FLOW DIVERTER FOR HOPPER OF ASPHALT PAVING MACHINE

Abstract

An asphalt paving machine includes a hopper for receiving asphalt material and a distributing auger for distributing asphalt material onto a roadway to be paved. A hopper conveyor is provided to carry asphalt material from the hopper to the distributing auger. The hopper conveyor has a rear end that is adjacent the distributing auger, an outside edge, and a flow diverter that is adapted to divert asphalt material being carried by the hopper conveyor away from the outside edge thereof.

Description

FIELD OF THE INVENTION

The present invention relates generally to asphalt paving machines, and more particularly, to a flow diverter for the asphalt material conveyor of a paving machine that helps to avoid segregation in asphalt material being transported to the distributing auger.

BACKGROUND OF THE INVENTION

Paving of a roadway with asphalt material is generally carried out by a paving machine that is supplied with asphalt material by a number of supply trucks and/or a material transfer vehicle. Asphalt material is comprised of an asphaltic binder and aggregates of various sizes, including both coarse and fine aggregate materials. Because the equipment needed to produce asphalt material is expensive and the space required is extensive, asphalt material is typically produced in a production facility that is dedicated to such purpose. Consequently, it is frequently necessary to transport the asphalt material from its place of origin to a paving machine at a remote paving site. Even if the asphalt material is ultimately loaded into a material transfer vehicle for transport to the paving machine, it is usually transported from the production site in dump trucks. The loading of such material into the dump beds at the production site is accomplished by dropping the asphalt material from an overhead hopper or silo into the truck bed. Such loading operations, as well as the vibrations and jostling associated with vehicular transport to the paving machine (or to a material transfer vehicle for transport to the paving machine) tend to separate the asphalt materials into coarse and fine fractions in the truck bed. Although some material transfer vehicles include mechanisms for re-mixing the asphalt material, segregation in the asphalt material that occurs during transport of the asphalt to the paving machine continues to be a problem.

A typical asphalt paving machine is self-propelled and driven by a wheeled or tracked drive system. Typically, a hopper is located at the front end of the machine to receive asphalt material from a truck or material transfer vehicle, and a conveyor system typically comprised of one or more slat conveyors located below the hopper transfers the asphalt material from the hopper to a transverse distributing auger that is mounted near the rear of the machine. Some conventional asphalt paving machines have two slat-type hopper conveyors that are located beneath the hopper. Each hopper conveyor in this type of machine includes a drive shaft on one end and an idler shaft on the other end. Drive sprockets are mounted on both ends of the drive shaft and idler sprockets are mounted on both ends of the idler shaft. A pair of continuous drive chains are also provided for each hopper conveyor, one of which is wrapped around the idler sprocket and around the corresponding drive sprocket on the same side. An angled chain protector plate covers the chains on both sides of each conveyor, so that asphalt material cannot fall on the chains and stop their motion. The asphalt material conveyed by the hopper conveyors is deposited onto and across the roadway or other surface to be paved by the distributing auger. A floating screed located at the rear end of the machine behind the distributing auger compacts the asphalt material and forms the asphalt mat.

It is common for asphalt material that is dumped into the hopper of a paving machine to separate into non-homogenous size fractions as it is carried by the hopper conveyors from the hopper to the distributing auger. In particular, it is common for asphalt materials including a higher-than-desired proportion of larger-sized aggregate materials to fall into the corners at the front end of the hopper from the delivery truck or material transfer vehicle. This non-homogenous asphalt material will tend to flow along both sides of each hopper conveyor to the distributing auger. The discharge of non-homogenous asphalt material onto the roadway by the distributing auger results in an asphalt mat of non-uniform density. It would be desirable if a device could be provided that would tend to remix the asphalt materials being transported by the hopper conveyors to obtain the desired size homogeneity of asphalt materials in the asphalt mat produced by the paving machine.

ADVANTAGES OF THE INVENTION

Among the advantages of a preferred embodiment of the invention is that it provides a flow diverter for the hopper conveyor of a paving machine that facilitates the transport of a more homogeneous mixture of asphalt materials by aggregate size through the conveyor tunnel to the distributing auger. Other advantages and features of this invention will become apparent from an examination of the drawings and the ensuing description.

