The present invention relates to patching devices, and more particularly, to vehicle mounted patching systems for patching potholes and the like and incorporating a novel method and apparatus for providing a protective top layer.
Asphalt patching systems are well known in the art. For example, U.S. Pat. No. 5,263,790 issued Nov. 23, 1993 and U.S. Pat. No. 5,419,654 issued May 30, 1995, teach a patcher comprising a motor driven, wheeled vehicle having a gravel hopper for holding aggregate and a storage tank for liquid emulsion, typically asphalt, as well as pressurized conduits for respectively advancing gravel and asphalt to a mixing head. The asphalt emulsion is delivered from the storage tank to the mixing head by feed lines. The mixing head is arranged to extend from a free end of a swingably mounted, telescoping boom, which is moveable in both horizontal and vertical planes as well as being selectively extendable and retractable to expedite desired positioning of the mixing head above a roadway surface to be patched, i.e., repaired. The pressurized conduits may also be initially employed to blow debris from the pothole or crevice prior to being repaired whereupon an emulsion such as asphalt, with or without aggregate, is delivered to the mixing head. The need for rolling or tamping is eliminated by the use of high-pressure air.
Present day techniques for repairing a pothole includes:
Due to the need to return roadways to use as quickly as possible after a repair operation, it is nevertheless disadvantageous to use a top coat of pulverized stone since tires of passing vehicles often kick up the pulverized stones into other vehicles causing damage to front, rear or side windows, doors, fenders and the like. Also the top layer of crushed stone contrasts with the darker, surrounding road surface.
It is therefore desirable to provide method and apparatus for repairing a pothole which enables immediate use of the repaired surface while preventing damage to vehicles passing along the repaired surface and to provide a repair which blends into the road surface. In addition, the apparatus described herein is capable of performing the novel method requiring a minimal amount of operator intervention.
The method and apparatus for performing the method of the present application comprises a vehicle mounted patching system for patching potholes and the like and incorporating method and apparatus for feeding materials used in patching operations as well as removing and flushing asphalt emulsion from the feed lines of the patcher vehicle to completely recycle the cleaning agent used to flush the feed lines after a patching operation, as well as eliminating any external discharge of potentially toxic materials.
The embodiments of the present invention will be understood from a consideration of the detailed description and drawings, wherein like elements are designated by like numerals, and wherein:
Chassis 12 supports a gravel hopper 16 and an enclosure 18 of substantially hexagonal shape which contains an asphalt supply tank 20. The asphalt is normally heated to maintain a temperature of the order of 135 to 160 Degrees F.
A front boom assembly 21 is pivotally mounted to the front end of the cab 14 to enable the boom assembly to swing in a horizontal plane by means of pneumatic cylinder 24, shown in
A flexible hose 35 communicates between gravel hopper 16 and a mixing head 34 arranged at the free end of boom assembly 21. Flexible hose 35 couples gravel hopper 16 to mixing head 34 through a telescoping delivery assembly 36.
The details of the movement of the boom assembly and its various components are set forth in U.S. Pat. No. 5,419,654 which is incorporated herein by reference and further details of the boom assembly and its operation are omitted herein for purposes of simplicity.
It is sufficient to understand, however, that a heated asphalt emulsion and aggregate are respectively fed to the mixing head under suitable air pressure as will be described in detail below.
The hollow, insulated non-collapsible hose 44 typically contains five (5) different fluid carrying lines as well as electrical wires as will be described below in greater detail. Non-collapsible hose 44 is maintained substantially taut regardless of the expansion or retraction of the telescoping delivery tube assembly 36, under control of piston cylinder 16, as is described in detail in the aforementioned issued U.S. Pat. No. 5,419,654.
