WO2025106528A1

WO2025106528A1 - Pavement repair system and method of repairing pavement

Info

Publication number: WO2025106528A1
Application number: PCT/US2024/055698
Authority: WO
Inventors: John H. DONAHUE
Original assignee: E D Etnyre and Co
Current assignee: E D Etnyre and Co
Priority date: 2023-11-14
Filing date: 2024-11-13
Publication date: 2025-05-22
Anticipated expiration: 2026-05-14

Abstract

A pavement repair system has a heated mixing tank on a vehicle for melting pavement patch and mixing it with aggregate. The tank has an agitator for mixing having a helical flight for lifting the aggregate. The system has a discharge chute and a lock for locking the discharge chute in a variety of positions by inserting a catch in a plurality of holes corresponding to the positions. A method of repairing pavement involves mixing molten pavement patch and applying the mixture to a void in a pavement. The pavement patch may be melted and mixed in a tank having a scraper. The applying of the melted pavement patch or mixture can include directing the discharged mixture with a chute, and locking the chute in a suitable position for applying to the void.

Description

PAVEMENT REPAIR SYSTEM AND METHOD OF REPAIRING PAVEMENT CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Application No. 63/598,768, filed November 14, 2023, the contents of which are incorporated herein by reference in their entirety.

FIELD OF THE INVENTION

[0002] The invention relates to devices, systems and methods for patching cracks and holes in roadways, particularly ones having concrete or asphalt pavements.

BACKGROUND

[0003] Mastic kettles are used to melt asphalt or rubberized crack sealer, mix gravel with the molten asphalt or rubberized crack sealer, and then discharge the molten patching mixture to patch or fill large cracks and holes in concrete or asphalt pavements. [0004] Mastic kettles take a significant time to heat, melt and properly mix the asphalt or rubberized crack sealer before the molten mixture can be discharged. A need therefore exists for a mastic kettle that is faster to prepare the patching mixture.

[0005] The most economical mastic kettles discharge the patching mixture by gravity. The patching mixture is very viscous so the discharge of material can be slow particularly as the mixing tank approaches empty. Because the patching mixture typically contains gravel, pumps are generally not used. A need therefore exists for a mastic kettle that can discharge quicker without a large price increase.

[0006] An operator is needed to direct the discharge of patching mixture from the mastic kettle towards the crack or hole. The operator holds a discharge chute in position over the crack. If the operator releases the chute, the chute will move by gravity towards its lowest point, which may not be over the crack. A need therefore exists for a chute that is less laborious.

SUMMARY OF THE INVENTION

[0007] The invention is, in one embodiment, a pavement repair system for melting pavement patch and mixing it with aggregate for filling voids in a pavement. The system has a heated tank for melting pavement patch and an impeller in the heated tank for mixing the molten pavement patch with aggregate. The impeller has a helical flight for lifting the contents of the heated tank up the flight. The system also has a motor connected to the impeller for turning the impeller.

[0008] The helical flight may be a ribbon flight. Preferably, the flight makes at least two rotations around a shaft to which the flight is attached. The impeller may be narrowest at a top of the impeller. The helical flight may be a conical helical flight. The impeller has a start and the impeller may also have a scraper at the start of the flight. The impeller may have a first rotational direction for mixing the heated tank and a second rotational direction for pushing the molten pavement patch and aggregate out of the heated tank.

[0009] The system may also have a tank outlet and a paddle for pushing contents of the tank towards the tank outlet. The paddle is below at least a part of the flight. The paddle may be behind the start of the flight by 45-135 degrees. Preferably, the tank outlet is located in a floor of the heated tank adjacent a sidewall of the heated tank. Preferably, the tank outlet passes through a burner chamber.

[0010] The heated tank is preferably directly above a burner chamber. The heated tank preferably has a tank outlet located in a floor of the heated tank adjacent a sidewall of the heated tank. Preferably, the tank outlet passes through the burner chamber.

