US1196362A - Sand-blast apparatus. - Google Patents

Description

F. 1. HULL.

SAND BLAST APPARATUS.

.1PP11CA1111N F1L11oc1.1.1912. MQGSSGQ, Patented Aug. 29, 1916. 4 SHEETS-SHEET 1.

my- M F. l. HULL.

SAND BLAST APPARATUS.

APPLncATIoN FILED ocT. 7. 1912.

1,1 96,362. Patented Aug. 29, 1916.

4 SHEETS-SHEET 2.

@50i/immo@ t i. L HULL.

SAND BLAST APPARATUSA APPLICATION mio ocr.1. 1912l 1,1 96,362. Mentod Aug. 2S), l.

4 SHEETS-SHEET 3.

4 SHEETS-SHEET 4.

Patented Aug. 2S), 1916.

UMTED STATES .PATENT OFFICE.

FOSTER J'. HULL, OF HAGERSTOWN, MARYLAND, ASSIGNOR TO THOMAS W. PANGBORN COMPANY, OF HAGERSTOWN, MARYLAND, A. CORPORATION OF NEW YORK.

SAND-BLASTl APPARATUS Specification of Letters Patent.

Application filed October 7, 1912. Serial No. 724,292.

To f/ZZ whom t may concern: n

Be it known that l. Fos'rnn J. HULL, a citizen of the United States. and a resident of Hagerstown, county yfot' W'ashington, and State of l\flaryland, have invented certain new and useful Improvements in Sand-Blast Apparatus, of which the following is a specitication. Y Q

My invention relates to improvements in sand blast apparatus, and jmrticularly to improvements in what are known as sand blast barrels.

Sand blast barrels are commonly used for cleaning small castings, and other small objects. and comprise a rotary barrel, drum or container, into which a charge of the castings or other objects to be cleaned is introduced, and V'then the barrel is caused to ro tate, and at the same time sand blast apparatus Vis operated, the blast or blasts beingl caused to impinge upon the castings, etc.. in the barrel.

My invention consists in the novel mountingy or support of the blast nozzles, in the novel means employed for supplying abram sivo material to such nozzles, in the novel arrangements for charging the barrel, in the novel arrangements for discharging the contents of the barrel, in thc novel means provided for delivering sand continuously from the barrel to the sand hopper in the normal operation of the machine. and in other features hereinafter described and particularly printed out in thc appended claims.

The objects ot' my invention are to com bine high efficiency of blasting operation with oase of handling and facility in receivA ing and discharging castings and other objects to be acted upon; to malte the appa-- ratus self-contained, dispensing with accesv sory apparatus. other than the necessary exhaust connection for removing dust: to so design the machine that it may be set on any hind of lloor without excavation and without foundation. and Without extensions below the tloor line. such as sand pits. elevators, settling chambers. etc.; to so construct the machine that the blasts shall spread with approximate uniformity over the entire charge ot the drum. and shall reach objects which lieI at the ends of Stich drum equally as well asthose near the center of the drunntocause the blasts to act sidewise on the articles to be cleaned, as well as radially. so that edges, recesses, sides, etc., of the castings or other objects shall be exposed to the action of the blasts: to render the direction of action of the blasts adjustable during the operation Patented Aug. 29,1916.

of the machine; to render the sand hopper of the machine accessible at all times, and to render the sand feed visible so that it is easy to determine by visual inspection that all of the blasts are operating properly; to provide for ready cleaning of the sand inlet, while the machine is in operation, in case sach sand inlet should become obstructed; to provide for the ready charging and discharging of the drum; to make the apparatas automatic in action, simple, durable, cflicient and compact; to so design the apparatas` that relatively small power shall be required tor its operation; toadequately pro Lect the gears, hearings, etc., from' dust and wear. and to provide for the ready replacing of such parts of the machine as are necessarily exposed to the abrasive action of the blast.

Other objects of my invention will appear hereafter.

l. 'will now proceed to describe my invention with reference to the accompanying drawings. and will then point out the-novel features in claims.

ln said drawings: Figure l shows a front view or" the machine, the charging door of the case inclosing the drum being shown in open position. Fig. 2 shows a rear elevation ot the machine. Fig. 3 shows a detail side elevation of the sand blast manifold and Fig. l shows an end view of such manifold. Fig. 5 shows a detail transverse section of tht sand feed box. Fig. 6 shows an elevation of the lett hand side of the machine, and Fig. T shows an elevation of the right hand side ot the nnichine.' Fig. 8 shows a transverse section of the machine. Fig. 9 shows a vertical section of the machine, the section being taken through thc axis of rotation of the drum. Fig. 10 is a fragmentary detail sectional View of the locking mechanism for the door of the drum. Fig. 11 is a fragmentary longitudinal section of the blast nozzle n ia nilold.

