US3279337A

US3279337A - Vehicle for treating road surfaces with a slurry

Info

Publication number: US3279337A
Application number: US357123A
Authority: US
Inventors: Arthur J Weaver
Original assignee: Highway Equipment Co
Current assignee: Highway Equipment Co
Priority date: 1964-04-03
Filing date: 1964-04-03
Publication date: 1966-10-18
Anticipated expiration: 1983-10-18

Description

VEHICLE FOR TREATING ROAD suRFAcEs WITH A sLURRY Filed Aug. 5, 1964 A. J. WEAVER Oct. 18, 1966 4 Sheets-Sheet 1 NHA - INVENTOR en/06f /AVf/e? ATTORNEYS A. J. WEAVER 3,279,337 VEHICLE FOR TREATING ROAD SURFACES WITH A SLURRY 4 Sheets-Sheet 2 INVENTOR en/0e f M1/7 t ATTORNEYS Oct. 18, 1966 Filed Aug. 5, 1964 A. J. WEAVER Oct. 18, 1966 VEHICLE FOR TREATING ROAD SURFACES WITH A SLURRY Filed Aug. 3, 1964 4 Sheets-Sheet 3 I N VENTOR A. J. WEAVER VEHICLE FOR TREATING ROAD SURFACES WITH A` SLURRY Filed Aug. 5, 1964 4 Sheets-Sheet 4 5 ATTORNEYJ United States Patent O 3,279,337 VEHICLE FOR TREATING ROAD SURFACES WITH A SLURRY Arthur I. Weaver, Omaha, Nebr., assignor, by mesne assignments, to Highway Equipment Company, Cedar Rapids, Iowa, a corporation of Iowa Fied Apr. 3, 1964, Ser. No. 357,123 12 Claims. (Cl. 94-44) The present invention relates to a vehicle for spreading material onto the surface of a road and, more particularly, to a vehicle in which, while moving, -a slurry is mixed from a mixture of yasphalt emulsion, water, aggregate and fines, the slurry then being spread onto the road to provide a seal for the surface of the road.

In recent years it has been found that existing roads can have their life extended by the simple maintenance of spreading a mortar-like slurry onto the surface of the road, the slurry filling up the cracks and providing a new and useful working surface. The slurry is provided with sufficient fines and aggregate Ito provide a non-skid surface as well as the desired thickness of the sealing coat.

The road treatment with asphaltic slurry restores the road grade, is fast to apply and economical in that it extends -the life of an existing road. However, difficulties have been encountered in the prior methods and apparatus Vof applying a uniform slurry to the road surface for sealing the same. One of the commonest means of mixing a slurry and then applying it to the road has been to use a conventional type of concrete mixer in which measured amounts of water, asphalt emulsion, aggregate and nes were placed at the start of the run and then the concrete type of mixer was moved along ahead of a screed. The slurry mixture was owed from the concrete type of mixer into the screed with the maintenance men spreading lthe same therein for ldistribution to the road. It was diflicult with this type of apparatus to control the quality of the slurry throughout an entire run and it was very necessary that the slurry be immediately applied as it could not remain in the mixer for extended lengths of time.

An object of the present invention is to provide a Vehicle in which the slurry is progressively made up as the vehicle moves along and progressively discharges the same therefrom, the vehicle having separate storage areas for a supply of water, asphalt emulsion, aggregate, and fines.

Another object of the present invention is to provide a vehicle yfor mixing and delivering a slurry to a road `surface, the system of mixing including means to lcontrol accurately the mixture of the water, asphalt emulsion, aggregate, and fines.

Ancillary to the preceding object, it is a further object of the present invention to provide a road treating vehicle in which the operators `of the same can have a visual indication of the proportion of mixture yof water and asphalt emulsion at any time during a run, adjustments being capable of being made at any time such adjustments are necessary.

Further, it is an object of the present invention to provide a system of mixing a lslurry in which the vehicle can be stopped at any time with the system closed down and yet the system can be started up again discharging at the same proportions prior to its shutdown without any major adjustment in its controls.

