US3483804A - Apparatus for applying bitumen and aggregate to a road surface - Google Patents

Description

Dec. 16. 1969 T. A. NOLAN APPARATUS FOR APPLYING BITUMEN AND AGGREGATE TO A ROAD SURFACE Filed Feb. 9, 1968 .4 Sheets-Sheet l INVENTOR.

. N O L A N Dec. 16, 1969 r. A. NOLAN 3,433,304

APPARATUS FOR APPLYING BITUMEN AND AGGREGATE TO A ROAD SURFACE Filed Feb. 9, 1968 .4 Sheets-Sheet 2 I E i' m 49 INVENTOR.

THOMAS A. NOLAN Dec. 16. 1969 T. A. NOLAN 3,483,804

APPARATUS FOR APPLYING BITUMEN AND AGGREGATE TO A ROAD SURFACE Filed Feb. 9, 1968 )4 Sheets-Sheet 5 INVENTQR.

THOMAS A. NOLAN BY ATTORNEYS Dec. 16. 1969 T. A. NOLAN APPARATUS FOR APPLYING BITUMEN AND AGGREGATE TO A ROAD SURFACE .4 Sheets-Sheet 4- Filed Feb. 9, 1968 R. mm mm m & Q EM W O 1 N H. 1 H Hm A. S A 8 w H T. mm mm 5 @NQM Jilw ATTORNEYS United States Patent O 3,433,804 APPARATUS FOR APPLYING BITUMEN AND AGGREGATE TO A RUAD SURFACE Thomas A. Nolan, RD. 7, Box 242, Medina, Ohio 44256 Filed Feb. 9, 1968, Ser. No. 704,289 Int. Cl. Eillc 19/18 US. Cl. 94-44 6 Claim:

ABSTRACT OF THE DlISCLOSURE A self-propelled paving machine carries at its front end an aggregate-receiving hopper whose forward edge is low enough to receive ag regate from a dump truck pushed ahead of the hopper. A rotatable roller coacts with an adjustable slot near the bottom of the hopper to control the amount of aggregate deposited on the road. A spray bar ahead of the deposit zone places a layer of hot bitumen on the road to bind the aggregate thereto. Short stub screw conveyors inside the hopper distribute the aggregate from the dumping point laterally outward. All shaft drives are outside of the hopper so that access to the top thereof is unobstructed save for the screw conveyors and thin plates which support the inner ends thereof. A fifth-wheel connection at the rear end of the machine is adapted to couple with a coacting connection near the front end of a standard bitumen transport tank vehicle to insure continuous operation for long periods of time. This fifth-wheel connection is movable laterally by power while the machine is in operation to prevent 3 the tank vehicle scraping a road guard while paving a curve. Conduit means is provided to permit pumping bitumen out of a heated end of the tank vehicle and to return it to an unheated end thereof. Remote controlled valve means controls the rate of supply of bitumen to the spray bar.

This invention relates to improvements in a machine for continuously paving a road surface by first depositing a layer of hot bitumen and quickly thereafter spreading a layer of rock or slag aggregate thereupon. Means are provided for depositing a controlled amount of bitumen evenly across the surface being paved and also for depositing a controlled amount of aggregate evenly distributed on the bitumen layer. This enables the contractor to carefully control the unit costs for a long strip of paving. One of the novel features of this invention is the provision of a fifth-wheel connection near the rear end of the paving machine adapted to connect with a like connection of a standard bitumen transport tank vehicle having a very large capacity, such as 10,000 gallons, so that the machine will run for long periods of time without refilling the hot bitumen reservoir tank. An aggregate receiving hopper is provided at the front end of the paving machine and pushes a standard dump truck ahead of it which gradually empties the aggregate from the dump truck into the hopper. As is usual in such cases, the dump truck can be replaced from time to time without stopping the paving machine because of the reservoir of aggregate material in the hopper.

Another feature of the present invention is to provide an aggregate storage hopper substantially clear and open at the top save for two stub screw conveyors located inside the hopper near the end walls thereof and having their inner ends supported by a thin plate. Drive means for the screw conveyors and for the aggregate feed roll and piping for the spray bar are all located outside of the aggregate receiving hopper.