[0011] The invention is, in a second embodiment, a pavement repair system for melting pavement patch for filling voids in a pavement. The system includes a heated tank for melting the pavement patch. The heated tank has an outlet. The system has a chute for the directing the molten pavement patch towards a void in a pavement. The chute is in fluid communication with the outlet. The chute has a discharge end for discharging the molten pavement patch from the chute. The discharge end is movable laterally. The system also has a lock for locking the discharge end in a plurality of lateral positions. The system may also be used to mix aggregate with the pavement patch.

[0012] Preferably, the lock when locked allows up and down movement of the discharge end. The lock may have a plurality of holes corresponding to the plurality of lateral positions. The plurality of holes may be located along an arc. The lock may also have a catch for insertion into the plurality of holes. Insertion of the catch into one of the plurality of holes locks the discharge end in one of the plurality of positions. The catch may include a pin movable within the lock. The lock may have a sleeve for the pin. The sleeve has two holes. The first hole retains the pin in a non-inserted position and the second hole retains the pin in an inserted position.

[0013] Preferably, the sleeve moves with the chute. The chute may be pivotally mounted to a chute pivot for movement in the direction of the first and second sides. The plurality of holes may be located along an arc around a pivotal axis of the chute pivot.

[0014] The invention in a third embodiment is a method of repairing pavement. The method includes melting pavement patch in a tank, discharging the molten pavement patch from the tank, and applying the molten pavement patch to a void in a pavement.

[0015] Preferably, the method also includes mixing pavement patch with aggregate by rotating an impeller having a helical flight in a first direction. Preferably, discharging molten pavement patch includes discharging the mixture of pavement patch and aggregate by rotating the impeller in a second direction opposite to the first direction.

[0016] The method may include directing the discharged molten pavement patch with a chute towards the void and locking the chute in a position to apply the molten pavement patch to the void. Locking the chute may include inserting a catch into one of a plurality of holes of a lock. The method may include moving the tank along an elongated direction of the void during the applying of the mixture from the locked chute.

[0017] The method may include delivering the tank adjacent to the void.

[0018] The invention in a fourth embodiment is a method of repairing pavement. The method includes melting pavement patch in a heated tank, discharging the molten pavement patch from the tank and down a chute, and locking the chute in a position to apply the mixture to the void. The chute has a discharge end for discharging the molten pavement patch from the chute and the discharge end of the chute is movable laterally.

[0019] The method may include mixing the pavement patch with aggregate in the tank by rotating an impeller comprising a scraper in a first direction. Discharging the molten pavement patch may include discharging the mixture of pavement patch and aggregate by rotating the impeller in a second direction opposite to the first direction. [0020] Locking the chute may include inserting a catch into one of a plurality of holes of a lock.

[0021] The method may also include applying the molten pavement patch to the void. The method may include moving the tank along an elongated direction of the void during the applying of the molten pavement patch. The method may also include delivering the tank adjacent to the void.

[0022] The invention in a fifth embodiment is a pavement repair system for melting pavement patch and optionally mixing it with aggregate for filling voids in a pavement. The system has a heated tank for melting pavement patch. The heated tank has a floor. The system also has a burner chamber for providing heat to the tank through the floor. The burner chamber is directly below the heated tank. The system also has an impeller in the heated tank for mixing the contents of the tank including the molten pavement patch and a motor connected to the impeller for turning the impeller. The impeller has a scraper sufficiently close to the floor to induce flow of molten pavement patch along the floor to prevent thermal degradation of the pavement patch. The impeller has a first rotational direction for mixing the heated tank and a second rotational direction for pushing the contents of the heated tank out of the heated tank.

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] FIG. 1 is a schematic plan view of a trailer-mounted kettle system.

[0024] FIG. 2 is a rear elevation view of a tank of the kettle system of FIG. 1.

[0025] FIG. 3 is sectional view of an upper chamber of the tank of FIG. 2 viewed from the right.

[0026] FIG. 4 is a side perspective view of an impeller in the upper chamber of FIG. 3.

[0027] FIG. 5 is an elevation view of the impeller of FIG. 4 relative to the bottom of the tank (shown schematically).

[0028] FIG. 6 is a bottom perspective view of the impeller of FIG. 4.

[0029] FIG. 7 is a magnified view of the discharge chute of FIG. 2 oriented straight behind.

