US 3828478 A
A fluid-jet-abrasive device and system according to the present invention comprises a fluid-jet gun having a trigger means adapted to operate a pressure-control valve, to allow fluid to flow therethrough and pass out of the spray-nozzled distal end of the gun under extremely high pressures and velocities, the fluid under pressure being supplied through an interconnected flow system having a water-tank reservoir, a pumping unit being coupled at one end thereof to the water tank and at the opposite end to the pressure inlet of the gun by means of a recirculating conduit system. The gun includes a separate inlet port through which various types of abrasive materials are passed and mixed with the fluid to be sprayed under high pressure, the abrasive material being stored in a tank having a material-flow regulator operably attached thereto for automatically controlling the feeding of the abrasives to the gun.
Claims available in
Description (OCR text may contain errors)
United States Patent 1191 Bemis Aug. 13, 1974 FLUID-JET-ABRASIVE DEVICE AND Primary Examiner-Donald G. Kelly SYSTEM Attorney, Agent, or FirmFrancis X. Lo Jacono, Sr.  Inventor: Edwin G. Bemis, 1357 La Serena m, Brea, Calif. 92621  ABTRACT A fluid-jet-abrasive device and system according to  Flled: June 1973 the present invention comprises a fluid-jet gun having  APPL 373 4 7 a trigger means adapted to operate a pressure-control v valve, to allow fluid to flow therethrough and pass out of the spray-nozzled distal end of the gun under ex-  US. Cl. 51/11, 51/12 tremely high pressures d velocities, the fl under  Int. Cl. B24c 7/00 pressure being Supplied through an interconnected  Field of Search 51/8, 11, i2 flow System having a watemank reservoir, a pumping unit being coupled at one end thereof to the water  References C'ted tank and at the opposite end to the pressure. inlet of UNITED STATES PATENTS the gun by means of a recirculating conduit system. 1,658,645 2/1928 McGee 51/8 UX The gun includes a Separate inlet P through which 2,200,587 5/1940 Tirrell 51 /12 X various types of abrasive materials are passed and 2,372,058 3/1945 Campbell 51/11 UX mixed with the fluid to be sprayed under high pres- 2,577,465 12/1951 Jones .L 51/8 sure the abrasive material being tored in a tank hav- 2,938,305 5/1960 BiPeS 51/12 ing a material-flow 1 regulator operably attached 3*407'538 10/1968 Ashwonh 5 1/ 11 thereto for automatically controlling the feeding of the 3,768,210 10/l973 Johnson.... 5l/l2 abrasives to the g 3,79l,078 2/1974 Fleisher 5l/l2 X 18 Claims, 14 Drawing Figures Power Drive fin Pumps 40 hllafi Pirssura 77/ 0 It) Wo/er Plan I 46 res/v:
feservo/r 28 z En g l ,m
PATENIE we: 31914 SHEEI 1 OF 4 PAIENIEmum 31924 3,828,478
sum u or 4 FLUID-JET-ABRASIVE DEVICE AND SYSTEM BACKGROUND 1. Field of the Invention This invention relates generally toa tool and a system for removing paint, rust, scale and the like from the outer surfaces of workpieces; and, more particularly, it pertains to such a tool and a system adapted for use wherein the fluids and abrasive materials are intermixed within the tool and expelled at extremely high pressures and velocities.
2. Description of the Prior Art As is well known in the art, various problems and difficulties have been encountered in providing an apparatus having suitable means whereby a pollution-free, fluid-abrasive process can be operated under simple and average conditions. Up to the present time, the most common devices for removing asperities from the surfaces of the workpieces have incorporated various machines that provide the very old air-sand, drysandblasting methods whose cloud of dust is frowned upon by ecologists and pollution-control departments, as well as individuals who happen to live or work near sandblasting operations,
As an example of some of the existing problems encountered, there is the removal of painted traffic markings from the streets and highways of city, county and state projects. Thus, with the use of a dry-sandblasting unit, clouds of dust are formed, creating not only an ecology problem but a traffic hazard where areas and lanes of traffic are blocked for excessive time periods. Hence, numerous complaints are filed by motorists and shopkeepers alike, and there is a high incidence of damage suits filed as well.
