1. Field of the Invention
The present invention relates to systems and methods for milling installed pavement, such as asphalt, concrete, and tarmac. More specifically, the present invention relates to systems and methods that enhance the thorough milling of installed pavement.
2. The Relevant Technology
Pavement milling is currently employed to remove existing pavement for reconstruction, resurfacing, or reuse. Known pavement milling assemblies are attached to a drivable construction vehicle, such as a front end loader, forward of the wheels or tracks thereof. The construction vehicle then propels the attached pavement milling assembly over pavement preselected for milling.
Known asphalt milling assemblies have drawbacks, however.
For example, known pavement milling assemblies reliably retain the pavement material being milled, only when the depth of the cut of the pavement material to be milled is the maxim milling depth attainable using the pavement milling assembly being employed. Otherwise, known pavement milling assemblies permit dislodged paving material that is being pulverized into granules to escape from the milling assembly, becoming lost or unusable. Typically, the pavement material that escapes from a pavement milling assembly in this manner has not been milled sufficiently to be in granules of a desirably small size. To avoid being wasted, the escaped pavement material must be collected manually and reprocessed in supplemental equipment before becoming of a size acceptable for reuse. This is costly and inefficient, and frequently is simply not performed at all.
Then also, most known pavement milling assemblies are supported in part on a wheel that upholds the front end of the pavement milling assembly on the surface of the pavement to be milled in the direction of the forward travel of the pavement milling assembly itself. This support of the pavement milling assembly on a relatively small area of pavement that is about to be milled determines the depth at which milling occurs. Unfortunately, as a propelling vehicle drives the pavement milling assembly from behind, over uneven surfaces, partially-milled material, or other debris, contact between the support wheel and the pavement is frequently lost entirely. Thus, it is difficult to precisely control the depth at which pavement milling occurs.
In addition propelling vehicles experience numerous mechanical problems, such as hydraulic leaks, that cause the connection between the propelling vehicle and the pavement milling assembly to drift, to adjust, or to be temporarily lost. If the depth of pavement milling is to be maintained constant, the occurrence of such exigencies require repeated corrective adjustments and accommodations to the propelling vehicle and to the attachment between the propelling vehicle and the pavement milling assembly.
The present invention has been developed in response to the present state of the art, and in particular, in response to the problems and needs in the art that have not yet been fully solved by known pavement milling assemblies.
According to one aspect of the present invention, a pavement milling sled is provided of the type that upholds a rotating pavement milling drum as the sled travels over pavement preselected for milling. The milling sled includes laterally-separated left and right runners, each of which has a lead end oriented toward the front of the sled and a lower face configured for sliding travel on the surface of the pavement. The lower faces of the runners are substantially coplanar and thereby define a floor of the sled.
A milling frame is mounted between the runners. The milling frame circumscribes a milling region in which rotation of the milling drum dislodges pavement located in the path of forward travel of the sled below the floor of the sled, pulverizes dislodged pavement, and deposits pulverized pavement to the rear of the sled. The milling frame itself includes left and right milling region sidewalls that extend upwardly from the floor of the sled on opposite sides of the milling region and a discharge baffle between the milling region sidewalls at the back of the milling region in close proximity to the floor of the sled. The proximity of the discharge baffle to the floor of the sled is adjustable.
The discharge baffle includes in combination a rear wall separated from the floor of the sled and extending upwardly between the milling region sidewalls at the back of the milling region and a vertically-adjustable pulverized pavement exit gate that depends from the wall. Optionally, the discharge baffle may include one or a plurality of pulverized pavement capture ledges on the rear wall facing the milling region and a pulverized pavement capture lip on the exit gate also facing the milling region.
A guard plate is secured between the milling region sidewalls forward of the milling region at a distance above the floor of the sled. The milling region sidewalls project forward of the guard plate to form opposed sidewalls of an entry scoop having a mouth located at the front of the sled. The entry scoop extends rearwardly from there into the milling region. A roofing plate bridges between the sidewalls of the entry scoop at a distance above the floor of the sled and a downwardly depending admission flap is pivotably mounted across the mouth of the entry scoop for movement into the entry scoop. The admission flap is precluded from pivoting outwardly of the entry scoop.
According to another aspect of the present invention, a pavement milling assembly includes laterally-separated left and right runners, a milling frame mounted between the runners enclosing a milling region, a milling drum upheld by the milling frame within the milling region, and a cover supported from the milling frame enclosing the milling drum. Rotation of the milling drum dislodges pavement located in the path of travel of the assembly below the floor of the assembly, pulverizes dislodged pavement, and deposits pulverized pavement to the rear of the assembly. The milling frame combines left and right milling region sidewalls extending upwardly from the floor of the assembly on opposite sides of the milling region, a guard plate secured between the milling region sidewalls forward of the milling region at a distance above the floor of the assembly, and a discharge baffle between the milling region sidewalls at the back of the milling region in close, but adjustable, proximity to the floor of the assembly.
