US3399492A

US3399492A - Sandblast truck assembly

Info

Publication number: US3399492A
Application number: US566783A
Authority: US
Inventors: Andrew R Crowe; Willard F Foster
Original assignee: C H HEIST OHIO CORP
Current assignee: C H HEIST OHIO CORP
Priority date: 1966-07-21
Filing date: 1966-07-21
Publication date: 1968-09-03
Anticipated expiration: 1985-09-03

Description

Sept. 3, 1968 A, R, CRQWE ET A4. 3,399,492

SANDBLAST TRUCK ASSEMBLY 5 Sheets-snee*l 1 Filed July 21', 1966 INVENTORS. Q/zd'rew R C'vfawe and Za'c'ZaraZFase-y W ATTORNEY @LEM N (S \N Sept. 3, 1968 A R, CROWE ET Al. 3,399,492

SANDBLAST TRUCK ASSEMBLY www5!) ATTOPNEY Sept. 3, 1968 A, R, CROWE ET Al. 3,399,492

SANDBLAST TRUCK ASSEMBLY Filed July 21, 1966 3 Sheets-Sheet 3 7 26 y f 9 9 706 770 709 2l' 'im 700 y* 1N VENTORS 27am@ W fToRA/EK United States Patent C) 3,399,492 SANDBLAST TRUCK ASSEMBLY Andrew R. Crowe, Williamsville, and Willard F. Foster, Alden, N.Y., assignors to C. H. Heist Ohio Corporation, Buffalo, N.Y., a corporation of New York Filed July 21, 1966, Ser. No. 566,783

Claims. (Cl. 51-8) The present invention relates to an improved sandblast truck assembly.

It is one object of the present invention tol provide an improved sandblast truck which can be readily loaded in an extremely convenient manner Awith a'large amount of sand capable of supplying a plurality of sandblasting units with enough sand for blasting for an entire day.

Another object of the present invention is to provide an improved sandblast truck in which the various components are oriented in such a manner that they are easily accessible for replacement, repair, and ease of operation.

A further objectof the present invention is to provide an improved sandblast truckhaving sand carrying and pneumatic circuits which are highly eicient in operation and which are not likely to malfunction or clog in use.

A still further object of the present invention is to provide a sandblast truck assembly which is highly economical to operate because it uses a plurality of vehicles to carry and store large quanties of bulk sand. Other objects and attendant advantages of the present invention will be readily perceived hereafter.

The improved sandblast truck assembly of the present invention includes a first vehicle which carries a plurality of sandblasting units and a bin mounted above the sandblasting units for holding a large supply of sand and feeding it to the sandblasting units as required during blasting, a second vehicle mounting a large compressor which may be selectively coupled to the sandblasting units in use but is either separated therefrom for ease of transportation or is linked to the first vehicle in transit by a physical connection such as a trailer hitch, and -a third vehicle for carrying a large amount of sand for supplying the bin of the first vehicle when empty. By the use of the foregoing combination, a freight `car full of sand can be purch-ased, completely unloaded into the first and third vehicles and conveyed to a site where sandblasting. is to be effected. Therefore, the expense of sandblasting can be maintained relatively low because the foregoing combination utilizes relatively low cost bulk sand and obviates the necessity for using relatively high priced bags of sand and further obviates the necessity for employing a person whose sole function is t-o continuously fill the sandblasting units from said bags of sand.

More specifically, the bin and the portions of the sandblasting units which receive sand from the bin are located Within the body of the truck. This arrangement protects the sand from the elements so that it will not cake. In addition, the portions of the sandblasting units which mix sand and compressed air and the valve units for selectively actuating the sandblast units are located on the outside of the truck body for ease of access during operation or for repairs. In addition, a portable s-and mover is carried on the truck carrying the sandblast units, and this mover is used to convey sand from a freight car to the tank car or from the tank car to the bin associated with the sandblasting units.