The improved sand blast machine herein illustrated temp-rises a.drum consisting'of side plat i tFig. 9) provided on their peripheries ith gear teeth 2 (Figs. 1 and 9) and a sur v@vlinder 3 the ends of such screen c fitting Within annular should n.. ,-:zwiiflcd on the inner faces of elicit' l 7,

upon a hollow these side plates 1. The side plates are held together by through-bolts 5 and are spaced apart by spacing sleeves 6 surrounding said through-bolts.- The screen cylinder 3 is provided with a swinging charging door 7 (see particularly Fig. 8), hinged to the screen cylinder and provided with suitable locking means hereinafter described. The side .plates 1 of the drum are provided with suitable journals 8 located within bearings 9 of an outer case, such case comprising a lower section 10 of substantial construction adapting it to support the drum and its load, and an upper section 11 of tighter construction. This upper section 11 of the outer case is provided on the front side of the machine With a door 12 adapted to swing about an axis substantially coincident with the axis of rotation of the drum. This door is supported by radius arms 13 secured to bearing rings 14 rotatably mounted upon the external cylindrical surfaces of the bearings 9 of the drum. Within the lower section 10 of the outer case of the machine, there is an inclined shelf 15 having in it a discharging opening 16; and a. swinging shell 17 is provided, which elf ink one position closes this opening lo, forming with shelf 15 an inclined surface down which sand from the drum may slide to a suitable screen 18 and thence to the sand hopper 19; While in its other position (the position shown in fuli lines in Figi *H he swinging ,shelf .17 forms a sla-fit' doa which the courge of the drinn may slide when the door of the drum is opened for discharging, The front of the lower section if" of the inclosing case is substantially open from the bottom up to the upper end oi' the inclined shelf 15, so that a car may be run directly into this inclosingr ease to the charge of the machine when the la ter discharged from the drum and slides dm." shelf 17. transverse support 52() is pro ed for suplfortini." the swiigiugl shelf l'i" i1: it? lowermost position; that is to say. the position of the drum is i it occupies vwhen the than" being discharged. A trausi' rse bruce 21 is provided for the lower ai ,tion 1l) of the outer cese of the machine, but this transverse brace 21 has lar '1- central aperture 22, so that acre s is eas r obtained to the space behind it and sand or other objects which may find their say into such space are easilyV removed. Another transverse brace 23 is provided at the front, but this is also provided with a, large central .rture 24 'through .ihir: "Wei-turc a tool f be iiitroijll=."efl it ne s. lr to assist in descent ci' the castings, ctc., along the The swinging. :if ,f l

one end With a 'lever 26 by which the swing' ing door 17 may be operated, and is also' provided with a weight 27, which crosses the perpendicular when the door 17- is moved from one p'osition to the other, so that said weight 27 causes thev door to remain in the one position or the other, unless positively moved. The weight Vof castings or the like dropping upon the door 17 when the drum is opened will be sufficient, ordinarily, however, to cause the door 17 to swing automatically to the position shown in Fig. 8.

The door 17, and the sides of the shelf 15, extend right to the surface of the shaft 25; the screen 18 also extends right to that shaft; and so does the inclined shelf 28, forming the bottom of the sand hopper 19. When the door 17 is in its closed position, therefore, sand escaping from the screen cylinder 3, is caused to pass through the screen 18 and into the sand hopper 19, Without opportunity to escape elsewhere.

The drum 1 3, is rotated by t,means of a shaft 29 (Figs. 8 and 9) provided with pinions 30 engaging the gear teeth 2 of side able reduction gearing 31-32 from a shaft 33 upon which are tight and loose belt pulleys 34 and 35. The shaft 33 extends through the machine and is provided on vits opposite side With a wheel 36 which forms convenient means for turning over the drum by hand when this is desirable, and may be used as a brake drum if desired.

