Berm hinge

Abstract

A screed assembly includes a first screed plate having a working surface and an edge. A pivot body connected with the edge of the first plate has an axis and a bearing surface about the axis. A second screed plate has a working surface and an edge slidably disposed against the bearing surface. The second plate is movably connected with the first plate and pivotable about the axis to adjust the second working surface relative to the first working surface. A first hinge member connected with the first plate has an inner surface about the axis and spaced from the bearing surface. A second hinge member connected with the second plate has an inner surface slidably disposed against the bearing surface and an outer surface slidably disposed against the first member surface so as to be retained between the pivot body and the first member, thereby movably connecting the plates.

Description

[0001] This application claims the benefit of U.S. Provisional Application No. 60/265,243, filed Jan. 31, 2001, and U.S. Provisional Application No. 60/265,247, filed Jan. 31, 2001.

BACKGROUND OF THE INVENTION

[0002] The invention relates to road paving vehicles, and more particularly to screed plate assemblies used on road paving vehicles.

[0003] Paving vehicles or “pavers” are well known and basically function to form a mat of paving material, such as asphalt or concrete, upon a base surface so as to construct a roadway, airport runway, parking lot or driveway. Pavers generally include a vehicle chassis or tractor that carries a bin/hopper for holding the paving material, a conveyor for transporting the material from the hopper to the rear of the chassis and an auger for spreading the material laterally across the roadbed to form a material head behind the chassis. A screed assembly is towed from the rear of the chassis and includes one or more upper frames and one or more screed plates mounted beneath the frames. The screed assembly is pulled into a mass or “head” of paving material deposited off of the rear of the chassis so that the screed plate(s) first “level” or establish a desired material thickness and then partially compact the paving material flowing under the plate. As a result, a strip or mat of paving material with a desired height or thickness is formed.

[0004] Certain screed assemblies include one or two screed plates that may each be pivoted or angled with respect to a longitudinal centerline of the paving vehicle. These plates, referred to as “berm” plates, are located at each outer lateral or side end of the screed assembly and are pivotally connected to an inner, generally horizontal screed plate. When the screed assembly is used to form a material mat, each berm plate forms an angled or sloped side section in the material mat, referred to as a berm. Such berms function as a curb for certain construction projects, for example, roadways built for residential areas. Certain berm-forming screed assemblies include a single plate and a frame that may be pivoted relative to another, primary screed frame to adjust the angle of the berm surface. Other berm-forming screed assemblies include an inner, generally horizontal screed plate and an outer plate that pivotably attached to an outer end of the inner plate.

[0005] With berm-forming screed assemblies, it is important to ensure that there is no gap or space between the adjacent ends of the outer berm plate and the inner horizontal plate. Such a gap creates an elevated stripe or ridge of material in the material mat extending along the intersection of berm section and the remaining section of the mat. Therefore, the screed assembly must be constructed such that a continuous screed working surface extends laterally across the entire width of the screed assembly (i.e., laterally with respect to the direction of paver travel). One approach to provide such a continuous surface is to arrange the berm screed plate with the adjacent inner horizontal screed plate such that a beveled edge of berm plate abuts against a mating beveled edge of the inner screed plate. The screed assembly is constructed such that the berm plate pivots with respect to the inner screed plate by bending or folding along the line of contact between the edges of the two screed plates.

[0006] However, a deficiency with this arrangement results from the fact that contact between the two screed plates is established along the lowermost points of the beveled edges of the plates. As the screed and berm plate wear, a gap is formed between the adjacent plates when these lowermost points on the beveled edges are worn away by the abrasive contact with the paving material. Once such a gap is created, paving material passes through the gap, causing an elongated, elevated stripe or ridge to be formed in the material mat, which must later be eliminated by appropriate repair operations (e.g., additional rolling).

[0007] In view of the above, it would be desirable to provide a berm screed assembly in which such a gap is not formed by wearing of the screed plates so as to thereby extend the effective product life of the screed assembly.

SUMMARY OF THE INVENTION

[0008] In a first aspect, the present invention is a screed assembly comprising a first screed plate having a working surface and a side edge. A pivot body is connected with the side edge of the first screed plate and has an axis and an outer surface including a circumferential bearing surface section spaced radially from and extending at least partially about the axis. Further, a second screed plate has a working surface and a side edge slidably disposed generally against the pivot body bearing surface. The second screed plate is movably connected with at least one of the pivot body and the first screed plate such that the second screed plate is rotatably displaceable about the pivot body axis to adjustably position the second plate working surface with respect to the first plate working surface.

