US2344476A - Abrading apparatus - Google Patents

Description

arch i4, 'i944- D. c. TURNBULL ABRA'DING 'APPARATUS Filed Dec.` 51, 1941 '7 Sheets-Sheet l INVENTOR. I l/rhul l March 14, 1944. D. c. TURNBULL ABRADING APPARATUS '7 Sheets-Sheet 2 Filed DeC. 51, 1941 March 14, 1944. y D Q TURNBULL. 2,344,475

ABRADING APPARATUS Filed Dec. 5l, 1941 v '7 Sheets-Sheet I5 lll" HIL

March 14, 1944. D. c. TURNBULL ABRADING APPARATUS Filed Deo. 151, 1941 '7 Sheets-Sheet 4 I N VEN TOR.

D. C. TURNBULL ABRADING `APPARATUS March 14, 1944.

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ABRADING APPARATUS Filed DSC. 3l, 1941 l 144 142 'l 145 I? 145 144 105 ,./100 104% d\\\\ A; l A 145 101 155 171 170 ,65 154 15g l l 146 J1(667 16.4 3 El, k ,LS, 156 r 55 2 A 15/ 155 154 /jg I i sb* m v A I u 7 sheets-sheet e m/ la .Y l INVENTQR Y azfm iflwifu/ P77 Mix@ March 14, 1944. D. c. TURNBULL ABRADING APPARATUS Filed Dec. 31, 1941 7 Sheets-Sheet 7 Patented Mar. 14, 1944 NITED STATES PATENT OFFICE ABRADING APPARATUS David C. Turnbull Mishawaka, Ind., assigner to The American Foundry Equipment Company, Mishawaka, Ind., a corporation of Delaware Application December 31, 1941, Serial No. 425,083

14 Claims. (Cl. 51-9) I crusted sand, and rough metal from certain areas thereof, while other areas which are to be positioned against a oor or wall, for example, require less thorough blast cleaning. This is particularly true of such metal ware as cast iron bathtubs, sinks and the like, whose exposed su1' faces are to be coated with a porcelain enamel tion and manipulate the workpieces in each of the blast streams.

An object of this invention is to provide improved blasting apparatus for conveying the workpieces into and through the blasting streams of a plurality of abrasive blasting wheels and for manipulating the workpieces in said streams in a manner to thoroughly clean and polish such areas as required through cleaning and to rough clean such areas as require only superficial cleaning.

Another object of this invention is to provide l improved blasting apparatus whereby the major which must be perfectly smooth. This requires that the hollow interior surfaces aswell as one or both exterior side wall surfaces and one or both exterior end wall surfaces be thoroughly cleaned so as not only to remove scale and encrusted sand but also to smooth out rough metal projections to provide a base surface to which the porcelain enamel will tenaciously adhere. The outside surface of the bottom wall of tubs and sinks, for example, need not be as thoroughly blast cleaned since these surfaces are in contact with the floor or Walls of the room and a're not exposed. l

Since the b last cleaning operation adds to the cost of manufacture in proportion to the extent of the blast cleaning performed, it is desirable to keep blast cleaning costs to a minimumv and -not unnecessarily blast clean surfaces which will not be exposed or do not require extensive blast cleaning but to concentrate the cleaning operation on the surfaces which are exposed and which are to receive the porcelain enamel or other coating, so that a high grade product can be produced which is eminently satisfactory for use and lasting in service.

High speed low cost cleaning can best be attained by the use of centrifugal blasting wheels having means associated therewith for accurately controlling the direction of fire of the abrasive blast, as illustratedr in Peik Pat. No. 1,953,566. Such abrasive throwing wheels are capable of throwing many hundreds of pounds of abrasive per minute at high abrading velocity with the projected stream fired in a predetermined direction and within a predetermined limited blasting zone. However, due tol the weight and speedy of rotation of such blasting wheels, it is generally most convenient to maintain the wheels in relatively stationary posi.-

portion of the abrasive projected from the centrifugal blasting wheels is. employed in cleaning such surfaces of the workpieces as require thorough and complete cleaning.