Notes on Construction

The use of the terms “a”, “an”, “the” and similar terms in the context of describing the invention are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising”, “having”, “including” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. The terms “substantially”, “generally” and other words of degree are relative modifiers intended to indicate permissible variation from the characteristic so modified. The use of such terms in describing a physical or functional characteristic of the invention is not intended to limit such characteristic to the absolute value which the term modifies, but rather to provide an approximation of the value of such physical or functional characteristic.

The use of any and all examples or exemplary language (e.g., “such as” and “preferably”) herein is intended merely to better illuminate the invention and the preferred embodiment thereof, and not to place a limitation on the scope of the invention. Nothing in the specification should be construed as indicating any element as essential to the practice of the invention unless so stated with specificity.

Various terms are specifically defined herein. These terms are to be given their broadest possible construction consistent with such definitions, as follows:

The term “asphalt material(s)” refers to a bituminous paving mixture that is comprised of an asphaltic binder and any of various aggregate materials, and which is used for paving purposes.

The terms “asphalt paving machine”, “paving machine” and similar terms refer to a finishing machine for applying asphalt material to form an asphalt mat on a roadway, parking lot or similar surface.

The term “paving direction”, when used in describing the operation of a paving machine or the relative position of a paving machine or a component of a paving machine, refers to the direction of advance of the paving machine as the paving operation is carried out.

The term “hopper conveyor” refers to a single conveyor or to one of a plurality of parallel conveyors that are adapted to convey asphalt material from the hopper of a paving machine to the distributing auger of the paving machine.

The term “conveying direction”, when used in describing the operation of a hopper conveyor of a paving machine or the relative position of a component thereof, refers to the direction that asphalt material is conveyed from the hopper towards the distributing auger as the paving operation is carried out. The conveying direction is generally 180° from the paving direction.

The terms “front” and “front end” of the paving machine refer to the end of the machine that leads in the paving direction. When referring to a hopper, hopper conveyor or other component of the paving machine, the terms “front” and “front end” refer to that portion of the hopper, hopper conveyor or component that is nearer the front end of the paving machine.

The terms “rear” and “rear end” of the paving machine refer to the end of the paving machine opposite the front end. When referring to a hopper, hopper conveyor or other component of the paving machine, the terms “rear” and “rear end” refer to that portion of the hopper, hopper conveyor or component that is nearer the rear end of the paving machine.

The terms “forward” and “in front of”, as used herein to describe a relative position or direction on or in connection with a paving machine or a hopper, hopper conveyor or other component of the paving machine, refer to a relative position towards the front end of the machine.

The terms “rearward”, “behind” and “rearwardly”, as used herein to describe a relative position or direction on or in connection with a paving machine or a hopper, hopper conveyor or other component of the paving machine, refer to a relative position or direction towards the rear end of the machine.

The terms “downward” and “downwardly”, as used herein to describe a relative direction on or in connection with a paving machine, a hopper or a hopper conveyor of a paving machine, refer to a direction towards the roadway that is being paved by the machine.

The terms “lower” and “below”, as used herein to describe the relative position of a hopper, hopper conveyor or other component of a paving machine, refer to a relative position that is in the downward direction.

The term “right”, when used herein to describe a relative position or direction on or in connection with a paving machine, a hopper or a hopper conveyor or other component of a paving machine, refers to the right side of the machine, hopper, hopper conveyor or component from the perspective of an observer facing the paving direction.

The term “left”, when used herein to describe a relative position or direction on or in connection with a paving machine, a hopper or a hopper conveyor or other component of a paving machine, refers to the left side of the machine, hopper, hopper conveyor or component from the perspective of an observer facing the paving direction.

The term “centerline”, when used herein to describe a relative position, direction or location on or in connection with a hopper or a hopper conveyor of a paving machine, refers to a line that is parallel to the conveying direction and located midway between the left outside wall of the hopper and the right outside wall of the hopper of the paving machine.

The term “outside”, when used herein to describe a relative position, direction or location on or in connection with a hopper or a hopper conveyor of a paving machine, refers to a position, direction or location line that is nearer an outside wall of the hopper (or a line that is parallel to the outside wall of the hopper) than the centerline.

The term “inside”, when used herein to describe a relative position, direction or location on or in connection with a hopper or a hopper conveyor of a paving machine, refers to a position, direction or location line that is nearer the centerline of the hopper than to an outside wall of the hopper (or a line that is parallel to the outside wall of the hopper).