[0009] In another aspect, the present invention is a hinge device for a screed assembly of a paving vehicle, the screed having first and second screed plates. The hinge comprises a pivot body attached to the first screed plate and having an axis and an outer surface including a generally circumferential bearing surface section extending at least partially about the axis. A first hinge member is connected with the first screed plate and has an inner circumferential surface disposed partially about the block axis and spaced radially from the bearing surface. Further, a second hinge member is connected with the second screed plate and has an inner circumferential surface slidably disposed generally against the bearing surface. The second hinge member also has an outer circumferential surface spaced radially from the second hinge member inner surface and slidably disposed generally against the first hinge member inner surface such that the second hinge member is slidably retained between the pivot body and the first hinge member to movably connect the second screed plate with the first screed plate.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The foregoing summary, as well as the detailed description of the preferred embodiments of the invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings, which are diagrammatic, embodiments that are presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. In the drawings:

[0011] FIG. 1 is a perspective view of a paving vehicle with a screed assembly and a hinge device in accordance with the present invention, shown performing a berm paving operation;

[0012] FIG. 2 is a more diagrammatic, broken-away, top plan view of the paving vehicle;

[0013] FIG. 3 is as rear elevational view of the screed assembly and the hinge device;

[0014] FIG. 4 is a top perspective view of the screed assembly and hinge device;

[0015] FIG. 5 is a broken-away, enlarged perspective view of the screed assembly and hinge device;

[0016] FIG. 6 is a broken-away, greatly enlarged side view of a first screed assembly half;

[0017] FIG. 7 is a broken-away, greatly enlarged side view of a second screed assembly half;

[0018] FIG. 8 is a broken-away, greatly enlarged side view of the hinge device shown in a first position; and

[0019] FIG. 9 is a broken-away, greatly enlarged side view of the hinge device shown in a second position.

DETAILED DESCRIPTION OF THE INVENTION

[0020] Certain terminology is used in the following description for convenience only and is not limiting. The words “upper”, “upward”, and “lower”, “downward” refer to directions toward and away from, respectively, a designated upper end of a screed assembly, a hinge device, or a component of either the assembly or the device. The words “inner”, “inward” and “outer”, “outward” refer to directions toward and away from, respectively, the geometric center of a hinge device or a specific portion or component thereof, or toward and away from, respectively, a pivot body axis or a designated paving vehicle centerline, the particular meaning intended being readily apparent from the context of the description. The terms “radial” and “radially-extending” refer to directions generally perpendicular to a designated centerline or axis, and refer both to elements that are either partially or completely oriented in radial direction. The terms “circumferential” and “circumferentially” refer to elements that are oriented so as to be partially or completely extending about a designated centerline or axis. The terminology includes the words specifically mentioned above, derivatives thereof, and words or similar import.

[0021] Referring now to the drawings in detail, wherein like numbers are used to indicate like elements throughout, there is shown in FIGS. 1-9 a presently preferred embodiment of a hinge device 10 in accordance with the present invention for a berm-forming screed assembly 12 used with a paving vehicle 1. The berm-forming or “berm” screed assembly 12 includes a first screed plate having a first working surface 15 and a second screed plate 16 having a second working surface 17. The hinge device 10 basically comprises a pivot body 18 attached to the first screed plate 14 and having a pivot axis 20 and an outer surface 22. The outer surface 22 of the body 18 includes a generally circumferential bearing surface section 24 that is spaced radially from, and extends at least partially about, the pivot axis 20. Further, the second screed plate 16 is movably connected with the pivot body 18 and/or with the first screed plate 16 such that the second screed plate 16 is rotatably displaceable about the pivot body axis 20 to adjustably position the second plate working surface 17 with respect to the first plate working surface 15.

[0022] More specifically, the first screed plate 14 has an inner side edge 26, the pivot body 18 being connected with the first plate side edge 26 , and the second screed plate 16 has an inner side edge 28. The second plate side edge 28 is slidably disposed generally against the pivot body bearing surface 24 such that the inner edge 28 of the second plate 16 remains substantially in contact with the bearing surface 24 when the second plate 16 rotatably displaces about the pivot axis 20.

[0023] Preferably, the hinge device 10 further comprises a first hinge member 30 connected with the first screed plate 14 and a second hinge member 32 connected with the second screed plate 16. The first hinge member 30 preferably has an inner circumferential surface 34 that is disposed partially about the pivot axis 20 and is spaced radially outwardly from the bearing 2+surface 24, as best shown in FIG. 6. Referring to FIGS. 8 and 9, the second hinge member 32 preferably has an inner circumferential surface 36 slidably disposed generally against the bearing surface 24 and an outer circumferential surface 38 spaced radially outwardly from the inner surface 36 and slidably disposed generally against the first hinge member inner surface 34. The second hinge member 32 is thereby slidably retained between the pivot body 18 and the first hinge member 30 so as to movably connect the second screed plate 16 with the first screed plate 14, as described in further detail below.