[0030] FIG. 8 is a magnified view of the discharge chute oriented to the left. DETAILED DESCRIPTION OF THE INVENTION

[0031] A pavement repair system 10 is shown in FIG. 1. System 10 is mounted to a vehicle 12, which can be a truck or a trailer (as shown), having a frame 13. Kettle system includes a propane tank 14, a fuel tank 16, typically the fuel is diesel, and a motor 18 connected to fuel tank 16. Motor 18 drives a hydraulic system 20, which includes a hydraulic oil tank 22 and a hydraulic pump in tank 22. It also drives an electrical generator for providing electricity to kettle system 10. Kettle system 10 also has a hot box 26 for heating tools 28 (typically having long handles).

[0032] System 10 has a kettle or tank 40. On the exterior of kettle 40 is a roof 42, a motor 44 above roof 42, an inlet door 46 and a burner 48. Motor 44 is preferably hydraulically driven by hydraulic system 20. Inlet door 46 is used for manually loading pavement patch and aggregate into kettle 40. As used herein, pavement patch, a.k.a., mastic, is generally petroleum based, e.g., asphalt, but can also be coal based, e.g., coal tar. Pavement patch often contains additives such as rubber, natural or synthetic. Pavement patch is a solid at room temperature and so it has to be melted so it can be applied to the road. Ordinarily, the pavement patch is used with a mineral aggregate such as crushed limestone, crushed Portland concrete, gravel, and crushed rock. Aggregate as used herein refers to mineral aggregate and other aggregates used to make or repair asphaltic pavements such as fibers (metal, glass, or carbon) and so-called engineered aggregate that include crushable capsules that contain substances for self-healing of the patch should the patch crack. Burner 48 preferably burns the fuel in fuel tank 16 and includes a blower.

[0033] T urning now to FIGS. 1 -3, the flames of burner 48 or the burner exhaust enters a burner chamber 50 below kettle or tank 40. Preferably, chamber 50 has a top wall 52, which is also a floor 53 to tank 40, through which heat is transferred into tank 40, i.e., chamber 50 is directly below tank 40. It is also possible that there is a chamber (not shown) containing a thermal transfer oil between floor 53 and top wall 52 to avoid overheating the pavement patch along floor 53. The mixing of tank 40 as will be discussed makes such a chamber unnecessary. Chamber 50 also has a cylindrical sidewall 54. As shown, sidewall 54 and sidewall 55 of tank 40 are unitary, but sidewall 54 could extend around sidewall 55 to allow the burner exhaust to surround sidewall 55 providing more heat transfer surfaces. Chamber 50 is also connected to a chimney 56. Chamber 50 may have baffles for better distributing heat and transferring heat.

[0034] With reference primarily to Figs. 2-3, tank 40 has a vent 58, an agitator 60 including a shaft 62 and impeller 64. Shaft 62 is connected to and driven by motor 44. Motor 44 can turn clockwise and counterclockwise. Shaft 62 is located along the vertical centerline of tank 40. Shaft 62 is supported by a bearing 66 on roof 42, bushing 68 on floor 53, and one or more support brackets 70.

[0035] With reference to Figs. 2-6, impeller 64 includes a flight 72, a scraper 74, a paddle 76, a pan 78 and one or more supports 80 supporting flight 72 from shaft 62 and extending radially from shaft 62. Flight 72 is arranged around shaft 62 such that, when shaft 62 is rotated in a first direction 82 (opposed to a second direction 84), flight 72 continues but goes up, much in the same way that the flight of a screw continues and moves vertically. Generally, flight 72 is helical, although the pitch of the helix can change, but can also remain the same throughout the flight. Preferably, flight 72 makes at least one half of a rotation, more preferably at least two-thirds of a rotation, still more preferred at least three quarters of a rotation around shaft 62. Preferably, flight 72 makes 4 or less rotations, more preferably less than 3 rotations, and still more preferably less than 2 rotations around shaft 62.