Accordingly, it can be seen that the use of drysandblasting methods is rapidly becoming restrictive, and new technology is now required. Ecology and pollution-control groups have been pressing the sandblasting industry to find a successful solution to the contamination problem.
Until the applicant's development of the fluidabrasive process herein disclosed, there was, to his knowledge, no replacement method fast enough to compete with dry-sandblasting methods.
SUMMARY The present invention discloses an apparatus and a high-pressure fluid system that will provide a means for removing paint, rust, scale and other asperities from the surfaces of various workpieces, such as traffic markings on streets and highways; cleaning of paint and marine growth from all types of marine vessels in preparation for new coatings; treating large structural steel elements used by the building industry; and the exposing of rock aggregate by erosion on the surfaces of new concrete buildings.
The above apparatus comprises a fluid-jet gun operably disposed within a high-pressure fluid system and adapted to receive various abrasive materials which are intermixed with the fluid to provide a dust-free process heretofore unobtainable in the industry.
The fluid-jet gun comprises a gun-type grip handle having a trigger means disposed therein for operable engagement with a high-pressure control valve positioned at the proximal end of the gun barrel, with a spray nozzle being secured to the distal end thereof.
Positioned intermediate the gun grip handle and the nozzle there is disposed a support handle which is also held by one hand of the operator or, it may be affixed to a stationary support, depending upon the particular application by the apparatus.
The high-pressure valve control includes an inlet and an outlet passage, the inlet passage being connected within the fluid system to receive the necessary fluid and pressure during operation of the device, the outlet passage being connected to the return line of the fluid system so that the fluid recirculates back through the system when the gun is not in'an operating mode. Thus, no waste of fluid can occur during a non-operating condition.
Included within the high-pressure fluid system is a water-storage tank, to receive flow from the outlet of the gun, and a centrifugal pump to transport the fluid from the storage tank back to a high-pressure pump which provides the required pressure to operate the apparatus, both pumps being operably connected to a power drive, such as an internal-combustion engine.
When the apparatus is in a working mode, the nozzle chamber is so designed as to receive an abrasive material such as sand, glass beads or metal shots, which is then-transported thereto by means of an inherent vacuum condition generated within the nozzle chamber.
The gun includes an inlet passage that communicates with the chamber and is connected by a conduit to an abrasive-reservoir tank which supplies the various abrasives to the gun. The abrasive is fed by gravity to the vacuum line whichis provided with a material-flowcontrol regulator disposed between the reservoir and the vacuum line. This regulator will not allow the abrasive material to discharge from the tank unless a jet stream is produced in the nozzle of the gun; thus, clogging of the vacuum line is prevented.
OBJECTS AND ADVANTAGES The present invention has for an important object a provision whereby paint, rust, scale and other asperities can be easily and quickly removed from various workpieces without polluting the surrounding area in which the apparatus is operated.
It is another object of the present invention to provide a fluid-jet device and system that is capable of high pressures at 1,000 to 20,000 P.S.l.
It is still another object of the present invention to provide a fluid-jet device that combines the use of a high-pressure water flow with an abrasive material, and that is more efficient to operate and gives a dust-free operating condition.
It is a further object of the invention to provide an apparatus of this character whereby operating time for any given assignment is considerably decreased, thus making it more economical to operate.
It is still a further object of the invention to provide an apparatus of this character that is easy to service and maintain.
Still another object of the invention is to provide an apparatus of this character that includes a materialflow-control regulator that has been heretofore unobtainable.
It is still another object of the invention to provide an apparatus of this character that is simple and rugged in construction.
Other characteristics, advantages and objects of this invention can be more readily appreciated from the following description and appended claims. When taken in conjunction with the accompanying drawings, this description forms a part of the specification wherein like references and characters designate corresponding parts in several views.