The bin on the first sandblast vehicle is provided with exhaust equipment for evacuating the bin during loading so that there will be no back-up of pressure therein which could hinder loading. In addition, the pneumatic circuits to the sandblasting units are such so as to prevent feedback of sand to parts of the equipment which should be kept sand-free. The various aspects of the present invention will be more readily understood when the following ICC portions of the specification are read in conjunction with the accompanying drawings wherein: v

FIG. 1 is a side elevational view showing a portion of the sandblast truck assembly which includes the truck carrying the Vsandblasting units and towing a trailer mounting a compressor;

FIG. 2 is a fragmentary side elevational view of a hose nounting a sandblast nozzle `and a pneumatic control conuit;

FIG. 3 is a side elevational view of a tank truck for carrying bulk sand;

FIG. 4 is a side elevational view of the trucky body of FIG. 1, partially in cross section, .showing the relationship between various components mounted on said truck;

FIG. 5 is a cross sectional view taken substantially along line 5--5 of FIG. 4;

FIG. 6 is a fragmentary view showing portions of the pneumatic circuit associated with the air cleaning equipment for supplying a sandblasters hood;

FIG. 7 is a cross sectional view taken subst-antially along line 7-7 of FIG. 5;

FIG. 8 is a cross sectional view taken along line 8-8 of FIG. 4 and showing a portion of the slide valve associated with the hopper which transfers sand from the bin to the sandblasting units;

FIG. 9 is a cross sectional View taken substantially along line 9 9 of FIG. 8;

FIG. 10 is a schematic view, partially in cross section, showing a portion of the mechanism forming a part of the Sandblasting unit;

FIG. 11 is a side elevational view of a sandblasting unit cover; and

FIG. 12 is a plan view of the sandblasting unit cover.

In FIGURES 1 and 3 the sandblasting truck assembly of the present invention is shown. This assembly includes a sandblasting truck 10 which includes 'a cab 11 and a closed body 12 which carries various parts of the sandblasting equipment. Trailer 13' mounting compressor 13 is attached to truck 10 by means of a trailer hitch 14. Trailer 13 is selectively detachable from truck 10, as required. Trailer 13' is a separate vehicle because compressor 13 is of a relatively large size which truck 10 is -incapable of carrying along with the remainder of its load. Instead of being mounted on trailer 13', the compressor 13 can be mounted on a separate truck. The third vehicle is a tank truck 15 consisting of a cab 16 and a tank car 17 having openings 18 on top for receiving sand and closed openings 19 on the ybottom for permitting sand to run out.

As mentioned briefly above, the economic advantage of utilizing the above described plurality of vehicles is two-fold. Firstly, the foregoing arrangement permits the low cost purchase of an entire freight car of bulk sand, which can be shipped to an area near the sandblasting site. A portion of the freight car load is stored in tank truck 15 and the remainder is carried within sand storage bin 20 housed within body 12 of the rst truck. In addition, bin 20 carries approximately nine tons of sand which is sufficient to supply

sandblasting units

21 and 21 for an entire day. The fact that lbin 20 is of this size eliminates the necessity for employing a man whose sole function is to dump bags of sand into the sandblasting units 21 and 21', as is required during blasting.

In order to ll tank 17 and bin 20 with sand from a freight car, a sand mover 22, which is mounted on truck 10, is used. Sand mover 22 is commonly known as a pneumatic abrasive conveyor and utilizes compressed air supplied by compressor 13 to move sand from one location to another. Sand mover 22 is removable from its position shown in FIGURES l, 4, 5 and 6 and may be located with its sand receiving portion 23 under any one of openings 19 of tank truck 15 for moving sand into bin 20 or may be located underneath a trap door in a freight car for moving sand from the freight car into openings 18. The movement of sand is effected through a suitable conduit analogous to conduit 24 leading from sand mover 22, as will become more apparent he reafter.

In addition, bin .20 may be selectively supplied by s'and mover 22 from tank 17 of truck 15 by placing the sand removing portion 23 of the unit underneath any one f trap doors 19 and moving the sand falling therethrough through a hose analogous to hose 24 (FIG. 4), into bin 20. To this end it will be noted that sand mover 22 fits within a hole 25 in the floor 26 of the truck 10. The lowermost portion of sand mover 22 includes legs 26 4which are mounted on base 27 supported from the truck body by struts 28. Suitable couplings or brackets (not shown) secure the legs 26 of sand mover 22 to base 27 and permit its removal under the foregoing circumstances, as required. In addition, fast disconnect couplings, under the Iforegoing circumstances, are used to detach hose 24 and conduit 29 from sand mover 22 to permit it to be placed underneath a freight car or tank car 17, as described above. The brackets, which may include suitable screws, wing nuts or the like, which attach legs 26 `to base 27 usually hold sand mover 22 in the position shown in FIGURES 4, 5 and 7 if the truck is to be used without tank 17, in which event, bagged sand, which is stored within the truck body 12, is dumped into the top 23 of sand mover 22 to lill bin 20. Once bin has been filled, it will supply

