CA1239302A - Asphalt repair apparatus - Google Patents

Abstract

Abstract of the Disclosure An apparatus for repairing potholes in an asphalt surface includes a frame which carries one or more luminous wall heaters in a position adjacent to and above the asphalt area to be repaired. Controls are provided to turn the heaters on and off so as to provide a soak time between sequential applications of heat to the asphalt area. The soak time permits heating of the deeper areas of asphalt so as to provide superior bond between the existing asphalt and the patching material.
Sections of the luminous wall heaters may be pivoted from a first position which provide a square configuration to a second posi-tion which provides a rectangular configuration.

Description

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ASPHALT REPAIR APPARATUS
¦ Background of the Invention I I. Field of the Invention I _ .
The present invention is directed to equipment for repairing asphalt road surfaces and the like, and more paretic-ularly to a patching apparatus which can be moved along the surface to be repaired and which includes a radiant heating panel for the heating of the existing asphalt surface prior by repair.
II. Description of the Prior Art The conventional method for repaixi~g potholes and the like in asphalt roadways or other asphalt surfaces has been to saw cut the existing road surface around the pothole, to then remove a portion of the asphalt around the damaged area by an air hammer down to the depth of damage, and subsequently fill the removed area with new asphalt.
This method of repair has several disadvantages.
The method is time consuming and requires expensive equipment.
The joint formed between the new asphalt and existing asphalt is weak, because the new and old asphalt are separated by a bond coat. The generally flat configuration of the saw cut edge provides a joint which is mechanically weak. In cold all-mates, moisture or water may be present on the existing asphalt when the new asphalt is laid over it, reducing the adhesion Jo Between the new and old asphalt. If repairs are only made during I dry conditions, then repairs can necessarily be made only during I, .
part of the year. Particularly with smaller patches, it is 'often economically unjustified to send a truck with conventional equipment to an an asphalt plant to obtain the hot mix asphalt ~30 necessary to repair the pothole Instead an inferior yet more :
expensive asphalt mix is employed to make a repair which is ; only temporary. This temporary repair must be made over and , ` : :
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over again, and eventually costs more than it would have cost to initially make a proper repair.
Summary of the Present Invention The present invention solves these and other problems by providing an apparatus for softening and reheating the exist-in asphalt prior to the application of the new asphalt. The apparatus preferably includes a hot mix asphalt supply as well as heat generating means for heating the existing asphalt, so that its use avoids the need for conventional equipment such as lo a jackhammer, saw or prying machine and the associated per-sonnet usually necessary for repairing potholes.
Unlike the equipment used to practice the described conventional method for repairing asphalt, the apparatus of the present invention includes a heat generating means to be used in a method in which the asphalt to be repaired is pro-heated, prior to filling the hole with new asphalt. A luminous wall heating panel heats the asphalt surface and causes heat to penetrate into the interior of the asphalt roadway so that when the pothole is filled with new asphalt, the new and old asphalt bond together to form a permanent and secure joint.
The apparatus of the present invention includes a thermostatic controlled hopper or container in which new hot mix asphalt can be carried. A heating means in the hopper main-twins the asphalt at the proper temperature for use. The appear-anus also includes an auger for delivery of the heated asphalt from the hopper to the point of use. Remote control means are provided so that the vehicle can be operated by a crew member from a position where the pothole to be repaired can be clearly seen. Advantageously, the apparatus can be self-propelled.

I The luminous wall heating panel which is used to heat the surface and the interior of the asphalt to be repaired is of the type heretofore commonly used in industrial furnaces or . 1 ( ( 393~
the like, and is of the general type shown in U. S. Patent No.