DESCRIPTION OF THE DRAWINGS Referring more particularly to the accompanying drawings, which are for illustrative purposes only:
FIG. 1 is a side-elevational view of the present invention included within a diagrammatic flow system;
FIG. 2A is an enlarged, fragmentary, sectional view showing the handle and pressure-control valve of the present invention;
FIG. 2B is a similar view to that of FIG. 2A and a con tinuation thereof showing the nozzle of the present invention;
FIG. 3 is a cross-sectional view taken along line 3 3 of FIG. 2A;
FIG. 4 is a cross-sectional view taken along line 4 4 of FIG. 2A;
FIG. 5 is a partial view of the pressure-control valve in an operating mode;
FIG. 6 is a perspective view of the rear bushing plug;
FIG. 7 is a perspective view of the front bushing plug;
FIG. 8 is a cross-sectional view taken substantially along line 8 8 of FIG. 28;
FIG. 9 is a cross-sectional view taken on line 9 9 of FIG. 28;
FIG. 10 is, also, a cross-sectional view taken along line 10 10 of FIG. 2B;
FIG. 11 is an enlarged partial view of the materialflow regulator;
FIG. 12 is a perspective view of a replaceable shield; and
FIG. 13 is a perspective view of the nozzle-supporting block.
DESCRIPTION OF THE PREFERRED EMBODIMENT Referring more particularly to the drawings, there is shown in FIG. 1 a fluid-jet gun, indicated generally at 10, said gun being illustrated as connected within a high-pressure fluid system. This fluid system includes a fluid-storage tank 12 from which fluid is pumped by means of a centrifugal pump 14 through conduit 16 into a high-pressure, triplex water pump 12, both pumps being driven by a power drive, indicated at 20. A suitable gasoline-operated engine has been used for the power drive 20, said engine having a pair of drive belts 22 and 24 which are respectively coupled to pumps 14 and 18 by pullies 26, 27, and double pulley 28.
Accordingly, said water pump 18 forces fluid (in this case, water) through conduit 30 which is connected to the inlet side of gun 10 by removable couple 32 attached to pipe fixtures 34, said fixtures being directly secured to said gun 10 whereby the high-pressure fluid enters therein. The operation thereof will be hereinafter described in more detail. However, the return-flow cycle is completed only when the gun 10 is in a nonoperating mode, at which time the flow of water is returned to storage tank 12 by means of a second set of pipe fixtures 35 affixed to the outlet side of said gun 10,
whereby said pipe fixture s ;,35 are coupled by asuitable coupling means 36 to a return conduit 38 which returns said water to the storage tank 12.
It should be mentioned at this time that an alternative system can include a gas 40 which is disposed within the high-pressure fluid system, such as seen in FIG. 1, and would be controlled by a valve 42, permitting highpressure gas flow to enter conduit line 30 to comingle with the high-pressure flow of water as it leaves pump Gases may be introduced into the flow system downstream of the high-pressure fluid pump 18 and upstream of the outlet jet of the high-pressure fluid-system, as indicated in FIG. 1. Gases such as carbon dioxide, nitrogen, oxygen, etc., may be introduced and comingled in a liquid or gaseous state with the fluid stream. As the comingled fluid and gas emerge from the high-pressure jet to virtually atmospheric pressure, the gas expands creating exceptionally high velocities, supplementing and increasing the fluid and abrasive velocities to several thousand feet per second as they pass through the sand-entrainment nozzle 130. Thus, the augmented energy imparted to the abrasive by the expanding gas or gases will provide an abrasivecleaning power not possible in any other system.
Thus, with the basic flow system described, we now refer to the detailed description of the fluid-jet gun 10, as seen in FIGS. 2A and 28. There is illustrated in FIG. 2A a high-pressure-control valve, generally indicated at 50, comprising a housing 52 having a generally T- shaped configuration wherein the horizontal portion thereof is a somewhat tubular member 54 having a pair of oppositely-disposed bores 56 and 58, respectively, with a reduced-diameter bore 60 interposed therebetween, forming shoulders 62 and 63, respectively. Inserted within bore 56 is a flow-return bushing 64 which fitssnugly therein, and is restricted in its movement by shoulder 62 of bore 56 and a threaded end cap 65. Said bushing 64 includes annular grooves 66 and 68 in which there are received O-rings 70 and 72, respectively, whereby pressure leaks are avoided. In addition to said return-flow bushing or means, there is provided a flow-discharge bushing or means, generally indicated at 75, said bushing being snugly fitted within bore 58 of housing 54 by an O-ring 76 received in an annular groove 77, and held in place by threaded coupling 78 and shoulder 63 of bore 58;
Each of said bushings 64 and is provided with concentric bores 80 and 82, respectively, wherein said bores communicate with the intermediate bore 60 of housing 54, said bore 60 being defined therebetween as a receiving chamber 84. Slidably received within the aligned concentric bores 80 and 82 is a slide valve, generally indicated at 85, having defined at its forward end thereof a contiguous pair of valve spools 86 and 88, respectively, adapted to be positioned in bores 80 and 82. The opposite end of said valve is slidably disposed in cap 65, to which there'is also mounted by nut 92 a gun-like handle,indicated generally at 90.
