US3771893A

US3771893A - Pavement material applying apparatus

Info

Publication number: US3771893A
Application number: US00134137A
Authority: US
Inventors: O Miller
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-04-15
Filing date: 1971-04-15
Publication date: 1973-11-13
Anticipated expiration: 1990-11-13
Also published as: CA977111A

Abstract

A vehicle having a resin blending and spraying assembly and an aggregate spreader assembly mounted thereon. The two assemblies are operated simultaneously and located so that aggregate is deposited on a resin coating applied on the pavement by spray means. The blending and spraying system includes a static and dynamic mixing means for blending multi-component resin compositions and also a novel resin flow and recycling arrangement. The aggregate spreader assembly is of lightweight construction and includes a feed roll which is arranged to assume a minimum of the weight of the aggregate 1n the aggregate spreader hopper.

Description

Unite States Patent [1'91 Miller Nov. 13, 1973 [54] PAVEMENT MATERIAL APPLYING 3,016,809 1/1962 McNeil] 94/44 X APPARATUS 2,241,863 5/1941 Lett 2,278,948 4/1942 Rodli 94/44 [76] Inventor: Orville L. Miller, 28, 116 Apache 3,245,329 4/1966 Nagin 94/22 Dr., Wheaton, 111. 60187 [22] Filed: Aim 15, 1971 Primary ExaminerNile C. Byers, Jr.

' Att0rney-Rummler & Snow [21] Appl. No.: 134,137

[57] ABSTRACT U-S- Cl. A vehicle having a resin blending and spraying assemlnt- CL- t and an aggregate spreader assembly mounted of Search thereon The two assemblies are operated simulta- 222/414; 239/66 neously and located so that aggregate is deposited on 1 a resin coating applied on the pavement by spray [56] References Cited means. The blending and spraying system includes a UNITED STATES PATENTS static and dynamic mixing means for blending multi- 1,892,566 12/1932 Coppock 222/414 X Component resin compositions and also a novel resin 2,430,020 11/1947 Johnson 239/668 fl and recycling arrangement The gg g 2,737,3l9 3/1956 Rayburn 222/414 X spreader assembly is of lightweight construction and 2, 12/1953 Price, 222/414 X includes a feed roll which is arranged to assume a min- Carpenter... imum of the of the aggregate 1n the aggregate 3,100,425 8/1963 Cartwright.. 94/44 spreader hOPPeL 3,l83,803 5/1965 Gierhart 94/44 3,026,780 3/1962 Stein 94/44 4 Claims, 19 Drawing Figures PAIENTED um 13 I975 sum 1 BF 4 //Vl/ENTOR.

ORV/LLE. L. MILLER B mw fv EH v5 1 PAVEMENT MATERIAL APPLYING APPARATUS BACKGROUND OF THE INVENTION The present invention relates to highway pavement surfacing apparatus and more particularly to an apparatus for applying a resin coating and a layer of aggregate such as stone chips, sand or the like on a highway pavement.

These resin coatings are applied for various purposes, among which are to overcome two basic problems. The first problem is, for instance, associated with bridge deck pavement. The second, for instance, is associated with the tendency of highways to. become slick and slippery and cause skidding.

A great many concrete bridges have been built in recent years. These bridges are built using a steel reinforced pavement. Extensive deterioration of this type bridge construction is occurring because of the action of moisture and in particular, salt water resulting from the winter use of de-icing salts. I

The salt solution may break down the concrete pavement or may penetrate surface cracks to react with the bridge reinforcing steel. This reaction causes expansion of the reinforcing steel because of the rust formation causing the concrete to pop out. At the same time, the corrosion of the steel reduces the effective strength of the bridge deck within a very few years.

The resin coatings have been applied as a membrane on these bridge structures to provide a surface which is completely impervious to penetration by moisture or salt solutions. The coating permanently adheres to the concrete pavement surface and has sufficient strength and toughness to resist penetration and displacement by asphalt paving machines which may subsequently apply asphalt resurfacing thereon.

Aggregate particles such as stone chips are sparsely deposited on the resin membrane immediately after applying the membrane and before it cures and hardens. The aggregate serves to key the asphaltic overlay to the pavement and thereby to prevent the formation of a slippage plane. The asphalt overlay may be eliminated if the aggregate is in the form of a hard wear-resistant material which is securely embedded in the membrane. The wear-resistant material must, of course, be capable of withstanding the traffic of automotive vehicles of all types.