Sandblasting units

21 and 21 for an entire day. This loading can be effected at any convenient time and thus obviates the necessity for a person to continuously lill the Sandblasting units during use.

In order to lill bin 20 by use of sand mover 22 while mounted on truck body y12, bags of sand are emptied into sand receiving portion 23 of sand mover 22. Sand mover 22 is commercially known as a pneumatic abrasive conveyor and a model which has been used is known as PAC Model 24 made by Clementina Ltd. of San Francisco, Calif. and shown in its General Catalog No. 7, page 18 dated Mar. 1, 1965. It is only necessary for purposes of the present subject matter to know that sand which is dumped into portion 23 will be forced into conduit 24 leading from the bottom of sand mover 22 and moved into sand bin 20 through aperture 30 (FIG. 7). Air yfor operation of sand mover 22 is obtained through

conduits

29 and 31 leading from compressed air manifold 32 which is supplied with compressed air from tank 33 (FIG. l) of compressor 13, through a suitable hose 34 extending between tank 33 and manifold 32. At this point it is to be noted that lengths of hose 34 are mounted for storage in carrier compartment 35 located underneath truck body 10 and these lengths of hose, which are as long as the truck body, may be coupled together if it is desirable to locate I compressor trailer 13' at a distance from truck 10. The compressed air is conducted through

conduits

31 and 29 only when valve 3S is open.

Bin 20 is a container which is completely closed and relatively air-tight. Therefore, considering that the sand is moved through conduit 24 while entrained in compressed air, there must be a vent provided for evacuating air from bin 20 during filling. This is accomplished by a pneumatically actuated evacuator 36 which operates on the venturi principle to exhaust air from bin 20 through conduit 37 in communication with bin 20. More specifically,

conduits

38 and 39 effect communication between manifold 32 and air mover 36 when v'alve 40 is open, the amount of opening of said valve 40 determining the rate at which bin 20 is evacuated. It will be appreciated that if this evacuation was not effected, there would be a pressure build-up within `bin 22 which would interfere with sand loading. Dust from bin 20 will also be removed by air mover 36 and, if desired, .a dust collector bag can be mounted 0n the 9pol?. end 36 of air Y mover 36 to prevent sand dust from being thrown into the area where the truck is located. This is especially desirable Iwhere the truck is within an enclosure, such as a factory. The air mover 36 is a conventional device and one which has been used successfully is known as a Lamb Air Mover, Model DP 32-119 manufactured by the Mine Safety Appliance Company of Pittsburgh, Pa. and shown in its Bulletin No. DP-S at page 35 In order` to'see how full bin 20 is while it is being lled, a window 41 (FIG. 7) is provided on wall 47 of the bin. This window is held in position by a plurality of brackets 42, and may be selectively opened by removing brackets 42 and swinging the window about hinges 42' to permit access to the inside of bin 20. Light is pro- -vided for visual observation within bin 20 through superimposed sky lights 43 and 44 in the top of truck body 12 and the top 45 of bin 20, respectively. A rubber strip 46 (F-IG. 5), approximately two feet wide, extends between the rear wall 47 and the front wall 48 of bin 20, except where sky light 44 is located. This prevents the sand entering bin 20 from conduit 24 from excessively abrading top 45. In addition, a strip of rubber 49', approximately two feet wide and in line with strip 4'6 extends down the entire vertical portion of wall 48 to prevent sand abrasion. After sand bin 20 has been filled to the desired amount,

valves

35 and 40 are closed, and

the sand within the bin is ready for feeding to sandl blasting

units

21 and 21. It is again to be noted that bin 20 will carry a complete days supply of sand for the two blasting units. Therefore, there is no need to employ a person to fill the blasting units 21 and 21' during blasting because this is achieved automatically as will become more apparent hereafter.

