AU657104B2 - Improved road repair machines - Google Patents

Description

57/104 Po/00/01 Regulation 3.2 s a u c sc COMMONWEALTH OF AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT Name of Applicant: Actual Inventor(s): Address for Service: Invention Title: JAMES PHILIP TURNBULL and MARGARET TURNBULL JAMES PHILIP TURNBULL

AHEARNS

Patent Trade Mark Attorneys, GPO Box 185, Brisbane, 4001 "IMPROVED ROAD REPAIR MACHINES" The following statement is a full description of this invention, including the best method of performing it known to us: r Field of the Invention The present invention relates to the general fields of road and sealed ground surface construction or repair, and of fluid dispensing and spraying apparatus.

Object It is an object of the present invention to go at least partway towards providing novel or improved road repair apparatus, or at least to provide the public with a useful choice.

Statement of Invention In one aspect the present invention provides ground surface repair apparatus, including: a container for granular material; a tank for liquid; :means to provide pressurised airflow; and an eductor including an inlet, a jet and an outlet, said inlet opening into a chamber, and said jet projecting into said chamber at substantially right angles to said inlet, said chamber having a constricted portion, and said outlet leading out from said chamber beyond said constricted portion, wherein S said airflow is in use directed by said means into the chamber ooooo through said jet, and out through said constricted portion and said outlet; further including an active conveyor between said container for granular material and the inlet of said eductor; whereby granular material can be entrained in said airflow ,,by activation of said conveyor, and prevented from entrainment AJ Tr

K

0 1 3 in said airflow by deactivation of said conveyor.

Preferably the apparatus includes a dispensing hose and nozzle connected with said outlet, the tank for liquid having an outlet and liquid dispensing hose arranged to dispense said liquid at said nozzle, whereby said liquid can be entrained in said airflow at said nozzle. Preferably also said eductor inlet is comprised of a hopper, and said active conveyor is comprised of an endless belt conveyor, extending substantially horizontally between said container for granular material and said hopper. Preferably also said jet is movable relative to said chamber, whereby the length by which said jet projects into said chamber can be adjusted.

In accordance with a preferred embodiment, the ground surface repair apparatus as aforedescribed is mounted on a wheeled vehicle carrying an hydraulic pump, oil tank and air compressor constituting said means to provide pressurised K: ~airflow. Tn that embodiment, said active conveyor is suitably S" powered by said hydraulic pump, the speed of said conveyor being thereby adjustable. In all instances said constricted portion of said chamber preferably has a ceramic lining to resist abrasion.

The invention also embraces a method of repairing a ground e surface using apparatus as aforedescribed and including the steps of: o 2 cleaning said ground surface by blowing Pth said pressurised airflow; sealing said ground surface by blowing a liquid emulsion from said tank for liquid onto said ground surface with said airflow; 3a filling hollows in said ground surface with a mixture of said granular material and said liquid emulsion, by blowing said mixture into said hollows with said airflow; and capping said filled hollows by blowing additional granular material thereon with said airflow, wherein the entrainment of said granular material in said airflow is controlled by operation of said active conveyor.

Other features and aspects of the invention may be made apparent in the following description of a preferred embodiment.

Preferred Embodiment The following is c description of a preferred form of the present invention, given by way of example only, with reference to the accompanying drawings, in which: FIGURE 1 shows the preferred repair vehicle in perspective view; FIGURE 2 schematically illustrates the aggregate e outlet valve arrangement in the apparatus of FIGURE I.

In its preferred form, the present invention provides a S0 ~repair vehicle for repairing roads and other asphalt surfaces, wherein high pressure air, liquid emulsion and solid aggregate such as gravel can be discharged separately or in a mixture Sthiough a single nozzle, and wherein a venturi valve is used to draw the solid aggregate into the outlet hose to the nozzle.

Sealed ground surfaces, such as car parks, footpaths and more particularly roads, generally require periodic repair as traffic passing over them breaks up the surface and pick holes in it. Once a pot hole has been created in such a surface, it j. k~Ai"T -7 N T J grows relatively rapidly as the edges become more easy to break away, and the impact of passing vehicles on the surface at that point becomes progressively greater. It is therefore desirable to have mobile repair equipment available, to repair such damage relatively quickly and with as little disruption to normal traffic flow as possible. The preferred, form of the present invention g e b* C C