Another special feature of the machine is the provision of power means for moving the fifth-wheel connection of the machine laterally during operation of the machine "ice so as to prevent the transport tank vehicle from scraping road guard while paving around a curve.

Other objects and advantages of this invention will be apparent from the drawings and the descriptionand the essential features will be summarized in the appended claims.

In the drawings:

FIG. 1 is a side elevational view showing from left to right a dump truck for supplying aggregate, the paving machine of this invention having at the end nearest the dump truck a spray bar for depositing hot bitumen on the road surface and a receiving hopper for aggregate providing a spreader box for distributing the aggregate evenly across the road surface, and at the rear end of the paving machine a fifth-wheel connection for transporting a bitumen tank truck behind the paving machine with conduit connections for pumping the hot bitumen from the tank truck through the spray bar with return conduit means to discharge unused bitumen back into the tank truck;

FIG. 2 is a diagrammatic view of the spray bar stub screw conveyors for distributing aggregate in the aggregate hopper, an ag regate feed roll, together with drive means for the screw conveyors and the feed roll and the conduit connections necessary to pump hot bitumen from the supply tank through the spray bar and back to the tank with controls therefor;

FIG. 3 is an end elevational view, enlarged, of the aggregate receiving hopper, this view being taken from the opposite end seen in FIG. 1 with parts broken away to show the control of the aggregate;

FIG. 3a is a fragmental top plan view taken along the line 3a3a of FIG. 3 and showing a spray shut-01f arrangement;

FIG. 4 is a fragmental top plan view, enlarged, taken from the position of the line 44 of FIG. 1 to show the fifth-wheel connection for attaching a tank vehicle;

FIG. 5 is an end elevational view, enlarged, taken along the line 5-5 of FIG. 3; while FIG. 6 is a diagrammatic view showing a top plan view of the paths of travel of the support Wheels of the paving machine and the tank truck of FIG. 1 illustrating how such wheels pack down the materials deposited by the paving machine.

Referring to FIG. 1 of the drawings, the paving machine of this invention comprises a main frame 10 supported by wheel means 11 for travel on a road surface 12. The vehicle comprises an internal combustion engine 13 having a specially positioned radiator 14 which will be later described. The driver sits in the seat 15 and controls the steering wheel 16 which has control connections not shown with the wheels 11 so as to steer the vehicle. The equipment for driving and steering the vehicle are well known and need not be described here.

Rigidly supported at the front end of the main frame 10 is an aggregate receiving hopper or spreader box 17. As best seen in FIG. 3, this box has a front wall 18 inclined inwardly and downwardly and a rear wall 19 inclined inwardly and downwardly. Opposite side Walls 20 and 21, parallel to each other, are rigidly secured to the walls 18 and 19 providing a hopper almost completely closed save for the open top thereof. Near the upper end of the wall 18, there is provided a strongly reinforced bumper construction 22 by which it is possible to push a dump truck 23 ahead of the paving machine, the parts being so arranged that aggregate discharged from the rear end of the dump truck as seen in FIG. 3 is discharged directly into the aggregate receiving hopper. At the upper end of the wall 19 is provided a strong channel construction 24 having suitably Welded hex nuts 25 along the length thereof so that the spreader box structure may be bolted to the main frame 10 of the paving machine.

Means is provided for discharging a controlled amount of the aggregate 26 from a point near the bottom of the aggregate receiving hopper. To this end, an open slot 27 is provided extending from end to end of the hopper between the walls and 21. This opening is partially closed by a rotatable feed roller 28 which, as shown in FIG. 5, has a trunnion bar 28a rigidly secured axially at each end of the feed roll by means of plates 28b which are welded inside of the hollow feed roll and welded to the bar 28a. Bushings 29 are provided in each end and supported in the wall 20.

Means is provided above the feed roll 28 to control the amount of aggregate escaping from the hopper. This comprises an aggregate control gate 30 slidably mounted on the outside of plate 19 and held in position by stop shoes 31 welded to plate 19 and other guide means on plate 19 which are not shown. Movement of the box beam gate 30 toward and away from feed roller 28 is by means of two pneumatic cylinder motors 32, one near each side of the spreader box or aggregate hopper. Each cylinder is pivotally supported on a pin 33 mounted in ears 34 which are welded to the channel 24. The rod 32a of each motor is pivotally connected by a projection 33 which engages a pin 34 held in the bifurcated bracket 35 which is welded to the upper side of gate 30. Compressed air is provided by means not shown and remotely controlled to cause the air to exert pressure at either end of cylinder 32 against the piston therein to move gate 30 upward or downward. Upward movement is limited by the stops 31. A flexible flap 36 is provided extending the full length of feed roller 28 and secured to a hopper wall member 37 to prevent aggregate traveling out of the hopper except over the roller 28.

