PORTABLE PAVING MATERIAL MIXING APPARATUS

Abstract

A portable paving material mixing apparatus includes a material hopper, a rotatable mixing drum, and a discharge bed, all configured to be supported on a vehicle trailer. A burner heats material within the mixing drum. Embodiments of the mixing apparatus include a rejuvenator application system suitable for hot mix asphalt, cold mix asphalt, hot in-place recycling, and asphalt based concrete mixing. The apparatus rapidly processes a batch of material sufficient to fill 5-7 potholes, has sufficient carrying capacity to process multiple mixer batches, and stores prepared material in the discharge bed while the next batch is being prepared in the mixing drum. The apparatus enables a more efficient, less equipment-intensive paving repair process without the need for a separate millings loader or hot box.

Description

TECHNICAL FIELD

The present invention pertains generally to systems and methods for surface paving, and more particularly to a portable paving material mixing apparatus.

BACKGROUND OF THE INVENTION

Portable paving material mixers, also known as asphalt recyclers, are known in the art. Existing systems have several drawbacks which make them unsuitable for continuous, low cost, or small scale operations.

Existing systems to not have the ability to transport enough asphalt millings or other aggregate to fill the mixing drum multiple times. As a result, they must return to an aggregate storage site in between loads, or additional loads must be brought to the repair site by a dump truck or other heavy equipment.

Existing mixers do not have the capability to store a batch of mixed and heated material ready for application on the mixer itself. If an entire batch is not immediately used, it must be transferred from the mixer to an asphalt hot box for storage so that the mixer can process the next load.

In some existing mixers, the mixing drum itself is heated, and the material is heated via contact with the drum while being mixed. This heating method is quite slow, often resulting in down time for the paving crew. Other mixers use a direct material heating method, but are not configured to discharge prepared material without moving the heater away from the mixing drum. This method disrupts continuous operation of the mixer.

There is a need in the field for a portable asphalt paving mixer which allows continuous operation, processes multiple batches of material without additional equipment, applies rejuvenator or other additives during mixing, and provides more rapid turn-around times per batch.

BRIEF SUMMARY OF THE INVENTION

The present invention is directed to a portable paving material mixing apparatus which rapidly processes a batch of material sufficient to fill 5-7 potholes, has sufficient carrying capacity to process multiple mixer batches, and stores prepared material in a discharge bed for application while the next batch is being prepared. The apparatus enables a more efficient, less equipment-intensive paving repair process without the need for a separate millings loader or hot box.

Embodiments of the mixing apparatus include a rejuvenator application system suitable for hot mix asphalt, cold mix asphalt, hot in-place recycling, and asphalt based concrete mixing. The mixing apparatus may be assembled on a tandem axle trailer for towing by a vehicle with a 10,000 lb or greater towing capacity.

In an embodiment, a portable paving material mixing apparatus includes a hopper having an open top configured to receive aggregate. The hopper is positionable to transfer a portion of the aggregate to a rotatable mixing drum through an aperture in a front end of the drum. A burner is configured to heat material within the mixing drum. A discharge bed is positioned to receive mixed paving material from the mixing drum and configured for direct transfer of the mixed paving material to a paved surface for repairs. The hopper, mixing drum, and discharge bed are configured to be simultaneously supported on a vehicle trailer. Further provided is a system including the vehicle trailer.

In accordance with another embodiment, the discharge bed is configured for transfer of mixed paving material to the paved surface while the mixing drum is rotating. This feature permits continuous operation of the apparatus, as a first batch of paving material may be applied for repairs while a second batch is being prepared in the mixing drum. In another embodiment, the discharge bed is positioned below the mixing drum. In another embodiment, the discharge bed is heated.

In accordance with another embodiment, the mixing drum has a rear end and is positioned with a downward inclination from the front end toward the rear end. In another embodiment, the front end of the mixing drum is in contact with at least one wheel, and the wheel is configured to be mounted to the trailer.