Within the blast drum is mounted a. blast manifold 37 shown particularly in Figs.. 3,4, 8 and 9, This manifold is provided with journals 38, the bearings for which are formed by the end plates 39 of the bearings for the drum itself. Dust-tight packing 40 is provided to prevent sand from reaching these journals and bearings, and a lever 41 is provided, by which the manifold may be adjusted in position angularly. To hold the manifold in any position to which'it maybe adjusted, this lever 41 is providedl 'witha spring actuated latch dog 42 engaging teeth 43 (Fig. 7) on the peri hery of one of .the bearing end plates 39. he manifold is pro vided internally with ducts 44, 45, 4G and 47, `which ducts terminate, beyond the ends of the manifold, .in fittings 48 adapted to kreceive flexible hose. Duct 44 is a live air duct for the supply of air or other blast iii-iid, under pressure, to the blast nozzles, hereinafter mentioned, carried by the manifold. Duets 45, 46 and 47 are suction ducts. connected by hose 45a, 4Ca and 47 to sand feed boxes 49 at the rear of the machine and communicating with the sand hopper 19. of tl` rse feed boxes is shown in section in Fig.

:30, l defsJI ate sand blast'nozzlcs (-:lrried by the manifold 3 ln the rmistruction shown the manifold is provided with three of these nozzles and therefore there are three suction ducts, 45, 46 and 47, provided in the manifold. Of course the number of nozzles may be greater or less, in which case the number of suction ducts in the manifold will be correspondingly greater or less. 1n the particular construction of nozzles shown in Figs. 8 and 11, each nozzle is provided with a removable nozzle tip 5l held in place within the nozzle by a screw bushing 52. Each nozzle is connected, by a flexible tube 53, with the live air duct 44. Each nozzle comprises a suction chamber 54 to which is connected the corresponding suction duct, 45, or 46, or 47, as the case may be. It will be seen that when air under pressure is discharged through liveair duct 44, and the induction nozzle 55 (Fig. 8) forming the blast nozzle termination of that live air duct, suction is produced in chamber 54, which suction draws a mixture of sand and air from the corresponding feed box 49v up through the correspondmg hose 45, or 46, or '47, and the corresponding suction duct 45, or 46, or 47 of the manifold, the sand so drawn into the blast nozzle 50 mixing within that nozzle with the live air discharged through nozzle 55, and thence being projected with reat force from the blast nozzle 50 against t e contents of the drum.

In the arrangement of nozzles on the manifold shown articularly in Fig. 9 (which arrangement as been found to be especially advantageous) only the center nozzle is positioned approximately radially; the other two nozzles *are positioned obliquely so as to direct their blasts, the one toward one end of the drum, the other toward the other end of the drum. The angular positions of the two outer nozzles 50 are such with reference t'o the length of the drum and with reference to the angle of dispersion of the jets, from these nozzles, that the entire length of the drum is swept by the jets with substantial uniformity. The angular projection of the jets from the two side nozzles 50 is of great advantage as thereby the jets from these nozzles are able to clean sides and edges of the objects treated, and to penetrate into side recesses of such objects, as they could not 1f the jets were projected substantially radially.

As shown particularly in Fig. 5, each sand feed box 49 is provided with a port 56 communicating with the interior of the sand hopper 19. Each box is further provided with a suction pipe 57 having an inlet port 5224q which pipe 57 projects out beyond the sidi` of the box 49 and has connected to it an appropriate suction tube 45", or 46", or 47, as the case may be. Each of these boxes 49 is further provided with a baille 59, the position of the bottom of which is such as to prevent choking of thc supply port 58 of the feed pipe 57. It has been found that, except for this baille 59, there is a tendency, during periods of idleness of the machine, for the sand to bank up in the feed boxes 49, so as to completely close the openings 58; and` when this occurs, since entrance of air through these ports 58 is cut off, the feed is choked. But by the provision of the baffllc 59, the sand in the immediate vicinity of the ports 58 cannot rise so as to completely close said ports 58, however the sand may bank up behind the bathe 59. Between the lower edge of the baffle 59 and the ports the sand cannot exceed its natural angle of repose. The pipes 57 are rotatable for adjustment of the position of the ports 58 with reference to the lower edges of the battles 59, and therefore the rate of feed of the sand. The 'feed boxes 49 are customarily provided with swinging covers 60 which, when opened, permit visual inspection of the feed of the sand to each nozzle. 1t is therefore easy to determine while the machine is running, whether all of the nozzles are operating or not. In case any nozzle fails to operate, such failure will be due to clogging of the port 58 from one cause or another, and it is easy to introduce a tool and clear this port 58 from any obstruction without interfering with the operation of the machine. A door 61 on the rear side of the sand hopper 19, permits inspection of such hopper when desired, and Visual observation of the height and condition of sand therein. In the rear side of the outer case of the machine there is also provided an exhaust connection 62 to which may be connected a suitable eX- haust fan, for the removal of dust.

