configured to overlie the denser portions (e.g., portion 128c and / or a portion of 128b) of the paving material 128. In some aspects, the profile 212 of the second portion 228 of the screed plate 200 may be substantially parallel to the finished surface of the paving material 128.

[0023] In some aspects, the amount of curvature of the first portion 224 of the screed plate 200 may be determined based on the rate of compaction of the paving material 128 as the paving material is contacted by the screed system 108, as shown for example in plot 700 (FIG. 7). For example, in some aspects, the profile 212 of the screed plate 200 may be substantially parallel to the finished surface of the paving material 128 (e.g., the portion 128c) and then curves upward based on the rate of linear compaction per inch of travel across the second surface 208 of the screed plate 200. Such a profile 212 of the screed plate 200 may prevent pressure from being concentrated at or proximate the back end 220 of the screed plate 200.

[0024] In some aspects, the amount of curvature of the first portion 224 of the screed plate 200 may be determined based on the thickness of the paving material 128. For example, the curvature of the first portion 224 of the screed plate 200 may be increased and / or higher for screed plates 200 configured for paving deeper mats of paving material 128. In some aspects,an example of a deep paving mat is a mat of paving material configured to produce compacted pavement having a depth of 6 inches, for example. In other aspects the depth of the compacted pavement may be 4-8 inches. The curvature of the first portion 224 of the screed plate 200 may be decreased for screed plates 200 configured for paving shallower mats of paving material 128. In some aspects, an example of a shallow paving mat is a mat of paving material configured to produce compacted pavement having a depth of 1 inch, for example. In other aspects the depth of the compacted pavement may be 0.5-3 inches. As such, it may be advantageous to use a screed plate having a non-linear profile to contact the paving material 128. Such a screed plate produces a range of angles of attack, which can engage and compact the paving material more effectively than a screed plate having a linear profile that has a single angle of attack A.

[0025] In aspects in which the second surface 208 includes a pattern and / or a texture, in some aspects, the pattern and / or texture may be deeper at the curved portion of the screed plate 200. In such aspects, the depth of the pattern and / or texture may decrease as the curvature of the screed plate 200 decreases.

[0026] FIG. 3 illustrates a first screed plate 300 that has a substantially linear profile indicated by the line 304. The line 304 is substantially linear along substantially an entire length of the first screed plate 300. FIG. 3 also illustrates a schematic representation of a substantially nonlinear profile 308 of another screed plate, such as, for example, the screed plate 200 of FIG. 2. As shown in FIG. 3, the curvature of the line 308 is highest at the portion of the line 308 corresponding to a front end 312 of the screed plate and is lowest at the portion of the line 308 corresponding to a back end 318 of the screed plate. In some aspects, the profile 308 may be substantially linear at or proximate the back end 318 of the screed plate.

[0027] FIG. 4 illustrates a first screed plate 400 that has a substantially linear profile. The first screed plate 400 is substantially linear along substantially an entire length of the first screed plate 400. FIG. 4 also illustrates schematic representation of a substantially non-linear screed plate 404 (e.g., the lines 404). The screed plate 404 may be similar to the screed plate 200 described above. As shown in FIG. 4, the curvature of the screed plate 404 is highest at or proximate a front end 408 of the screed plate 404 and is lowest at or proximate a back end 412 of the screed plate 404. In some aspects, the profile of the screed plate 404 may be substantially linear at or proximate the back end 412 of the screed plate 404. In some aspects, a thickness T 1 of the screed plate 404 may be larger than a thickness T2 of the screed plate 400 as measured from the front end towards the back end of the screed plate.

[0028] FIG. 5 illustrates a first screed plate 500 that has a substantially linear profile. The first screed plate 500 is substantially linear along substantially an entire length of the first screed plate 500. A line 504 indicates a bottom surface (e.g., the surface configured to contact the paving material). A pattern or texture 508 extends from the bottom surface 504. The screed plate 500 is shown in an inverted configuration relative to the screed plates 200, 300, 308, 400, and 404.

[0029] With continued reference to FIG. 5, dashed line 512 illustrates a bottom surface (e.g., the surface configured to contact the paving material) of a screed plate having a non-linear profile. The screed plate indicated by the dashed line 512 is shown in an inverted configuration relative to the screed plates 200, 300, 308, 400, and 404. An example of such a screed plate is the screed plate 200 described above. The dimensions illustrated in FIG. 5 are example dimensions for a screed plate configured to pave an amount of paving material sized to produce a two inch deep finished paved surface (e.g., a paved surface having substantially a two inch depth of compacted paving material). These dimensions are shown and described relative to the bottom surface 504 of the first screed plate 500, which has a linear profile. These dimensions do not include any patterns and / or textures that may be on the bottom surface 512 of the screed plate having a curved profile and are not shown relative to the dimensions of the pattern and / or texture of the screed plate 500. In other aspects, the dimensions shown on FIG. 5 may be larger or smaller. For example, the dimensions will be larger for screed plates configured to produce deeper finished paved surfaces and the dimensions will be smaller for screed plates configured to produce shallower finished paved surfaces. It is further contemplated that the dimensions shown in FIG. 5 and described herein encompass dimensions falling within 20% of the dimensions provided herein.