In accordance with another embodiment, a channel is mounted between the hopper and the mixing drum and positioned such that aggregate is transferred from the hopper to the mixing drum via the channel. In another embodiment, the hopper has a chute configured to transfer aggregate therethrough, and the channel is shaped and dimensioned to receive at least a portion of the chute.

In accordance with another embodiment, the burner is mounted below the channel and positioned so that when the burner is lit flame from the burner projects into the drum through the aperture.

In accordance with another embodiment, the mixing drum includes an access panel in a sidewall through which material may exit the mixing drum to be received in the discharge bed.

In accordance with another embodiment, the apparatus includes an automatic rejuvenator application system having a reservoir configured to hold asphalt rejuvenator and a sprayer in fluid connection with the reservoir. The sprayer is positioned to transfer asphalt rejuvenator to the mixing drum through the aperture. In another embodiment, the rejuvenator application system is configured to dispense multiple types of rejuvenator based upon the paving application.

In accordance with another embodiment, the hopper has a hopper capacity, the mixing drum has a mixing drum capacity, and the hopper capacity is at least three times greater than the mixing drum capacity. This feature enables refilling the mixing drum multiple times from a single hopper load. In another embodiment, the total capacity of the apparatus, including the hopper, mixing drum, and discharge bed, is at least 3000 lbs.

Other embodiments, in addition to the embodiments enumerated above, will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the portable paving material mixing apparatus and method of use.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a left side view of a portable paving material mixing apparatus.

FIG. 2 is a right side view of the apparatus.

FIG. 3 is a reduced front view of the apparatus with some components of a trailer removed.

FIG. 4 is a reduced rear view of the apparatus.

FIG. 5 is a top plan of the apparatus.

FIG. 6 is a perspective view of the apparatus.

FIG. 7 is a cross-sectional view along the line VII-VII of FIG. 5.

FIG. 8 is a perspective view of the apparatus with some components removed.

FIG. 9 is a view of a control panel of the apparatus.

LIST OF DRAWING REFERENCE NUMERALS

• 1 trailer
• 2 jack stand
• 3 hopper
• 4 access panel 43 channel
• 5 propane tank 44 chain
• 7 control panel 45 stack
• 10 drum 46 drum wheels
• 11 rejuvenator pump 48 deflectors
• 12 hydraulic pump
• 13 burner 60 batteries
• 14 hitch receiver
• 15 heating torch
• 16 aperture
• 17 rejuvenator reservoir
• 18 rejuvenator sprayer
• 19 water tank
• 20 cone holder
• 21 safety light
• 22 winch
• 23 lifts
• 24 drum motor
• 25 protective cage
• 27 hose reel
• 28 rejuvenator spray button
• 29 burner timer
• 30 heater power switch
• 31 hopper controls
• 33 power management system
• 34 charging port
• 40 hydraulic cylinder
• 41 hydraulic fluid reservoir
• 42 chute
• 43 channel
• 44 chain
• 45 stack
• 46 drum wheels
• 48 deflectors
• 50 discharge bed
• 60 batteries

DETAILED DESCRIPTION OF THE INVENTION

Referring initially to FIGS. 1-6, there are illustrated left and right side, reduced front and rear, top plan, and perspective views, respectively, of a portable paving material mixing apparatus. The shown embodiment of the apparatus includes a hopper 3, a rotatable mixing drum 10, a burner configured to heat material within the mixing drum, and a discharge bed 50 positioned to receive mixed paving material from the mixing drum. The apparatus is shown assembled on a cooperating trailer 1. The drum is shielded by a protective cage 25, which is removed from the views of FIGS. 3-6 for clarity. The terms front, rear, left, and right are used herein with respect to the forward direction of the towing vehicle.