The second problem of localized slick and slippery conditions such as occurs at curves, traffic lights, railroad crossings and the like is also solved by a resin and aggregate coating as described above. The aggregate particles are selected to be of a very hard, durable material such as crushed calcined bauxite. As described heretofore, the aggregate is deposited before the membrane is cured or hardened.

The aggregate particles are generally selected to be of relatively small particles usually in the range A; to inch size to provide a smooth ride and at the same time provide a high friction skid-resistant surface. The coarse textured surface provides channels through which rain water can escape under tire traffic so that the hydroplaning tendency of high speed traffic is eliminated.

Many coating materials have been used for this purpose of which the thermo-setting resins, especially the epoxy resins, have been particularly successful in meeting the requirements. These resin systems are generally multi-component in the case of the epoxy resins. Ac-

cordingly, the application system requires means for thoroughly blending the components prior to applying the coating on the surface.

These prior resin application systems have used only static turbulence type blending apparatus such as the packed column type. This type static mixing is inadequate for the reason that satisfactory mixing is achieved only at the lower end of the viscosity range normally used in spraying.

Moreover, the prior blending systems were constructed such that excessive internal volume caused unnecessary waste of mixed resin and flushing solvent each time the machine was shut off. By a unique compact arrangement and sizing of pumps, lines, blenders and valves involving minimizing length and diameter of lines and a continuously downward flow permitting complete evacuation by gravity draining, the volumes of wasted resin and flushing solvent necessitated on shut down and the time required have been reduced to a small fraction of those required in prior machines. This economy feature extends the practical use of ma chine application to relatively small areas which were formerly applied by hand methods because of high operational cost of prior machines.

A further drawback in the prior systems has been caused by the aggregate applying apparatus. The prior aggregate spreading apparatus was generally of heavy weight and cumbersome structure which necessitated its being operated as a separate unit with its own wheels for support. These supporting wheels, if positioned outboard so as to straddle the resin and aggregate application, prevented applications up close to curbs and raised medians and the like and prevented making adjacent applications since this would necessitate one wheel riding on uncured resin. If the supporting wheels are positioned inboard of the ends of the spreader as in most conventional aggregate spreaders, the wheels riding on uncured resin cause undesirable wheel tracking and necessitate a great excess of aggregate in order to avoid pickup of resin on the tires. Prior machines in which both sprayer and aggregate spreaders are carried on and operated from a single vehicle are generally capable of handling only sand or fine aggregate (usually less than A inch in particle size) and are not capable of precise control of the rate or uniformity of aggregate deposition so that an excess of aggregate must be applied to insure complete coverage. When an excess of aggregate is applied over and above the optimum for adequate coverage, a porous condition known as honeycombing can occur, and a starvation of resin at the pavement surface can occur due to the high attraction of the uncured resin for the aggregate particle surfaces.

Moreover, the location of the aggregate feed roll with respect to the outlet opening of the hopper was such that a substantial weight and pressure of aggregate in the hopper was imposed oh the feed roll. This occurred because a large portion of the upper surface of the feed roll was exposed to direct contact with the aggregate in the hopper. For this reason, the feed roll in prior machines was of extremely heavy and rigid construction to prevent deflection or bending of the roll. Deflection causes a non-uniform discharge opening and a corresponding non-uniform distribution of the aggregate. The control of the rate of disposition of aggregate in prior machines was by a scrape-off action of a feed gate adjustably positioned at a preset distance from the rotating feed roll. This forced feed grinding action which is aggravated by the aforementioned burden on the feed roll, further tended to cause deflection or bending of the feed roll and necessitated a relatively higher power requirement and a heavily constructed power train. It was to overcome these inherent disabilities that the present invention was conceived.

SUMMARY OF THE INVENTION By the present invention, there is provided a vehicle having mounted thereon an improved arrangement for blending and spraying the resin and curing agent for application as a surface coating, and improved arrangement for spreading chips on the surface coating and means for doing both in a single continuous operation. The construction of the various components of the arrangements is such that the equipment may be easily accommodated on a light or medium duty flat bed truck.