SUMMARY OF THE INVENTION

The invention comprises an asphalt paving machine having a hopper that is adapted to receive asphalt material and a distributing auger that is adapted to distribute asphalt material onto a roadway to be paved. The asphalt paving machine has a hopper conveyor that is adapted to carry asphalt material from the hopper to the distributing auger. The hopper conveyor has a rear end that is adjacent the distributing auger, an outside edge, and a flow diverter that is adapted to divert asphalt material being carried by the hopper conveyor away from the outside edge of the hopper conveyor.

In order to facilitate an understanding of the invention, the preferred embodiment of the invention is illustrated in the drawings, and a detailed description thereof follows. It is not intended, however, that the invention be limited to the particular embodiment described or to use in connection with the apparatus illustrated herein. Various modifications and alternative embodiments such as would ordinarily occur to one skilled in the art to which the invention relates are also contemplated and included within the scope of the invention described and claimed herein.

BRIEF DESCRIPTION OF THE DRAWINGS

The presently preferred embodiment of the invention is illustrated in the accompanying drawings, in which:

FIG. 1 is a side view of a conventional paving machine to which a preferred embodiment of the invention may be mounted.

FIG. 2 is a top view of the hopper conveyor of a conventional paving machine such as is shown in FIG. 1.

FIG. 3 is a perspective rear view of a portion of the hopper conveyor that is shown in FIG. 2.

FIG. 4 is a top view of a hopper conveyor which has been modified to include flow diverters according to the invention.

FIG. 5 is a perspective rear view of a portion of the hopper conveyor that is shown in FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION

Referring now to the drawings, FIGS. 1-3 illustrate conventional paving machine 10, which includes hopper 12 at its front end 14 for receiving asphalt material from a dump truck or a material transfer vehicle. Paving machine 10 also includes operator's station 16, and track drive system 18 that is driven by engine 20 so as to move the paving machine during the paving operation in the paving direction indicated by arrow 22. The bottom of hopper 12 is open. exposing right hopper conveyor 24 and left hopper conveyor 25 (only one of which, right hopper conveyor 24, is shown in FIG. 1). Preferably, left and right hopper conveyors are slat-type conveyors that are mounted in a parallel configuration under the hopper. These conveyors convey asphalt material from hopper 12 through a conveyor tunnel under the engine and operator's station to a pair of transverse distributing augers, one of which, right distributing auger 26, is shown in FIG. 1. The distributing augers are located near rear end 28 of paving machine 10 and serve to distribute the asphalt material received from the hopper across the width of the roadway or lane to be paved. Floating screed 30 is attached to the paving machine by a pair of tow arms, one of which, tow arm 32, is illustrated in FIG. 1. Screed 30 serves to compact the asphalt material and form the asphalt mat 34.

As shown in FIGS. 2 and 3, right slat-type hopper conveyor 24 and left slat-type hopper conveyor 25 extend in a parallel configuration from the front end of hopper 12 (adjacent front end 14 of paving machine 10) towards the rear end of the paving machine. Right hopper conveyor 24 has an outside edge 36 that is nearer to right outside wall 38 of hopper 12. Right hopper conveyor 24 also has an inside edge 40 that is adjacent hopper centerline 42. Right hopper conveyor 24 includes drive shaft 44 on its rear end to which are mounted a pair of drive sprockets, one of which, drive sprocket 46, is shown schematically in FIG. 1. Right hopper conveyor 24 also includes idler shaft 48 on its front end to which are mounted a pair of idler sprockets, one of which, idler sprocket 50, is shown schematically in FIG. 1. A pair of continuous drive chains 52 and 54 are also provided for the right hopper conveyor, as shown in FIG. 3. Each drive chain is wrapped around the idler sprocket and around the corresponding drive sprocket on the same side of right hopper conveyor 24. Angled outside chain protector plate 56 covers chain 52 on outside edge 36 of hopper conveyor 24, and angled inside chain protector plate 58 covers chain 54 on inside edge 40 of hopper conveyor 24, so that asphalt material that falls on the chain protector plates is directed onto the slat conveyor. In similar fashion, left hopper conveyor 25 has an outside edge 60 that is nearer to left outside wall 62 of hopper 12. Left hopper conveyor 25 also has an inside edge 64 that is adjacent hopper centerline 42. Left hopper conveyor 25 also includes a drive shaft (not shown) on its rear end to which are mounted a pair of drive sprockets (also not shown), and an idler shaft (not shown) on its front end to which are mounted a pair of idler sprockets (also not shown). A pair of continuous drive chains 66 and 68 are also provided for the left hopper conveyor, as shown in FIG. 3. Each drive chain is wrapped around the idler sprocket and around the corresponding drive sprocket on the same side of left hopper conveyor 25. Angled outside chain protector plate 70 covers chain 66 on outside edge 60 of hopper conveyor 25, and angled inside chain protector plate 72 covers chain 68 on inside edge 64 of hopper conveyor 25, so that asphalt material that falls on the chain protector plates is directed onto the slat conveyor.