The latch mechanism for holding the charging door 7 of the blast drum 13 closed, is shown particularly in Figs. 1, 8 and 1.0, and comprises a latch lever 63 pivoted at 64 to the door 7 and connected, on opposite sides of its pivot, to sliding spring-actuated bolts 65 adapted to engage suitable locking recesses 66 provided on the inner surfaces of the side plates 1 of the blast drum. When the door is closed the bolts 65 engage the outer surface of the drum and hold the door closed. The pivot for the door 7 is at 67 (Fig. 8).

The operation of the machine is as follows: In charging the machine the swing'- ing door 12 of the outer case is raised, the blast drum l--3 turned around until its door 7 is opposite the opening left by the raising of the door l2, and then the door 7 is opened and latched in open position, and the charge of castings or other objects to be sand blasted is introduced into the drum. The doors 7 and 12 are then closed. the rotation of the drlun started, and air or other blast fluid under pressure admitted to duct 44. ln practice the drum 1*-3 is rotated about three rcvolut ions per minute., in the direction of arrow shown in Fig. 8. The

articles to be sand blasted therefore occupy approximately the position indicated in dotted lines in Fig. 8. 'The diameter' of the drum 1 3 and the position of the blast nozzles 50 within that drum. is so regulated in the design of the machine,that

the surface of the pile of material to bblasted is about six inches from the 0rilices of the blast nozzles, it having been learned by actual experience that this is the most eflicient distance of the nozzles from the work, using the ordinary abrasive materials and ordinary blast pressures. .As the drum rotates the material within it is tumbled about, new surfaces being constantly exposed to the action of the blasts. When the sand blasting has been continued for a sullieient lengtlriof til'negftlie supply of air under pressureto duct l 'sdiscontinued, so stopping the lastini. The cover l2 is raisedraiul, comes opposite tlegopcili'n' raising ol' said cover.:l 'sa'idldo and late-hed in open pos rotated until the=d0or`w L; opposite the )peninglttinf4` rl`he contents ot.' the 'di'.uir

automatically froln t'li'e "dirait amgl f swing'un,r shelf 17 hasnot"allfemlv'lnicnf lowered to the position shown in fitage, the weight of the objects upon vitjwill moiiejlit to that position` whereupon charge of the drinn will. slide downthisswingin" Shelf lT to the lloor, or upon atei: whici in ay have been run in underneaththis slielfli' to rrreis'e the charge. new charge' may `then be introduced into the drumfand the door 7. and the shelf li' returned yto their` closed positions and the rotation ofthe drum ref stuur-d. rl`hcn upon turn'ungy on the supply ot' live air to duct i4 a suction is immediately produced in chamh'er a-l'and 4communicated through the llexible hosefl, 46? and a'r" which automatically re'fstarts the llow ol sand from sand boxes 49.

`dhile. in Fig. S l have indicated a position assumed by the charge of the machine..

during` the rotation of the drum. itwfill life obvious that this angular position ofthe srnlufe olthe charge wlth respert'to the horizontal will vary with varying speeds ofy tlnA drum and with varying; nature of the contents nl the charge,` ound' castings (shot for example)A would assume only a relatively small angle; while' spiders and objects with projections may naturally assume quite an oblique angle. ln order that, not'withstanding this variation in ingle ot the. surface of the charge. the hiaat may be projected as uiirectly as posagainst the. charge, the` manifold 3T e rotatable as shomnnnd may be adjusted through a wide angler, .while the machine is in operation. Ahother advantage of the rotatabilitl.; of thel manifold is that other ing provided which this rotatability makes it easy to move the manifold into position opposite the door 7, when the nozzle tips must be removed or the air connections renewed.

It will be observed that in this machine the sand flow is automatic; there is no sand valve to manipulate. Sand starts to flow when the air is turned on, an'd stops flowing when the air is turned olf. There being a "sight feed to each blast nozzle, if any nozzle fails to operate, for any reason. that .fact may be readily determined by inspeetion of the corresponding feed box.

