US2628456A - Sandblasting device - Google Patents

Description

Feb. 17, 1953 R. R'. BERG 2,623,456

SANDBLASTING DEVICE- Filed Jan. 15, 1952 2 SHEETS-SHEET 1 AIB PRESSURE u INVENTOR. Roll 72 R. Ber

2 ATTORNEYS Feb. 17, 1953 R BERG I 2,628,456

SANDBLASTING DEVICE Filed Jan. 15, 1952 2 SHEETS-SHEET 2 VIII/111111 VII/Ill:

VII/1111111111,111/1,111]r4 a II INVENTOR. JPcaZ Qh R-Berg m: WYMM ATTORNEYS Patented Feb. 17, 1953 u NI TE 1) s TAT Es PATENT o-F Fl-(Z 2;62's,45s'

S-ANDBLASTING DEVICE Ralph E. -Berg;: Menlo Park, N. J assignor to.-

Maribl astcorporation, Jersey City, N. J.,.acor'- poration of New Jersey AppIication Janua-ry IE, 1952, Serial No. 266;538

9 Claims This invention relates to improvements. in. abrading. equipment and, more particularly, to; an improved sandblasting; device.

Among the objcctsi'of July-invention are to. pro-'- vide sandblasting equipment having. means: for; recovery. of the sand or other. abrasive. material used in the abrading. process;

Another object of this invention. is provide sandblasting. equipment comprising. in a singlev unit'abiastin gun and abrasive recovery"means:v

Other obj ectsof-this invention are to eliminate the inconveniences: and dangers commonly experienced-with the presently knownsandblasting equipment. Among these inconveniences expe. rienced are the necessity to employ'persormel to clean up. used sand :from areas wheresuoh equip? ment is used; the inability 'tocarry on other work: such as. maintenance and repair in the vicinity: while blasting equipment is beingruse'd; the high; dust concentration in the vicinity of sucliieq-uip..- ment which impairs" the operators vision and eificiency, andthe necessity to fully protectexposed machinery and other equipment from the deleterious effects of abrasives before: blastingcan be performed: Amongth'e' dangers present in the use of the commonly known blastingaequipment are the danger-iof silicosis from-breathing. dust laden air and therdanger of falls-from sliding on discarded'sand present on'staginggde'eks; and other surfaces.

Further objects of this invention are to lower, the cost of sandblasting-by eliminating the-wast-- age due to the discarding-of sandiwhich isfiusedf only once in'a blastingoperation; Thu'saexpensive charges for-transportation, warehousingand handling are considerably reduced:

These and'otherobjects and advantages will become apparent from the following descriptionand the accompanyingd-rawings in which:

Figure 1 is a schematicview ofthes-sa-ndblastw ing equipment;

Figure 2 is a sectional View inpartial eieVation of the gun forming a part of myainvention';

Figure 3 isa viewtakenorrline"33of Eigure 2, and looking in the direction or" the arrows;

Figure 4 isan-elevational. view=partly inwsection showing a portion of; the gunshown-ain Fig.- ure 3 and a means for distributing abrasive 'ma terial to the-gun; and

Figure 5 is a sectional view of a modifiedlformk of gun;

Similar referencexcharacters in theseveral fi'g uresindicate similar parts'z As heretofore: indicated the commonly usedblasting equipment has many objectionableia tures: I have overcome these objections by developing a means of recovering abrasive materialiimmediately adjacent the point of application of r such --m-ateria1-1 to surfaces being abraded.

Thisis accomplished-by employing-a gun comprisinga hood havingdischargeports which are disposed-so-as-to direot.streams of abrasive toward surfaces to be cleaned in a convergent manner; and an abrasive'exh-austing meansfor removing the used abrasiveiromthe hood.' The.

hood is so 4 constructed-f that the abrasive material will be trapped thereininstead of being allowed to fall where it-may. The abrasive isthusrecovered instead of being 4 wasted: or permitted a :recovery linel4; a recovery tank and a source ofvacuum which is not shown.