2,828,813 and No, 3,008,513. An air-gas mixture is delivered through fire bricks carried in a frame to provide what is come money called a luminous wall. Such heaters have been known to be very efficient, for instance, the type used by Applicant is capable of delivering up to 2000~ F in just one minute, and can penetrate the asphalt with from 30,000 to 120,000 BTU's per square foot.
Attempts have been made in the past to use such heaters for heating asphalt, but there have been difficulties caused primarily by the intense heat generated by such heaters. If luminous wall heater are continuously kept over the surface of the asphalt for a time sufficient to heat the interior of the asphalt to the desired temperature, the surface of the asphalt will ignite. This has not been a problem with infrared heating systems or other devices because they do not produce the intensity of heat provided by luminous wall radiant heaters.
These other types of heaters, however, are fuel inefficient and generally do not provide enough heat to heat the asphalt to the necessary depth. Their use results in significant injury to the environment, due to the release of significant amounts of pollutants into the air, and damage to overhanging plants and trees near the roadway shoulder.
I; Applicant has discovered that luminous wall heaters can be successfully employed to preheat asphalt surfaces for Jo ' repair, if a "soak time" is provided for heat to be delivered to the interior of the asphalt. this soak time is a time be-tweet applications of heat which is sufficient to permit the I, heat to soak into the interior of the layer of asphalt. Without such a "soak time", it is impossible to heat the interior of the asphalt layer to the necessary temperature to create the desired bonding, without igniting the upper surface of the

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asphalt. There must be an interval between the periods of time ¦ that the upper asphalt surface is subjected to heat from the luminous wall, to permit the heat to penetrate and raise the temperature of the interior of the asphalt.
In the apparatus of the present invention ! this is accomplished by providing means for turning the luminous wall heater on and off at regular, short intervals. The off time provides a time for the surface to cool while heat is penetrate in into the asphalt.
Preferably, the apparatus includes a means for moving the apparatus across the asphalt surface. Three heating panel sections are mounted in such a way as to permit movement to a first position which provides a square configuration and to a second position which provides a rectangular configuration.
In each configuration four distinct heating zones are preferably provided, each individually controlled.
Brief Description of the Drawings A wetter understanding of the present invention will be had upon reference to the following detailed description, when read in conjunction with the accompanying drawing sin which like reference characters refer to like parts throughout the several views, and in which:
FIG. 1 is a side view of the preferred embodiment of the present invention;
FIG. 2 is a side view of another preferred embodiment of the present invention;
I; FIG. 3 is a cross-sectional view taken along line 3-3 of FIG. 1 and enlarged somewhat for clarity;
FIG. 4 is a cross-sectional view taken along line ¦ 4-4 of FIG. 1 and enlarged somewhat for clarity, FIG. 5 is a fragmentary top view of the preferred embodiment f the present invention;

, . 1 ' 1 ~239302 FIG. 6 is a fragmentary end view of the preferred embodiment of the present invention; and FIG. 7 is a partial side view of the preferred embody-mint of the present invention enlarged somewhat for clarity.
Detailed Description of the Preferred Embodiment of the Present Invention With reference now to FIGS. 1 and 2, an apparatus 10 according to the present invention is the reshown and includes a frame 12. Preferably, a first pair of wheels 14 is provided .0 forward of the center of gravity of the apparatus 10, and a second pair of wheels 16 is provided rearwardly of the center of gravity of the apparatus 10.
The forward pair of wheels 14 is affixed to the frame 12 by a hydraulic lift (not shown) in such a manner that the Lo forward wheels 14 can be lifted to the position 18 (shown in phantom in FIG. 1) and thereby pivot the apparatus 10 about the axis of the rearward wheels 16. Conveniently, the front end of the apparatus 10 coos not abut the asphalt pavement while the forward wheels 14 are raised. Instead, a stand 20 (FIG. 2) is affixed to the front end of the frame 12 for the steady post-toning of the apparatus 10. Although the stand 20 can comprise a simple jack type stand, preferably the stand 20 comprises a drivable front wheel 22 FIGS. 1 and 7) which is brought into inactive contact with the asphalt surface by the raising of the .
forward pair of wheels 14 and lowering the wheel 22. Lowering of the forward pair of wheels 14 into inactive contact with the pavement and raising the wheel 22 results-in the front wheel ¦ 22 being raised off the pavement sufficiently to move it out of inactive contact with the pavement to permit the apparatus 10 to be pulled behind a conventional truck (not shown).
A means 24 for generating heat to be applied to the area of pavement be repaired is plvotably affixed to the .. 1 g ~23930~:

¦ rear of the frame 12 opposite the stand 20, for example, by a pair of hinges 26. The heat generating means 24 is pivot able between a lower position (FIG. 1) whereat the heat generating means 24 is dispose adjacent to and above the asphalt area to be repaired, and an upper position (FIG. 2) upwardly pivoted away from the asphalt, by actuation of a pair of hydraulic cylinders 28. The hydraulic cylinders 28 each have a first end 27 affixed to the heat generating means 24, and a second end 29 affixed to the frame 12. The means for actuating the hydraulic cylinders is not shown and can be of any conventional or well known construction.
The heat generating means 24 is preferably powered by a mixture of air and propane gas. A motor 30 is attached to the frame and drives a blower 32 which withdraws propane gas from one of a plurality of tanks 34 disposed on the frame.
The blower 32 mixes the propane gas with air and provides this mixture to the heat generating means 24 through one or more conduits 36.
As is best shown in FIG. 3, the heat generating means 24 preferably comprises a luminous wall heating panel 38 having a substantially planar heating surface 40 position able adjacent to and above the asphalt area to be repaired. Such luminous wall heating panels 38 are sty commonly used in industrial furnaces and are shown in U. S. Patent No. 2,828,813 and No.
3,008,513. The luminous wall heating panel 38 is constructed quite similarly to the furnaces shown in these patents and come - proses a housing 44 defining a plurality of plenums aye and 46b. The housing 44 carries fire brick 48 therein and is provided with a plurality of perforations 50 which allow communication between the plenums 46 and the interior surfaces of the fire brick 48.

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- pa -However, as shown in Figure 3, the luminous wall heating panel 38 according to the present invention significantly differs from the luminous walls disclosed by the cited references in the degree of strength/rigidity with which it is formed. Particularly, the inner portion of housing 44 (having perforations formed therein) extends completely outwardly to where it is connected to the outermost member/shell of the housing 44. In the conventional furnace structures of the cited references, on the other hand, the perforated, inner walls 16/15 of the furnace housing are positioned remotely from the outermost walls of the furnace housing. Further, the fire brick 48 of the present luminous wall 38 are not formed with supplemental, unrestricted holes (such as holes 21 disclosed in patent 2,828,813 or passages 17 disclosed in patent 3,008,513) for distributing a gas/air mixture through the brick.

1;~39~0~ 1 The gas-air mixture is supplied to inlets 52 to the plenums aye and 46b from the fuel tanks 34 and the blower 32 by the conduit 36 and through controls shown schematically at 54. The gas-air mixture flows through the perforations 50 and the porous fire brick 48 to a firing face 56 at which the mixture burns to create a luminous heating surface.
The plenums aye and 46b are preferably separated by a wall 58, and the air-gas mixture is separately provided to the plenums aye and 46b by inlets 52. The flow of gas is con-trolled by two controls 54 and valves 60 so that a plurality - of distinct heating zones aye and 62b t62c and 62d also in FIG.
6) are provided on the firing face 56. In this way, each or all of the zones aye, 62b, etc. can be fired to accoIr~nodate areas of different sizes which require patching.
Skirting 64 is provided around the periphery of the luminous wall heating panel 38 to aid in retaining the heat in the work area.
Preferably, the heat generating means 24 (FIGS. 1, 5 and 6) comprises three coplanar luminous wall heat sections 66, 68 and 70, in order to increase the precision with which heat is applied to the asphalt area to be worked. Conveniently, the forward luminous wall section 66 is approximately six foot wide by three foot long (6' wide by 3' long), the left luminous wall section 68 is two and one-half (2 v2'j feet wide by three (3') feet long, and the right luminous wall section 70 is three (3') feet long by three and only (3 1/2') feet wide. Each of the left and right heating panel sections 68 and 70 are attached to the forward heating panel sections 66 by a hinge 72. The axis of each of the hinges 72 is disposed perpendicularly to pa the plane of the luminous wall sections 66, 68 and 70 so that the left and right luminous wall panel sections 68 and 70 may be pivoted outwardly so as to abut wide surfaces 73 of the ion end `