Bin 20, in addition to the above structure, also includes two downwardly depending leg or hopper portions 49 which terminate in outlet portions 50 above Sandblasting units 21 and 21'. It is to be noted that hopper portion 49 has slanting side walls 51, slanting side walls 52, slanting front walls 53 and slanting rear walls 54 (FIG. 5). The angularity of all of the foregoing walls is such that sand cannot rest on these walls but must slide into outlet 50.

To selectively permit sand to drop from either of legs 49 of bin 20, a slide valve construction 55 is provided in each of outlets (FIG. 8). Each slide valve 55 includes a frame portion 56 consisting of grooved side members 57, and a plate 58 slidable in grooves 59. Plate 58 includes a handle portion 60 and an aperture 61. When aperture 61 is aligned with the inside of outlet portion 50, sand will drop through outlet portion 50. When the solid portion 62 lies within the confines of outlet portion 50, sand will not be able to drop through the latter. The slide valve S5 remains in the position shown in FIGURE 8 whenever the Sandblasting units fare operating to thereby supply the Sandblasting units 21 and 21' with sand, on demand, as will become more apparent hereafter.

Sandblasting

units

21 and 21 are identical and therefore only unit 21 will be described. Sand blasting unit 21 (FIG. 10) includes a sand receiving portion 63 1ocated at the top thereof and includes a cylindrical wall portion 64 and a downwardly sloping frustoconical bottom 65 leading to neck 66. A poppet valve 67 selectively moves upwardly into engagement with annular O-r-ing seal or seat 68 to close neck 66 to prevent sand from falling throughneck 66 into chamber 69. Valve 67 seats on O-ring '68 whenever Sandblasting is being effected, as will become more apparent hereafter. However, at this point it is to be noted that the lowermost portions of outlets 50 lie below the upper rim 71 of sand receiving portion 63. Therefore, whenever valve 67 is closed, the sand flowing from outlet 50 will back up into outlet 50 to thereby stop the ow of sand automatically. Whenever valve 67 d-rops to the position shown in FIGURE 10 away from seat 68, the sand within sand receiving portion 63 will drop through neck 66 into chamber -69 and flow through outlet 50 will again commence.

Whenever Sandblasting is to be effected, the sandblast operator manually moves lever 72 from its dotted line position shown in .FIGURE 2 and holds Ait in its solid line position against the bias of a spring to thereby close a valve which permits air to bleed from control conduit 73 when the valve is open. Control conduit 73 is attached to hose 74 by brackets 75. Hose 74 in turn isconnected by quick coupling connection 76 to the quick coupling connection 76 mounted at the outlet of end abrasive control valve 77, which permits sand to fall from chamber 69 within sandblast unit 21 into T 78 carrying a stream of compressed air from conduct 79 to sandblast hose 74. A nozzle v80 is located at the end of hose 74 and the sandblaster aims this nozzle at the area to be blasted while holding lever 72 in the solid lineposition. Lever 72 is a deadman switch which permits the blasting unit to operate and compressed air to ow through conduit 74 only when lever 72 is held in its solid line position. A coupling 81 is located at the end of control conduit 73 for joining with coupling 82 at the end of conduit 83 (FIG. 4) leading to normally open remotely actuated valve 84 which is in series with conduit 85 leading to normally closed remotely actuated valve 86, the normal positions being occupied when the Sandblasting unit is not operating. When valve 84 is normally open it permits venting of chamber 69 to the atmosphere through conduit `87, valve portion 84' of valve 84 and conduit 88. See FIGURES 4 and 10. When chamber 69 isV vented in the foregoing manner while valve 84 is normally open, poppet valve 67 may return to the position shown in FIGURE because valve 86, having valve portion 86', is then normally closed to prevent compressed air from being supplied from conduit 90 to piston 89 on which poppet valve 67 is mounted. There is suicient looseness between piston 89 and cylinder 92 in which it rides to permit piston 89 to settle to the position shown in FIG- URE 10 when `air pressure is not applied against it, that is, when valve 86 is in its normally closed position. As noted above, valve 84 is normally open to permit venting and valve 86 is normally closed to prevent air flow into chamber '69 whenever the deadman valve 72 is in the dotted line position. However, when the deadman valve 72 is moved to its solid line position,