Two separate stub screw conveyors 38 and 39 are provided, one near each of the side walls 20 and 21 for distributing the aggregate laterally outwardly from a central zone of the hopper where it is deposited from the dump truck. As seen in FIG. 5, the outer end of each screw conveyor has a shaft 39a which is supported in a bushing 39b supported in the hopper side wall 20. The inner end of each screw conveyor is supported by a thin plate 40, preferably not more than one-half inch thick and not greater in thickness preferably than the diameter of the screw conveyor shaft. This plate 40 as seen in FIG. 3 is welded to plates 18 and 19. It will be noted as this description proceeds, that the access of the aggregate to the interior of the hopper is unimpeded except by the stub screw conveyors 38 and 39 and the thin plates 40 which support the inner ends thereof.

Drive means is provided for the screw conveyors and the feed roller. Referring to FIGS. 2, 3 and 5, a take-off shaft 41 driven from a transmission 42 which in turn is driven by the engine 13, is releasably connected to a gear case 43 which drives shaft 44a in one direction and drives 44b in the opposite direction. Gear case 43 is supported from plates 45 which are welded to the back wall plate 19 outside of the hopper. Near side wall 20 the shaft 44b is supported in a bushing 46 which is mounted on a bracket 47 which in turn is welded to the outside face of the wall plate 19. A similar bushing supports the laterally outer end of shaft 44a near the other side of the hopper. A remote control electrically operated clutch 48 controls the transmission of power from shaft 441) to a sprocket 49 on the laterally outermost end of shaft 44b. This clutch is supported from bracket 47 and is remotely controlled from the operators seat. A drive chain 50 drivingly connects sprocket 49 with a sprocket 51 on the end of shaft 39a of the screw conveyor 39. In like manner, electrically operated clutch 48a drivingly connects shaft 44b with a sprocket 49a which is connected by chain 50a with sprocket 51a on the shaft 38a of screw conveyor 38. It should be understood that the driving connections are such that the screw conveyors 38 and 39 are driven in a. direction to push the aggregate from the center of the hopper laterally outwardly.

The drive means for the aggregate feed roller 28 is by means of sprocket 52 on shaft 44b, drive chain 53, and sprocket 54 on a jack shaft 55 which has its outer end supported in a bushing 56 mounted on side wall 20 and its inner end supported in a bushing 57 which is mounted on a bracket 58 which in turn is welded outside of the hopper wall 19. Shaft 55 turns a sprocket 59 on its outer end which is connected by drive chain 60 with a sprocket 61 mounted on the trunnion 28a of the feed roller 28. Control of the feed roller is by means of a remotely controlled electrically operated clutch 62 which controls the transmission of power through jack shaft 55 to the sprocket 59. This is controlled from the operators seat.

It will be noted that the screw conveyors and the aggregate feed roll are driven from the transmission 42 which in turn takes its power from engine 13. Therefore. the faster the paving vehicle travels, the faster the rotation of the screw conveyors and the aggregate feed roll.

The hot bitumen spray 63 which is placed on the roadway ahead of the deposited aggregate comes from a pinrality of spray nozzles 64 which are mounted on the lower side of spray bar 25 which, in turn, is rigidly supported near the front end of the hopper structure. A supply pipe 66 is connected with one end of the spray bar and a return conduit 67 is connected with the opposite end. Those portions of pipe 66 and 67 which are supported on the outside of the side walls 20 and 21 of the hopper structure are releasably connected with other conduits on the paving vehicle 10 such as 66a, which receives bitumen through a hose connection 66b which is releasably con nected to the transport tank 68 and preferably extends through the bottom of such tank through pipe 66c to the rear portion of the tank vehicle where heating means 69 is provided. In a similar manner, the portion of pipe 67 which is mounted on the hopper structure is releasably connected with a conduit 67a on the paving machine which passes upwardly through a tower 70 on the vehicle and is connected by a hose 67b which is releasably connected inside the tank 68 with a pipe 670 which preferably discharges downwardly toward the bottom of the tank and at the opposite end thereof from the intake of pipe 660. This arrangement causes a continuous circulation through the tank 68 which the recirculated bitumen from pipe 67c gradually moving toward the rear of the tank where it is reheated and again pumped out through pipe 660.