Still another object of the present invention is to provide a system of making or mixing a slurry, the system being self-contained on a vehicle in which the slurry is discharged, the system also including visual means to determine the total amount of asphalt emulsion utilized during a run.

Another object of the present invention is to provide Patented Oct. 18, 1966 ice an improved type of pug mill for mixing a road surface sealing slurry, the pug mill having means lfor thoroughly agitating and mixing the material prior to its discharge onto a road surface.

Ancillary to the preceding object, it is a further object of the present invention to provide a pug mill for mixing a sealing slurry, the pug mill utilizing paddle-type agitators having paddles which may be adjusted for pitch so as to determine the rate of flow of the material being mixed from the time it enters the pug mill until the time it is discharged therefrom.

These and other objects and advantages of the present invention will appear more fully in the following speciiication, claims, and drawings, in which:

FIGURE l is a perspective view of the vehicle of the present invention, the view being taken from a position to the left and rear of the vehicle;

FIGURE 2 is a view of the system for mixing the slurry on the vehicle of FIGURE 1, the view being substantially diagrammatic;

FIGURE 3 is an enlarged vertical sectional view through the pug mill of the vehicle -of the present invention, the view being taken :substantially on the line 3 3 of FIGURE 4; and

FIGURE 4 is a sectional view from the rear -of the vehicle and taken substantially on the line 4--4 of FIGURE 3.

`Referring now to the drawings wherein like characters or refe-rence numerals represent like or similar parts, the present invention utilizes .a conventional wheeled vehicle generally designated by the numeral 10 which may be a truck having the usual frame structure 12 on which is mounted the drivers cabin 14, engine 16, steering wheels 18 and tandem driving wheels 20; 'Mounted on the frame structure 12 is an asphalt emulsion tank 22 or reservoi-r having an inlet 24 for 'lling the same with asphalt emulsion. The .asp-halt emulsion tank 22 has a capacity in the order of 470 gallons of asphalt emulsion. Mounted closely adjacent the asphalt emulsion tank 22 on the frame structure 1-2 is a water tank or reservoir 26 having an inlet 28 for filling with water. The water tank has a capacity in the order of 470 gallons of water.

Carried on the frame structure 12 of the vehicle just behind the asphalt emulsion tank 22 and beneath the water tank 26 is a water cooled constant speed engine 30V, the controls for the engine being mounted at the operators platform 32 adjacent the rear of the vehicle. The water cooled const-ant `speed engine 30 is capable of driving a jack shaft 33 (FIGURE 2) which can be started or stopped by a master clutch (not shown) operable from the operators platform 32.- A more detailed explanation of the purpose of the mai-n jack shaft 33 to simultaneously drive the various units of the Islurry mixing and delivering vehicle will be discussed later in the specification.

Just to the rear of the water tank 26 is an aggregate hopper 34, the hopper having a capacity in the orde-r of 71/2 cubic yards of aggregate of a desired size or grade. The aggregate hopp-er 34 feeds aggregate into an endless conveyor belt structure 36 (FIGURE 2), the conveyor belt ystructure 36 dumping the aggregate from the hopper 34 into a pug mill mixer 38, las best shown in FIGURES 3 and 4. A vertically adjustable gate structure 40 extending around the lower portion of the hopper 34 determines the volume of .aggregate delivered t-o `the conveyor belt structure 36 and from there to the pug mill mixer 38. The rnore the gate struct-ure 40 is opened vertically or spaced from the conveyor belt structure 36, the more aggregate is delivered thereto and vice versa. Conveyor belt structure 36 is driven through a ysuitable chain drive URE 2, at a predetermined known speed, lthe chain drive 42 being driven through a clutch (not shown) by the main jack shaft 33.

At the re-ar of the vehicle is a second hopper 44 for mineral lines such as sand or the like. The capacity of the hopper 44 is in the order of 1000 pounds and the hopper is provided with a converging throat portion 46 in which a metering feed roller (not shown) is provided, the feed roller lbeing operated by a hydraulically operated motor 48. The hydraulically operated motor 48 contro-ls the speed of the metering feed roller in t-he converging throat 46 and thus the amount of fines delivered to the pug mill mixer 38 can `be accurately determined.