The teachings of the present invention provide a pavement milling assembly that allows pavement being milled to remain confined in a milling region, where full pavement particle pulverization can be effected. As a result installed pavement can be milled into any desirable size. Material size is controlled by limiting the amount of pavement released at the rear of the pavement milling assembly. This present invention also improves control of milling depth by having stabilizing units in the form of elongated runners that average the surface conditions outside of pavement preselected for milling.
These and other features of the present invention will become more fully apparent from the following description, or may be learned by the practice of the invention as set forth hereinafter.
In order that the manner in which the above-recited and other features and advantages of the invention are obtained will be readily understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:
The presently preferred embodiments of the present invention will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout. It will be readily understood that the components of the present invention, as generally described and illustrated in the figures herein, could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description of the embodiments of the present invention, as represented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of presently preferred embodiments of the invention.
The word “exemplary” is used exclusively herein to mean “serving as an example, instance, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments. While the various aspects of the embodiments are presented in drawings, the drawings are not necessarily drawn to scale unless specifically indicated.
For this application, the phrases “connected to,” “coupled to,” and “in communication with” refer to any form of interaction between two or more entities, including mechanical, electrical, magnetic, electromagnetic, and thermal interaction. The phrase “attached to” refers to a form of mechanical coupling that restricts relative translation or rotation between the attached objects. The phrases “pivotally attached to” and “slidably attached to” refer to forms of mechanical coupling that permit relative rotation or relative translation, respectively, while restricting other relative motion.
The phrase “attached directly to” refers to a form of attachment by which the attached items are either in direct contact, or are only separated by a single fastener, adhesive, or other attachment mechanism. The term “abutting” refers to items that are in direct physical contact with each other, although the items may not be attached together. The terms “integrally formed” refer to a body that is manufactured integrally as a single piece without requiring the assembly of multiple pieces. Multiple parts may be integrally formed with each other, if the parts are formed from a single work piece.
Pavement milling assembly 12 includes a pavement milling sled 18 that upholds a complex superstructure 20 that includes the active components of pavement milling assembly 12. These active components of pavement milling assembly 12 include a pavement milling drum and a drive train operably connected therewith to cause rotation thereof. Each is concealed in
Pavement milling sled 18 will be discussed in detail in relation to subsequent of the drawings, but it should be noted at the outset that pavement milling sled 18 travels on the surface of pavement 14 on a left runner 26 that is fully visible in
Each of left runner 26 and right runner 28 has an elongated, flat lower face that is configured for sliding travel directly on the surface of pavement 14. The lower face of left runner 26 is in a substantially coplanar relationship with the lower face of right runner 28. Accordingly, the lower faces of left runner 26 and right runner 28 will, for convenience of description herein, be used to defining a common floor F of pavement milling assembly 12 and of pavement milling sled 18 thereof. Due to the abundant detail included in
Left runner 26 and right runner 28 afford stable support for pavement milling assembly 12 upon the surface of pavement 14. By contacting the surface of pavement 14 over a relative extensive area, left runner 26 and right runner 28 together function to average out irregularities in the surface of pavement 14 and maintain the rotating pavement milling drum inside pavement milling assembly 12 in a relatively invariant vertical relationship to pavement 14. This results in a uniform depth to the pavement milling effected by the travel of pavement milling assembly 12 caused by propelling vehicle 10. Left runner 26 and right runner 28 also function to hold in place the portions of pavement 14 located directly there beneath, which the rotating pavement milling drum inside pavement milling assembly 12 dislodges and pulverizes the portion of pavement 14 between left runner 26 and right runner 28. This contributes to the creation of straight sides to the trench cut into pavement 14 by the pavement milling action of pavement milling assembly 12 in traveling there over.
Such a trench 36 formed in pavement 14 by pavement milling assembly 12 is shown by way of better understanding in
There, significant subcomponents of pavement milling assembly 12 mentioned earlier are shown in exploded perspective above pavement 14, while propelling vehicle 10 has been omitted entirely. Milling drum cover 22 and drive train cover 24 can be seen to be carried directly on a superstructure scaffold 38. Also carried directly on superstructure scaffold 38 are the active components of superstructure 20, rotatable milling drum 40 and a drive train 42 that includes an engine 44 and a drive belt 46. Engine 44 is operably interconnected by drive belt 46 to milling drum 40 in such a manner as to cause milling drum 40 to engage in rotation R as shown.