Figures -2-and3 showone formof gun-which.I- The gun comprises a hollow have invented. hood l6 of a generallydefined frusto-conical shape. The hood-is open atboth its base Hand its opposite. or apex end. l8..- Attached to the narrower end Wis 51,- recovery tube l9. Four nozzles-29: are mounted in equally spaced relation on the perimeter ofithe hoodj The-nozzles shown. comprise tubes having generally cylindricaLpassageways-ll. Y Hoses22 may be readily attached to thenozzles by coupling means 23;

Openings- 24 are provided in'hood I6. in align-- ment with passageways 2 Asshown, the, nozzles. and opeiiingsi are so disposed that; abrasives-material will be. directed toward a-- point-onthe central' axis-ofthe hood which liesbeyon'cl ther base;- The nozzles are mounted-approximately normal to the outer hood surface; Of course thenozzles may-be mounted" ata' differentangle with respect-to the hood and the abrasive material need not be-direct'ed toward a; poihtozith central axis." Also it is clear that thehood may be -oi a shape different from that shown; However the hood is so formed,

and the nozzles are so mounted, that the sand or other material strikes the surface to be abraded or treated, such as surface 25, at an angle such that efficient abrasive action is obtained, and so that the material will rebound in a manner which will not interfere with the incoming particles so as to lower their average kinetic energy to any great extent. The path of the particles is shown by the arrows in Figure 2. The distance of the nozzle from the surface to be abraded when the gun is positioned as shown in Figure 2 can be chosen so as to give the best performance under given conditions.

It has been found that the best performance is obtained when the nozzles direct the sand at an angle to the surface to be abraded which is in the range of from to '75 degrees.

Figure 4 shows the distributing means i2 in detail. The distributing means comprises a body or chamber having a central inlet passageway 3| which is connected to four outlet passageways 32. The outlet passageways 32 are equally spaced from each other and diverge equally outwardly from the central passageway 3!. The body 30 is cored out at 33 to receive inlet conduit 34 and has four similar flanged openings 35 to receive hoses 22. The hoses 22 and conduit 34 may be held in place by screws 36 and 31, respectively, which are similar to screws 38 on coupling 23. Of course any convenient coupling means may be employed. A dome shaped streamlined divider 39 is provided within body 38 for directing abrasive material into outlets 32.

In the modified form of gun illustrated in Figure 5, the hood 40, which is of a shape similar tohood l6 but which is reversely positioned with respect to hood It, has bracket elements 4! secured thereto in any convenient manner. The bracket elements are equally spaced around the hood, and of course a supporting bracket means which is continuous around the hood may be provided instead. Flanged back plate 42, spacer and sealing means 43 and chamber hold down clip 44 are secured to flanges 45 of brackets 4| by rivets 46. Back plate 42 and spacer 43 are-annular in shape. The spacer is also secured to the back plate by rivets 41 as is hold down clip 48.

The two hold down clips 44 and 48 are of annular configuration and each have flanges such as 49 and 50 which cooperate with ledges formed on an annular chamber 5| so as to maintain the legs 52 and 53 of the chamber firmly against sealing means 43.

An opening 54 extends through plate 42 and spacer 43 into the chamber. Supply tube 55 is attached to plate 42 so as to align passageway 56 with opening 54. Of course the supply tube as well as opening 54 may be placed anywhere around the annulus inscribed by chamber 5|.

Equally spaced projections 51 having Venturi orifices 58 extend outwardly from the chamber. The nozzles are so arranged that abrasive material will be directed to a point on the central axis of the conically shaped hood beyond the base thereof. Edge 60 would normally be considered the base but is not so called in this modification.

Return tube BI' is centrally mounted in plate 42 by any convenient means such as by welding. The tube may be of any suitable construction. Tube 6| extends inwardly of the hood to a point where the rebounding abrasive is likely to be directed thereinto.

The orifices are so directed that sand will not strike the outer surfaces of pipe 6!. The Venturi construction in the nozzle results in in- 4 creased speed of the particles of sand. The nozzle outlets in both modifications are much smaller than are required in guns having a single central outlet. Consequently the streams of abrasive are more readily directed toward a desired location or point.

From the foregoing description it will be clear that I have developed sand blastin equipment which overcomes many of the disadvantages of older equipment of a similar nature. With my device recovery of abrasive material is assisted by the directional rebounding of abrasive and fluid medium from surfaces being treated. The directional rebounding is so effective that recovery of a substantial part of the abrasive is possible without the use of a vacuum if desired. A short return line pitched downward into the collecting hopper can be employed if no vacuum return is utilized. Blasting may be performed without hood or other equipment totally obscuring the area being treated. Actual contact with the surface by the equipment is not necessary, an advantage when blasting very rough surfaces, welded seams, corners, rivets or other surface irregularities.