Hopper 3 holds aggregate, such as asphalt millings, and has an open top which is readily accessible for loading, such as with a scoop or bucket loader. In one embodiment, the length of hopper 3 as measured from the side is sufficiently long to receive material from a bucket loader; for example hopper 3 may be open along a 60″, 66″, or 72″ length. In another embodiment, hopper 3 has a 3000 lb capacity. Hopper 3 is positionable to transfer aggregate into drum 10. In the shown embodiment, hopper 3 is positioned by operation of a hydraulic pump 12 in connection with hydraulic cylinders 40. Hydraulic fluid may be stored in a reservoir 41.

FIG. 7 is a cross-sectional view along the line VII-VII of FIG. 5, showing hopper 3 in alternate positions for loading aggregate into drum 10. Hydraulic pump 12 (see FIG. 2) drives one or more telescoping hydraulic cylinders 40 to position hopper 3 from resting on trailer 1 (position A) to a raised position (B, in dashed lines) along the directional arrow.

Hopper 3 includes a chute 42 projecting toward drum 10 so that when hopper 3 is in the raised position, B, aggregate is poured from the hopper into drum 10 through an aperture 16 in the front end of the drum. In an embodiment, drum 10 has a 700 lb operating capacity.

Hopper 3 has a sufficient capacity to refill the drum multiple times. In other embodiments, the hopper capacity is at least three times greater than the mixing drum capacity. After loading drum 10, hopper 3 is lowered back to resting position A.

As shown in FIG. 7, drum 10 is preferably positioned at a downward angle θ toward the rear of trailer 1. After aggregate is loaded into drum 10, the drum may be rotated to force the aggregate toward the back of the drum. This process clears the front of the drum, allowing the addition of more aggregate if desired.

In an embodiment, a channel 43 is mounted between hopper 3 and mixing drum 10. Channel 43 is positioned such that aggregate being transferred from the hopper is poured through channel 43 into the mixing drum. In another embodiment, channel 43 is shaped and dimensioned to receive at least a portion of chute 42 when the hopper is positioned to transfer aggregate. In other embodiments, aggregate may be poured directly from the hopper into the mixing drum.

FIG. 8 is a perspective view of the apparatus with some components, such as the hopper and structural components, removed for clarity. FIG. 8 shows a burner 13 which is positioned to heat material within mixing drum 10. In an embodiment, burner 13 is propane fueled; several propane tanks 5 may be seen in FIGS. 1 & 2. In another embodiment, burner 13 may be diesel fueled. Burner 13 is positioned in front of drum 10 for heating material in drum 10 through aperture 16. When in use, flames from burner 13 project into drum 10, directly and rapidly heating material inside drum 10. Drum 10 is rotated while burner 13 is firing to evenly heat the material. Direction of rotation is indicated by the arrow of FIG. 4. In an embodiment, several material lifts 23 are mounted on the internal wall of drum 10 to provide proper agitation of the material. Due to the angle θ of the drum (see FIG. 7) the drum is angled away from the burner, and flames from the burner do not come in contact with the material. In one embodiment, flames from burner 13 project between about 18-242″ into drum 10.

The burner is operated for a period of time sufficient to bring the material in the drum to a temperature suitable for application. In one embodiment, material is brought from ambient temperature to 400° F. after 2-5 minutes of burner operation. Burner operating times required will vary based on ambient temperature and amount of material being heated. In one embodiment the burner is turned off automatically by a timer 29 (FIG. 9).

In another embodiment, the burner may be mounted on a pivoting burner arm positionable out of the way of the drum when aggregate is being loaded and in front of drum for heating material.

In FIGS. 1-7 a stack 45 is located above channel 43. Stack 45 serves to deflect material being poured into channel 43, and also functions as an exhaust stack when burner 13 is in operation.

Referring now to FIG. 4, a drum motor 24 is operatively connected to drum 10. In the shown embodiment the drum motor is connected by a chain 44 to a planetary gear system or sprocket to rotate drum 10 (chain 44 shown surrounded by a cage in FIGS. 1 & 2). The front end of drum 10 rests upon drum wheels 46 (best shown in FIG. 8), which support the load of drum 10 and permit it to rotate (as indicated by the arrow) when driven by the drum motor.