As was described above, the aggregate hopper 16 is coupled to the mixing head 34 by means of the telescoping assembly 36 also shown, for example, in
Coolant from the engine cooling system of the patcher 10, which is typically heated to a temperature in the range of 135-160 and preferably 150 degrees F., enters into a hot water inlet coupling 34b and circulates through the hollow interior of the mixing head defined by the inner and outer cylinder walls 34c and 34d, shown in
The emulsion storage tank 18 is coupled to an inlet port 102a of a multi-port valve 102 having a common outlet port 102b which is selectively coupled to one of the ports respectively arranged at 3 o'clock, 6 o'clock, 9 o'clock and 12 o'clock positions about the sidewalls of valve 102. Valve 102 is preferably enclosed within an insulating jacket 104 having inlet and outlet ports 104a and 104b for respectively introducing hot water from the engine cooling system into jacket 104 and for returning the hot water to the engine cooling system. The hot water flowing through jacket 104 maintains asphalt emulsion passing through valve 102 in a heated, flowable condition to prevent clogging of the valve 102.
When valve 102 is moved to the position coupling 12 o'clock port 102a to common port 102b, heated asphalt from tank 18 passes through valve 102 and enters asphalt line 106, which is one of the lines that is enclosed within the hollow, insulated non-collapsible hose 44, shown in
A valve assembly, preferably a one-half inch (0.50″) ball valve assembly 108, is connected in line 106 and is operated under the control of a custom linear actuator 109 operated under control of an actuator switch 111 located in the patcher cab 14 to provide an adjustable flow rate of the asphalt emulsion through line 106. Line 106 is split by a T-coupler 110, providing a first branch 112a which is coupled to the common inlet port 114a of control valve 114 and a second branch 112b coupled to common inlet port 116a of control valve 116.
Multi-position control valves 114 and 116, as well as valve 102, are substantially identical in design and function, as will be more fully described in connection with
The control valve 116 shown in
The valve assembly 116 comprises a hollow housing and is further provided with a pair of openings 116g and 116h along respective diagonal side surfaces for receiving coolant from the patcher engine cooling system to heat the valve and thereby maintain asphalt passing through the control valve 116 during a patching operation to be in a heated, flowable state and thereby prevent the control valve 116 (as well as control valves 114 and 102) from becoming clogged with cooled emulsion.
An air supply line 118 derives air under pressure directly from the air brake supply of the patcher air brake system (i.e., without any reduction in pressure), not shown for purposes of simplicity. Air pressure of the order of 120 psi is supplied to the air line 118. A T-coupler 120 feeds the pressurized air to branch lines 122a and 122b, each of which are respectively coupled to inlet ports 114b and 116b of multi-position valves 114 and 116.
Ports 114c and 116c of multi-position valves 114 and 116 are respectively coupled through one-way valves 122 and 124 to one of the inlets 34f and 34g which extend through outer and inner jacket walls 34c and 34d of mixing head 34 (see
As was previously mentioned, the aggregate passes through curved member 40 and into the hollow interior of mixing head 34 where the aggregate is admixed with and coated by the liquid emulsion and then passes through the outlet end 34h of the mixing head 34 for deposit into a pothole or other crevice or recess being and/or repaired. As was mentioned above, air under pressure may be introduced into mixing head 34 while the emulsion feed lines and aggregate line are closed, to clean debris from a pothole. Also, air under pressure enters the flexible hose 35 and telescoping assembly 36 to advance the aggregate into the mixing head 34.
Check valves 122 and 124 are preferably respectively coupled between outlet ports 114c and 116c and couplings 34f and 34g, allowing emulsion to pass in only one direction and enter into the mixing chamber of mixing head 34 while preventing any reverse flow of the asphalt emulsion from the mixing head back into the control valves 114 and 116 through ports 114c, 116c.
The one-way check valves 122 and 124 are preferably provided with jackets having inlet and outlet ports similar to the ports 116g and 116h of valve 116, as shown in
Control valves 114 and 116 are further provided with outlet ports 114d and 116d. Back flush conduits 126 and 128 are coupled between ports 114d, 116d and recovery tank 130. Flush tank 132 contains solvent under pressure, employed for flushing the feed lines 106, 112a and 112b. Recovery tank 130 is located above flush tank 132 to provide for the flow of fluid by gravity from recovery tank 130 to flush tank 132, when normally-closed valve 134 is open. Any suitable cleaning agent having cleansing and/or flushing capabilities may be used.