C•

C

o *2 **f -4as shown in FIGURE 1 comprises truck-mounted road repair apparatus wherein compressed air, liquid emulsion and a solid aggregate are all provided from the same vehicle, and dispensed from the same outlet, so that no other vehicles or equipment are required to undertake a standard road repair, the personnel in the truck being able to complete the repair using only the equipment carried or. the truck. By this means, the number of vehicles and amount of equipment required on a road repair site may be minimised, reducing traffic obstruction to a minimum, and the logistic difficulties in moving a road repair unit from one site to another may also be minimnised. The apparatus includes a hydraulic pump and oil tank; an air compressor; an emulsion tank 11 of approximately 300 litre capacity; an aggregate hopper 12 of approximately 1 to 3 cubic metre capacity; a feed conveyor 13 powered by the hydraulic pump; a large aggregate and air hose 14; a smaller emulsion hose 15; a nozzle 16 at which the hoses 14 and 15 are joined; and an, eductor 20, The hoses 14 and and nozzle 16 are preferably supported by a jointed, swinging arm 17 at the rear *of the vehicle.

In use, a pothole is repaired by first tsing the air compressor and a blower 18, 20 and blowing air through the hose 14 and nozzle 16, to throw dirt, debris, water and the like out of the pothole. A valve is then opened on the smaller hose 15 to e0 Go* add emulsion from the tank 11, and seal the inside surface of the pothole, filling small cracks and hollows, and providing a smooth, sticky coating inside the hole and over damaged parts of the rim. The conveyor 13 and eductor 20 are then operated to add a flow of solid aggregate such as gravel or sand through the large hose 14, along with the air and emulsion. The combination is sprayed under pressure into the pothole to fill it. Finally, the valve on the smaller hose may be closed so that a coating of "dry" aggregate can be applied over the 0 see:filled pothole, to give a substantially dry, non-sticking surface while the 30 emulsion is setting.. By using a single nozzle for all parts of the operation, the process can beutad relatively swift and efficient. Blowing the aggregate into C the pothole under strong air pressure not only makes rolling unnecessery, it can actually provide a more dense, more !strong repair. Furthermore, the amount of aggregate required can be more accurately judged, because it is compacted at the same time as it is dispensed into the hole.

1i'203AUC2.N91fJp Feeding a solid aggregate such as gravel through apparatus of this type can however be damaging to the apparatus. In particular, the valve controlling the flow of aggregate into the system will generally wear out very quickly, compared with a valve controlling liquids or gases, and a mechanical pump such as a rotary conveyor used to push the aggregate down the hose 14 will also wear out very quickly. Dust or grit may also cause clogging and jamming in the moving parts, and both the valve and the pump may be difficult to operate or start if the apparatus is turned off while those parts are still filled with aggregate.

These problems may be overcome in the present invention by the use of a venturi eductor 20, comprising both valve and pump. As shown in FIGURE 2, the eductor 20 uses an air flow from the blower 18 to the hose 14 to suck solid aggregate into the hose 14 through an inlet 21 at right angles to the flow. In use, the feed conveyor 13 dispenses aggregate into a hopper leading to the inlet 21, from the main aggregate hopper 12. The eductor 20 is comprised of the inlet 21, an air jet 22, and a constriction tube 23 immediately downstream of the jet 22.

The various parts may be made from any of a variety of materials, such as 'o carbon steel or stainless steel, and in particular, the constriction tube 23 may .have a ceramic lining to resist abrasion. The eductor 20 has no moving parts, 20 and is therefore much less susceptible to wear.

*0 The feed conveyor 13 may simply be turned off to halt flow of aggregate into the inlet 21, so that the eductor 20 only pulls more air in through the inlet 21, when the apparatus is needed for blowing rather than for dispensing aggregate.

This allows the apparatus to be switched between blowing and dispensing ,modes without any duplication of parts, or valve apparatus. The rate of aggregate flow or volume of aggregate being dispensed can also be adjusted, up to a maximum determined by the size of the eductor and rate of air flow, simply by adjusting the speed of the feed conveyor 13.

For specialised applications, two or more feed conveyors 13 leading from "separate bins or hoppers 12 might be provided, to feed different aggregates into the inlet 21 as required. Alternatively, gate valves might be provided on separate hoppers 12, dispensing onto the same feed conveyor 13.

As a further alternative, the hopper 12 migat feed directly into the eductor inlet 5203AUC2.N91/jp 6 21, with a gate valve to shut off aggregate flow when the apparatus is to be used as a blower. This is considered to be less preferable at present, because the valve used to shut off flow may be subject to wear and/or clogging, and consequently may present a weak point in the system.