Two wheels 46 are present in the shown embodiment, however, more or fewer wheels could be used.

FIGS. 6 & 8 show a removable access panel 4, or door, in the sidewall of drum 10. When access panel 4 is removed and drum 10 is rotated, heated material is discharged from the drum through the opening left by removal of access panel 4. Again, the angle θ of drum 10 serves to move material toward the rear of the drum and out to discharge bed 50 (see FIG. 4). Drum 10 may be rotated in alternating directions to more efficiently discharge material. One or more deflectors 48 may be provided to direct material into discharge bed 50. Access panel 4 may also be removed when material is not being discharged, such as to permit temperature monitoring of the material with an infrared thermometer.

In one embodiment, the discharge bed 50 is heated to keep material ready for application. This feature eliminates the need to transfer mixed paving material to a separate hot box for storage prior to application. In one embodiment, the discharge bed has a 500 lb carrying capacity. In the shown embodiment, the discharge bed is positioned below the mixing drum and the mixing drum may be rotated while the discharge bed is full. This configuration permits continuous operation of the system, in that while a first batch of paving material is being laid down from the discharge bed a second batch may be heated in the mixing drum.

Material may be transferred from the discharge bed directly to the paving surface. In one embodiment the discharge bed is about 18 inches above the ground for easy manual transfer of material. Material may then be spread and compacted if desired for the application.

In an embodiment, the apparatus includes an automated rejuvenator application system including a rejuvenator pump 11, rejuvenator reservoir 17, and rejuvenator sprayer 18 (see FIGS. 1 & 7). Rejuvenator is stored in reservoir 17 and pumped by pump 11 to sprayer 18 which sprays rejuvenator onto the material in drum 10 through aperture 16 (see FIG. 8). In an embodiment, reservoir 17 is a bucket that is easily interchanged when more rejuvenator is needed. When material in drum 10 has been heated to the appropriate temperature, for example about 275° F., an operator activates the rejuvenator spray which evenly distributes rejuvenator onto the material in drum 10. Drum 10 is then rotated for a period of time sufficient to evenly blend rejuvenator with the paving material, for example 3 minutes.

In an embodiment, sprayer 18 is configured to permit the spray to reach material in the back of drum 10. Sprayer 18 may protrude slightly through aperture 16 to ensure that all rejuvenator is transferred to drum 10. Sprayer 18 is located out of the way of both burner 13 and the region toward the rear of the drum where material tumbles when drum 10 is rotated.

In an exemplary embodiment, the rejuvenator is comprised of 5 gallons of light oil (such as a plant based oil) and between 8-12 ounces of asphalt cutback, which includes a petroleum solvent.

In another embodiment, the rejuvenator system includes a plurality of pumps 11 and reservoirs 17 for different applications, such as hot in-place asphalt recycling, cold-mix asphalt patching, or mixing concrete with asphalt millings as an aggregate. Alternatively, solid additives, such as binders, may be added to the material in drum 10 through aperture 16 or access panel 4.

Referring again to FIGS. 1 & 2, an embodiment of trailer 1 includes a jack stand 2 and a hitch receiver 14. Other equipment may be stored on trailer 1, such as a heating torch 15, a safety cone holder 20, a water tank 19 and hose reel 27, a winch 22, batteries 60, a power roller, a tool rack, a fire extinguisher, or the like.

Safety lights 21 are mounted to cage 25. The system may automatically operate the safety lights or generate a warning sound when the burner is in operation or when the mixing drum is rotating.

FIG. 9 shows an embodiment of a control panel 7 (see also FIGS. 2 & 6) which is readily accessible for curbside operation of the portable mixer. Controls available at the panel include heater power switch 30 and burner timer 29, hopper controls 31, rejuvenator spray activation button 28, a power management system 33, and a charging port 34. Multiple rejuvenator spray buttons are provided in some embodiments. Control panel 7 may also include an emergency shutoff switch.