Referring now to FIG. 2, connected in series in the lines 66a and 66b is a pump 71 driven by suitable means not shown for pumping the hot bitumen from the tank transport 68 to the spray bar 65. In the return lines 67a and 67b, there is inserted in series a flow control valve 72 which preferably is mounted on the tower 70. This valve is controlled by a power means 73 which is here shown as an air cylinder which is provided with suitable air flow lines 74 which extend back to a control mechanism not shown adjacent the drivers seat 15. Thus, the driver can at all times set the position of valve 72 to get the proper flow of bitumen to the spray bar 65. Obviously, by closing off valve 72 by controlling air pressure in lines 74, greater pressure is built up in the spray bar and vice versa. The spray pressure may at all times be read on the gauge 75 which is connected by pipes 75' with the pressurized bitumen flowing from line 67a to valve 72.

Control valves 76 and 76a are provided respectively in the supply and return lines for the control of the flow of the bitumen material. A by-pass 77 communicates between lines 66a and 67a in one setting of the valves 76 and 76a. This setting, to cause flow through by-pass 77, is utilized when changing transport tank 68 or at the end of the work day when the spray bar and connecting lines are to be flushed out. In one setting of valves 76 and 76a the flow is from tank 68 through spray bar 65 and back to the tank through the lines previously indicated and in the direction of the arrows of FIG. 2. At the end of a work day, valves 76 and 76a are set to provide communication through by-pass 77 and then valve 78 is opened communicating with a supply tank 79 which may contain kerosene or any other suitable cleaning fluid. Pump 71 is then operated to transmit the cleaning fluid from tank 79 through pipes 66a, 66, spray bar 65, pipe 67, 67a and 77 until all of these pipes and the spray bar are cleaned of bitumen.

The bitumen transport tank 68 of this invention is so long that provisions must be made to prevent it striking against a road guard when paving around a curve. Referring to FIGS. 1, 4 and 6, the fifth-wheel connection 80 near the rear end of the paving machine has previously been referred to as coacting with a fifth-wheel connection 81 on the transport tank vehicle 68. Referring to FIG. 4, this fifth-wheel connection 80 is mounted on a platform 82 which in turn is mounted for lateral sliding movement on the vehicle by bushings 82a which slide along parallel bars 83 which, in turn, are rigidly connected to a subframe 84 which is rigidly fixed on the frame of the paving machine. Hydraulic jack 85 is mounted on the sub-frame 84 and has a piston rod 85a fixed to a bracket 86 rigid with the member 82. Pressure fluid control lines 87 for the jack 85 lead back to a position adjacent the drivers seat so that he may operate the jack 85 to move the fifth wheel 80 laterally relative to the vehicle frame 10 while the vehicle is in motion. In one embodiment of this invention, the fifth wheel 80 is movable to either of the dot-dash positions to the left or right of center of the vehicle by as much as one foot in either direction. This is sutficient to permit the tank truck vehicle 68 to follow behind the paving machine around any usually encountered curve without the tank vehicle scraping the road guard.

An additional advantage of this improved paving machine is that the pneumatic tires of the paving machine and the associated tank transport vehicle are so arranged that they will press down the major portion of the ag gregate deposited on the road bed by this machine. Referring to FIGS. 1 and 6, it will be noted that the front wheels 11 of the paving machine track inside of the rear wheels 11 of the same machine. The tank transport vehicle has at least two pairs of wheels 38 on each side thereof and these in turn do not follow the tracks of either of the pairs of wheels 11. It results from this arrangement that more than 75 percent of the layer of aggregate laid down is rolled over by the combined pneumatic tires 11 and 88.