The lightweight construction is made possible in part by the structure of the chip spreader. The lightweight construction of the chip spreader is necessary in order to permit its use, without supporting wheels, in combination with the resin spraying unit, on a single vehicle such as a small or medium sized utility truck. A resin spray bar is positioned rearward of the rear vehicle wheels and the aggregate spreader is even further rearward. This relationship makes it essential that the weight of the aggregate spreader be held to a minimum to effect the best possible load distribution on the supporting vehicle. The positioning of a chip storage hopper forward of the rear axle further facilitates this weight distribution on the supporting vehicle.

A further feature of the invention resides in the epoxy resin blending and spraying system. The blending system provides means for mechanically as well as statically mixing the resin and the curing agent. This makes it possible to achieve adequate mixing over the complete range of viscosities at which the resin may be BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of the flat bed truck having an epoxy resin sealer applicator embodying the structure of the present invention mounted on the frame thereof;

FIG. 2 is a cross-sectional view taken generally along the lines 2--2 of FIG. 1 and showing in particular a fragmentary end view of the piping extending between the epoxy resin and curing agent supply sources and the homogenizing unit for blending the resin and curing agent;

FIG. 3 is an enlarged fragmentary view of the piping taken generally along the lines of FIG. 2;

FIG. 4 is a cross-sectional view taken generally along the lines 44 of FIG. 1 showing in particular the mixing unit for statically mixing the epoxy resin and curing agent;

FIG. 5 is a side elevational view of the homogenizing unit;

FIG. 6 is a cross-sectional view of the homogenizing unit taken generally along the lines 6-6 of FIG. 5;

FIG. 7 is an exploded view of the homogenizing unit impellers;

FIG. 8 is an enlarged view of the shear teeth shown in the encircled portion of FIG. 7;-

FIG. 9 is a fragmentary perspective view of the spreader assembly for spreading the aggregates;

FIG. 10 is a cross-sectional view of the spreader assembly taken generally along the lines 1010 of FIG.

FIG. 11 is a fragmentary side elevational view of the bearing on which the chip spreader feed roll is mounted and showing in. particular the manner in which the bearing is mounted on the frame;

FIG. 12 is a cross-sectional view through the feed roll showing in particular the manner in which the expanded metal surface is applied on the base cylinder;

FIG. 13 is a fragmentary perspective view of the spray bar and the hanging strap arrangement therefor;

FIG. 14 is a cross-sectional view taken generally along the lines 1414 of FIG. 13;

FIG. 15 is an enlarged side elevational view of the power drive system of the present invention;

FIG. 16 is a cross-sectional view taken generally along the lines 16 -16 of FIG. 15 and showing the connection between the lever arrangement for disconnecting the power drive from the spreader roller;

FIG. .17 is an enlarged fragmentary view of the drive system showing the belt to feed roll drive system in driving engagement with the drive pulley and showing the drive belt disengaged in phantom line position of the components;

FIG. 18 is an enlarged cross-sectional view taken generally along the lines 18-l8 of FIG. 15; and

FIG. 19 is a schematic flow diagram of the resin and the curing agent blending and spray system.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, the resin blender and chip spreader apparatus 10 is shown applied on a flat bed frame 11 of a motor vehicle 12. The apparatus 10 comprises generally an epoxy resin blending and spraying system 13 and an aggregate distribution system 14.

The resin blending and spraying system 13 is regulated and controlled so as to supply a resin coating at a predetermined uniform rate. The resin coating is formed by blending two or more fluid components at a predetermined ratio such as a resin component with a curing agent component prior to spraying on a surface so as to cause the hardening or setting of the resin after it has been sprayed. To this end, as shown in FIGS. 1, 28 and 19, the resin blending and spraying system 13 comprises a supply of the resin and curing agent maintained in

separate supply tanks

16 and 17. The

supply tanks

16 and 17 have

separate distribution lines

18 and 19, respectively, which merge at ajuncture 54 from whence the mixture flows to a mixing unit 21 and a homogenizing unit 22.