[0024] Referring now to FIGS. 1 and 2, the berm screed assembly 12 of the present invention is preferably connected with a main screed assembly 2 towed behind a paving vehicle or paver 1. The paving vehicle 1 includes a chassis or tractor 3 having a front end 3a, a rear end 3b and a longitudinal centerline 4 extending between the front and rear ends 3a, 3b, respectively. Further, the main screed assembly 2 includes a main or primary screed 5 and a pair of screed extensions 6, most preferably front-mounted, laterally movable or extendable screed extensions 6 (only one shown). Preferably, the main screed assembly 2 includes two berm screed assemblies 12 of the present invention, each mounted to the frame of a separate one of the two screed extensions 6, as discussed further below.

[0025] Each berm screed assembly 12 is substantially identically constructed, but oppositely arranged with respect to the paver centerline 4, such that only one screed assembly 12 will be described in detail herein. As best shown in FIG. 2, the screed assemblies 12 are each connected with the paving vehicle 1 (i.e., through attachment to the main screed assembly 2) such that the first screed plate 14 is located inwardly of the second screed plate 16; in other words, the first and second screed plates 14 and 16, respectively, which each have a respective geometric center C1 and C2 (FIG. 2), are arranged such that the perpendicular distance between the second plate center C2 and the vehicle centerline 4 is greater than the perpendicular distance between the first plate center C1 and the centerline 4. With this arrangement, the second screed plate 16 is adjustably positionable with respect to the first screed plate 14 such that when the vehicle 1 is used to construct a mat of material M, an angled shoulder or berm B may be formed at the outer lateral or side edge E of the mat M.

[0026] The above description provides a basic disclosure of the primary components and functionality of the hinge device 10 and berm screed assembly 12 of the present invention. To provide a more complete understanding of the present invention, each of these primary components/functions is described in further detail below.

[0027] Referring now to FIGS. 4-6, the first screed plate 14 is preferably formed as an elongated, generally rectangular plate having a generally constant thickness t1 (FIG. 6). The rectangular plate 40 has a lower surface providing the first lower working surface 15 and has an opposing, generally flat upper surface 41. Further, the plate 40 has inner and outer side edges 26 and 27, a front upwardly-bended leading edge or nose 42 and a rear edge 43. Also, a pair of attachment blocks (FIG. 4) are spaced laterally apart and attached to the inner surface 42a of the nose 42, which are used to connect the first screed plate 14 with a screed frame 13, as discussed below.

[0028] Referring to FIGS. 4, 5 and 7, the second screed plate 16 is generally formed as an elongated, generally rectangular plate having a generally constant thickness t2 (FIG. 7), each thickness t1 and t2 preferably having about the same measured value, i.e., the two screed plates 14 and 16 are preferably of substantially equal thickness. The second rectangular plate 46 has a lower surface providing the second working surface 17 and has an opposing, generally flat upper surface 47. Further, the plate 46 has inner and outer side edges 28 and 29, a front upwardly-bended leading edge or nose 48 and a rear edge 49. Also, an attachment block 50 (FIG. 4) is attached to the inner surface 48a of the nose 48 near the outer side edge 29 and is used to movably connect the second screed plate 16 with the screed frame 13, as discussed below.

[0029] Further, the inner side edge 28 of the second screed plate is formed so as to have a concave, partially-circular contact surface 51 with an inside radius RC (FIG. 7) that is slightly larger than the outside radius RP of the pivot body 18. With this configuration, the edge contact surface 51 is juxtaposable against and slidably displaceable around or along the pivot bearing surface 24. In other words, substantially the entire concave contact surface 51 of the second plate 16 remains in contact with and slides along the convex bearing surface 24 of the pivot body 18 when the second screed plate 16 is rotatably displaced with respect to the first screed plate 14 (FIGS. 8 and 9). However, if the pivot body 18 is alternatively connected with the second screed plate 16 instead of with the first screed plate 14, the inner side edge 26 of the first screed plate 16 is preferably formed with a surface similar to the concave edge contact surface 51 (structure not depicted).

[0030] Although it is preferred that the screed plates 14, 16 are generally flat (except at the nose sections 42, 48), thin and rectangular, the screed plates 14 and/or 16 may be constructed having any other appropriate or desired shape or structure as long as the hinge device 10 and the screed assembly 12 are capable of functioning basically as described herein. For example, either or both plates 14, 16 may be square-shaped rather than rectangular, may have a substantial thickness (i.e., formed as a block rather than a plate), may have a separately attached (rather than integrally formed) nose 42 or 48 or formed without a nose section, etc. The screed assembly 12 of the present invention is not limited to having screed plates 14, 16 with any particular structure and scope of the present invention encompasses all appropriate screed plate structures that enable the hinge device 10 and screed assembly 12 to function generally as described herein.

[0031] Referring to FIGS. 4-6 and 9, the pivot body 18 is preferably formed as an elongated, generally cylindrical bar 52 having a generally continuous circumferential outer surface 22 that completely encircles the pivot body axis 20. The bar 52 is preferably shaped as a solid circular cylinder so as to have generally circular axial cross-sections (i.e., cross-sections spaced along the axis 20). Referring specifically to FIG. 6, the bar 52 has an outside diameter DP that is about two times, or twice as great, as the value of each thickness t1 and t2 of the two screed plates 14, 16, for reasons discussed below.