[0030] As shown in some aspects, a length LI of the screed plate indicated by the line 512 may be 20 inches. The screed plate indicated by the line 512 includes a first portion 516 proximate a front end 520 of the screed plate and a second portion 524 proximate a back end 528 of the screed plate. The first portion 516 is configured to contact the looser portion of the paving material (e.g., portions 128a and / or 128b of the paving material 128 shown in FIG. 2). It is contemplated that the first portion 516 has a non-linear profile. In some aspects, the first portion 516 may be curved. In the configuration shown in FIG. 5, the first portion 516 has a length L2 of 6.7 inches. The bottom surface 512 of the first portion 516 may extend 0.87 inches below the bottom surface 504 of the linear screed plate 500 proximate the front end 520. The bottom surface 512 of the first portion 516 may extend 0.29 inches below the bottom surface504 of the linear screed plate 500 spaced from the front end 520 (e.g., at or proximate back end of the first portion 516). As indicated by the line 512, the bottom of the screed plate indicated by the line 512 is non-linear.

[0031] The second portion 524 is configured to contact the denser (e.g., less loose) portion of the paving material (e.g., portions 128c and / or 128b of the paving material 128 shown in FIG. 2). In some aspects, the second portion 524 may have a linear profile proximate the back end 528 of the screed plate indicated by the line 512. In some aspects, a portion of the second portion 524 proximate the first portion 516 may have a non-linear profile. In some aspects, the second portion 524 may have a linear profile. In the configuration shown in FIG. 5, the second portion 524 has a length L3 of 13.3 inches. The bottom surface 512 of the second portion 524 may extend 0.29 inches below the bottom surface 504 of the linear screed plate 500 proximate the first portion 516. The bottom surface 512 of the second portion 524 may extend 0 inches below the bottom surface 504 of the linear screed plate 500 spaced from the front end 520 (e.g., at or proximate the back end 528 of the screed plate indicated by the line 512).

[0032] FIG. 6 illustrates a side view of an example screed plate 600 according to aspects of the present disclosure. The example screed plate 600 is substantially similar to the screed plate 200 of FIG. 2. Therefore, the screed plate 600 is only described in detail to the extent that it differs from the screed plate 200. Like numerals are used to refer to like parts between the screed plate 600 and the screed plate 200.

[0033] A profile of the screed plate 600 is shown schematically using the dashed line 612. As shown in FIG. 6, the shape of the profile 612 changes from a front end 616 of the screed plate to a back end 620 of the screed plate 600. A first portion 624 of the screed plate 600 has nonlinear profile 612. For example, in the aspect illustrated in FIG. 6, the first portion 624 of the screed plate 600 has a curved profile 612. Although the profile of the first portion 624 is curved, the first and second surfaces 604, 608 of the first portion 624 are formed from a plurality of substantially planar plates 610 that are oriented to form a substantially curved surface. In some aspects, each of the planar plates 610 may form a segment of the curved profile 612. In some aspects the plurality of planar plates 610 may include two or more planar plates. As the screed plate 600 is used, the vertices 614 formed between adjacent plates 610 may wear, such that the second surface 608 of the first portion 624 of the screed plate 600 becomes curved. The first portion 624 of the screed plate 600 is configured to engage the loosest portion 128a of the paving material 128 and at least some of the portion 128b of the paving material 128a.

[0034] A second portion 628 of the screed plate 600 may have a linear profile or a substantially linear profile. The second portion 628 of the screed plate is configured to overlie the denser portions (e.g., portion 128c and / or a portion of 128b) of the paving material 128. In some aspects, the profile 612 of the second portion 628 of the screed plate 600 may be substantially parallel to the finished surface of the paving material 128.

[0035] While the aspects described herein have been described in conjunction with the example aspects outlined above, various alternatives, modifications, variations, improvements, and / or substantial equivalents, whether known or that are or may be presently unforeseen, may become apparent to those having at least ordinary skill in the art. Accordingly, the example aspects, as set forth above, are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and scope of the disclosure. Therefore, the disclosure is intended to embrace all known or later-developed alternatives, modifications, variations, improvements, and / or substantial equivalents.

[0036] Thus, the claims are not intended to be limited to the aspects shown herein, but are to be accorded the full scope consistent with the language of the claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more.” All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed as a means plus function unless the element is expressly recited using the phrase “means for.”