Patcher 10 operation is initialized by assuring that air pressure provided to the asphalt storage tank 18 and the flush tank 132 are within the range of 50-70 psi and that the air brake system is developing air pressure in the range of 100-120 psi. Valve 136, coupled near the outlet of the air brake pressure source 118, is a regulator valve which, when open, regulates the output pressure introduced into the flush tank 132 and the asphalt storage tank 18, through valve 102, to obtain the desired pressure levels mentioned above. The control arms of valves 114 and 116 are then placed in the 12 o'clock position, causing air entering conduits 122a and 122b to pass through valves 114 and 116 and enter into the feed lines 112a and 112b. The air brake pressure source fed to the line 118 and entering T-coupler 120 bypasses the valve 136 and thus provides maximum pressure (i.e., 100-120 psi) entering the 12 o'clock ports 114b, 116b of valves 114 and 116 and exiting common ports 114a, 116a, lines 112a, 112b and coupler 110, to clear line 106. The control arm of valve 102 is then placed in the 12 o'clock position. The actuator switch 111 in the patcher cab 14 (see
During a typical patching operation, a pothole in the roadway surface is cleaned by blowing high-volume air into the pothole. Air under pressure is introduced into feed line 106 from port 102c and common port 102b by placing the operating arm of valve 102 in the 3 o'clock position and placing the operating arms of valves 114 and 116 in the 6 o'clock position, enabling air under pressure to exit through dispensing head 34.
In a second step, a tack coat of emulsion may be applied to the surface of the area to be treated.
In a third step, a mixture of aggregate admixed with heated emulsion is emitted from the mixing head 34 to fill the pothole. The operating arm of valve 102 is then placed in the 12 o'clock position and valves 114 and 116 are placed in the 6 o'clock position to cause emulsion to flow (under pressure) from the supply tank 18 to mixing head 34 through 102, 106, 112a, 112b, 114, 116 and 112-124.
A finished coat of a dry material may then be applied. The 3 o'clock port of valve 102 can also receive air to blow out the feed line 106, if desired. It has been found that sprayed injection patching is the most economical and longest lasting method for pothole repair.
In order to clean the internal lines of asphalt emulsion while at the same time eliminating any external discharge of fluid from the system and completely recycling the asphalt and solvent, control valves 102, 114 and 116 are operated in the following manner:
A shut-down storage operation is initiated by introducing air into the feed lines by operating switch 111 in cabin 14 to fully close the ball valve 108. The operating handles of control valves 102, 114 and 116 are respectively moved to the 3 o'clock, 12 o'clock and 12 o'clock positions. Ball valve 108 is then opened and maintained open for approximately 1 to 2 minutes until the air pressure in the feed lines drops (monitored by an air pressure gauge in cab 14) whereupon the ball valve 108 is fully closed.
Valves 114 and 116 are then respectively moved to the 9 o'clock and 3 o'clock positions. The operating arm of control valve 102 is then moved to 6 o'clock position, coupling flush tank 132 to feed line 106 through ports 102d, 102b of valve 102 in readiness to perform a flushing operation. Actuator 109 is operated to open ball valve 108, causing solvent in pressurized flush tank 132 to enter the 6 o'clock port 102d of valve 102 and pass through valve 102, feed lines 106, 112a and 112b and valves 114 and 116 and then to recovery tank 130 through back flush lines 126 and 128. One of these hoses, such as hose 128, is preferably formed of a clear transparent material, enabling an operator to view the cleaning agent as it moves from flush tank 132, through valve 102, feed lines 106, 112a, 112b, valves 114 and 116 and back flush lines 126, 128 and enter into recovery tank 130, shown in
The cleaning agent is returned to flush tank 132 from recovery tank 130 by respectively moving valves 114 and 116 to the 3 o'clock and 9 o'clock positions and closing valve 102 (by moving valve 102 to the 9 o'clock position). The air supply line to flush tank 132 and to the emulsion tank 18 is closed by closing valve 136. The air under pressure in flush tank 132 is vented to the atmosphere by opening valve 138 as shown in
Closed valve 134 is then opened for 2-3 minutes to drain the recycled cleaning agent, delivered by gravity to recovery tank 130 by lines 126 and 128, back into flush tank 132 and valve 134 is then closed.