[0032] With the pivot body 18 formed as a cylindrical bar 52, the bearing surface 24 is thus provided by a section or portion of the continuous outer circumferential surface 22. The bearing surface 24 is thus convex and has a radius RP that is substantially constant at all points or positions on the surface both radially about the body outer circumference and axially along the pivot axis 20. Preferably, the pivot body 18 is disposed against the inner side edge 26 of the first screed plate 14 such that the axial length (not indicated) of the body 18 extends along and parallel to the side edge 26. The pivot body 18 preferably contacts the screed plate 14 along a top corner between the side edge 26 and the upper surface 41, such that a semi-circular upper half of the pivot body 18 is generally located above the plate upper surface.

[0033] When the bar 52 is positioned as described above, a wedge-shaped recess 56 (FIG. 6) is defined between the bar 52 and the plate side edge 42. Preferably, the recess 56 is filled with weldment material 57 (FIGS. 8 and 9) to fixedly attach the pivot body 18 to the first screed plate 14, the weldment material 57 being applied such to form a continuous surface 58 connecting the pivot outer surface 22 with the first screed working surface 15. Alternatively, the inner edge 26 of the first plate 14 may be formed with a concave surface (not depicted) similar to the inner edge 28 of the second plate 16, against which surface the pivot body 18 may be closely disposed.

[0034] Although the pivot body 18 is preferably a solid, circular cylindrical bar 52 as described above, the pivot body 18 may be formed with any appropriate shape or structure, as long as a portion of the body 18 provides the convex outer circumferential bearing surface 24 as described herein. For example, the pivot body 18 may be tubular with a circular, semi-circular or complex-shaped outer surface (none shown). Further for example, the pivot body 18 may be formed as a block, bar or tube or an assembly of attached together bars/plates, having any desired shape, such as circular, partially-circular, partially-rectangular and/or prismatic (no alternatives shown), as long as a portion of the particular body's outer surface provides the outer circumferential bearing surface 24 as described herein.

[0035] As yet another example, the pivot body 18 may be integrally formed with one of the two screed plates 14 or 16 (structure not depicted), such as for example, by forming the particular plate 14, 16 as a casting having an edge portion providing the pivot body 18 or as a stamping with a side edge formed or bended to provide the pivot body 18. The present invention encompasses all desired or appropriate constructions of the pivot body 18 that includes a convex outer circumferential bearing surface 24 and enable the hinge device 10 to function as generally described herein.

[0036] Referring to FIGS. 4-6, 8 and 9, the first hinge member 30 is preferably formed as a generally arcuate plate 60 having a first lengthwise side edge or end 62, an opposing second lengthwise side end 64, and opposing front and rear widthwise ends 65 (only rear end shown). Preferably, the hinge plate 60 is generally formed as a rectangular plate bended lengthwise, shaped generally similar to an axially-extending portion of a circular tube, as best shown in FIG. 5, so as to have a concave lower surface providing the inner circumferential surface 34 of the first hinge member 30. Further, the hinge plate 60 is formed such that the inner surface 34 has an inside radius RI1 (FIG. 6) that is slightly larger than an outside radius RO2 (FIG. 7) of the second hinge member 32, for reasons discussed below.

[0037] Referring particularly to FIG. 6, preferably, the first hinge member 30 is connected with the first screed plate 14 by attaching the hinge plate first side end 62 to the screed upper surface 41 at a position proximal to the screed inner edge 26. The first hinge plate 60 extends over the plate edge 26 such that hinge plate second side end 64 is spaced horizontally beyond the screed plate inner edge 26 and is “free” or unattached. Further, the hinge plate 60 is positioned with respect to the pivot body 18 such that the concave plate inner surface 34 is spaced radially outwardly from the convex outer bearing surface 24 of the pivot body 18 by a radial distance dR, as indicated in FIG. 6. The radial distance dR has a value that is slightly greater or larger than the thickness t2 of the second screed plate 16. Further, the first hinge plate 60 is preferably fixedly attached to the first screed plate 14, such as by welding, braising, riveting, etc., but may alternatively be removably attached by appropriate means, such as by threaded fasteners or separate mounting brackets (none depicted).

[0038] Still referring to FIG. 6, by spacing the first hinge plate from the pivot body 18 in the above-described manner, a curved or arcuate retention gap 66 is formed between the facing circumferential surfaces 24, 34 of the pivot body 18 and the first hinge member 30, respectively. The retention gap 66 is sized and shaped to receive a substantial portion of the second hinge member 32, as discussed in further detail below. With the pivot body 18 and the first hinge member 30 attached to the first screed plate 14 in the manner described above, a first screed assembly half 68 is formed, which is movably connected together with a second screed assembly half 78, as discussed below.