Superstructure scaffold 38 is in part secured to pavement milling sled 18 by a latch 48 that cooperates with a coupling structure 50 located at front 32 of pavement milling sled 18. Other similar coupling structures 52, 54 at the rear of pavement milling sled 18 cooperate with additional latches not shown in
A lead portion 56 of trench 36 is seen to have been cleared by the rotation of milling drum 40 of any of pavement 14, while the following portion 58 of trench 36 to the rear thereof is filled with loose, pulverized pavement granules 60 that have been deposited in portion 58 of trench 36 to the rear of pavement milling sled 18 for possible use as fresh road bed material.
Milling frame 70 includes a left milling region sidewall 74 and a right milling region sidewall 76 that extend upwardly from floor F of pavement milling sled 18 on opposite sides of milling region 72. Left milling region sidewall 74 and right milling region sidewall 76 are typically heavy elongated metal plates that are positioned on the tops, respectively, of right runner 28 and left runner 26 and secured thereto by various sturdy attachment systems, such as by fasteners, bolts, welding, or screws. During pavement milling, left milling region sidewall 74 and right milling region sidewall 76 prevent the lateral escape of dislodged fragments of pavement 14 from the sides of pavement milling sled 18. Consequently, those fragments of pavement 14 remain within milling region 72 to become fully pulverized into granules, such as pulverized pavement granules 60 shown in
Milling frame 70 includes additional structures that serve to confine fragments of pavement 14 within milling region 72.
One of these, a milling region front wall 78, extends upwardly above floor F of pavement milling sled 18 at the front of milling region 72. During pavement milling, milling region front wall 78 prevents the escape of dislodged fragments of pavement 14 from the front of pavement milling sled 18.
In the rear perspective of pavement milling sled 18 shown in
To optimize the effect of guard plate 80 relative to pavement lift-up, guard plate 80 should be located in as close proximity as possible to milling frame floor FM. Nevertheless, other design factors must be balanced in the design of pavement milling sled 18, and
For this to occur, however, pavement milling sled 18 is also provided at front 32 thereof with an elongated, downwardly depending admission flap 84 (shown in
The portion of milling sled 18 between admission flap 84 and gap 82 can thus conveniently be conceived as an entry scoop 90 to milling region 72. The opposed sidewalls of entry scoop 90 are in this conception the portions of left milling region sidewall 74 and right milling region sidewall 76 that project forward of guard plate 80 or of milling region front wall 78. A roofing plate 92 bridges between these forward projections of left milling region sidewall 74 and right milling region sidewall 76 at a distance commensurate with the size of gap 82 above milling frame floor FM. Admission flap 82 is mounted across the mouth of entry scoop 90 at front 32 of milling sled 18.
Discharge baffle 100 includes a rear wall 102 that is rigidly secured between right milling region sidewall 76 and left milling region sidewall 74. Rear wall 102 does not extend as far downwardly toward milling frame floor FM as do left milling region sidewall 74 and right milling region sidewall 76. Instead, rear wall 102 has a lower edge 104 that is at a distance D102 above milling frame floor FM. The opposite ends of rear wall 102 are attached to left milling region sidewall 74 and to right milling region sidewall 76 by a respective retention bracket 106.
The adjustable portion of discharge baffle 100 is a pulverized pavement exit gate 108. Pulverized pavement exit gate 108 depends by the upper edge 110 thereof toward milling frame floor FM on a pair of hinges 112 that are attached to the opposite side of rear wall 102 from milling region 72. Consequently, pulverized pavement exit gate 108 can be pivoted as suggested by arrows P in
To enhance the effectiveness of discharge baffle 100 in retaining particles of pavement 14 within milling region 72, a plurality of pulverized pavement capture ledges 122 on pulverized pavement rear wall 102 facing the milling region 72. Similarly, pulverized pavement exit gate 108 is provided with a pulverized pavement capture lip 124 near lower edge 114 thereof facing milling region 72.
The teachings of the present invention allow a road-repair crew to easily repair or re-surface an area of a road very quickly and easily. Because particles of dislodged pavement are confined with as rotating milling drum within a small milling region, a pavement milling assembly embodying those teachings capable of fully pulverizing those particles, even if the milling drum is not at its full depth.
The present invention may be embodied in other specific forms without departing from its structures, methods, or other essential characteristics as broadly described herein and claimed hereinafter. The described embodiments are to be considered in all respects only as illustrative, and not restrictive. The scope of the invention is, therefore, indicated by the appended claims, rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.
This patent application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/015,937 that was filed on Dec. 21, 2007, for an invention titled, SYSTEMS AND METHODS FOR INCREASING MATERIAL REGRINDING AND CONTROLLING MILLING DEPTH.
Number | Date | Country | |
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61015937 | Dec 2007 | US |