Lam aware that heretofore sand blast barrels'have been employed wherein blasts are introduced from oppositii ends of the barrel. When this is done. the blast iets must travel a considerable distance before they encounter the main portion of the charge in the barrel. and it is well known that the ellieieney ot' the blast decreasesI greatly with increase in distance. Flnthermore, the two blasts introduced from opposite ends of the i drum have a tendency to neutralize each other. To obviate these objections,y sand blast barrels have been built in which the entire sand blast mechanismI is' located within the barrel, a` plurality of nozzles beproject the sautlblasts normally against the surface of theiharge. The location ot' the sand bl. t mechanism within the barrel itself-` is4 ex, emely objectionable. and the normal Iarrangeinent of the nozzles does not provide etlicient distri bution. ol' the iets. ly the arrangement of 100 nozzles shown herein. l'attain substantially uniform distribution ol' the jets overthe surfacey ol' the charge without interference between several jets. The door T bein;y hinged near the top ot the charging and dis` charging opening in the drum. and being arranged to swing.: inwardly, is out of the way, in its inward irwition, both when the drum is being rliarged and when the drlun'is being` discharged. and does not conllirt vor 11o interferewith the covering over ot' the drum 'diy the curved cover ll and door l; which are separated, troni the drum by a few inches only. 'In addition. the door 'i'. when at its inner position; and when the drum is being: 1.15 disclmrged, forms an abutment to prevent the objects within the drum .from fallingjr Yacross the dischargingopening; in the drum, to the opposite side ot' such opening' 'and bevond, instead ol" passing out through such iipenine'. as they should. ASince the swinging door l2 of the case it: substantiallyconf centric with the drum. and swings upward and backward, no additional head room is required 'to permit the raising' ot' said door 125 .l2 such as would be required if the door were a vertically slidinj T door. and no additional space in front of the machine re quired. as would bey the rase il' the said door swung outwardly.

lll)

What I claim is:-

1. Sand blast apparatus such as described, comprising a rotary screen drinn, a blast nozzle therein, and a case inclosing said drum and having, beneath the drum, a sand receptacle, said case having an opening, opposite the side of the drum and located, in greater part, above the axis of the drum, and having a door for such opening whereA by access may be obtained to theY drum, said drum having in its side, and adapted to register with the opening of the case, a charging opening, and having alsoa door, for closing such charging opening, arranged to swinginwardly and upwardly vwithin the drinn when the opening of said drum is in registry with the opening of said ca se; said case provided with a sloping shelf beneath the drum, ai ranged to permit sand falling thereon from the drum to slide by gravity into said sand receptacle.

2. Sand blast apparatus such as described, comprising a rotary screen drum,'and afcase inclosing said drum and having, beneath the drum, a sand receptacle, said case having an opening, opposite the side of the drum, through which the drum may be charged, said drum having in its side, and adapted to register withv the opening of the case, a charging openingf-,and having also a door for closing .such chargingopening, said door pivoted near that-,edge of said charging opening'of the druin which is the upper edge when the said charging opening of the drum yis in registry 'with the opening of the case, and arranged to swing inwer ly and upwardly Within the'Y drum; said ease provided with means beneath the drum arranged to ermit sand falling from 'the drum to sli e by gravity into said sand re 1 ceptacle.

3. Sand comprising a rotary screen drum, and a blast nozzle therein, said drum having in its side an inwardly swinging charging door, bearing therefor and a case inelosing said drum the top of which case is eylindricai and comprises an upwardly and rearwardly swinging charging door whereby access may be obtained to the drum, and bearings for said door, mounted upon and arranged to turn about the bearings te.: said drum.

4. Sand blast apparatus such as described, comprising a rotary vscreen drum, and a case inclosing said drum, a sand receptacle, said case having an opening, opposite the side of the drum, through which the drum may be charged, said drum having in its side, and adapted to register with the opening of the case, a charging opening, and having also a door for elosingsueh charging open ing,`said door pivoted near thatA edge of said charging opening of the drum which is the upper edge when the said charging opening of the drum is in registry with the opening blast apparatus such as described,A

of the case, and arranged to swing inwardly and upwardly within the druin, and latching mechanism for the door of the drinn adapted to hold the doorl in either its closed or its open position; said case providedrwith means beneath the drum arranged to *permit sand falling from the ldrum to slide by gravity into said sand receptacle.

5. Sand blast apparatus such as described, comprising in combination a rotary screen drum, a blast nozzle therein, a support for said drum coinprisinga casing inclosing the drum and having an inclined shelf adapted to receive Sand escaping from the drum, said shelf having an opening through which the contents of said drum may he discharged, and a swinging shelf arranged in one posi tion to close such opening in the inclined shelf, and in another position to form a slide down which the material ldischarged from the drum may pass; said drum provided with a discharge door.