[0039] Referring now to FIGS. 5 and 7-9, the second hinge member 32 is preferably formed as a generally arcuate plate 70 having a first lengthwise side end 72, an opposing second lengthwise side end 74 and opposing front and rear widthwise ends 75 (only rear end shown). Preferably, the second hinge plate 70 is formed as a rectangular plate bended lengthwise so as to be shaped similar to an axially-extending portion of a circular tube (FIG. 5), and is thus shaped similarly to the first hinge plate 60. More specifically, the second hinge plate 70 has a concave lower surface providing the inner circumferential surface 36 of the second hinge member 32 and a convex upper surface providing the outer circumferential surface 38 of the second hinge member 32, as best shown in FIG. 7.

[0040] The second hinge plate 70 is constructed such that the concave inner circumferential surface 36 has a inside radius RI2 (FIG. 7) that is slightly larger or greater than the outside radius RP of the pivot body outer bearing surface 24. Further, the convex outer surface 38 of the second hinge plate 70 has an outside radius RO2 that is slightly smaller or lesser than the inside radius RI1, of the first hinge member inner surface 34. With this structure, the second hinge plate 70 is configured to be inserted into the retention gap 66 between the first hinge plate 60 and the pivot body 18, as discussed below.

[0041] Referring particularly to FIG. 7, preferably, the second hinge member 32 is connected with the second screed plate 16 by attaching the hinge plate first side end 72 to the screed plate upper surface 47 at a position adjacent to the screed plate inner side end 28. More specifically, the second hinge plate 70 is located such that a lower edge 36a of the hinge plate inner circumferential surface 36 is substantially aligned with the upper edge 51a of the screed plate contact surface 51. As such, the two circumferential surfaces 36, 51 share a common centerline 77 (end view only) (FIG. 7) and form a generally continuous inner circumferential surface extending between the hinge plate free end 74 and the screed plate lower edge 51b. Further, as with the first hinge plate 60, the second hinge plate 70 is preferably fixedly attached to the second screed plate 16, but may alternatively be removably attached by appropriate means.

[0042] Further, the second hinge plate 70 extends beyond the second screed plate edge 51 such that the hinge second side end is spaced horizontally from the screed plate inner edge 28 and is “free” or unattached. With the second hinge member 32 attached to the second screed plate 16 in the manner described herein, a second screed assembly half 78 is formed, which is movably connected together with the first screed assembly half in the following manner.

[0043] Referring now to FIGS. 5, 6, 8 and 9, the hinge device 10 is assembled together, so as to movably connect the first and second screed plates 14, 16, in the following manner. First, the second screed plate assembly 78 is positioned with respect to the first screed plate assembly 68 such that the inner surface 36 of the second hinge plate 70 is disposed on a rear portion of the outer surface 22 of the pivot body 18, with the second hinge plate 70 being rearwardly of and axially adjacent to the first hinge plate 60. More specifically, the front end 75 of the second hinge plate 70 is positioned at the rear opening 66a into the retention gap 66 so as to be adjacent to, but spaced radially inwardly of, the rear end 65 of the first plate 60 (FIG. 6).

[0044] Then, the entire second plate assembly 78 is displaced in a frontward direction along the pivot body axis 20 such that the second hinge plate 70 slides along the pivot body outer surface 22, enters and becomes increasingly disposed within the gap 66, until the second hinge plate rear end 75 is generally radially aligned with the first hinge plate rear end 65. Further, the opposing front and rear ends 75 (only rear end shown) of the second hinge plate 70 are spaced apart along the pivot body axis and are generally radially aligned with the respective front and rear ends 65 (only rear shown) of the first hinge plate 60, as best shown in FIG. 5. When the second hinge plate 70 is disposed within the retention gap 66 as described, a substantial portion of the second hinge plate 70 is disposed or “sandwiched” radially between the first hinge plate 60 and the pivot body 18. More specifically, the lower concave inner circumferential surface 36 of the second hinge plate 70 is disposed substantially against the convex pivot body bearing surface 24 and the upper convex outer circumferential surface 38 of the second hinge plate 70 is disposed substantially against the concave first plate inner circumferential surface 34, as best shown in FIGS. 8 and 9.

[0045] Referring to FIGS. 4 and 5, preferably, when the second hinge plate 70 is disposed within the retention gap 66 as described, first and second retainer blocks 80, 82, respectively, are each connected with the first screed plate 14 and located so as to be disposed proximal to a separate one of the front and rear ends 65 of the second hinge member 34. The second hinge plate 70 is thereby sandwiched axially between the two blocks 80 and 82, such that the retainer blocks 80, 82 limit linear displacement of the second hinge member 32 in directions generally along the pivot body axis 20. Preferably, each retainer blocks 80, 82 is formed as a generally flat, rectangular prism, the second block 82 being larger and having a cut-out or notch 81 providing a stop portion 83, as discussed below. The first retainer block 80 is fixedly attached to the nose 42 so as to extend generally horizontally across the pivot axis 20 and abuts against the front end (not shown) the second hinge plate 70. The second retainer block 82 is removably attached to the first screed plate upper surface 41 such that the stop portion 83 extends generally horizontally over the pivot axis 20 and abuts against the rear end 75 of the second hinge plate 70, thereby “trapping” the second hinge plate 70 between the two retainer blocks 80, 82.