Another object of this invention is to provide improved blasting apparatus whereby` the exposed surfaces of bathtubs, sinks, and like hollow metal may be thoroughly blast cleaned, whereby a tenacious bond between the enamel coating and metal can be effected and a smooth finish produced and whereby the non-exposed or concealed surfaces may be subjected to only rough cleaning.

A further object of this invention is to provide improved blasting apparatus which is substantiallyl automatic, foolproof, smooth and eflcient in operation, sturdy and lasting in construction, simple in design, and` which permits higher production speed at relatively lower costs than apparatus of this type heretofore provided.

Other objects will become apparent as the disclosure proceeds.

Various other features and advantages of the invention will be apparent from the yfollowing particular description and from an inspection of the accompanying drawings.

Although the novel features which are believed to be characteristic of this invention will be particularly pointed out in the claims appended hereto, the invention itself, as to its objects and vadvantages,.and the manner in which it may be carried out, may be better understood by referring to the following description taken in connection with the accompanying drawings forming a part thereof, in which Fig. l is a top plan view of my improved blast cleaning apparatus illustrating the manner in which hollow metal ware such as bathtubs are subjected to thorough blast cleaning on the exposed surfaces thereofand to minor blast cleaning on the non-exposed surfaces which require only superficial blast cleaning;

Fig. 2 is an enlarged elevational view of that part of the blast cleaning apparatus embodying one cleaning zone where thorough cleaning of certain exposed surfaces is effected as it appears when viewed along line 2-2 of Fig. 1;

Fig. 3 is an enlarged elevational view of that part of the blast cleaning apparatus embodying another cleaning zone where the certain exposed exterior surfaces are thoroughly cleaned and where certain unexposed surfaces are superflcially cleaned as it appears when viewed along line 3-3 of Fig. 1; g

Figs. 4 to 8, inclusive, are diagrammatic illus-f trations of the `blast cleaning operation carried out in the blasting zone as illustrated in Fig. 2; Fig. 3 showing the operation as it appears when viewed along line 4-4 of Fig. 2; Fig..5 showing the operation as it appears when viewed along line 5-5 of Fig. 2; Fig. 6 showing the operation as it appears when viewed along line 6 6 of Fig. 2; Fig. 7 showing the operation as it appears when viewed along line 'I-'I of Fig. 2; and Fig. 8 showing the operation as it appears when viewed along line 8-8 of Fig, 2;

Figs. 9 to 13, inclusive, are diagrammatic illustrations of the blast cleaning operation carried on in the other blasting zone as illustrated in Fig. 3; Fig. 9 showing the operation as it appears when viewed along line 9--9 of Fig. 3; Fig. 10 showing the operation as it appears when viewed along line Ill-I0 of Fig. 3; Fig. l1 showing the operation as it appears when viewed along line II-II of Fig. 3; Fig. 12 showing the operation as it appears when viewed along line I2-I2 of Fig. 3; and Fig. 13 showing the operation as it appears when viewed yalong line I3-I3 of Fig. 3;

Fig. 14 is an enlarged vertical cross-sectional view through one of the work-supporting hangers and the mechanism for guiding the hangers and suspended workpieces through the first blasting zone as the same appears when looking along line I4-I4 of Fig. 1;

Fig. 15 is a fragmentary top view of the mechanism for guiding the hangers through the blasting zone shown in Fig. 2;

Fig. 16l is an enlarged vertical cross-sectional view through one of the work-supporting hangers and adjacent spinner chain-guiding and bulging devices, as the same appears when looking along line IS-IS of Fig. 3;

Fig. 17 is an enlarged fragmentary vertical cross-sectional view showing a portion of a worksupporting hanger and adjacent spinner chainguiding and supporting devices as the same appear when viewed along line I'I-I'I of Fig. 3; and

Fig. 18 is a top plan view of the apparatus which is designed to carry the ware or articles tov be cleaned through the cabinet in a direction opposite to that illustrated in Fig. 1 and in which only onel set of centrifugal blastingwheels are employed.

Similar reference characters refer to similar parts throughout the several views of .the drawings and the specification.