It is possible to utilize the herein disclosed features for wood treating where it is desired to clean out soft portions of wood to create grain effect or otherwise to treat wood. The features may also be utilized in paint spraying wherein the vacuum would recover obnoxious fumes. Also in cleaning tanks of sludge, inflammable or otherwise dangerous fumes will be removed by my device.

While I have shown and described a preferred form of my invention, it will be understood that variations in details of form may be made without departure from the invention as defined in the appended claims.

I claim:

1. An abrasive gun comprising a hollow frustoconical shaped hood having means forming a central opening at the apex thereof, said hood being open at its base, means forming spaced openings extending through the body of said hood, nozzles mounted in said hood each having an outlet opening aligned with one of the spaced openings extending through said hood, said nozzles being mounted so as to direct abrasive supplied thereto toward the central axis of said hood in a direction generally toward the hood base, and means for removing the material through the apex opening of the hood.

2. An abrasive gun comprising a hollow hood having two open ends, nozzles mounted on said hood having outlet openings for directing abrasive material supplied thereto, openings in said hood aligned with said nozzle openings, said openings and nozzles being so arranged that said nozzles direct abrasive material toward the center axis of said hood and in a direction generally toward one of said ends, and means to remove the abrasive material in a direction generally opposite to that from which it is supplied by said nozzles.

3. An abrasive device comprising a frustoconical hood having inner and outer open ends, nozzles mounted on said hood, said nozzles having outlets for discharging abrasive material supplied thereto toward said outer open end, said nozzles being so mounted that abrasive material supplied thereto is directed toward the central axis of said hood, and suction means for returning said abrasive material through said inner open end.

4. An abrasive gun comprising a irusto-conical shaped hollow hood open at both its ends, means mounting abrasive discharging nozzles on said hood, said nozzles being so mounted and formed that abrasive material supplied thereto is directed toward the central axis of said hood at one end thereof and suction means for removing said abrasive material through the other of said ends of the hood.

5. An abrasion gun comprising a frusto-conical shaped hollow hood open at both its ends, means mounting abrasive discharging nozzles on said hood, said nozzles being so mounted and formed that abrasive material supplied thereto is directed toward the central axis of said hood at one end thereof, said hood having means forming an outlet for said abrasive material at the other end thereof, and means for removing abrasive material from said hood through said outlet.

6. An abrasion gun comprising a frusto-conical shaped hollow hood having open ends, one of said ends being adapted to be positioned adjacent a surface to be abraded, nozzles mounted on said hood, said nozzles being so mounted and formed that abrasive material supplied thereto is directed toward a position on the central axis of said hood beyond the said one of said ends and abrasive removing means providing a vacuum at the other of said ends of the hood.

7. In abrading equipment a gun comprising a frusto-oonical hollow hood having a central axis and an open end adapted to be positioned adj acent material to be abraded, nozzles mounted or the periphery of said hood having outlets disposed so as to direct abrasive material supplied thereto to a position on the central axis of said hood, means for distributing abrasive material to said nozzles comprising means forming a chamber, means connecting said chamber to each of said nozzles and means for supplying abrasive material to said chamber.

8. In abrading equipment a gun comprising a frusto-conical hollow hood having a central axis and an open end adapted to be positioned adjacent material to be abraded, nozzles mounted on the periphery of said hood having outlets disposed so as to direct abrasive material supplied thereto to a position on the central axis of said hood, means for distributing abrasive material to said nozzles comprising means forming a chamber, means connecting said chamber to each of said nozzles and means for supplying abrasive material to said chamber, said hood having means forming an outlet for abrading material, means for removing said material from said hood through said outlet.

9. An abrasion gun comprising a irusto-ccnieal shaped hood having open ends, means mounted on the hood forming a distributing chamber, nozzles formed on said chamber and connected thereto, said nozzles being so formed and disposed that the abrasive material supplied to the chamber is directed toward the central axis of said hood beyond one end thereof, and means mounted on said hood centrally of said chamber for removing the abrasive material through the other end of the hood.

RALPH R. BERG.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 467,155 Clarke Jan. 19, 1892 2,399,385 Rasmussen Apr. 30, 19% 2,455,514 Mead Dec. '7, 1948 FOREIGN PATENTS Number Country Date 448,411 Germany Aug. 1'7, 192'?

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