6. Sand blast apparatus such. as described, comprising in combination a rotary screen drum, a blast nozzle therein, a casing inelosing said drum and provided beneath theI drum with a` sand hopper, said casing haw' ing beneath the druina screen forming the top of such sand hopper, and having also an inclined shelf adapted to receive sand escaping from the drum, such shelf having in it an opening for the-escape 'of material. discharged from such drum, and a swinging shelf which in one position closes such open ing and in another position foi-ins a slide down which the material disclnirged/from the drum may pass; saidd-rum provided with a discharge door.

7 Sand blast apparatus such as described, comprising in combination a rotary screen drum, a blast nozzle therein, a. support for saidy drum comprising a casing inclosing the drum and having an inclined shell adapted to receive sand escaping from the drum, saidshelf having an opening through which the contents of said drum .may be disA charged, and a swinging shelf arranged in one position .to close such opening in the in clined shelf', and in another position to forni a slide down which the material discharged from the drum may pass; said drum provided with a discharge door; and a support r'against which such swinging shelf:I rests 'Whenniaterial discharged from the drum is passing over it.

8. Sand blast apparatus such .as described, comprising i'n combination a rotary screen drinn, a blast nozzle therein, a support for said druif'l, comprising a casing inclosirig the drum and having an inclined shelf, adapted to receive sand escaping from the drun'i, said shelf having an opening through which the contents of said drinn may be discharged, and a swinging shelf arranged in one position to close such opening in the inclined lli@ shelf, and in anothel` position to form a slide .down which the material discharged from the drum vmay pass; said ydrum provided with a discharge door, and means tending to hold said swinging shelf in either of such two positions.

` 9. Sand blast apparatus such as described, comprising in combination a rotary screen drum, a blast nozzle therein, a support for said drum comprising a casing inclosing the drum and having an inclined shelf adapted to receive sand escaping from the drum, said shelf having an opening through which the contents of said drum may be discharged, and aswinging shelf arranged in one position to close such opening in the inclined shelf, and in another position to form a slide down-which the material discharged from the drum may pass; said drum provided with adischarge door, said case being open f in .the;-, lix `1e of discharge of material down "such 'swinging shelf.:

0..Sand blast apparatus comprising. in bination a rota drum, and a blast manifold therein provided with a plurality 4of blast nozzles, said manifold having a plu- .rality of'sand supply ducts, one for each Such nozzle, and avm also means, other thansaidand supply ucts, forv supplying blast-duid under pressure to said nozzles.

11. I Sand blast apparatus comprising in biation a rotary drum, a blast manitherein` provided with a plurality of l .,'ozzles, said manifold having a plurality lofjfsaand supply ducts, one for Ieach such'nozzle, andmeans'for supplying blast uidffuxder pressure to said nozzles, said maniioldbeing rotatable, whereby the angle "of proe'ction of the blasts maybe varied. 40

lcombination a rotary drum, a sand blast .12.' and blast apparatus comprising in f manifold therein provided with a plurality of nozzlesl arranged to project their blasts diver ently with respect to 'one another, said mani old being rotatable, and being provided'with means for supplying of sand and air to said nozzles.

13. Sand blast apparatus comprising in one of which is hollow, and a blast nozzle support within said drum and rotatably mounted within one of said journals 16. Sand blast apparatus comprising in combination a rotary drum having journals, one of which is hollow, a blastA nozzle support within said drum and rotatably mounted within one of said journals, said support provided at its end with air and sand connections.

17. Sand blast apparatus comprising inA combination a rotary drum having `journals, one of which is hollow, a blast nozzle support within said drum and rotatably mounted within one of said journals, and means for adjusting the angular position of said support v.

18. Sand blast apparatus comprising in combination a rotary drum having hollow journals, a blast nozzle manifold within said drum and rotatably mountedrwithin said hollow journal, said journals being open at the ends, said manifold provided with a plurality of blast: nozzles and 'with ducts for the supply of sand,` and -blast fluid under pressure to said nozzles, said ducts terminating at the ends of said manifold. j

In testimony whereof I have signed this specification in the presence of two subscribing witnesses. y FOSTER J. HULL. Witnesses:

CnAs. B. Borna ZELLER, G. C. ANDERSON.

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