The distribution line 18, as shown in FIGS. 1, 2 and 3, comprises a generally horizontal flexible hose 23 extending from an outlet 24 at the tank 16. The flexible hose 23 is connected to an input port 26 of a positive displacement metering pump 27 having means providing an automatic bypass through a pressure relief valve 28 when the pump discharge pressure reaches a predetermined value, as for example 1 pounds per square inch. The relief valve operates only as a safeguard against excessive pressure and is not an operational part of the system. Connected at an outlet of the pump I 27 is a T-coupling 31 to one end of which there is connected a fitting having a thermometer 32 which permits the reading of the temperature of one of the component streams. Connected to the other end of the T- coupling 31 is a three-way valve 33 which is manually controlled, as more fully to be explained hereinafter, to

switch the flow between the line 52 connected to the port 38 of positive displacement pump 39 at the otherend. The positive displacement pump 39 includes a pressure relief valve 41 which functions the same as the pressure relief valve 28. The outlet port 42 of the pump 39 is connected to the stem portion of a T-coupling 43. Inserted in one end of the T-coupling 43 is a thermometer 44 which measures the temperature of the other component stream. Connected to the opposite end is a manually operated three-way valve 46 to permit the flow through the line 53 to the mixing unit 21 or recycled back to the inlet 45 of the tank 17 by way of a pipe As shown in particular in FIGS. 2 and 3, the

threeway valves

33 and 46 are actuated to their different positions by a common actuating means 48 which is in the form of a substantially U-shaped handle of which the legs 51 are fastened to the projecting ends of the respective valve stems extending outwardly of the housings of the

valves

33 and 46.

The three-

way valves

33 and 46 connected by the common actuating handle 48 are thus mechanically coupled for instantaneous and simultaneous action to change the flow of the component streams either (a) to merge the streams, blend and spray or (b) return each stream back to the

storage tanks

16 and 17.

As shown in particular in FIGS. 1, 4 and 19, the flow from the

output lines

52 and 53 of the three-way valves ""33 and 46 merges at a T-coupling 54 which is connected to an elbow coupling 56 connected to the input end 57 of the mixing unit 21. The mixing unit 21 (FIG. 4) includes an outer sleeve 58 of iron pipe or the like and an inner lining 59 of an open mesh material such as expanded metal which may be spiraled within the outer sleeve 58. The open mesh expanded metal lining 59 creates a swirling and impingement turbulence action on the epoxy resin and the curing agent so that the latter are mixed by the stationary members of the mixing means. This type of mixing is generally described as As shown in particular in-FIGS. 5-8, the homogeniz- I ing unit 22 comprises an open sided housing 62 including a cup-shaped section having a generally tangentially projecting outlet 63. Enclosing the open side of the housing 62, including the outlet 63, is a cover plate 64. Fixed to a base of the housing 62 is a disk 66 having an inner row and outer row of a plurality of equally spaced and

upstanding projections

67 and 68, respectively. The inner and

outer projections

67 and 68 are angularly staggered relative to each other, and are of unequalnumber relative to each other to eliminate vibration due to simultaneous shear action of individual teeth. Fixed to one end of a shaft 69 rotatably journaled on the cover plate 64 in a bearing 71 is a second disk 72 having inner rows and outer rows of angularly staggered and spaced

projections

73 and 74 radially spaced at greater distance than the

projections

67 and 68, respectively, of the fixed disk. Thus, as shown, the outer row of projections 74 of the rotatable disk 72 is disposed outboard of the outer row of projections 68, while the inner row 73 is disposed between the inner and

outer rows

67 and 68 of the stationary disk 66.

Fixed to the outer end of the shaft 69 for rotating the disk 72 is a pulley 76 about which there is trained a drive belt 77. The drive belt 77 is driven by a pulley on the power source.

The statically mixed epoxy resin and curing agent enters the homogenizing unit 22 via an axially located inlet 78 extending through the base of the housing 62 and the disk 66. The statically mixed resin and curing agent is thus subject to the shearing action caused by the interaction of the

projections

67, 68, 73 and 74 on the rotating disk 72 and stationary disk 66. The dynamically and mechanically mixed epoxy resin and curing agent, as shown in FIGS. 1, 13, 14 and 19, flows to pressure gauge P at outlet 63 of homogenizer 22 and then through a hose 79 to a spray bar 81 having a plurality of discharge openings 82 which are spray nozzles of standard design..The spray bar 81 is suitably fastened to extend tranversely of and inboard of the rear end of the vehicle frame by hanger straps 83, as shown in FIGS. 13 and 14, which can be adjusted to raise or lower the spray bar 81.