This handle is adapted with a trigger means which comprises a trigger 94 pivotally connected to handle 90 at its upper end by any suitablemeans 96, and operably pinned at 98 to the exposed end of valve 85, whereby said valve can be made to slide from one mode of operation to another. Included within the trigger means is a biasing means whereby both'the trigger 94 and the valve 85 is forced forward to provide a nonnally closed control valve (non-operating mode), said biasing means being shown as a plunger 100 spring loaded by spring 102 disposed withinthe handle 90, whereby said plunger is in direct engaging contact with the exposed valve stem 103.
Referring now in particular to FIG. 2A, there is a slidable valve 85 positioned in a non-operating mode; i.e., valve spool 88 is biased to its forwardmost attitude, thereby closing off access to bore 82 of bushing 75 by means of O-ring 104 to chamber 84. In turn, however, said adjacent'spool 86 is so positioned that a positive communication between bore 80 and chamber 84 is provided.
Thus, when the high-pressure flow system is activated, as previously described and shown in FIG. 1, fluid pressure is forced through pipe 34 into inlet port 106 which directly connects to chamber 84, and passes therethrough into bore 80 around spool 86 and out of a plurality of radial apertures'108 disposed about an annular channel 110 of bushing 64. 1
An outlet passage 112 communicates with the annular channel 110 and, thus, permits a return flow of the water back through pipe 35, thereby recirculating through the system until trigger 94. is manually biased by a gripping motion moving the valve 85 rearwardly to an attitude as shown in FIG. 5. At this time, the valve is considered to be in an open mode; i.e., spool 86 has now moved to obviate access of the water to bore 80 of bushing 64 by means of O-ring 114, thus repositioning O-ring 104 to allow water flow from pipe 34 to traverse through chamber 84 and into bore 82 of bushing 75. As the water flow enters bore 82, there is provided a plurality of radial apertures 116 disposed in an annular channel 118, whereby the pressurized fluid is passed therefrom into elongated horizontal slots 120. Each of said slots are aligned with and correspond to respective apertures 116. (See FIG. 4.)
To prevent'any back pressure from occuring, an end 'wall 122 is provided at the forward end of bore 82.
With wall 122 so disposed, the piston valve 85 is provided with a central relief bore .124, whereby said valve can freely slide within the bushing 64 and 82..
Thus, the flow of fluid will continue from slots 120 through passage 126 of coupling 78 into conduit 128, from which it passes and is received in a spray-nozzled means, generally indicated at 130, said spray-nozzle means being disposed at the distal end of the jet gun 10.
Referring now to FIGS. 28, 8', 9 and 10, there is shown a detailed construction of the spray-nozzled means 130 comprising a rectangular, box-like housing 132 having a removable, interchangeable, housing sleeve 134 disposed at the forward end of the housing. Removably fitted within the opposite end of the housing 132 is a nozzle-support block 136 which is locked therein by a set screw 138. The block is provided with a central bore 139 having both open ends internally threaded, as indicated at 140 and 142.
Received within the threaded-end 140 is conduit 128 from which the fluid under pressure is received and passes therethrough in nozzle 144, the nozzle being threaded in end 142. It should be herein noted that a nozzle of a suitable type is used to provide a flat, highpressure spray 145, as shown in FIG. 2B, and a wide horizontal configuration as seen in FIG. 8 thus, insuring a wide, brush-like stroke when in operation. Due to the particular high-pressure system as hereinbefore described, as the water spray egresses from the distal end of the housing, it can be generated to provide between 1,000 to 20,000 PSI.