The pug mill mixer 38 is .provided adjacent its lower side near the center thereof with a discharge spout 50 swiveling on a vertical axis, the discharge spout enabling the slu-rry discharged from the .pug mill mixer to be evenly spread over the screed or squeegee 52. The screed 52 .is adjustable for various widths depending on the width of a road surface to be treated. It -is also adjustable vertically from the surface of the road by means of a hydraulic motor 56 ('FIGURE 2) so that different thicknesses of slurry can be laid yon -the road surface.

At this time, it will be understood that the slurry delivered by the vehicle 10 to the surface of the road may have varying deg-rees of viscosity depending on the proportions of asphalt emulsion, water, aggregate and fines. Where large holes must be filled to resurface an existing road, then more aggregate is added to provide a thicker coat that will ktill up the large holes and cracks. On the other hand, less aggregate is provided where the surface of the road is relatively new and uncracked and it is merely desired to provide a sealing coat to the road surface. In this instance, fines are fed to the asphalt emulsion yand Water mixture along with some aggregate, the ines providing a gripping surface for the iinished road. tin any even-t, and depending upon the type of surface being treated, it is necessary to maintain a uniform slurry throughout a run on a particular type of road surface. Even though the vehicle may `be stopped for periods of time, it must be able to be started up and the slurry delivered must be uniform with that previously laid if the condition of the road surface warrants such uniformity. By a novel system of controls, the slurry mixing and applying or distributing vehicle 10 of the present invention obtains these results, kas well as provid ing for changing the physical characteristics of the slurry as the vehicle is moving Where there are changes in the road surface being treated.

Referring now in detail to FIGURE 2, the various systems for feed-ing the asphalt emulsion, water, aggregate 4and lines in proper proportions Iare clearly shown. Thev asphalt emulsion tank 22 has Huid connecting means 58V extending between it and suitable nozzles 60, for example three. In more detail, the fluid connecting means 58 for' the asphalt emulsion tank 22 is provided with a shut off valve 62 just at the outlet from the tank 22, this valve permitting the tank to be isolated from the systemwhenit is desired to clean or ush the system. A ilter 64 is provided and after the asphalt emulsion passes throughy the filter emulsion pump Asphalt emulsion then passes under a lpredetermined pres- 64, it then ows into the inlet ofyan asphalt sure from the outlet of the pump 66 through a totalizing meter -68 which will give the operator the total amount of gallons used at any time so that he may have an indication of how much asphalt emulsion remains in the storage tank 22.

From the totalizing meter 68, the asphalt emulsion flows through a flow meter 70 located in the rear of the vehicle and visible from the operators platform 32. From the liow meter '70, the asph-alt emulsion flows through a selectively operable metering valve 72, also positioned within easy access of an operator on the platform 32. .The meter- 'ing valve 72 is set by the operator to give the desired gallons per minute -of asphalt emulsion required by a partic- 66 driven by the main jack shaft 33.`

ular slurry consistency. In order that this valve may be left set and not have to be reset each time the system is stopped and started, a plurality of shut off valves 74 are provided for each of the plurality Iof nozzles 60, all lof the shut off valves 74 being in series with the metering valve 72 and being capable of being operable by a single lever 76.

Since the pump 66 for the asphalt emulsion can pump more liquid than is discharged from the nozzles 60, a return system 78 from the outlet of the pump 66 to the asphalt tank 22 is provided. Liquid ii-ows through the piping of the system 78 when a pressure relief valve 80 therein opens.

The Water tank 26 is connected to the pug mill mixer 38 by means of a fluid connecting means diagrfammatically indicated at 82. In more detail, a water pump 84 is provided in the fluid connecting means 82, the pump 84 being driven by the main jack shaft 33, which, as mentioned before, is utilized to drive the asphalt emulsion pump 66 as well as the aggregate conveyor belt structure 36. The water pump 84 supplies the water under pressure to the pug mill mixer 3S by means of a spray bar (not shown in FIGURE 1 but diagrammatically shown `at 86 in FIGURE 2). After the Water is pumped from the water pump 84, it passes through a iiow meter 88 measuring the gallons of Water flowing per minute, the flow meter 'being located at the rear of the truck closely adjacent the iiow meter 70 so that the operator can simultaneously observe and check the proportions of Water and asphalt emulsion.