Referring now to FIGS. 1 and 9-12, there is shown the aggregate distributing system 14 of the present invention. The system comprises generally a storage hopper 84 mounted on the frame lla secured at its lower end to bed frame 11, and an aggregate spreader assembly 85. The aggregate stored in the hopper 84 is transferred to the spreader assembly 85 by way of a pair of inclined chutes 86. The quantity of stones deposited on the chutes 86 may be controlled by a variable opening slide-gate 87 of standard construction. The rate of feed is controlled in accordance with the demand dictated by the rate of disposition of the aggregate onto the resin binder surface applied by the spray bar 81.

The spreader assembly 85 is of lightweight construction to permit the combining of both spraying of resin and application ofthe aggregate in a single operation on one vehicle. Both the spray bar 81 and aggregate spreader assembly 85 are located rearward of the rear wheels of the supporting vehicle in order to eliminate wheel pick-up of uncured resin and wheel tracking on spread aggregate. The spreader assembly 85 should be at a distance, for example, 3 feet rearward of the spray bar 81 sufficient to provide a time interval between resin and aggregate application to (I) allow air bubbles to escape, (2) to facilitate a leveling out of imperfections inherent in nozzle sprayed coatings, and (3) to increase viscosity of the resin by temperature reduction through loss of heat to pavement surface. The increase in viscosity controls the tendency of the resin due to strong surface attraction to migrate excessively to the aggregate particle surfaces thereby leaving a coating thickness on the pavement surface incapable of protecting it from salt and water. It is readily apparent that the aggregate spreader 85 overhanging the rear wheels by several feet, it must be as light in weight as possible in order to maintain proper load distribution between front and rear wheels on the supporting vehicle. The spreader assembly 85 comprises a substantially rectangular open frame 88 which is attached to the rear end of the truck bed frame 11. A spreader hopper 89 is formed by side sheets 91 between which a slope sheet 92 is fixed by means of angle irons 93. The slope sheet 92 may be sloped at about the same angle as the chutes 86 of about 45. Disposed on the opposite end of the frame 88 is an angularly and radially adjustable gate sheet 94 having a pair of angle irons 96 attached along the opposite edges thereof. Pivotally attaching the gate sheet 94 to side sheets 91 and to frame 88 are pivot pins 97 which have off-center eccentric heads projecting through angle irons 96.

By rotating pivot pins 97, the feed gate opening 107 between the lower edge 106 of gate sheet 94 and slope sheet 92 can be varied. Said mechanism is hereinafter called the first feed control means.

For supporting the lower end of gate sheet 94 and to control the feed gap opening 107a between the lower terminal edge 106 of gate sheet 94 and the periphery of the feed roll hereinafter described, stop bolts 98 are threaded into projecting lugs 99 fixed to the side sheets 91.

Intermediate the length of the spreader hopper 89 there is fixed a horizontal support bracket 101 to which there is pivotally attached a clevis end 102 on one end of a threaded bolt 103 which extends through an opening in the gate sheet 94. Threaded on the bolt and engaging the under side of the gate'sheet 94 is a nut 104 which provides support for the gate intermediate the length thereof.

Said mechanism for controlling feed gap 107a is hereinafter called second feed control means.

Disposed mainly beneath the gate sheet 94 and extending lengthwise of the opening 107 offset rearwardly is a feed roll or spreader 108 which serves to smoothly and uniformly spread the chips on the previously applied resin sealing coat. The feed roll 108 comprises a hollow cylinder 109 made from a lightweight material such as aluminum. Wrapped about the outer circumference of the cylinder 109 is an open mesh expanded metal covering 111, as shown in FIG. 12. The longitudinal edges 112 of the covering 111 are embedded in the cylinder 109 and may be adhered therein by the same adhesive. The expanded metal surface provides an indented surface on which the aggregate is picked up as it emerges from the slot 107 and is uniformly spread onto the resin sealer. At the same time, the expanded metal and aluminum tube combination maintains the weight of the spreader assembly 85 at a minimum. It is to be noted that the lightweight construction is made possible in part because of the offset relationship wherein the feed roll 108 is offset from feed gate 107 and under the gate sheet 94 to protect it from the force and weight of the aggregate in the hopper and also to eliminate the grinding action inherent in prior devices thereby smoothing the flow of aggregate to the feed roll. Thus the power required is minimal. Only the weight of aggregate which has emerged from the feed gate opening 107 is imposed on the feed roll 108. This minimizes the structural rigidity requirements which are required to maintain the feed roll 108 within the load deflection limits necessary to maintain a uniform gap between the edge 106 of feed gate 94 and the feed roll 108.