[0046] With the first and second screed plate assemblies 68, 78 and the two retainer blocks 80, 82 assembled as described, the second hinge member 32 is slidably retained between the pivot body 18 and the first hinge member 30 to movably or rotatably connect the second screed plate 16 with the first screed plate 14. The first hinge plate 60 always at least partially overlaps the second hinge plate 70 when the second plate 70 is rotatably displaced about the pivot axis 20. As such, when the second screed plate 16 is rotatably displaced or pivoted about the pivot axis 20, the second hinge plate 70 slides beneath the first hinge plate 60 such that the free end 74 of the second plate 70 moves generally between a first position Pi (FIG. 7) more proximal to the free end 64 of the first hinge plate 60 and a second position P2 (FIG. 8) more proximal to the upper surface of the first screed plate 14.

[0047] Referring to FIGS. 1-3, the screed assembly 12 preferably further includes a screed frame 13 disposed generally above the first and second screed plates 14, 16, respectively. The screed frame 13 is preferably formed as a generally rectangular, box-like assembly of plates and has a lower end 87 to which the first screed plate 16 is removably attached. Preferably, the screed frame 13 forms part of a screed extension 6 connected with a main screed 5, and most preferably, a laterally movable or extendible screed extension 6. Alternatively, the screed frame 13 may be fixedly attached to a lateral end or side of the main screed 5 or may be formed as an integral end portion of the main screed 5 (neither shown).

[0048] Referring specifically to FIG. 3, the berm screed assembly also preferably includes a connective member 88 having a first end 89 connected with the frame 13 and a second end 90 connected with the second screed plate 16. The member second end 90 is linearly displaceable with respect to the member first end 89 so as to cause the second screed plate 16 to rotatably displace about the pivot body axis 20. Preferably, the connective member 88 is formed as a hydraulic cylinder including a cylinder body 91, with an outer end of the cylinder body 91 providing the connective member first end 89, and an extendable rod 92, the free end of the rod 91 providing the connective member second end 90. The end of rod 92 is preferably pivotably attached to the second screed plate attachment member 50, most preferably by a pin shaft (not indicated), to connect the rod 92 with the second screed plate 16.

[0049] With a connective member 88 constructed as a hydraulic cylinder, fluid flow within the cylinder body 90 causes the rod to extend and retract, which thereby moves or displaces the attached section of the second screed plate 16. The displacement of the attached section of the second screed plate causes the entire second plate 16 to rotatably displace about the pivot axis 20, while the contact surface 51 of the second plate 16 slides along or about the bearing surface 24 of the pivot body 18. Alternatively, the hydraulic cylinder 88 may be inverted such that the rod 91 is attached to the frame 13 and the cylinder body 90 is attached to the second plate 16. Further, the connective member 88 may alternatively be provided by any other appropriate connective device/assembly having a second end 89 displaceable with respect to a first end 90, such as for example, a threaded rod and nut/threaded hole arrangement, a cable and pulley device, a rack and pinion structure, or a linkage mechanism.

[0050] Preferably, the screed plates 14 and 16, the hinge plates and 70, and the screed frame 13 are each preferably fabricated from plates of low carbon steel that are hardened by appropriate means at surfaces likely to experience wear, such as for example, the working surfaces 15 and 17. The pivot body is preferably cut from an appropriate length of a circular rod of low carbon steel, with the outer surface 22 hardened by appropriate means. Further, the connective member 88 is preferably a commercially available hydraulic cylinder. However, it is within the scope of the present invention to fabricate any of the components of the hinge device 10 and the screed assembly 12 from any other appropriate material and in any other appropriate manufacturing process.

[0051] Referring now to FIGS. 1 and 2, the screed assembly 12 of the present invention may be used to either to form a standard or conventional mat of material M (not shown) or a material mat M with one (FIG. 1) or two (FIG. 2) side berm sections B. The different operating modes of the berm screed assembly 12 are provided by the capability of moving or adjusting the second screed plate 16, and thus the entire second screed assembly 78, between first and second positions P1 (FIG. 8) and P2 (FIG. 9), respectively, as indicated in the drawings by “tracking” the position of the second end 74 of the second hinge plate 70 for reasons of convenience only. In the first position P1, shown in FIG. 8, the second plate working surface 17 and the first plate working surface 15 are generally disposed in a common horizontal plane (not indicated). In other words, the screed plates 14, 16 are generally aligned such that an angle &bgr; (FIG. 8) between the plates 14, 16 is substantially zero degrees. With the two screed plates 14, 16 arranged in this manner, the berm screed assembly 12 forms a material mat M having a generally horizontal upper surface S across the entire lateral width of the screed assembly 12.