Referring to FIG. 3, it will be noted that the side wall plates and 21 extend beyond the front and rear walls 18 and 19 at the points marked 20a on FIG. 3. This provides support for the bumper structure 22, the spray bar 65, and the driving mechanism for the screw conveyors and the aggregate feed roll. This also makes possible the attachment of skid plates 89 under opposite side walls of the hopper structure, these skids being turned up front and rear so that the hopper may be rested on a surface or even pulled over a surface when not mounted on the paving machine.

Means is provided for lifting the hopper vehicle by a crane or the like and this comprises a lifting bar 90 rigidly attached at 91 and 92 to the upper ends of the side wall 20 and a similar structure on the opposite side wall.

The radiator 14 for engine 13 is of the usual type containing water cooled by an air fan (not shown) which pushes air through the radiator. As seen in FIG. 1, this radiator faces laterally away from the paving machine and is positioned back of the engine 13 and to the rear of the operators seat 15. In this position the radiator receives a minimum of fine bitumen spray floating in the air in the general vicinity of spray bar 65.

Means is provided for shutting off the spray nozzles 64 when bitumen is not being deposited. Referring to FIGS. 3 and 3a, bitumen from the spray bar 65 reaches each spray nozzle through the hollow core 93 of a plug valve 94. This valve is of a known type wherein a port leading into the core 93 in one position communicates with the interior of the spray bar and upon a relatively slight angular movement of the core, the port is closed and com munication is shut 013?. The angular position of each core is controlled by a generally U-shape pin 95 which extends laterally away from the plug valve and is looped over an actuator pin 96 carried by an actuator bar 97 which is slidably supported in an upwardly opening channel 98. The channel is rigidly supported by members 99 welded to the front wall 18 of the hopper 17. Means is provided for reciprocating the control bar 97 in the direction of the arrows of FIG. 3a by a pneumatically operated cylinder and piston motor 100 having its piston rod 101 connected to bar 97. Means not shown is provided to supply air either through line 102 or 103 to the cylinder of this air motor so as to open or close all of the spray nozzles 64 simultaneously remotely controlled by the operator. Means is provided for disconnecting valve actuators 95 from pins 96 whenever it is desired to deposit bitumen for less than the full length of the spray bar 65.

The operation of this invention should now be clear. With the parts in the position of FIG. 1 and with the engine 13 operating, the operator actuates the cylinders 32 to position the gate 30 at the desired position to control the discharge of aggregate from the hopper. He also adjusts the valve 72 so as to get the proper supply of bitumen to the spray bar 65. Pump 71 operates at all times and spray nozzle control valves 93, 94 are closed when not paving, permitting free circulation from and to tank 68 through spray bar 65. Spray nozzle control valves 93, 94 are opened by air cylinder 100 as soon as the machine moves forward to pave. The entire structure shown in FIG. 1 then moves forward depositing bitumen through the sprays 63 and depositing aggregate 66 discharged by the feed roll 28 immediately on top of the bitumen before it has had time to cool. It will be understood that the operator of the dump truck remains in the cab to control the tilting of the body of the dump truck to slowly discharge the aggregate into the receiving hopper of the paving machine. The operator of the paving machine can see into the aggregate hopper and can operate the screw conveyors 38 and 39 by means of the clutches 48 and 48a whenever it is necessary to spread the aggregate from the center of the hopper laterally sideways. The operator of the paving machine is at all times in control of the rate of feed or" the aggregate and of the hot bitumen, but this would ordinarily take a very small proportion of his time which is, therefore, free to control the vehicle accurately along the roadway. Whenever one of the dump trucks 23 is empty, it simply pulls out of the way and another full truck backs in front of the paving machine which continues slowly down the road working on the aggregate stored in the aggregate hopper. The tank vehicle 68 supplies an enormous amount of bitumen, say of the order of 10,000 gallons, and this will last for a very long period of time. If necessary to change tanks 68, the operator stops the paving machine for a short period during which hoses 66b and 67b are disconnected from the tank vehicle, the fifth-wheel connection 80, 81 is broken, and a new tank vehicle attached, after which connections 66b and 67b are restored and the vehicle is ready to proceed.

In connection with the bitumen handling system, the usual filters, control valves and piping details are used, but are not shown as it would only complicate the drawings. Also, exhaust heat from various engines are piped to various parts handling bitumen to prevent the same congealing where it might cause trouble.