Each angled chain protector plate extends from the front end of hopper 12 through the conveyor tunnel. Because the width of the opening in the bottom of hopper 12 onto hopper conveyors 24 and 25 is the same at the front end and the rear end 74 of hopper 12, larger-sized aggregate materials that fall to the corners at the front end of the hopper are pulled straight back by the slat conveyors, thus creating a stream of non-homogenous asphalt material along the outsides of the hopper conveyors and continuing through the conveyor tunnel. The asphalt material that falls off the rear end of the hopper conveyors adjacent to the distributing augers thus comprises a non-homogenous mixture. resulting in an inferior asphalt mat.

FIGS. 4 and 5 illustrate the modification of the hopper conveyors to include a pair of flow diverters. As shown therein, right slat-type hopper conveyor 124 and left slat-type hopper conveyor 125 extend in a parallel configuration from the front end 114 of hopper 112 towards the rear end of the paving machine. Right hopper conveyor 124 has an outside edge 136 that is nearer to right outside wall 138 of hopper 112. Right hopper conveyor 124 also has an inside edge 140 that is adjacent to hopper centerline 142. Right hopper conveyor 124 includes a drive shaft on its rear end (not shown, but substantially similar to drive shaft 44 of right hopper conveyor 24). A pair of drive sprockets (also not shown, but substantially similar to drive sprocket 46) are mounted on the drive shaft of right hopper conveyor 124. Right hopper conveyor 124 also includes an idler shaft on its front end (not shown, but substantially similar to idler shaft 48 of right hopper conveyor 24). A pair of idler sprockets (also not shown, but substantially similar to idler sprocket 50) are mounted on the idler shaft of right hopper conveyor 124. A pair of continuous drive chains 152 and 154 are also provided for the right hopper conveyor, as shown in FIG. 5. Each drive chain is wrapped around the idler sprocket and around the corresponding drive sprocket on the same side of right hopper conveyor 124. Angled outside chain protector plate 156 covers chain 152 on outside edge 136 of hopper conveyor 124, and angled inside chain protector plate 158 covers chain 154 on inside edge 140 of hopper conveyor 124, so that asphalt material that falls on the chain protector plates is directed onto the slat conveyor. In similar fashion, left hopper conveyor 125 has an outside edge 160 that is nearer to left outside wall 162 of hopper 112. Left hopper conveyor 125 also has an inside edge 164 that is adjacent hopper centerline 142. Left hopper conveyor 125 also includes a drive shaft (not shown) on its rear end to which are mounted a pair of drive sprockets (also not shown), and an idler shaft (not shown) on its front end to which are mounted a pair of idler sprockets (also not shown). A pair of continuous drive chains 166 and 168 are also provided for the left hopper conveyor, as shown in FIG. 5. Each drive chain is wrapped around the idler sprocket and around the corresponding drive sprocket on the same side of left hopper conveyor 125. Angled outside chain protector plate 170 covers chain 166 on outside edge 160 of hopper conveyor 125, and angled inside chain protector plate 172 covers chain 168 on inside edge 164 of hopper conveyor 125, so that asphalt material that falls on the chain protector plates is directed onto the slat conveyor.

Right flow diverter 174 and left flow diverter 176 are located at the rear end of the hopper conveyors on their outside edges. Preferably as shown in FIGS. 4 and 5, right flow diverter 174 comprises diverter plate 178 that is supported by diverter bracket 180. Similarly, left flow diverter 176 comprises diverter plate 182 that is supported by diverter bracket 184. The diverter plates can be located at any of various positions along the outside edges of the hopper conveyors; however, it is preferred that they be located at the rear end of the hopper conveyors where the asphalt material is discharged onto the distributing augers. Preferably, the angle and length of the diverter plates are selected so that the inwardmost extent of each diverter plate is inside the outer chain protector plate on the outside of the hopper conveyor with which it is associated. Preferably, the angle θ of each diverter plate with respect to the outside edge of the hopper conveyor with which it is associated is within the range of about 10° to about 20°, most preferably about 14°. The placement of diverter plates with respect to the rear ends of the hopper conveyors will cause asphalt material being carried along the outsides of the hopper conveyors to be directed away from the outside edges of the hopper conveyors and towards hopper centerline 142. The modification of the hopper conveyors to include flow diverters as described herein serves to re-direct any non-homogenous asphalt material being carried along the outsides of the hopper conveyors away from the outside edges of the hopper conveyors so that such material can be re-mixed with the more homogenous asphalt material being carried inside the outside edges of the hopper conveyors by the distributing augers, thereby resulting in an improved asphalt mat of uniform density.