valves

84 and 86 reverse to thereby cause normally opened valve 84 to close and normally closed valve 86 to open. When valve 84 closes, portion 84 thereof will close to terminate venting of chamber 69 through conduits .'87

and 88, Therefore, when valve portion 86 of valve 86 opens, compressed air will ow through

conduits

90 and 91 to chamber 69. In so doing, it will drive piston 88 upwardly until poppet valve 67 seats on seat '68. Thereafter the existence of .pressure within chamber 69 will cause a force to be applied against face 93 of valve 67 to hold it in a closed position, the compressed air being supplied to chamber 69 through the space between piston y89 and cylinder 92.

Valves

84 and 86 are commercially available and known under the trade name Recova Valve identified as Model No. Rl-310 manufactu-red by Clementina Ltd. of San Francisco, Calif. and shown in their General Catalog No. 7 dated Mar. 1, 1965 atpage v9.

The compressed :air is supplied to Sandblasting unit 21 from manifold 32 which runs underneath truck floor 26 and terminates at T 91' which is in communication with conduit 92 leading to main valve 93' which is opened before compressed air can be supplied to sandblast unit 21 and closed when ow of compressed air Iis to be prevented. It is to be noted that valve 93- islocatedbelow the truck body so that it is accessible from outside of the truck. After valve 93 is opened, the compressed air passes to moisture trap 94 which removes oil and moisture from the compressed air. Moisture trap 94 may be of the type which is identified as a Wilkerson No. 1125-12 MS and manufactured by the Wilkerson Corp.

of Englewood, Colo. yand shown in its Catalog No. 159 dated Aug. 3, 1965 at page 5. Moisture trap 94 is in communication with valve 86 described in detail vabove which is normally closed when lever 72 is not depressed (FIG. 2). At this point it is to be noted that the compressed air which passes through condu-its 85, 83 and 73 enters these conduits from an internal connection within valve body 86. As can be seen from FIGURES 5 and 10, valve 86 is in communication with check valve 95 through conduit 96. Check valve 95 permits flow only into sandblast unit 21 but will prevent back-flow to thereby prevent sand from entering valve 86.

After valve 86has been opened, as a result of the moving of lever 72 to its solid line position, compressed air passes into conduit 79 (FIGS. 4 and 10) and thereafter passes through check valve 97 into T 78 underlying sand control valve 77. As is well known in the art, the sand will drop through valve 77 into the air stream passing through T 78 and this mixture will then pass into hose 74 leading to nozzle 80. Because chamber 69 is pressurized with substantially the same pressure in T 78, the sand will drop by gravity into the T 78; that is, compressed air in T 78 will not tend to flow into chamber 69. The check valve 97 prevents back flow of sand into conduit 79. Sand control valve 77 is commercially available from Clementina Ltd. noted above, and a model which has been successfully used is known as SV-60 shown in the .above companys General Catalog No. 7 dated Mar. 1, 19.65 at page 10.

A valve 98 is located in conduit 79 for selectively providing flow of air in large amounts to unclog T 78 if this should become necessary. During operation of the sandblast unit 21 valve 98 is maintained in `an open position. If for any reason there should be clogging, valve 98 is closed and then opened and it Iwill permit large amounts of air to pass through conduit 79 substantially instantaneously to thereby provide a dislodging effect on any sand which may be clogging T 78.

It is to be especially noted that all of the above described pneumatic circuitry except for the venting arrangement, consisting of

conduits

87 and 88 and valve 84, are located below the truck floor in an exposed position where they can be easily reached for manipulation, replacement or repair.

Connected to manifold 32 at T 91 and leading to sandblast unit 21 is a pneumatic circuit which is identical in all respects to that described above which conducts compressed air to sandblast unit 21. Therefore, for the sake of brevity, a detailed explanation of this circuit will not be made.