After the high-velocity, high-pressure, water spray has been established and is issuing from said spray housing, there is at this time an injection and intermingling with spray 145 an abrasive material that enters the housing through inlet passage 146 of duct 148, said duct being an integral part of said housing.
Hence, there is provided an abrasive-material reservoir defined by tank 150, as seen in FIG. 1, said tank being operably communicated with said inlet duct 148 by means of a conduit 152. One end of said conduit is adapted with a suitable coupling means, as indicated at 154, with the opposite end thereof connected to an outlet, material-flow regulator, indicated generally at 156. Said flow regulator is inter-disposed between'said conduit 152 and said reservoir 150. A more detailed description of said regulator will hereinafter be presented.
Accordingly, as the extremely high-pressure flow issues from the nozzle 144 in the form of a high-velocity stream of fluid, there is established an area of pressure lower than ambient pressure, this area occurring in the chamber 160 of housing 132 at the junction of passage 146 with said housing. Hence, a vacuum condition is created throughout the flow system of the abrasive material leading to the reservoir 150.
Generally, a venturi disposed in the nozzle housing would be needed to provide the vacuum with the-system. However, this would not allow for the free, uninterrupted, high-pressure flow of the fluid spray and said mixture to issue from the nozzle end with the impact needed for the required end results. Hence, it should be noted that the high vacuum is directly created by the particular configuration of the fan spray 145, that being a spray having a substantially pyramidal shape wherein the base portion thereof is equal to the height and width of the rectangular opening of the nozzle, as illustrated in FIGS. 2B and 8. Thus, it can be seen that the spray is enlarged at its base adjacent to the open end just prior to its total egress. Due'to the enlarged base of the spray coming into contact with the inner walls of the housing, there is provided a very rapid drop in pressure throughout chamber 160, allowing the abrasive material to freely flow into the. nozzle and become a part of the fan spray to abrasively impinge upon a workpiece to be cleaned at velocities heretofore unobtainable.
Thus, it can be seen that, as the control valve 50 is operated by means of the trigger 94, the water is permitted to flow through nozzle 144, creating the vacuum condition and causing a flow of abrasive material to enter housing 132, thence comingling with the spray and issuing from the spray housing, as indicated in FIGS. 28 and 8.
Due to the comingling of the water 162 and abrasive material 164 adjacent the nozzle outlet, the abrasive material causes wear in the lower wall 165 and, therefore, a'U-shaped, wear plate 166 is positioned therein whereby the abrasive wear is effective only on said replaceable wear plate 166.
Further, as the mixed spray is ejected through the housing, wear could also present a problem; but here, also, a second wear member 168 is disposed and is defined as a rectangular, box-like, tubular member having four sides to protect the internal areas of the housing that come into contact with the mixed abrasive spray.
This tubular member is, also, replaceable and, in addition, provides a means by which housing sleeve 134 is mounted to form the complete spray-housing means 130. I
Referring now to FIG. 11, there is illustrated a more detailed view of the material-flow regulator 156. Depending from the bottom of tank 150 is an outlet nipple 170 having threaded thereto a valve 172 which is opened just prior to activating the apparatus, whereby the abrasive material will flow therethrough and out of depending pipe 174.
The flow regulator 156 comprises a funnel-like cup 176 and includes depending pipe 174 as an element thereof, to provide an automatic control of the abrasive into conduit 152. The automatic control regulator operates in conjunction with the opening and closing of the control valve 50. Thus, the operation of the regulator allows the abrasive material, such as sand particles, to discharge from pipe 174 into receptacle or cup 176 and down through nipple 178, which is connected into the vertical opening of a T-joint 179. Sand joint 179 receives conduit 152 on its downstream side while the upstream side receives a pipe 153 which is opened to ambient pressure. When the high-pressure fluid system is recirculating the water back to the storage tank 12, valve 50 is in a closed mode, with no vacuum occurring in chamber 160. Therefore, no flow of sand through conduit 152 can occur.