Further provided is a system wherein the apparatus is delivered assembled and mounted to the trailer.

In terms of use, a method of operating a portable paving material mixing apparatus includes (refer to FIGS. 1-9):

• • a. providing a portable paving material mixing apparatus including:
    • i. a vehicle trailer 1;
    • ii. a hopper 3 having an open top configured to receive aggregate and being positionable to transfer a portion of the aggregate to a rotatable mixing drum 10 through an aperture 16 in a front end of the drum;
    • iii. a burner 13 configured to heat material within the mixing drum;
    • iv. the drum having an access panel 4 in a sidewall through which material may exit the mixing drum to be received in a discharge bed 50;
    • v. the discharge bed positioned to receive mixed paving material from the mixing drum and configured for direct transfer of the mixed paving material to the paved surface; and,
    • vi. the hopper, mixing drum, and discharge bed supported on the vehicle trailer;
  • b. providing aggregate;
  • c. loading the aggregate into the hopper;
  • d. positioning the hopper to transfer an appropriate amount of aggregate from the hopper to the drum and returning the hopper to a resting position;
  • e. rotating the drum to force aggregate toward a rear end of the drum;
  • f. operating the burner so that a flame projects into the drum but does not come in direct contact with material in the drum, for a period of time sufficient to heat the material to a predetermined application temperature;
  • g. rotating the drum while the burner is on;
  • h. stopping rotation of the drum and opening the access panel;
  • i. rotating the drum to discharge material from the drum to the discharge bed; and,
  • j. moving material from the discharge bed to the paving surface.

The method further including:

• • repeating steps (d) and (e) until a desired quantity of aggregate is in the drum.

The method further including:

• • simultaneously performing steps (g) and (j).

The method further including:

• • after (i), heating material within the discharge bed.

The method further including:

• • in (a), the apparatus further including:
    • a reservoir 17 configured to hold asphalt rejuvenator; and,
    • a sprayer 18 in fluid connection with the reservoir, the sprayer positioned to transfer asphalt rejuvenator to the mixing drum through the aperture; and,
  • before (f): providing asphalt rejuvenator in the reservoir and operating the sprayer to transfer the asphalt rejuvenator to the mixing drum.

The embodiments of the apparatus and method of use described herein are exemplary and numerous modifications, combinations, variations, and rearrangements can be readily envisioned to achieve an equivalent result, all of which are intended to be embraced within the scope of the appended claims. Further, nothing in the above-provided discussions of the apparatus and method should be construed as limiting the invention to a particular embodiment or combination of embodiments. The scope of the invention is defined by the appended claims.

Claims

1. A portable paving material mixing apparatus configured to prepare aggregate for repairing a paved surface, the apparatus cooperating with a vehicle trailer, the apparatus comprising: a hopper having an open top configured to receive aggregate and being positionable to transfer a portion of the aggregate to a rotatable mixing drum through an aperture in a front end of the drum;a burner configured to heat material within the mixing drum;a discharge bed positioned to receive mixed paving material from the mixing drum and configured for direct transfer of the mixed paving material to the paved surface; and,the hopper, mixing drum, and discharge bed configured to be simultaneously supported on the vehicle trailer.

2. The apparatus of claim 1, wherein the discharge bed is configured for transfer of paving material to the paved surface while the mixing drum is rotating.

3. The apparatus of claim 2, wherein the discharge bed is positioned below the mixing drum.

4. The apparatus of claim 1, wherein the mixing drum has a rear end and is positioned with a downward inclination from the front end toward the rear end.

5. The apparatus of claim 4, wherein the front end of the mixing drum is in contact with at least one wheel, and the wheel is configured to be mounted to the trailer.

6. The apparatus of claim 1 further including: a channel mounted between the hopper and the mixing drum and positioned such that aggregate is transferred from the hopper to the mixing drum via the channel.