It will be noted that the water flows from the flow meter through a line 90 and valve 92 to a line 94. The line 94 leads directly to the spray bar 86, but it has in it a selectively operable metering valve 96 for controlling the amount of flow in the line 94 and in series with the same is a shut oi valve 98 for permitting the shutting off of water without changing the setting of the metering valve 96. A second water system having a line 100 extends from the line 82 on the inlet side of the meter to a spray bar 102 located beneath the vehicle and forward of the screed 32. The purpose of the spray bar 102 is to wet the road surface prior to the distributing of the slurry thereon so as to provide a better bond. The line 100 is provided with a metering valve 104 selectively operable to give the desired volume of gallons per minute as well as a shut oi valve 106 so that the spray bar 102 can be stopped or started without disturbing the volume setting of the valve 104.

Normally, the line 100 is connected to the line 82 for- Ward of the flow meter 88 and a valve 108 is provided therein which is normally open. When it is desired to obtain a reading on the gauge 88 for the flow to the meter bar 102, -a line is connected to line 100 and the l-ine 90 on the outlet side of the flow meter, the line 110 having a valve 112 which is normally closed. Additionally, the line 94 is connected forward of the flow meter 88 by means of a line 114 having a normally closed valve 116 therein. All lof the

valves

108, 112, 92 and 116 are operated simultaneously with the

valves

108 and 92 being normally open so that the iiow meter 88 is reading Vthe liow rate of the Water being supplied to the mixer. When it is desired to determine the amount of Water flowing to the spray -bar 102, then the operating handle is actuated so as to close the valve 108 and the valve 92 and open the

valves

112 and 116. Water going to the pug mill mixer 38 will then by-pass the ow meter 88 Whereas water going to the spray bar 102 will tiow through lthe iiow meter.

A hydraulic system is provided for operating both the motor 48 for feeding fines from the hopper 44 and the motor 56 for vertically adjusting the screed or squeegee 52. In more detail, a hydraulic pump 122 operable by the main jack shaft 33 causes hydraulic fluid from a reservoir 124 to ow through the line 126 under pressure to a valve means 128 operable by handles 130 and 132. By actuation of the handle 130 the hydraulic circuit from the line 126 Vmay be made through the line 134 to the hydraulic motor 40 and then return through the return line 136 to a lter 138 and from there back to the reservoir 1,24. On the other hand, when the other lever 132 is operated, the hydraulic circuit from the hydraulic pump 122 -can be operated thr-ough the li-ne 126 to the line 140 and to the hydraulic motor 56 and from there back to the return line 136 through the ilter 138 to the reservoir 124. Since the hydraulic pump 122 has a variable capacity, both

motors

48 and 56 may be operated simultaneously if it is so desired to change the screed during a run.

It will now be seen that the present invention provides a. wheeled vehicle for mixing and distributing a slurry to a road surface in accurately desired proportions. The system enables the operator to st-op the same without changing his volume settings and then st-art up again. Further, the operator has a visual indication at all times as to the exact proportions of water and asphalt emulsion being mixed in the pug mill 38.

The novel pug mill mixer 38 of the present invention is best shown in FIGURES 3 `and 4. It will be noted that the pug mill 38 includes an elongated chamber 142 extending transversely of the vehicle and which is divided longitudinally of the vehicle into two separate compartments 144 and 146 by a transversely extending baille 148. The baffle 148 is provided at each of its ends with openings or

apertures

150 and 152 so that the slurry being mixed in the compartment 146 will ow to the lower compartment 144.