[0037] Further, the word “example” is used herein to mean “serving as an example, instance, or illustration.” Any aspect described herein as “example” is not necessarily to be construed as preferred or advantageous over other aspects. Unless specifically stated otherwise, the term “some” refers to one or more. Combinations such as “at least one of A, B, or C,” “at least one of A, B, and C,” and “A, B, C, or any combination thereof’ include any combination of A, B, and / or C, and may include multiples of A, multiples of B, or multiples of C. Specifically, combinations such as “at least one of A, B, or C,” “at least one of A, B, and C,” and “A, B, C, or any combination thereof’ may be A only, B only, C only, A and B, A and C, B and C, or A and B and C, where any such combinations may contain one or more member or members ofA, B, or C. Nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims.

[0038] Clause 1. A screed plate comprising: a first surface configured to engage a screed system of a paver; and a second surface opposite the first surface, the second surface configured to contact a paving material, wherein the second surface has a non-linear profile in a direction from a front end to a back end of the screed plate.

[0039] Clause 2. The screed plate of clause 1, wherein the non-linear profile has a curved shape.

[0040] Clause 3. The screed plate of clause 2, wherein the non-linear profile is smooth.

[0041] Clause 4. The screed plate of clause 2, wherein the non-linear profile includes a plurality of linear segments that collectively form a curved shape.

[0042] Clause 5. The screed plate of clause 1, wherein a first portion of the second surface proximate the front end of the screed plate has the non-linear profile.

[0043] Clause 6. The screed plate of clause 5, wherein the non-linear profile has an amount of curvature, and wherein the amount of curvature of the non-linear profile corresponds to a compaction rate of the paving material.

[0044] Clause 7. The screed plate of clause 6, wherein the amount of curvature decreases from the front end of the screed plate toward the back end of the screed plate.

[0045] Clause 8. The screed plate of clause 6, wherein the amount of curvature is higher for deeper mats of paving material than for shallower mats of paving material.

[0046] Clause 9. The screed plate of clause 5, wherein a second portion of the second surface proximate the back end of the screed plate has a linear profile.

[0047] Clause 10. The screed plate of clause 1, wherein the non-linear profile is configured to evenly distribute a pressure applied to the paving material in the direction from the front end to the back end of the screed plate.

[0048] Clause 11. The screed plate of clause 1, wherein the second surface includes a pattern including at least one of a repetitive wave form pattern, a repetitive v-shaped pattern, a repetitive diamond-shaped pattern, a repetitive block shaped pattern, a pattern of undulations, a variably shaped wave pattern, or a combination thereof.

[0049] Clause 12. The screed plate of clause 11, wherein a depth of the pattern is deeper proximate a front end of the screed plate.

[0050] Clause 13. The screed plate of clause 1, wherein the non-linear profile is configured to prevent pressure from being concentrated at or proximate the back end of the screed plate.

Claims

CLAIMSWhat is claimed is:

1. A screed plate comprising: a first surface configured to engage a screed system of a paver; and a second surface opposite the first surface, the second surface configured to contact a paving material, wherein the second surface has a non-linear profile in a direction from a front end to a back end of the screed plate.

2. The screed plate of claim 1, wherein the non-linear profile has a curved shape.

3. The screed plate of claim 2, wherein the non-linear profile is smooth.

4. The screed plate of claim 2, wherein the non-linear profile includes a plurality of linear segments that collectively form a curved shape.

5. The screed plate of claim 1, wherein a first portion of the second surface proximate the front end of the screed plate has the non-linear profile.

6. The screed plate of claim 5, wherein the non-linear profile has an amount of curvature, and wherein the amount of curvature of the non-linear profile corresponds to a compaction rate of the paving material.

7. The screed plate of claim 6, wherein the amount of curvature decreases from the front end of the screed plate toward the back end of the screed plate.

8. The screed plate of claim 6, wherein the amount of curvature is higher for deeper mats of paving material than for shallower mats of paving material.

9. The screed plate of claim 5, wherein a second portion of the second surface proximate the back end of the screed plate has a linear profile.

10. The screed plate of claim 1, wherein the non-linear profile is configured to evenly distribute a pressure applied to the paving material in the direction from the front end to the back end of the screed plate.

11. The screed plate of claim 1, wherein the second surface includes a pattern including at least one of a repetitive wave form pattern, a repetitive v-shaped pattern, a repetitive diamond-shaped pattern, a repetitive block shaped pattern, a pattern of undulations, a variably shaped wave pattern, or a combination thereof.

12. The screed plate of claim 11, wherein a depth of the pattern is deeper proximate a front end of the screed plate.

13. The screed plate of claim 1, wherein the non-linear profile is configured to prevent pressure from being concentrated at or proximate the back end of the screed plate.

Images