Although this description contains many specifics, these should not be construed as limiting the scope of the invention, but as merely providing illustrations of the presently preferred embodiment thereof, as well as the best mode contemplated by the inventor of carrying out the invention. The invention, as described herein, is susceptible to various modifications and adaptations, as would be understood by those having ordinary skill in the art to which the invention relates.

Claims

1. An asphalt paving machine comprising: (a) a hopper that is adapted to receive asphalt material;(b) a distributing auger that is adapted to distribute asphalt material onto a roadway to be paved;(c) a hopper conveyor that is adapted to carry asphalt material from the hopper to the distributing auger, said hopper conveyor having: (i) a rear end that is adjacent the distributing auger;(ii) an outside edge;(d) a flow diverter that is adapted to divert asphalt material being carried by the hopper conveyor away from the outside edge of said hopper conveyor.

2. The asphalt paving machine of claim 1 wherein the flow diverter comprises a diverter plate which is supported by a diverter bracket.

3. The asphalt paving machine of claim 2 wherein: (a) the hopper conveyor has a drive chain on its outside edge;(b) an outer chain protector plate is provided to cover the drive chain on the outside edge of the hopper conveyor;(c) the diverter plate is located so that its inwardmost extent is inside the outer chain protector plate on the outside edge of the hopper conveyor.

4. The asphalt paving machine of claim 2 wherein the diverter plate is disposed at an angle with respect to the outside edge of the hopper conveyor that is within the range of about 10° to about 20°.

5. The asphalt paving machine of claim 2 wherein the diverter plate is disposed at an angle of about 14° with respect to the outside edge of the hopper conveyor.

6. An asphalt paving machine comprising: (a) a hopper that is adapted to receive asphalt material, said hopper having: (i) a right outside wall;(ii) a left outside wall;(iii) a centerline that is located midway between the left outside wall and the right outside wall;(iv) a front end;(b) a distributing auger that is adapted to distribute asphalt material onto a roadway to be paved;(c) a right hopper conveyor that is adapted to carry asphalt material from the hopper to the distributing auger, said right hopper conveyor having: (i) a front end that is adjacent the front end of the hopper;(ii) a rear end that is adjacent the distributing auger;(iii) an outside edge;(iv) an inside edge that is adjacent the centerline of the hopper;(d) a right flow diverter that is adapted to divert asphalt material being carried by the right hopper conveyor away from the outside edge of said right hopper conveyor;(e) a left hopper conveyor that is adapted to carry asphalt material from the hopper to the distributing auger, said left hopper conveyor having: (i) a front end that is adjacent the front end of the hopper;(ii) a rear end that is adjacent the distributing auger;(iii) an outside edge;(iv) an inside edge that is adjacent the centerline of the hopper;(f) a left flow diverter that is adapted to divert asphalt material being carried by the left hopper conveyor away from the outside edge of said left hopper conveyor.

7. The asphalt paving machine of claim 6 wherein: (a) the right flow diverter comprises a right diverter plate which is supported by a right diverter bracket;(b) the left flow diverter comprises a left diverter plate which is supported by a left diverter bracket.

8. The asphalt paving machine of claim 7 wherein: (a) the right diverter plate is disposed at an angle with respect to the outside edge of the right hopper conveyor that is within the range of about 10° to about 20°;(b) the left diverter plate is disposed at an angle with respect to the outside edge of the left hopper conveyor that is within the range of about 10° to about 20°.

9. The asphalt paving machine of claim 7 wherein: (a) the right diverter plate is disposed at an angle of about 14° with respect to the outside edge of the right hopper conveyor;(b) the left diverter plate is disposed at an angle of about 14° with respect to the outside edge of the left hopper conveyor.