. ~393~2 ¦ luminous wall section 66. Thus, the configuration of the heat generating means 24 can be changed from a first position which produces a six (6') feet by six (6') feet square configuration (as shown in FIGS. 1, 5 and 6) to a second portion which produces a three (3') feet by twelve (12') feet rectangular configuration (as shown in phantom in FIG. 5). In practice, it is found that -such a change takes less than five (5) minutes to complete.
The forward luminous wall section 66 includes two individually controlled heating zones and each of the other luminous wall sections 68 and 70 include a single individually controlled heating zone. The independent firing of the luminous wall sections 66, 68 and 70, and their associated zones, as pro-voided by controls 54 and valves 60 permits very precise control of the heat applied to the asphalt area to be patched.
Referring again to FIG. 1, the frame 12 additionally includes a rear member 74 which carries the heat generating means 24. The hydraulic cylinders 28 are affixed to the rear frame member 74 and the rear frame member 74 is pivotal affixed to the frame 12 by the hinges 26. The heat generating means 24 is suspended on the bottom of the frame rear member 74 by a plurality of rollers 76 (FIG. 5) attached to the heat goner-cling means 24, in rolling engagement with one or more I beams 78 (FIG. l) on the rear frame member 74. A hydraulic cylinder (not shown) is affixed to the heat generating means 24 and the rear frame member 74 in order to transversely move the heat generating means along the rear frame member 74, in the affection of arrow 80 (FIG. 5). Preferably, the total extent of movement is about one foot either side of a central position.
A hopper 82 (FIGS. 1, 2 and 4) is mounted on the frame 12 between the fuel tanks 34 and the heat generating means 24.
The hopper 82 is thermostatically controlled by known means (such ¦ as heaters 81, FIG. 4) and maintains new asphaltic material ~L~39302 it therein at a temperature at which the material can be manipulated The hopper 82 can also be used to reclaim old or new asphalt by heating it at a sufficiently high temperature. The hopper 82 includes a pair of lids 84 (FIG. 4) which are openable from either the center or the sides of the center 83. This is par-titularly convenient since asphalt plants generally feed asphalt to a vehicle from a point above the vehicle, while laborers can still open the hopper lid 84 from the side and manually load new or recycled asphalt into the hopper 82.
.0 An auger delivery system 86 for supplying new asphalt to the roadway being repaired extends from the bottom of the hopper 82 and over the heat generating means 24 to a point adja-cent the outer edge of the heat generating means 24. the auger delivery system 86 is hydraulically operated by conventional .5 means and comprises a tube or trough 88 and an auger or a screw feeder 90 carried in a portion of the trough 88. A hand crank 92 (FIG. I is disposed on the outer end of the auger 90 to permit the auger delivery system 86 to be cleaned.
Preferably, the screw feeder or auger 90 comprises three pieces, each of whose rotation is keyed to the rotation of the other pieces. A first auger piece is disposed in a first trough part 96 (FIG. 1), which extends to the rearward periphery of the heat generating means 24. The first trough part 96 is connected by a hinge 102 to a second trough part 100 in which is disposed a second auger piece trot shown). The second trough part 100 is pivot ably connected to the hopper 82 by a hinge 104.
The second trough part 100 and the second auger piece are gent orally disposed above the forward luminous wall 66. Finally, a third auger piece 98 (FIG. 41 is disposed in a hollow in the hopper 82 and is in intimate contact with the asphaltic material contained in the hopper 82. The third auger piece 98 is hydra-locally driven by a hydraulic motor (not shown).
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This construction of the auger delivery system 86 permits the delivery of asphaltic material to a point adjacent the rear edge of the heat generating means 24 regardless of the configuration in which the luminous wall sections 66, 68 and 70 are disposed. In the square configuration, the auger delivery system 86 is extended its full length, and asphalt is delivered to the rear edges of the luminous wall sections 68 and 70. however, when the right and left luminous wall sea-lions 68 and 70 are pivoted outwardly so as to provide a fee-angular configuration of the heat generating means 24, the first trough part 96 is folded upwardly about the hinge 102 and allowed to rest on the second trough part 100 (it the post-lion shown in phantom in FIG. 1), breaking the interconnection of the first auger piece and the second auger piece. The asphalt tic material is thus delivered by the auger delivery means 86 to a point adjacent the rear edge of the forward luminous wall section 66. When the heat generating means 24 is pivoted up-warmly, away from the asphalt surface to be repaired, by the actuation of the hydraulic cylinders Thea second trough part 100 pivots upwardly about the hinge 104. Interference with the raising of the heat generating means 24 by the auger delivery system 86 is thereby avoided.
The apparatus 10 also includes a means 106 capable of being hand held on either side of the vehicle for remotely ; 25 - controlling the actuation of the various components of the appear Tess 10. The details of construction of the remote control means Jo should be apparent to one skilled in the art, in light of the ;. : elements and functions of the apparatus as described.
!: `; The remote control means 10~ is particularly advantage-1 I out when the stand 20 includes a driven front wheel 22 twig. 7).
I Preferably, the front wheel 22 is driven by a motor 105 carried j in the r out of the frame 12. In thin runner, longitudinal 1~3930Z