In the compartment 146 there is provided an elongated paddle mixer 156 including .a shaft 157 having a plurality of paddle blades 158 mounted thereon. The shaft 157 is suitably journalled in the side walls 160 of the pug mill mixer 38, the shaft having ends extending therefrom `and provided with a sprocket for receiving a chain drive 160. The chain drive 160 is driven in time sequence with other units of the system from the main jack shaft 33.

vIt will be noted by specific reference to FIGURE 4 that the fines and Water will be entering the compartment 146 .at the end of the conveyor 36. The asphalt emulsion is also injected into the compartment at this point. The arrows in FIGURE 4 'represent the flow pattern of the liquids and material as they are being mixed from the center of the compartment 146 toward each of the side Walls 160 of the pug mill mixer 38. The resulting mixture then ows through the

respective openings

150 and 152 into the second compartment 144 where it is further mixed by a paddle mixer 162. The paddle mixer 156 has its paddle blades 158 so arranged that their pitch on the opposite sides of the center of the compartment is reversed to cause the spreading out of the slurry toward the

openings

150 and 152. Further, the blades 158 may be adjusted t0 either increase or decrease the rate of flow of the slurry toward the openings or

apertures

150 and 152. The paddle mixer 162 in the compartment 144 is substantially identical with the paddle mixer 156 except that its blades 164 on opposite sides of the center of the `compartment 144 are so arranged that when they rotate they force the slurry towards the center where it is discharged through the swivel spout 50. The paddle blades 164 are likewise adjustable and the shaft 166 is rotatably supported in suitable bearings in the side walls 160 with one end of the shaft having an extension on which is a sprocket, the sprocket having a chain drive 170 thereon which is driven oi of a sprocket on the shaft 157.

By providing two compartments for the pug mill, very accu-rate control and thorough mixing of the slurry can be obtained. Also, the rate of iiow of the slurry through the mill can be controlled so as to change the mixing time, the change being made by adjusting the paddle blades of each of the paddle mixers in the separate compartments.

Having set forth the nature, objects and advantages of the present invention, it will be perceived that certain modifications, changes and adjustments may be made without departing from the principles and spirit of the invention. Therefore, the terminology. used throughout the speciication and the details of the drawings are but for the purpose of description and not limitation, the scope lof the invention being defined in the claims.

What is claimed is:

1. In a vehicle of the class described for preparing a slurry and applying the same to seal a road surface, the improvement comprising: a vehicle frame structure; an asphalt emulsion tank, a Water tank, an aggregate hopper, and a fines hopper, all supported on said vehicle frame structure; means for mixing and distributing a slurry made from proportional amounts of asphalt emulsion, water, aggregate and fines; first fluid connecting means between said water tank .and said mixing means, said fluid connecting means including a water pump, and flow metering means for controlling the volume of ilow of water delivered to said mixing tank; a second fluid connecting means between said `asphalt emulsion tank and said mixing means, said secondv fluid connecting means including an emulsion pump and ilow metering means lfor controlling the volume of flow of asphalt emulsion; hydraulically operated motor means for feeding fines from said nes hopper to said mixing means; a hydraulic system including a reservoir and variable speed hydraulic pump for controlling said hydraulic motor and the quantity of fines delivered thereby; and conveyor means for delivering aggregate lfrom said aggregate hopper to said mixing means.

2. The vehicle as claimed in claim 1 including means to simultaneously operate said water pump, asphalt emulsion pump, hydraulic pump and conveyor means whereby the rate of delivery may be simultaneously changed for the water, asphalt emulsion, aggregate and lines.

3. The vehicle as claimed in claim 1 in which said flow metering means in said tirst Huid connecting means includes a metering valve means selectively set to control the volume of ow through said first fluid connecting means and a shut olf valve means in series with mete-ring valve means and selectively operable between an olf and on position; and in which said flow metering means of said second uid connecting means includes a metering valve means selectively set to control the volume of flow through said second fluid connecting means and a shut off valve means in series with the metering valve means and selectively operable between an off and on position.

4. The vehicle as claimed `in claim 1 including a irst ow meter in said irst connecting means and a second ow meter in said second fluid connecting means, both of said ow meters being simultaneously visible to the operator.

5. The vehicle as claimed in claim 1 including a totalizing meter positioned on the outlet side of said emulsion pump, said totalizing meter indicating the total amount of asphalt emulsion used from said asphalt emulsion tank.

6. The vehicle as claimed in claim 1 in which the said mixing and distributing means includes a mixing chamber and a screed positioned at the rear of the vehicle and beneath said mixing chamber, said screed being adjustable vertically.