At this time, the sand 164 will back up into cup 176 to a point where the level of sand indicated at 180 rises just above the discharged end of pipe 174, as seen in FIG. 11. Due to the ambient pressure being equal over the surface of sand at 180 to that of the sand stored in the reservoir 150, the discharge of sand from the reservoir stops, as stated, at approximately the level indicated at 180 in cup 176. lt should also be noted that the sand does not flow out of pipe 153, and this is also due to the ambient pressure entering the open end 182.
lnversely, however, the flow of sand through conduit 152 is activated when said control valve 50 is positioned in an open mode, creating a vacuum in chamber 160, thus reducing the pressure with respect to the ambient pressure and allowing the sand to once again flow therethrough, with the higher ambient pressure entering both through the cup 176 with the sand and through the pipe 153.
This system is capable of accepting all US. standardsized particles, from 16 through 90 mesh sizes. The abrasive materials will vary, depending on'the working I conditions as well as the composition of the workpiece being affected by the impinging particles against the surface of the workpiece. As previously mentioned, the workpiece could be a road surface, a concrete structure, or a metal structure, for example. Thus, sand, glass beads, metal shots, etc., can be used within the system of the apparatus as disclosed.
Included as part of the jet gun is a support means, generally indicated at 190, disposed intermediate the ends of conduit 128'and-comprising a support member 192 which receives a depending leg 194. This leg is used by the operator of the device when said device is held in his hands, but can be easily adapted to be used with other existing control means, such as jacks or booms, where it is impossible for the operator to hold said device during its working operation.
In addition, the device is also provided with an abrasive protection shield, shown in FlG. 1 secured at the forward end of said gun, comprising a transparent shield 195 attached to a bracket 196. Thus, as the operator works in close proximity with the workpiece, he is protected from the jet blast and/or foreign particles that might stray during an abrasive operation. It should be understood that said protective shield can be located at any point along the gun, but for best results it is shown at the forward end thereof.
The invention and its attendant advantages will be understood from the foregoing description and it will be apparent that various changes may be made in the form, construction and arrangement of the parts of the invention without departing from the spirit and scope thereof, or sacrificing its material advantages, the arrangements hereinbefore described being merely by way of example, and I do not wish to be restricted to the specific forms shown or uses mentioned, except as defined in the accompanying claims.
1. A fluidjet-abrasive device in combination with a high-pressure fluid flow and abrasive material, said device comprising:
a fluid-jet gun;
a handle attached to said gun at one end thereof;
a spray-nozzle means disposed at the opposite end of said gun and having an inlet port to receive said abrasive material therein to comingle with said fluid flow;
a high-pressure-control valve disposed intermediate said handle and said nozzle means, said valve having an inlet port, a return-flow-outlet port and a discharge end; and
a trigger means operably engaging said control valve and disposed in said handle thereof.
2. A fluid-jet-abrasive device as recited in claim 1,
a high-pressure, fluid-flow system interconnected to said gun through said inlet port and said returnflow-outlet port; and
an abrasive-material-flow system.
3. A fluid-jet-abrasive device as recited in claim 2, wherein said abrasive-material-flow system comprises:
a reservoir tank in which said abrasive is stored therein, said tank having a discharge end;
a material-flow regulator operably secured to said reservoir tank; and
conduit means interconnected between said material-flow regulator and said inlet port of said nozzle means whereby said abrasive material is transported from said reservoir to said nozzle means.
4. A fluid-jet-abrasive device as recited in claim 3,
wherein said nozzle means includes a vacuum means whereby said abrasive material is caused to flow from said reservoir into said nozzle means.
5. A fluid-jet-abrasive device as recited in claim 4,
wherein said nozzle means includes:
a housing having a rectangular, box-like configuration;
a spray nozzle secured in one end of said housing,
thereby discharging a high-pressure-fluid flow received from said discharged end of said control valve, the opposite end of said housing being open;
a vacuum chamber disposed intermediate said spray nozzle and said abrasive-inlet port, wherein a lowpressure condition is created when said highpressure fluid issues from said spray nozzle.
6. A fluid-jet-abrasive device as recited in claim 5,
wherein said housing includes:
a removable, forwardly-disposed, housing sleeve;
a nozzle-support block removably secured within one end of said housing and having a bore therethrough in which said spray nozzle is received therein; and
a conduit connected between said control valve and said nozzle-support block, whereby high-pressure fluid is transported to saidnozzle means when said trigger means operates said control valve.