[0052] In the second position P2, as shown in FIG. 8, the second screed plate 16 is angled with respect to the first screed plate such that the second working surface 17 is disposed at a vertical angle &bgr; with respect to the first working surface 15. More specifically, the first working surface 15 is disposed in a generally horizontal plane and the second working surface 17 is disposed in an angled plane (i.e., at angle &bgr;) that extends upwardly and outwardly from the inner edge 28 of the second screed plate 16. Although only two positions P1 and P2 are depicted, the second screed plate 14 is positionable at any desired position between the depicted first and second positions P1, P2, which are the presently preferred limits of the displacement of the second screed plate 16, such that the angle &bgr; may have any value between about 0° (FIG. 7) and about 45° (FIG. 8). Further, in the second position P2, the screed plate 16 may be at a greater angle &bgr; with respect to the first plate 14 than as presently preferred, such as for example, so that the angle &bgr; has a value of about 60°. Furthermore, if desired, the screed assembly 12 may alternatively be constructed such that the second screed plate 16 is capable of being negatively sloped or angled with respect to the first screed plate 14 (i.e., sloped in a direction downwardly and outwardly from the first plate 14).

[0053] When the two screed plates 14, 16 are positioned with the angle &bgr; being greater than 0° (as shown in FIG. 9), a continuous screed working surface is provided by the first and second plate working surfaces 15, 17, respectively, and a portion of the pivot body outer surface 22 between the inner side edge 26 of the first screed plate 14 and the inner side edge 28 of the second screed plate 16. With this configuration, the screed assembly 12 forms the material mat M with two sections, a first angled berm section B and a remaining, generally horizontal section R, as shown in FIGS. 1 and 2. More specifically, the angled berm section B is located at the lateral side or edge of the material mat M and has an upper surface SA disposed at about the vertical angle &bgr; with respect to an upper surface SR of the remaining section R of the material mat M, as indicated in FIG. 1. In the preferred application where the paving vehicle 1 has two berm-forming screed assemblies 12, the two screed assemblies may be used to form a single berm B at either one of the side edges E of the material mat M (FIG. 1), two berms B each located at a separate one of the two edges E of the material mat M (FIG. 2), or a conventional material mat M without any berms (not shown).

[0054] To change between the basic operating modes, or to adjust the berm angle &bgr; between the screed working surfaces 15 and 17, the second screed plate 16 is rotatably displaced about the pivot body axis 20 by use of the hydraulic cylinder connective member 88, as described in detail above. Preferably, the screed operator adjusts the position of the second screed plate 16 through a controller (not shown) configured to automatically operate the preferred hydraulic cylinder 88. Further, when the paving vehicle 1 has two screed assemblies 12 as preferred, the operator preferably independently operates each of the two cylinders 88 of the two screed assemblies 12.

[0055] As with all screed plates, after a period of use, the material of the first and second screed plates 14 and 16 will, to a certain extent, wear or abrade away such that the thickness t1 and t2 of each plate 14, 16, respectively, decreases. As the screed plates 14 and 16 wear away, the bottom or lower portion 18a of the pivot body 18 also wears away by a similar amount of material thickness. Specifically, as the portion of the second plate 16 proximal to the plate inner edge 28 wears away, the lowermost edge 51b of the contact surface 51 progressively “moves” upwardly about the outer circumference of the pivot body 18, but still remains in contact with an adjacent portion of the pivot body 18 (the material of which is also worn away with the adjacent portions of the plate 16). As such, no gap is ever formed between the inner edge 26 of the first screed plate 14 and the inner edge 28 of the second screed plate 16. Thus, the hinge device 10 enables the screed assembly 12 of the present invention to have a substantially continuous working surface across the lateral width of the two screed plates 14 and 16 throughout a normal product life of the screed plates 14, 16.

[0056] It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims.

Claims

1. A screed assembly comprising:

a first screed plate having a working surface and a side edge;

a pivot body connected with the side edge of the first screed plate and having an axis and an outer surface including a circumferential bearing surface section spaced radially from and extending at least partially about the axis; and

a second screed plate having a working surface and a side edge slidably disposed generally against the pivot body bearing surface, the second screed plate being movably connected with at least one of the pivot body and the first screed plate such that the second screed plate is rotatably displaceable about the pivot body axis to adjustably position the second plate working surface with respect to the first plate working surface.

2. The screed assembly as recited in claim 1 wherein the edge of the second plate remains substantially in contact with the bearing surface when the second plate rotatably displaces about the pivot body axis.

3. The screed assembly as recited in claim 1 wherein the first plate working surface, the second plate working surface and a portion of the pivot block outer surface extending between the edge of the first plate and the edge of the second plate form a generally continues screed working surface.