The feed roll 108 includes a shaft 113 extending through plates at each end thereof and which are rotatably joumaled in bushings 114 and the shafts are mounted on the frame 88. As shown in FIG. 11, the bushings 114 are mounted in a housing 116 having a pair of slots 117 which accommodate pins 118 projecting from the frame. Yieldably holding the bushing housing 116 in a limit position, as dictated by the periphery of the feed roll in contact with the angle iron 92a, the pins 118 engaging the slots 117, is a pair of tension springs 119. One end of the spring 119 is fixed to the bushing housing 116 and the other end to the frame 88. This yieldable mounting of the spreader bushings 114 provides a continuous and constant contact pressure between angle iron 92a which forms the terminal edge of the slope sheet 92 and the feed roll 108 and permits the feeding of occasional non-uniform and large aggregate particles.

The feed roll 108 is rotated clockwise, as viewed in FIG. 10, by a sprocket 121 fixed to one of the shaft ends 113 and driven by a sprocket chain 122 driven by a second sprocket 123 carried on a shaft 124 rotatably mounted on the upper part of the frame 88. The shaft 124 is driven by the power train.

The power train, as shown in particular in FIGS. 1 and 15, includes a power source which may be a gasoline engine 125. Driven by the gasoline motor 125 is a sprocket 126 and pulley 12?. A sprocket chain 128 is trained over the sprocket 12 6 and

sprocket wheels

129 and 131 fixed to the shaft of the

positive displacement pumps

27 and 39, respectively.

Pump sprockets

129 and 131 are appropriately sized relative to each other to effect the appropriate volume ratio of the component streams for the particular resin being used. Disposed between the pump 39 and the engine 125 in engagement with the sprocket chain 128 is a tachometer 134..The tachometer 134 driven by sprocket 135 (see FIG. 15) can be used to control rate of resin application by controlled variation of rotational speed of pumps.

The drive belt 77 is trained over the pulley 127 and the pulley 76 connected to the homogenizing unit 22 and is used to power the latter. An idler pulley 136 may be used to maintain the belt 77 taut.

FIGS. 1, 9 and 15 to 18 illustrate the means for driving the aggregate feed roll 108. As shown, a belt 137 extending between a pulley 138 mounted on the pump shaft 132 and a pulley 139 carried by the shaft 124 (FIGS. 9 and 15) drives the sprocket 123 which in turn drives the feed roll sprocket 121 by means of the sprocket chain 122. For providing a rapid disconnect between the feed roll 108 and the pump sprocket 129, there is provided a disconnect linkage 140. As shown, the disconnect linkage 140 includes a pair of

arms

141 and 142 of which one end of each is turnably pinned to the upper end of rigid arm 145 disposing said arms to pivot at the center line of pump shaft 132. The other end of the

arms

141 and 142 are provided with flanged rollers 143. The

arms

141 and 142 are angularly displaced and arranged so that the roller 143 does not engage the belt 137 while the latter is in driving engagement with the pulley 138. Holding the

arms

141 and 142 in driving engagement as shown in FIG. 17 solid lines is one end of a lever 144 and one end of a second shorter lever 146. The other end of the shorter lever 146 is pivotally connected intermediate the ends of the lever 144. The other end of the longer lever 146 is connected to a brace 147 of which one end is fastened to the framing and the other end is journaled to the shaft 124 which carries the pulley 139 for driving the feed roller 103.

Connected between the framing and the shaft 124 is an over center toggle-like linkage assembly 148. As shown in particular in FIGS. and 16, the toggle linkage 148 includes a link 149 of which one end is pivotally connected to the framing. The other end is connected by means of a pin 151 to a U-section link 152. Also pivotally connected to the pin 151 is one end of a second U-section 153 to the other end of which there is connected one end of an intermediate link 154. The other end of the intermediate link 154 is pivotally attached to the brace 147. The other end of the link 152 is also connected to the brace 147. Rigidly fixed to the link 152 is a handle 156.

Upon turning the handle 156 counterclockwise as viewed in FIG. 15, the common pivot pin 151 moves upwardly and at the same time causes the brace 147 to turn clockwise. Upon turning clockwise, the brace 147 connected to the shaft 123 flexes the latter upwardly so that the pulley 133 also moves upwardly in the direction of the arrow. At the same time, the brace 147 lifts the lever 144 upwardly so that the

arms

141 and 142 are rotated to the position shown in phantom in FIG. 17 so that the belt 137 is out of engagement with the pulley 138. In this manner, the power is cut off to the feed roll 108 to stop rotation thereof.