as well as transverse positioning of the heating panel 24 can be achieved.
Use of the apparatus 10 to repair a pothole or the like on an asphaltic surface is straightforward. The heat gent crating means 24 is positioned adjacent to and above the area to be patched, and the configuration of the luminous wall sea-lions I 68 and 70, and the particular heating zones 62, are selected in order to precisely heat the area to be repaired.
Heat is applied for a sufficient a unto of time to initiate heating of the asphalt, but not for a period of time long enough to result in the ignition of the upper surface of the asphalt roadway. The seating zones are sequentially turned on and off to provide a soak time when this heat is off. In this way the heat is permitted to soak into the asphalt without igniting the upper layer.
The use of the thermostatically controlled hopper 82 provides particular advantage in that it obviates the need to use an expensive yet inferior cold mix for small repairs, or for repairs made when local asphalt plants are closed. Hot mix asphalt is conveniently obtained some period of time in advance of the time when a repair is to be made. The amount obtained is an amount which makes it economically feasible for 1, a truck to travel to the asphalt plant. The mix obtained from j the plant is preferably laid out on a hard, non melting surface in a layer approximately 4" to 6" thick. A pick is dragged jug, through the hot mix asphalt so as to make grooves therein spear-7 axed by about 18 inches. A cross hatching series of grooves I,! results in the formation of squares of asphalt about 18 inches on a side. The asphalt is allowed to cool, and the squares are broken from one annular and are then stored in a sheltered area until they are needed. A sufficient quantity of broken i asphalt i placed in the thermostatic hopper and heated o'er ` I ( ~;~3930~

night. By the time of use the next day, the broken pieces have melted into a smooth and uniform hot asphalt mix. thus, hot mix asphalt is available for use, even if the local asphalt plant is closed on a given day or night, or if a patch is too e small to economically justify sending a truck to an asphalt plant. Permanent repairs can be made, instead of the temporary and poor quality repairs which would be made by conventional methods.
It should be apparent that reclaimed asphalt material lo can, if desired, be used instead of new material.
It has been found that the asphalt repair apparatus 10 of the present invention, because it employs a luminous wall heater, is much more efficient than other asphalt equipment now in use. the apparatus 10 makes it possible for a reduced number of crew men to be used to repair asphalt roadways and repairs can be accomplished throughout the year, even in those areas which experience harsh winters. The use of other equipment such as air hammers and saws is avoided.
Because the luminous wall heaters are substantially pollution free, the introduction of pollutants into the atoms-phone is avoided. Also, because the area to which heat is apt plied by the luminous wall heaters can be precisely controlled, from the pivotal configuration of the heaters, as well as the selection of heating zones, the use of extraneous heat which would damage vegetation on the roadway shoulder or above the roadway is avoided.
Having described my invention, however, many modify-; cations thereto will become apparent to those skilled in the art to which it pertains, without deviation from the spirit of it j the present invention, as defined by the scope of the appended claims.