7. The apparatus of claim 6 further including: the hopper having a chute configured to transfer aggregate therethrough; and,the channel being shaped and dimensioned to receive at least a portion of the chute.

8. The apparatus of claim 6 wherein the burner is mounted below the channel and positioned so that when the burner is lit flame from the burner projects into the drum through the aperture.

9. The apparatus of claim 1 further including: an access panel in a sidewall of the mixing drum through which material may exit the mixing drum to be received in the discharge bed.

10. The apparatus of claim 1 further including: a reservoir configured to hold asphalt rejuvenator; and,a sprayer in fluid connection with the reservoir, the sprayer positioned to transfer asphalt rejuvenator to the mixing drum through the aperture.

11. The apparatus of claim 1, wherein the hopper has a hopper capacity, the mixing drum has a mixing drum capacity, and the hopper capacity is at least three times greater than the mixing drum capacity.

12. The apparatus of claim 1 having a total capacity of at least 3000 pounds.

13. The apparatus of claim 1, wherein the discharge bed is heated.

14. A portable paving material mixing apparatus configured to prepare aggregate for repairing a paved surface, the apparatus comprising: a vehicle trailer;a hopper having an open top configured to receive aggregate and being positionable to transfer a portion of the aggregate to a rotatable mixing drum through an aperture in a front end of the drum;a burner configured to heat material within the mixing drum;a discharge bed positioned to receive mixed paving material from the mixing drum and configured for direct transfer of the mixed paving material to the paved surface; and,the hopper, mixing drum, and discharge bed supported on the vehicle trailer.

15. The apparatus of claim 14 further including: the discharge bed being configured to transfer paving material to the paved surface while the mixing drum is rotating;the hopper having a hopper capacity, the mixing drum having a mixing drum capacity, and the hopper capacity being at least three times greater than the mixing drum capacity;a reservoir configured to hold asphalt rejuvenator; and,a sprayer in fluid connection with the reservoir, the sprayer positioned to transfer asphalt rejuvenator to the mixing drum through the aperture.

16. A method for preparing paving material to repairing a paved surface, the method comprising: a. providing a portable paving material mixing apparatus including: i. a vehicle trailer;ii. a hopper having an open top configured to receive aggregate and being positionable to transfer a portion of the aggregate to a rotatable mixing drum through an aperture in a front end of the drum;iii. a burner configured to heat material within the mixing drum;iv. the drum having an access panel in a sidewall through which material may exit the mixing drum to be received in a discharge bed;v. the discharge bed positioned to receive mixed paving material from the mixing drum and configured for direct transfer of the mixed paving material to the paved surface; and,vi. the hopper, mixing drum, and discharge bed supported on the vehicle trailer;b. providing aggregate;c. loading the aggregate into the hopper;d. positioning the hopper to transfer an appropriate amount of aggregate from the hopper to the drum and returning the hopper to a resting position;e. rotating the drum to force aggregate toward a rear end of the drum;f. operating the burner so that a flame projects into the drum but does not come in direct contact with material in the drum, for a period of time sufficient to heat the material to a predetermined application temperature;g. rotating the drum while the burner is on;h. stopping rotation of the drum and opening the access panel;i. rotating the drum to discharge material from the drum to the discharge bed; and,j. moving material from the discharge bed to the paving surface.

17. The method of claim 16 further including: repeating steps (d) and (e) until a desired quantity of aggregate is in the drum.

18. The method of claim 16 further including: simultaneously performing steps (g) and (j).

19. The method of claim 16 further including: after step (i), heating material within the discharge bed.

20. The method of claim 16 further including: in (a), the apparatus further including: a reservoir configured to hold asphalt rejuvenator; and,a sprayer in fluid connection with the reservoir, the sprayer positioned to transfer asphalt rejuvenator to the mixing drum through the aperture; and,before (f): providing asphalt rejuvenator in the reservoir and operating the sprayer to transfer the asphalt rejuvenator to the mixing drum.