Linkage

153 and 154 form a second over center toggle which in the disengaged position to said members extend in a straight line.

At the same time, the spreader linkage disconnect 140 is positioned in the engaged position as shown in full lines in FlGS. 15 and 17 so that the drive belt 137 is operative to drive the pulley 139 and thereby the pulley 139 fixed to the drive shaft 124. The drive sprocket 121, sprocket chain 122, and the sprocket 123 are then operative to rotate the spreader 108 for applying the stone chips.

In operation, the epoxy resin and curing agent, if necessary, may be heated to the temperature required for the desired viscosity by heating means, not shown. The speed of the motor 125 is then adjusted by well known means and is maintained constant by a governor to achieve the desired resin application rate by controlling the output at the

positive displacement pumps

27 and 39. The pump speed and thereby the application rate may be determined at the tachometer 134.

The resin and curing agent are blended and spraying is initiated prior to initiating the actuation of the feed roll 108. This is accomplished by moving the handle 48 to simultaneously cause the resin and curing agent to flow from the

tanks

16 and 17 through the

lines

18 and 19 into the static mixing unit 21'and homogenizing unit 22 from wherein the blended mixture is applied on the surface by means of the spray pipe 81. The spray pipe 81 is disposed forward of the spreader hopper assembly 85 so that the power thereto need not be actuated until the hopper outlet is over the applied binder surface.

The rate of aggregate disposition is controlled by (l varying both the angular and radial position of the gate sheet 94, (2) by increasing or reducing rotational speed of the feed roll 108, and (3) by increasing or reducing the forward speed of the vehicle. Then the feed gate 87 at the storage hopper is adjusted to keep the spreader hopper 89 sufficiently filled to keep feed gate opening 107 amply covered with aggregate. The aggregate freely flows downwardly on the chutes 86 into the spreader hopper 89. The aggregate accumulates over the feed gate opening 107 and is stopped from further flow by the periphery of the feed roll 108. The feed roll 108, because of its rough indented surface provided by the expanded metal, carries the aggregate initially upward and then over the circumference as it rotates and drops the stones substantially vertically onto the previously coated surface of resin binder. The resin binder with the aggregate deposited thereon then cures to a hard surface with the aggregate firmly embedded therein.

After the application is completed, the handle 48 in the blender system 13 is turned to simultaneously recycle the epoxy resin and curing agent through the

lines

34 and 47 to the

respective tanks

16 and 17. The spreader roller 108 is stopped by turning the toggle linkage 148 such that the drive between the

pulleys

138 and 139 is terminated, as explained heretofore. At the same time, further flow of the aggregate from the storage hopper 84 is cut off by closing the slide gate 87. Extremely uniform aggregate distribution and accurate control of rate of application (lb. per sq. yd.) permits the depositing of optimum amount. This eliminates the excessive displacement of the uncured resin by an excessive thickness of aggregate and eliminates or minimizes loss of expensive aggregate and clean-up of loose aggregate after the resin has cured.

1n the operation of the machine, the sequence of actions by the operator are as follows:

1. Preliminary to start-up,

storage tanks

16 and 17 are simultaneously filled using

pumps

27 and 39 from storage, usually 55 gallon drums which have been pre-' viously heated (if necessary) to temperatures sufficient to reduce viscosity to within the sprayable range of 75 to 150 centistokes at 140 F. Pumps 27 and 39 are then operated for a few minutes with three-

way valves

33 and 46 in recycle position to assure uniform temperature conditions in

storage tanks

16 and 17 and to ascertain the temperature of each component by reading

thermometers

32 and 44.

2. The aggregate storage hopper 84 is filled and gate 87 is opened allowing aggregate to flow by gravity through chutes 86 to fill the spreader hopper.

3. Having established the desired rates of application of the particular resin and aggregate, the operating variables, such as pump speed, forward speed of vehicle, aggregate feed openings and rotational speed of feed roll, are determined'by calculation or from prepared graphs.