The air pressure release valve 138 which bleeds air from tank 132 to the atmosphere is closed and valve 136 is opened to repressurize tank 132 and emulsion supply tank 18 from pressure source 118, completing the back flush operation and retaining all of the solvent and emulsion in the closed system. The connections for the flush operation may be reversed by coupling the flush tank 132 to valves 114 and 116 and coupling the recovery tank 130 to valve 102, if desired.
The Patcher 10 is provided with apparatus for providing a top coat of dry rubber pulverized to form small pieces of a size typically range of 0.00625 to 0.375 inches in diameter and referred to herein as particulate. To accomplish this and making reference to
The closed-loop sprocket chains 228 and 229 are entrained about a pair of driven sprockets 230 and 231 mounted to free wheelingly rotate about a shaft 239. Sprocket chains 228 and 229 are further entrained about a pair of drive sprockets 226, 227 rotatable together with shaft 241.
The hydraulically driven motor 224 shown in
Drive sprockets 226, 227 and 227a are fixedly joined to common shaft 241, whereby rotation of output shaft 225a is imparted to sprockets 226, 227 and 227a. Making reference to
During the phase of the patching operation when a pothole is being cleared of debris, valve 214 is electrically operated to open to its maximum size opening for delivering air at maximum pressure to the dispensing head 34. Valve 216 is closed at this time. The aforementioned valve positions of valves 214 and 216, i.e., valve 214 being operated to deliver hydraulic fluid at maximum pressure to blower 222 and valve 216 being closed, are also the positions utilized when heated, flowable material from the storage tank 18 is being fed to the dispensing head 34.
During the operating phase when it is desired to deliver particulate from hopper 232 through the dispensing head 34, valve 214 is operated to provide hydraulic fluid to the blower motor at a reduced pressure causing the output of the blower to be reduced to accommodate a reduced air flow, which is adequate for delivery of the particulate from main hopper 232. Simultaneously with the operation of valve 214 to the position to reduce hydraulic fluid pressure to the hydraulic motor for the blower, valve 216 is opened to deliver hydraulic fluid to the hydraulically driven motor 224 for rotating drive sprocket 226 through gear assembly 225, which couples the rotary drive from hydraulically driven motor 224 to the shaft 241 upon which sprocket 226 is mounted, thereby rotating shaft 241 and drive sprockets 226 and 227 to move sprocket chains 228 and 229 and paddles 235 in order to deliver the particulate in main hopper 232 to dispensing hopper 237 through opening 232b under the control of the paddles 235. The drive imparted to shaft 241 is delivered to the rotary air-lock 245 by sprocket 227a, sprocket chain 242 and driven sprocket 243.
The time interval during which the particulate from main hopper 232 is dispensed from the dispensing head 34 for deposit upon the surface of a filled pothole may be controlled by observation by the operator in the patcher cabin 18 of the depositing operation, the deposit operation being easily observed from the cabin 18 since the dispensing head is fully in view of the operator during the dispensing operation. Alternatively, or in addition, an adjustable timer may be provided as part of the controls for operating valves 214 and 216 as well as adjusting gate 232a to control the rate of flow of particulate from main hopper 232 into dispensing hopper 237.
The apparatus shown in
The particulate of rubber firmly bonded to fibrous material is delivered from the main hopper 132 in substantially the same manner as the particulate which does not contain any fibrous material. The particulate of rubber bonded with fibrous material is combined at the dispensing head with emulsion from the heated storage tank 18.
As another alternative, the particulate may be fibrous material which has been shredded and/or otherwise processed for feeding into the dispensing head 34 to be admixed with flowable material from the storage tank 18. Since the individual fibers are nearly weightless as a practical matter, apparatus as shown in
This application claims the benefit of U.S. Provisional Application No. 61/243,656 and filing date of Sep. 18, 2009, which is incorporated by reference as if fully set forth.
Number | Date | Country | |
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61243656 | Sep 2009 | US |