4. The screed assembly as recited in claim 1 wherein the second plate is movable between a first position where the second plate working surface and the first plate working surface are generally disposed in a common horizontal plane and a second position where the second plate working surface is disposed at a vertical angle with respect to the first plate working surface.

5. The screed assembly as recited in claim 1 wherein the pivot body is formed as a generally cylindrical bar having a generally continuous circumferential outer surface encircling the pivot body axis.

6. The screed assembly as recited in claim 1 further comprising:

a first hinge member connected with the first screed plate and having a circumferential inner surface spaced radially from the pivot body outer surface; and

a second hinge member connected with the second screed plate and having an inner circumferential surface disposed generally against the pivot body outer surface and an outer circumferential surface disposed generally against the first hinge member inner surface such that the second hinge member is retained at least partially between the first hinge member and the pivot body to movably connect the second screed plate with the first screed plate.

7. The screed assembly as recited in claim 6 wherein:

the first hinge member is formed as a generally arcuate plate having a first end connected with the first screed plate and a second, opposing free end; and

the second hinge member is formed as a generally arcuate plate having a first end connected with the second screed plate and a second, opposing free end, the first hinge plate at least partially overlapping the second hinge plate such that the free end of the second hinge plate is displaceable generally between a first position proximal to the free end of the first hinge plate and a second position proximal to the first screed plate.

8. The screed assembly as recited in claim 6 wherein:

the second hinge member has opposing ends spaced apart along the pivot body axis; and

the screed assembly further comprises first and second retainer blocks each connected with the first screed plate and disposed proximal to a separate one of the ends of the second hinge member so as to limit linear displacement of the second hinge member in directions generally along the pivot body axis.

9. The screed assembly as recited in claim 1 further comprising:

a screed frame disposed generally above the first and second screed plates and having a lower end, the first screed plate being removably attached to the lower end of the frame; and

a connective member having a first end connected with the frame and a second end connected with the second plate, the connective member second end being displaceable with respect to the connective member first end so as to rotatably displace the second screed plate about the pivot body axis.

10. The screed assembly as recited in claim 1 in combination with a paving vehicle for forming a mat of material.

11. The screed assembly as recited in claim 10 wherein:

the paving vehicle has a front end, a rear end and a longitudinal centerline extending between the front and rear ends;

the first and second screed plates each have a geometric center and the screed assembly is connected with the paving vehicle such that the distance between the second plate center and the vehicle centerline is greater than a distance between the first plate center and the centerline; and

the second screed plate is adjustably positionable with respect to the first screed plate such that when the vehicle forms a mat of material, an angled shoulder is formed at an outer edge of the mat.

12. A hinge device for a screed assembly of a paving vehicle, the screed having first and second screed plates, the hinge comprising:

a pivot body attached to the first screed plate and having an axis and an outer surface including a generally circumferential bearing surface section extending at least partially about the axis;

a first hinge member connected with the first screed plate and having an inner circumferential surface disposed partially about the block axis and spaced radially from the bearing surface; and

a second hinge member connected with the second screed plate and having an inner circumferential surface slidably disposed generally against the bearing surface and an outer circumferential surface spaced radially from the second hinge member inner surface and slidably disposed generally against the first hinge member inner surface such that the second hinge member is slidably retained between the pivot body and the first hinge member to movably connect the second screed plate with the first screed plate.

13. The hinge device as recited in claim 12 wherein:

the first screed plate has a working surface and a side edge, the pivot body being attached to the first plate side edge; and

a second screed plate has a working surface and a side edge slidably disposed generally against the pivot body bearing surface, the second screed plate being rotatably displaceable about the pivot body axis to adjustably position the second plate working surface with respect to the first plate working surface.

14. The hinge device as recited in claim 13 wherein the edge of the second plate remains substantially in contact with the bearing surface when the second plate rotatably displaces about the pivot body axis.

15. The hinge device as recited in claim 12 wherein the pivot body is formed of a generally cylindrical bar having a generally continuous circumferential outer surface encircling the pivot body axis.

16. The hinge device as recited in claim 12 wherein:

the first hinge member is formed as a generally arcuate plate having a first end connected with the first screed plate and a second, opposing free end; and

the second hinge member is formed as a generally arcuate plate having a first end connected with the second screed plate and a second, opposing free end, the first hinge plate at least partially overlapping the second hinge plate such that the free end of the second hinge plate is displaceable generally between a first position proximal to the free end of the first hinge plate and a second position proximal to the first screed plate.

17. The hinge device as recited in claim 12 wherein:

the second hinge member has opposing ends spaced apart along the pivot body axis; and

the hinge device further comprises first and second retainer blocks each connected with the first screed plate and disposed proximal to a separate one of the ends of the second hinge member so as to limit linear displacement of the second hinge member in directions generally along the pivot body axis.