The preferred system provides a means for impelling and controlling a flow of solid, abrasive aggregate, without any mechanical apparatus in the path of flow. The air jet 22 may be adjustable lengthwise within the body of the eductor although this is probably not necessary for most applications of the present invention. As the jet 22 projects further into the eductor 20, the volume of material drawn into the eductor decreases, and the discharge pressure increases. Conversely, if the jet 22 is withdrawn, the input volume increases and the discharge pressure decreases. With regard to road repair applications, the density of aggregate is unlikely to vary sufficient±y to warrant such adjustment, and similarly the optimal discharge pressure for packing the aggregate into a pothole, without causing it to ricochet out again, is unlikely to vary from one job to another.

Liquids might be fed into the eductor 20 to be mixed with the solid aggregate and/or the air flow, out this is considered to be less preferred at present. By introducing liquids such ooooo as the emulsion from the emulsion tank 11 at the outlet nozzle 16, the large hose 14 is kept relatively dry and clean, avoiding caking or build-up of material on the inside.

It will be apparent that the described and illustrated embodiments may be subject to further modifications of constructional detail and design as will be apparent to persons 6a skilled in the art, without departing from the broad scope and ambit of the invention as definec~ by the appended claims.

9.

9 9 9 .9 9* 9 9 9 99 9 9 9 C *9 9 9 9.

99 9 9 9 9* 9 9 9 9 .9 9 999...

9

~XJ-.

S.'

p.,

V

Claims (9)

1. Ground surface repair apparatus, including: a container for granular material; a tank for liquid; means to provide pressurised airflow; and an eductor including an inlet, a jet and an outlet, said inlet opening into a chamber, and said jet projecting into said chamber at substantially right angles to said inlet, said chamber having a constricted portion, and said outlet leading out from said chamber beyond said constricted portion, wherein said airflow is in use directed by said means into the chamber through said jet, and out through said constricted portion and said outlet; further including an active conveyor between said container for granular material and the inlet of said eductor; Swhereby granular material can be entrained in said airflow 0 by activation of said conveyor, and prevent6d from entrainment in said airflow by deactivation of said conveyor. 0* e

2. Ground surface repair apparatus as claimed in Claim i, wherein a dispensing hose and nozzle is connected with said outlet, and wherein the tank f-r liquid has an outlet and liquid dispensing hose arranged to dispense said liquid at said 0 a nozzle, whereby said liquid can be entrained in said airflow at said nozzle.

3. Ground surface repair apparatus as claimed in Claim 1 or Claim 2, wherein said eductor inlet is comprised of a hopper, and wherein said active conveyor is comprised of an endless 8 belt conveyor, extending substantially horizontally between said container for granular material and said hopper.

4. Ground surface repair apparatus as claimed in any one of Claims 1 to 3, wherein said jet is movable relative to said chamber, whereby the length by which said jet projects into said chamber can be adjusted.

Ground surface repair apparatus as claimed in any one of Claims 1 to 4, mounted on a wheeled vehicle carrying an hydraulic pump, oil tank and air compressor constituting said means to provide pressurised airflow.

6. Ground surface repair apparatus as claimed in Claim wherein the active conveyor is powered by said hydraulic pump, ee the speed of said conveyor being thereby adjustable. rJ o *e e

7. Ground surface repair apparatus as claimed in any one of Claims 1 to 6, wherein said constricted portion of said chamber S has a ceramic lining to resist abrasion. 0

8. A method of repairing a ground surface using apparatus as claimed in any one of Claims 1 to 7, including the steps of: cleaning said ground surface by blowing with said pressurised airflow; sealing said ground surface by blowing a liquid emulsion from said tank for liquid onto said ground surface with said airflow; filling hollows in said ground surface with a mixture of 9 said granular material and said liquid emulsion, by blowing said mixture into said hollows with said airflow; and capping said filled hollows by blowing additional granular material thereon with said airflow, wherein the entrainment of said granular material in said airflow is controlled by operation of said active conveyor.

9. Ground surface repair apparatus substantially as herein described with reference to the accompanying drawings. A method of repairing a ground surface substantially as herein described. DATED this 16th day of November, 1994. :JAMES PHILIP TURNBULL and MARGARET TURNBULL S' By their Patent Attorneys AHEARNS e6 i** e *eeee ie e o* ABSTRACT A repair vehicle (10) for repairing roads and other asphalt surfaces, wherein high pressure air, liquid emulsion from a tank (11) and solid aggregate from a hopper (12) such as gravel can be discharged separately or in a mixture through a single nozzle (16) and wherein a venturi valve (20) is used to draw the solid aggregate into the outlet hose to the nozzle. 9 k 0. Figure 1