As can be seen from FIGURE 1, sandblast unit 21 is mounted on the truck by means of four struts 99 which `depend downwardly from the underside of the t-ruck and are secured -at their upper ends to suitable beams, not shown. Struts 99 are provided in spaced relationship about the periphery of cylindrical sandblast unit 21. Horizontal struts 100 (FIGS. 1 and 7) connect front and rear pairs of struts 99. A plurality of struts 101 extend upwardly from struts 100 and securely hold sandblast unit 21 in position. Bolts may be used to effect the foregoing connection to thereby permit sandblast unit 21 to be removed from mounted relationship on the truck. It is to be noted from FIGURE 4 that the central portion of sandblast unit 21 tits through aperture 102 in oo-r 26. Because there is no connection between lower portion 50 of the hopper and the top of sandblast unit 21, once struts 101 are detached, the sandblast unit 21 may be removed from the truck.

In order to prevent the spilling of sand on oor 26 incidental to the actuation of valve 67 (FIG. 10), a cover 105 (FIGS. 11 and 12) is provided for sandblast unit 21. Cover 105 includes the circular portion 106 having a flange 107 depending perpendicularly from the peripheral edge thereof for Perpendicular flanges 108, 109 and 110, which are joined as shown in FIGURE 12, are adapted to slide into contiguous relationship with three sides of lowermost portion 50 of hopper 20, as shown in FIGURE 4. The absence of a fourth side opposite to flange 109 and the absence of an arcuate flange analogous to 107 permits cover 105 to be mounted on sand blast unit 21 by moving it from yright to left to occupy the orientation shown in FIGURE 4. t

The truck body 12 also carries an air purifier f or supplying pure air to the hoods which are worn by sandblasting personnel during a Sandblasting operation. In this respect, an air purifier 111 (FIG. 6) is mounted on floor 26 and receives its air supply via conduit 112 from take-off plug 90' proximate moisture trap 94. The

air purifier may be one which is commercially known as a Sandstorm Type A made by the Sandstorm Mfg. Co. of Fresno, Calif., and shown in its General Catalog No. 594-1 at page 29. This purifier removes foreign matter and generally makes the compresse-d air suitable -for human use. Purifier 111 is in communication with plugs 113 through T 114 and conduits 115 and 116. Plugs 113 are normally closed except when a hose `is connected to them for conveying the compressed air to the sandblast hoods. As can be seen from FIGURES 4 and 5, plugs 113 are located underneath floor 26 on opposite sides of the truck body.

While preferred embodiments of the present invention have been disclosed it will be readily appreciated that it is not limited thereto but may be otherwise embodied within the scope of the following claims.

We claim:

1. A sandblast truck assembly comprising a truck including a body portion mounted thereon, a sand storage Vbin on said Ibody portion, hopper means located at the bottom of said sand storage bin, a sandblast unit including a sand receiving portion located below said hopper means for receiving sand therefrom, a compressed air conduit, first conduit means including first valve means for selectively effecting communication between said compressed air conduit and the inside of said sandblast unit, means on said sandblast unit 'for receiving a sandblast nozzle and hose assembly, second conduit means includfing second valve means for selectively effecting communication between said compressed air conduit and said means for receiving said sandblast nozzle and hose assembly, pneumatic sand mover means, third conduit means for effecting communication between said pneumatic sand mover means and said sand storage bin for conveying sand from said pneumatic sand mover means to said sand storage bin, and fourth conduit means for effecting communication between said pneumatic sand mover means and said compressed air conduit to provide compressed air for moving sand from said pneumatic sand mover means to said storage bin through said third conduit means.

2. A sandblast truck assembly as set forth in claim 1 including aperture means in said sand storage bin, air mover means, and fifth conduit means coupling said air mover means to said aperture means for exhausting said sand storage bin when said pneumatic sand mover is moving sand into said sand storage bin.

3. A sandblast truck assembly as set forth in claim 2 including sixth conduit means extending between said compressed air conduit and said pneumatic air mover means for supplying compressed air to said air mover means.

4. A sandblast truck assembly as set forth in claim 1 wherein said sand receiving portion of said sandblast unit is unattached relative to said hopper to lfacilitate removal of said sandblast unit from its location below said hopper.

5. A sandblast truck assembly as set forth in claim 4 including a cover plate for said sandblast unit for preventing sand from falling outside of said sandblast un1t.