[0036] Preferably, flight 72 tapers inwardly as flight 72 goes up. Preferably flight 72 is substantially conical, e.g., conical within manufacturing tolerances. The cone makes an angle 88 (shown in FIG. 5) with the horizon. As shown, it is approximately 60 degrees. Conceivably, the angle is 0-30 degrees, 15-45 degrees, 30-60 degrees, 45-75 degrees or 60-90 degrees.

[0037] Flight 72 may extend from an outer edge 86 to shaft 62 like a screw does. Preferably, flight 72 is a ribbon flight, i.e., does not extend to shaft 62, so that flight 72 does not interfere with mixing by acting as a shelf. Preferably, flight 72 even when tapered overlaps vertically between the flight at one level and the flight at the next level throughout flight 72, but at least for 1 or 2 rotations. Flight 72 is generally level radially throughout its length around shaft 62. [0038] Scraper 74 is located at the start of flight 72. Scraper 74 actually does not scrape along bottom wall 52 or sidewall 55 but by being close to bottom wall 52 induces flow along bottom wall 52 when impeller 64 rotates in first direction 82 to prevent thermal degradation of the pavement patch and to keep the bottom wall 52 relatively clean and to prevent buildup on bottom wall 52. Scraper 74 as shown extends closer to shaft 62 than flight 72, extending substantially all the way to bushing 68 except for providing clearance and manufacturing tolerances. As shown, scraper 74 leans forward approximately 45 degrees relative to vertical.

[0039] Paddle 76 is attached to or rigidly connected to shaft 62. As shown, it is attached to one of the supports 80. Paddle 76 is below flight 72. Paddle 76 as shown extends closer to shaft 62 than flight 72, extending substantially all the way to bushing 68 except for providing clearance and manufacturing tolerances. It is preferably located 90- 150 degrees behind the start of flight 72 and scraper 74 in first direction 82, more preferably 100-140 degrees, even more preferably 110-130 degrees.

[0040] Pan 78 has a bottom plate 90, a sidewall 92, which is attached at its top to flight 72. Pan 78 is also formed by scraper 74 and paddle 76. Pan 78 provides support and mechanical integrity to flight 72.

[0041] Without mixing, aggregate, particularly mineral aggregate, will tend to drop to the bottom of tank 40 as it is about twice as dense as pavement patch. Rotation of impeller 64 in first direction 82 is expected to raise the aggregate. First there is the flow along bottom wall 52 and then sidewall 55 caused by scraper 74. Second, aggregate on or immediately above the upper surface 94 of flight 72 will tend to be “picked up” by flight 72 and elevated.

[0042] When the impeller turns in second direction 84, paddle 76 helps push the tank contents towards a tank outlet 96. Tank outlet 96 is located preferably in 53 adjacent sidewall 55. Outlet 96 slopes downwardly through burner chamber 50 assisting the flow of the molten mixture by gravity; preferably outlet 96 is not connected to a pump. A gate valve 98 having a long handle 100 controls the flow of the molten mixture. On the other side of gate valve 98 is a funnel 102 for directing the molten mixture into a chute 104. [0043] Chute 104 can be said to be in fluid communication with outlet 96. Chute 104 has an elongated body 106 having a discharge end 108 and an open top. Attached to chute 104 by discharge end 108 is a burner holder 110 for holding a propane torch for preventing pavement patch from congealing on chute 104. Also attached to chute 104 is a bracket 112, which has a ring 114 which can be attached to a chain (not shown) attached to a bracket 116 for controlling the slope of chute 104. Chute 104 is pivotally attached to frame 13 by a bracket 118. Chute 104 is pivotally mounted to bracket 118 by a first pivot 120 allowing up and down motion of discharge end 108 and a second pivot 122 allowing side to side motion of discharge end 108. A ball pivot could be used instead of the two pivots.