A tachometer wheel for registering the number of feet paved is provided but is not shown. This is a wheel which is automatically raised whenever the bitumen spray nozzles 64 are closed by the air cylinder 100 and is automatically lowered in contact with the pavement whenever spray nozzles 64 are opened. This forms no part of the present invention and is, therefore, not shown.

What is claimed is:

1. In a self-propelled paving machine for continuously laying a coating of bitumen and depositing thereon a layer of aggregate, having a main frame, wheel means on said frame for travel of said machine on a surface to be paved, power means on said frame operatively connected with said wheel means for driving said machine along said surface, means for steering said wheel means, a trough-shaped aggregate receiving hopper extending transversely of said main frame in front of said wheel means and adapted to receive aggregate from a rear dumping supply truck traveling forwardly in front of said receiving hopper, said hopper having side walls and having front and rear walls extending between said side walls, at least one of said front and rear walls sloping downwardly toward a discharge slot extending between said side walls near the bottom of said hopper; the combination therewith of a rotatably mounted aggregate fee'd roll extending between said side walls at least partially closing said slot and having an upper portion of its periphery extending out through said slot. means for rotating said feed roll in timed relation to the travel of said machine in a direction to carry aggregate out of said slot and to drop said aggregate from said roll onto said surface, variably adjustable gate means mounted on said hopper for movement toward and away from said upper portion of said feed roll and adapted to control the amount of aggregate carried out of said hopper by said feed roll, bitumen spray means connected with said hopper in front of said discharge slot and extending substantially for the length of said slot, bitumen intake conduit means carried by said main frame communicating with one lateral end of said spray means, a pump in series in said conduit means having a capacity for spraying more bitumen than can pass through said spray means, bitumen outlet conduit means communicating with the other lateral end of said spray means, a bitumen transport tank vehicle having its front portion connected with said main frame and having its rear portion supported on said surface by wheel means and having bitumen heating means therein, means for connecting said pump and said bitumen intake conduit means for pumping heated bitumen from said tank vehicle, means for connecting said bitumen outlet conduit means to discharge into said tank vehicle, and variably adjustable means restricting said outlet conduit means and maintaining and adjustable back pressure on said bitumen supply to said spray means.

2. In a self-propelled paving machine as defined in claim 1, a fifth wheel connection between said main frame and a front portion of said bitumen transport vehicle, and means for moving said fifth wheel connection laterally of said main frame, whereby said machine may accurately surface a road shoulder near a guard rail on a curve without said transport tank vehicle engaging said guard rail.

3. A self-propelled paving machine as defined in claim 2, wherein said fifth wheel connection moving means includes power means adapted to move said fifth wheel connection laterally while said vehicle is in motion.

4. A self-propelled paving machine as defined in claim 1, wherein substantially the sole obstruction inside the walls of said hopper above the level of said aggregate feed roll consists of two separate screw conveyors above the level of the feed roll, one near each of said hopper side walls, each screw conveyor on a separate stub shaft extending inwardly from its associated side wall, and means outside of said hopper for driving said screw conveyors in directions to feed aggregate laterally outwardly in said hopper.

5. A self-propelled paving machine as defined in claim 4, wherein bearings are provided outside said hopper walls for opposite ends of said aggregate feed roll and for the outer ends of said screw conveyors, and the sole support for inner ends of said screw conveyor stub shafts consists of brackets inside of said hopper walls having a hon"- zontal dimension not substantially greater than the diameter of the central shaft of said conveyors.

6. A self-propelled paving machine as defined in claim 1, including an operators seat on said main frame operatively associated with said steering means, and remote control means for adjusting said gate means and for adjusting said outlet conduit means restricting means from said operators seat.

References Cited UNlTED STATES PATENTS 2,241,863 5/1941 Lett 94-44 2,557,471 6/1951 Romig 280-468 2,653,031 9/ 1953 Butler 280-468 2,979,341 4/1961 Thomas 280-468 XR 3,016,809 1/ 1962 McNeill 94-44 XR 3,100,425 8/ 1963 Cartwright 94-44 3,199,423 8/1965 Dickey 94-44 3,270,633 9/1966 Holland 94-44 JACOB L. NACKENOFF, Primary Examiner US. Cl. X.R.

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