7. The vehicle as claimed in claim 6 wherein said mixing chamber includes agitator means, and means to drive said agitator means simultaneously with said Water pump, asphalt pump, hydraulic pump, and conveyor means.

8. The vehicle as claimed in claim 6 including means to adjust said screed vertically, said means including a hydraulically operated motor, operable to raise and lower said screed, and means for driving said motor from said variable speed hydraulic pum-p, said last-mentioned means including a Valve selectively operable to connect said screed motor into and out of said hydraulic system.

9. The vehicle as claimed in claim 6 including a spray bar carried in front of said screed and means connecting said spray bar to said first uid connecting means whereby Water may be tapped therefrom to wet the 7 road in front of said screed prior to distribution of slurry onto the road surface.

10. The vehicle as claimed in claim 6 in which said mixing 'chamber extends transversely across the vehicle, said mixing chamber being provided With a transversely extending baffle dividing the same into two elongated compartments, the -irst of said compartments receiving the Water, asphalt emulsion, aggregate and lines at the middle thereof, a paddle mixer in said rst compartment -for moving the slurry outwardly from the center toward each side of said iirst compartment, said second compartment having `a paddle mixer therein and receiving the slurry at the sides thereof and moving the same toward the middle, said second compartment having a spout extending from the middle thereof for discharging the slurry into the screed.

11. In a pug mill for mixing a slurry of Water, asphalt emulsion, aggregate and fines, the improvement comprising a baffle Wall dividing said pug mill into a rst elongated compartment, 'and a second elongated compartment positioned vertically below `and offset horizontally with respect thereto, both of said compartments extending in a Igenerally horizontal direction, means for supplying the Water, asphalt emulsion, aggregate and iines to be mixed at substantially the center of said first compartment, agitating means in said lirst compartment for moving and mixing the slurry towards opposite sides of said -first compartment, outlet ports at each end of said baille whereby slurry being mixed in said irst compartment is transfer-red at each of the ends of said second compartment, and

agitator means in said second compartment for moving References Cited by the Examiner UNITED STATES PATENTS 441,563 11/1890 Hotchkins V94-40l 1,727,340 9/ 1929 Flory 94-42X 2,657,092 lO/1953 Jones 94-44 X 2,867,421 l/ 1959 Camm 94-42 X 3,016,809 l/ 1962 McNeill 94-44 X 3,199,423 Y 8/ 1965 Dickey 94--44 N. C. BYERS, Assistant Examiner.

CHARLES E. OCONNELL, Primary Examiner.

Claims

1. IN A VEHICLE OF THE CLASS DESCRIBED FOR PREPARING A SLURRY AND APPLYING THE SAME TO SEAL A ROAD SURFACE, THE IMPROVEMENT COMPRISING: A VEHICLE FRAME STRUCTURE; AN ASPHALT EMULSION TANK, A WATER TANK, AN AGGREGATE HOPPER, AND A FINES HOPPER, ALL SUPPORTED ON SAID VEHICLE FRAME STRUCTURE; MEANS FOR MIXING AND DISTRUBUTING A SLURRY MADE FROM PROPORTIONAL AMOUNTS OF ASPHALT EMULSION, WATER, AGGREGATE AND FINES; FIRST FLUID CONNECTING MEANS BETWEEN SAID WATER TANK AND SAID MIXING MEANS, SAID FLUID CONNECTING MEANS INCLUDING A WATER PUMP, AND FLOW METERING MEANS FOR CONTROLLING THE VOLUME OF FLOW OF WATER DELIVERED TO SAID MIXING TANK; A SECOND FLUID CONNECTING MEANS BETWEEN SAID ASPHALT EMULSION TANK AND SAID MIXING MEANS, SAID SECOND FLUID CONNECTING MEANS INCLUDING AN EMULSION PUMP AND FLOW METERING MEANS FOR CONTROLLING THE VOLUME OF FLOW OF ASPHALT EMULSION; HYDRAULICALLY OPERATED MOTOR MEANS FOR FEEDING FINES FROM SAID FINES HOPPER TO SAID MIXING MEANS; A HYDRAULIC SYSTEM IN-