[0044] As shown in most detail in FIGS. 7 and 8, there is a lock 130 for locking discharge end 108 in a plurality of lateral positions. Lock 130 has a plurality of holes 132, preferably at least 4, more preferably at least 7, even more preferably at least 10 and still more preferably at least 12 holes, corresponding to the plurality of lateral positions. Holes 132 can take any suitable form including notches or grooves similar to teeth on a gear, slots that are open on one end or slots that are closed at opposed ends as shown. Holes 132 are preferably elongate like a slot to permit up and down movement of discharge end 108. Preferably, discharge end 108 can be raised above horizontal in order to stop the flow of pavement patch mixture from the chute to the ground. Preferably discharge end 108 can be lowered to approximately 6 inches off the ground to better direct the pavement patch mixture. Holes 132 are located along an arc around second pivot 122 in a plate 134. Plate 134 may be referred elsewhere as an index plate. Plate 134 is preferably circular for most of its periphery and has a central hole 136 providing access to first pivot 120 and second pivot 122 for maintenance. Holes 132 are arranged along an arc around a pivotal axis 138 of second pivot 122. Holes 132 if elongate, have a longitudinal direction arranged radially to the pivotal axis 138 (illustrated as a dashed line in FIG. 8).

[0045] Lock 130 has a catch 140. The shape of catch 140 depends on the shape of holes 132. Here, catch 140 comprises a pin 142, which is movable within a sleeve 144 attached to chute 104. Sleeve 144 has one or more holes 146 (not at the sleeve ends) for holding pin 142 in a locked or unlocked position, preferably a first hole 146a for an unlocked position and a second hole 146b for a locked position. Holes 146 can take any suitable form including notches or slots that are open on one end (as shown), preferably, angularly displaced (as shown) along the axis of the sleeve 144. Hole 146a and hole 146b may overlap at the top of sleeve 144 as long as there is some separation or structure to prevent pin 142 from slipping from hole 146a to hole 146b. Pin 142 has a projection 148 fitting hole or holes 146. Projection 148 can be fixed or can be movable, for example, a spring loaded ball in which case only a single hole 146 is necessary or two holes 146 that are in alignment along the length of sleeve 144.

[0046] Another embodiment of the invention is a method of filling voids in a pavement. Initially system 10 is delivered to a job site where there is pavement having voids, e.g., cracks and potholes, to be filled. Once at the job site, solid pavement patch is loaded into tank 40 through inlet door 46. Motor 18 is turned on. Burner 48 is turned on. Agitator 60 driven by motor 44 turns in the first direction to mix tank 40 and to enhance the transfer of heat from burner chamber 50 to more quickly heat pavement patch. While the specific order and timing of the above steps can be varied, it is generally preferred to add the pavement patch and aggregate simultaneously into tank 40 through inlet door 46. Indeed, the pavement patch and aggregate may be purchased together in a single package. Alternatively, the pavement patch may be added first and the aggregate added later once melting of the pavement patch has begun. Once the tank is mixed and the temperature of the pavement patch mixture has reached a target temperature, typically as determined by a thermocouple 150 (shown schematically) connected to a control system for automatically regulating the temperature of tank by automatically turning burner 48 on and off, or by looking at a temperature gauge 152 (shown schematically), gate valve 98 is opened allowing molten mixture to flow out of tank outlet 96 into chute 104.

[0047] Chute 104 is then manually pivoted to direct the molten mixture into a pavement void. Chute 104 can then be locked in position while the specific void is filled by lock 130. If the void is a pothole, vehicle 12 may be stopped for a time so that enough molten mixture is discharged to fill the pothole. If the void is a crack, vehicle 12 may move forward in the elongated direction of the crack; many cracks are oriented in the direction of travel of the pavement so generally vehicle 12 merely moves forward in the direction of travel of the roadway.

[0048] From an unlocked position, such as shown in FIG. 7, lock 130 is operated by lifting pin 142 by a handle 154 until projection 148 exits hole 146a and then pin 142 is rotated and lowered such that projection 148 enters hole 146b and pin is inserted into one of the holes 132 to lock 130. Lock 130 is shown in a locked position in FIG. 8, but note that chute 104 has been rotated relative to FIG. 7.

[0049] From a locked position, lock 130 can be unlocked by undoing catch 140 by lifting pin 142 so that lifting pin 142 is removed from the hole 132 that it was in and is above plate 134. If chute 104 contains pavement patch, it may be desirable to lift discharge end 108 to prevent pavement patch from continuing to flow off of chute 104. Chute 104 can then be repositioned by pivoting chute 104 around pivot 122 to a desired position and then pin 142 can be inserted a hole 132 corresponding to the desired position. The chute 104 can then be released by the operator. If chute 104 was still lifted, releasing chute will cause discharge end 108 to drop as holes 132 are elongate.