I claim:

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Claims (17)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED, ARE DEFINED AS FOLLOWS:

1. An apparatus for the heat treatment and patching of an area of an asphaltic surface comprising:

a support means:

means for generating heat, said heat generating means being mounted to said support means in a position to heat said asphaltic areas and said heat generating means comprising a luminous wall heating panel having a substantially planar surface positionable adjacent to and above said asphaltic area;

means for moving said planar surface away from said asphaltic area;

said luminous wall heating panel including a plurality of porous firebrick; and said firebrick having no supplemental, unrestricted gas distribution holes formed therein.

2. The invention according to claim 1 wherein;

said heat generating means is mounted on the rear end of said support means; and said moving means comprise at least one hydraulic cylinder having one end attached to said heat generating means and the other end attached to said support means so as to pivot said planar surface away from said asphalt area.

3. The invention according to claim 1, wherein said moving means comprises means for moving said support means to a position whereat said planar surface is not adjacent to and above said asphalt area.

4. The invention according to claim 3, wherein said frame comprises at least one pair of wheels, one each of said pair on opposite sides of said support means.

5. The invention according to claim 1, further comprising means for moving said heat generating means transversely to said support means in a horizontal plane.

6. The invention according to claim 1, further comprising means for remotely controlling the operation of said apparatus.

7. The invention according to claim 5, additionally comprising a front wheel mounted to said support means opposite said heat generating means.

8. The invention according to claim 1 wherein:
said luminous wall heating panel is provided with a plurality of separated, individual zones and means for individually controlling the heat generated by each of said zones between a plurality of output valves during a heating operation of the apparatus.

9. The invention according to claim 1, wherein said heat generating means comprises a plurality of coplanar luminous wall heaters, each of said plurality of luminous wall heaters being pivotal connected to at least one other of said luminous wall heaters by a hinge, the axis of each of said hinges being disposed parallel to the axes of the others and perpendicular to the plane of said luminous wall heaters.

10. The invention according to claim 1, further comprising a heated container for asphaltic material, mounted to said support means.

11. The invention according to claim 10, further comprising a screw auger connected to said support means and said container for the delivery of asphaltic material outside the periphery of said apparatus.

12. The invention according to claim 11, wherein said planar surface is pivotable away from said asphalt area, and said auger is positioned over said heat generating means and segmented so as to be pivotable in unison with said planar surface.

13. The invention according to claim 7, additionally comprising two pairs of wheels, one pair of wheels disposed forward of the center of gravity of said apparatus, and the other pair of said wheels disposed rearwardly of the center of gravity of said apparatus, and means affixed to said support means and said front pair of wheels for raising and lowering said front pair of wheels so that the weight of the vehicle is shifted to said front wheel.

14. The invention according to claim 1, wherein said support means comprises a frame.

15. The invention according to claim 1, wherein:
said luminous wall has a rigid, non-flexible construction and further includes an inner, perforated plate member positioned above said firebrick, and an outermost housing member surroundingly connected to peripheral edges of said plate member.

16. The invention according to claim 8, wherein:
said heat generating means comprises a plurality of luminous wall heaters, each of said plurality of luminous wall heaters being affixed to at least one other of said luminous wall heaters by a hinge having an axis disposed perpendicularly to the plane of said luminous wall heaters so that at least one of said luminous wall heaters can be pivotal moved relative to another of said luminous wall heaters and the configuration of the heat generating means can be easily changed to a plurality of positions; and each of said luminous wall heaters defines at least one of said individually controlled heating zones of said luminous wall heating panel.

17. The invention according to claim 8, wherein:
said individually controlled heating zones of said luminous wall heating panel are spaced longitudinally of said apparatus.