4. Having thus established the magnitudes of the four operating variables, the machine is operated by the following sequence of actions:

a. With

pumps

27 and 39 operating with

valves

33 and 46 in recycle position,-the pumps are brought to the desired operating speed by throttle adjustment of motor to the correct speed as indicated on the tachometer.

b. The truck driver causes the vehicle to move forward at the desired rate of speed which he controls by well known tachometer or other control methods.

c. As the spray bar reaches the line where the application is to begin, the operator moves handle 48 to the spray position which initiates the spraying of mixed resin on the pavement in the manner previ ously described herein.

d. As the machine moves forward to where the aggregate spreader reaches the point of initial spraying, the operator then moves lever 156 which starts the operation of feed roll and chip spreading operation.

e. As the spray bar reaches the line where the application is to stop, the operator moves handle 48 on the spray unit to the recycle position thus terminating the spraying operation.

f. As the chip spreader reaches the end of the application, the operator moves the lever 156 to disengaged position, which stops the operation of the chip spreader.

g. Successive adjacent applications are continued in a like manner until the desired area has been treated.

5. Immediately on shut-down after completion of spraying or at any shut-down of more than a few minutes duration (depending on the pot life of the particular resin), the fluid system from the point of mixing of the components to the spray bar nozzles must be drained of mixed resin and subsequently flushed with a suitable solvent.

Although but one specific embodiment of this invention is herein shown and described, it is to be understood that numerous details may be altered or omitted without departing from the spirit of this invention as defined by the following claims.

I claim:

1. in a vehicle having a system for applying a resin fixed slope sheet on which said aggregate is deposited.

from said conveyor means, said fixed slope sheet having a terminal edge substantially in contact with the periphery of said rotatable roller, a sloping gate sheet having a terminal edge adjacent said slope sheet, means mounting said gate sheet for movement toward and away from said slope sheet to selectively space said terminal edge from said slope sheet to provide a first control means, and means further mounting said feed gate for turning movement about an axis parallel to the longitudinal axis of said feed roller in a selective angular position to provide a second control means wherein said terminal edge of said gate sheet is maintained a selective distance from the periphery of said rotatable roller, said gate sheet substantially covering the upper surface of said roller thereby to shield the feed roller from the weight of the aggregate in the spreader hopper and permit the free flow of aggregate as it passes through said feed gate to said roller.

2. The invention as defined in claim 1 wherein said feed roller comprises a hollow cylinder having an outer surface formed with an open mesh material.

3. The invention as defined in claim 2 wherein said cylinder is made from aluminum.

4. The device according to claim 1 wherein the slope sheet lies in a radial plane defined by the radius of the roller at an angle of from about 30 to 45 from hori zontal, and the terminal end of the gate sheet is spaced from the slope sheet to provide a feed gate opening, and the terminal end of the gate sheet is spaced from the periphery of the feed roll to provide a'feed gap opening relative to the feed roll whereby the control action of said feed control means occurs in conjunction with the controlled rotation of the feed roll.

Claims

1. In a vehicle having a system for applying a resin coating and a system for simultaneously spreading aggregate on a pavement surface coated with a resin, said aggregate spreader system comprising a storage hopper, a spreader hopper, means to convey aggregate from said storage hopper to said spreader hopper, a rotatable feed roller, said spreader hopper including a fixed slope sheet on which said aggregate is deposited from said conveyor means, said fixed slope sheet having a terminal edge substantially in contact with the periphery of said rotatable roller, a sloping gate sheet having a terminal edge adjacent said slope sheet, means mounting said gate sheet for movement toward and away from said slope sheet to selectively space said terminal edge from said slope sheet to provide a first control means, and means further mounting said feed gate for turning movement about an axis parallel to the longitudinal axis of said feed roller in a selective angular position to provide a second control means wherein said terminal edge of said gate sheet is maintained a selective distance from the periphery of said rotatable roller, said gate sheet substantially covering the upper surface of said roller thereby to shield the feed roller from the weight of the aggregate in the spreader hopper and permit the free flow of aggregate as it passes through said feed gate to said roller.

4. The device according to claim 1 wherein the slope sheet lies in a radial plane defined by the radius of the roller at an angle of from about 30* to 45* from horizontal, and the terminal end of the gate sheet is spaced from the slope sheet to provide a feed gate opening, and the terminal end of the gate sheet is spaced from the periphery of the feed roll to provide a feed gap opening relative to the feed roll whereby the control action of said feed control means occurs in conjunction with the controlled rotation of the feed roll.