[0050] Once lock 130 is locked, the person operating the chute is free to use a tool 28 to smooth out the pavement patch mixture in the void. Tools 28 may be placed in hot box 26 to keep them warm so that the pavement patch mixture does not congeal on the tools. [0051] Note that agitator 60 generally turns in first direction 82 to keep the aggregate mixed up with the pavement patch while the mixture is applied to a void. It is not until the tank is mostly empty that agitator 60 turns in second direction 84 to assist the discharge of mixture.

[0052] While the invention has been described with respect to certain embodiments, as will be appreciated by those skilled in the art, it is to be understood that the invention is capable of numerous changes, modifications and rearrangements, and such changes, modifications and rearrangements are intended to be covered by the following claims.

Claims

What is claimed is:

1. A pavement repair system for melting pavement patch, the system comprising: a heated tank for melting the pavement patch, the heated tank having an outlet; a chute for the directing the molten pavement patch towards a void in a pavement, the chute being in fluid communication with the outlet, the chute having a discharge end for discharging the molten pavement patch from the chute, the discharge end of the chute being movable laterally; and a lock for locking the discharge end in a plurality of lateral positions.

2. The system of claim 1 wherein the lock when locked allows up and down movement of the discharge end.

3. The system of claim 1 wherein the lock comprises a plurality of holes, the plurality of holes corresponding to the plurality of lateral positions.

4. The system of claim 3 wherein the plurality of holes are located along an arc.

5. The system of claim 3 wherein the lock further comprises a catch for insertion into the plurality of holes, wherein insertion of the catch into one of the plurality of holes locks the discharge end in one of the plurality of positions.

6. The system of claim 5 wherein the catch comprises a pin movable within the lock.

7. The system of claim 6 further comprising a sleeve for the pin, the sleeve having first and second holes, the first hole retaining the pin in a non-inserted position and the second hole retaining the pin in an inserted position.

8. The system of claim 7, wherein movement of the chute moves the sleeve.

9. The system of claim 6, the chute being pivotally mounted to a chute pivot for lateral movement.

10. The system of claim 9 wherein the plurality of holes are located along an arc around a pivotal axis of the chute pivot.

11. A method of filling a void in a pavement, the method comprising: melting pavement patch in a heated tank, discharging the molten pavement patch from the tank and down a chute having a discharge end for discharging the molten pavement patch from the chute, the discharge end of the chute being movable laterally, and locking the chute in a position to apply the mixture to the void.

12. The method of claim 11 further comprising mixing the pavement patch with aggregate in the tank by rotating an impeller comprising a scraper in a first direction.

13. The method of claim 12 wherein the discharging the molten pavement patch comprises discharging the mixture of pavement patch and aggregate by rotating the impeller in a second direction opposite to the first direction.

14. The method of claim 11 wherein locking the chute comprises inserting a catch into one of a plurality of holes of a lock.

15. The method of claim 11 further comprising applying the molten pavement patch to the void.

16. The method of claim 15 further comprising moving the tank along an elongated direction of the void during the applying of the molten pavement patch.

17. The method of claim 15 further comprising delivering the tank adjacent to the void.

18. A pavement repair system for melting pavement patch and optionally mixing it with aggregate for filling voids in a pavement, the system comprising: a heated tank for melting pavement patch, the heated tank having a floor; a burner chamber for providing heat to the tank through the floor, the burner chamber directly below the heated tank, an impeller in the heated tank for mixing the contents of the tank including the molten pavement patch, the impeller having a scraper sufficiently close to the floor to induce flow of molten pavement patch along the floor to prevent thermal degradation of the pavement patch; and a motor connected to the impeller for turning the impeller.

19. The system of claim 18, wherein the impeller has a first rotational direction for mixing the heated tank and a second rotational direction for pushing the contents of the heated tank out of the heated tank.