6. A sandblast truck assembly as set forth in claim 4 including slide valve means at the bottom of said hopper for selectively closing said hopper.

7. A sandblast 'assemblyV as set forth in claim 6 wherein said vbody portion is enclosed and includes a floor, and wherein said sand receiving portion of said sandblast unit is located within said enclosed body portion and has a lower portion which projects downwardly below said floor, and wherein said first and second conduit means are exposed below said floor for ease of accessibility.

8. A sandblast truck lassembly Vas set forth in claim 1 including check valve means in said second conduit means for preventing ow of sand from said sandblast unit toward said compressed air conduit.

9. A sandblast truck assembly as set forth in claim 1 including check valve means in said first conduit means for preventing fiow of sand from said sandblast unit toward said compressed air conduit.

. 10. A sandblast truck assembly as set forth in claim 1 Including first check valve means in said first conduit means and second check valve means in said second conduit means, said first and second check valve means preventing ow of sand from said sandblast unit toward said compressed air conduit.

11. A sandblast truck assembly as set forth in claim 1 including -a second vehicle for carrying an air compressor, and sixth conduit means for selectively coupling said air compressor and said compressed air conduit.

12. A sandblast truck assembly as set forth in claim 11 including a third vehicle for hauling bulk sand.

13. A sandblast truck assembly as set forth in claim 12 wherein said sand mover is removably mounted on said truck so that it may selectively be located in position underneath said third vehicle to move sand from said third vehicle to said sand storage bin.

14. A sandblast assembly as set forth in claim 1 including a second sandblast unit including second means for receivinga second sandblast nozzle and hose assembly, and wherein said compressed air conduit comprises a manifold, seventh conduit means for effecting communication between said manifold and said means for receiving said second sandblast nozzle and hose assembly, and eighth conduit means for effecting communication between said manifold and the inside of said second sandblastlunit.

15. A sandblast assembly las set forth in claim 1 including window means for observing the depth of sand in said sand storage b in.

` References Cited UNITED STATES PATENTS 783,218 2/l905 Murray 51--12 3,070,924 l l/l963 Hastrup 51-8 l/1963 Blubaugh 51-8

Claims

1. A SANDBLAST TRUCK ASSEMBLY COMPRISING A TRUCK INCLUDING A BODY PORTION MOUNTED THEREON, A SAND STORAGE BIN ON SAID BODY PORTION, HOPPER MEANS LOCATED AT THE BOTTOM OF SAID SAND STORAGE BIN, A SANDBLAST UNIT INCLUDING A SAND RECEIVING PORTION LOCATED BELOW SAID HOPPER MEANS FOR RECEIVING SAND THEREFROM, A COMPRESSED AIR CONDUIT, FIRST CONDUIT MEANS INCLUDING FIRST VALVE MEANS FOR SELECTIVELY EFFECTING COMMUNICATION BETWEEN SAID COMPRESSED AIR CONDUIT AND THE INSIDE OF SAID SANDBLAST UNIT, MEANS ON SAID SANDBLAST UNIT FOR RECEIVING A SANDBLAST NOZZLE AND HOSE ASSEMBLY, SECOND CONDUIT MEANS INCLUDING SECOND VALVE MEANS FOR SELECTIVELY EFFECTING COMMUNICATION BETWEEN SAID COMPRESSED AIR CONDUIT AND SAID MEANS FOR RECEIVING SAID SANDBLAST NOZZLE AND HOSE ASSEMBLY, PNEUMATIC SAND MOVER MEANS, THIRD CONDUIT MEANS FOR EFFECTING COMMUNICATION BETWEEN SAID PNEUMATIC SAND MOVER MEANS AND SAID SAND STORAGE BIN FOR CONVEYING SAND FROM SAID PNEUMATIC SAND MOVER MEANS TO SAID SAND STORAGE BIN, AND FOURTH CONDUIT MEANS FOR EFFECTING COMMUNICATION BETWEEN SAID PNEUMATIC SAND MOVER MEANS AND SAID COMPRESSED AIR CONDUIT TO PROVIDE COMPRESSED AIR FOR MOVING SAID FROM SAID PNEUMATIC SAND MOVER MEANS TO SAID STORAGE BIN THROUGH SAID THIRD CONDUIT MEANS.