7. A fl'uid-jet-abrasive device as recited in claim 6,
wherein said housing includes:
a first removable wear plate positioned below the abrasive-inlet port; and
a second wear member having a box-like configura-' tion removably disposed within the forward area of said housing, whereby said housing and said housing sleeve are protected from abrasive wear.
8. A fluid-jet-abrasive device as recited in claim 5,
wherein said high-pressure-control valve comprises:
a valve housing having a plurality of communicating concentric bores disposed therein, and wherein one of said bores defines said discharge end, said housing including said inlet port and said returnflow-outlet port, each communicating with said concentric bores; central receiving chamber defined by one of said concentric bores, to receive direct fluid flow from said fluid-flow system;
a flow-return disposed within one of said concentric bores adjacent one side of said central chamber, and having a plurality of interconnected passages for fluid flow from said inlet port to said returnflow-outlet port, said flow-return means having a central bore therethrough;
a flow-discharge means disposed within said concentric bore defining said discharge end and positioned adjacent said central chamber opposite to that of said flow-return means, said discharge means being provided with a plurality of interconnected passages, with a central bore disposed therein communicating between said passages and said central chamber, whereby said fluid is discharged therefrom into said nozzle means; and
said return means and said discharge means, whereby movement thereof controls fluid flow in either said return means or said discharge means, said slide valve being actuated by said trigger means.
9. A fluid-jet-abrasive device as recited in claim 8,
a conduit interposed between said control valve and said spray-nozzle means, whereby fluid can traverse from said valve to said nozzle means when said trigger means is actuated.
10. A fluid-jet-abrasive device as recited in claim 5,
wherein said material-flow regulator comprises:
a depending pipe having an open, free end, the opposite end thereof being secured to said discharge end of said reservoir tank; y
a receptacle disposed below said free end of said slide valve slidably disposed within said bores of pipe, wherein said free end thereof is received within said receptacle and positioned below the upper, open, free end of said receptacle, the opposite end of said receptacle being attached to said conduit means; and means to introduce ambient pressure within said vacuum system, said means'being interposed between saidreceptacle and said conduit means, whereby a continuous flow of abrasive material is permitted to discharge from said reservoir tank when said control valve is actuated, providing a vacuum within said conduit means and, inversely, preventing flow from said reservoir when said valve is positioned for a fluid recycle mode. 11. A fluid-jet-abrasive device as recited in claim 4,
' wherein said high-pressur'e-fluid flow system compr1ses:
a fluid storage tank having an inlet and an outlet port,
said inlet port being interconnected to said returnflow-outlet port of said control valve;
a high-pressure-fluid-pump means operably interconnected to said outlet port of said storage tank to receive fluid flow therefrom, said means being operably interconnected to said inlet port of said control valve; and I a power-drive means coupled to said high-pressure- 12. A fluid-jet-abrasive device as recited in claim 1 l,
wherein saidhigh-pressure-pump means comprises a high-pressure pump having an outlet therefrom communicating with said inlet port of said control valve and an oppositely-disposed inlet; and
a centrifugal pump interposed between said fluid storage and said high-pressure pump and operably interconnected therebetween, whereby fluid is pumped from said storage tank to said pressure pump through said inlet of said pressure pump, both of said pumps being operably coupled to said power-drive means.
13. A fluid-jet-abrasive device as recited in claim 4, wherein said fluid-jet-gunincludes an abrasiveprotection shield secured to said gun.
14. A fluid-jet-abrasive device as recited in claim 11, wherein said fluid in said fluid-flow system consists of water, and wherein said fluid-flow system includes a gas injected into said system at a point between said control valve and said high-pressure pump.
15. A fluid-jet-abrasive device as recited in claim 7, wherein said abrasive material comprises a sand having various sized particles between 16 through mesh.
16. A fluid-jet-abrasive device as recited in claim 7, wherein said abrasive material comprises glass beads.
17. A fluid-jet-abrasi've device as recited in claim 7, wherein said abrasive material comprises metal shots.
18. A fluid-jet-abrasive deviceas recited in claim 5, wherein said high-pressure-fluid flow discharged from said spray nozzle forms a fan spray having a substantially pyramidal configuration wherein the base portion thereof is equal to the height and width of said rectangular housing, thereby creating said low-pressure condition within said. vacuum chamber.