Referring to the drawings, the blasting apparatus comprises generally a blast cabinet A into which the workpieces p are conveyed by workpiece suspension hangers B and B' which are adapted to roll along a circuitous track C. The surfaces of the workpieces p are blasted with abrasive during their travel through the cabinet A, by a plurality of centrifugal abrasive throwing wheels which operate to project controlled streams of abrasive against the surface of the workpieces. The workpiece-supporting hangers B and B' 'are continuously advanced through one blasting zone a and another blasting zone b by means of hangeradvancing mechanism D. The hangers and their supported workpieces are rdained inl a definite position during the initial stages of their advance through the blasting zone a and are then swung through a small arc'during the second stage of their advance through the blasting zone a by hanger-guiding and manipulating mechanism E. Mechanism F is provided for also rotating the workpiece-supporting hangers and the suspended workpieces during their travel through blasting zone b where the workpieces are subjected to further cleaning action.

As shown more particularly in Fig. l, the blast cabinet A comprises generally an entrance vestibule section I, a blast section 2 which contains blasting zones a and b, and an exit vestibule section 3. The entrance and exit vestibule sections provide hallways through which the work-supporting hangers move when entering and leaving the main blast section 2 disposed therebetween. Main blasting section 2 may be generally rectangular in outline having a relatively long front side wall 4 upon which the abrasive throwing wheels firing abrasive into the first blasting zone a are supported, and a rear side wall 5 which supports the blasting wheels firing abrasive into the secon'd blasting zone b. The cabinet may be closed at one end vby an end will 6 and the other end wall 'I may be provided with an entrance opening 8 through which the workpieces enter and an exit opening 9 through which the workpieces leave the lmain blasting section 2 of the cabinet. The entrance vestibule I provides a hallway through which the workpieces p enter the blasting section 2 through the entrance opening 8, the entrance vestibule I having enclosing side walls I0 and II and an entrance wall I2 having an enrance opening I3. The exit vestibule 3 is likewise defined by side walls I I and I4 and entrance Wall I5 having an exit opening I6.

The top of the entire cabinet A may be covered and enclosed by a top wall I'I which closes the top of the entrance Vesti-bule I, the main blasting section 2 and exit vestibule 3. The enclosing walls of the cabinet are braced and supported by suitable framing members so arranged and constructed as to rigidly support all the walls of the cabinet and the various operating mechanisms thereto attached. A plurality of rubber curtains or flaps I8 may be suspended in the entrance vestibule I and exit vestibule 3 to prevent the escape of abrasive from the main blasting section 2 through the entrance and exit vestibules. Suitable abrasive hoppers and abrasive cycling mechanism (not shown) may be incorporated with the cabinet for cycling the abrasive from and to the various abrasive throwing wheels and for removing foreign matter and broken abrasive and dust from the abrasive cycled to the abrasive throwing wheels.

The conveyor track C may be of any desired length to convey the workpieces from a loading zone c through the first blasting zone a, through the second blasting zone b, and out of the cabinet to an unloading zone d. That part of the track which supports the hangers in their travel through the primary bla-sting zone a and secondary blasting zone b is positioned above the top wall I'i of the cabinet, as illustrated more particularly in Figs. 2, 3, 14 and 16. 'I'hat part of the track C which extends along the loading zone combination of centrifugal blasting wheels and work-supporting hangers having associated therewith mechanism for retaining those areas of the workpieces which are to be thoroughly cleaned directly in the path of the centrifugally projected streams during their travel through one cleaning zone a so as`to thoroughly clean and prepare such areas for enameling or subsequent treatment, and to rotate the workpieces in other centrifugally projected streams projected at zone b so as to treat other surfaces to a lesser' degree or to such degree. as such other surfaces require. To more clearly illustrate this invention, the drawings illustrate a series of bathtubs undergoing blast cleaning treatment, lbut it will be understood that other hollow ware and `numerous other articles requiring the surfaces thereof to be treated in varying degrees by the abrasive blast may be cleaned by apparatus constructed in accordance with the principles of this invention.

Bathtub workpieces p, shown in the drawings for purposes of illustration. require that the interior bottom surface p1, the interior side wall surfaces p2 and p3, the interior end wall surfaces p4 and p5, the top edge surfaces p12, the interior corners p8, and one or both exposed exterior side wall surfaces p9 and p9 and one or :both exposed exterior end wail surfaces p1 and p11, be thoroughly and completely blast cleaned so that not only all scale and encrusted sand are removed but, in addition, these surfaces should be smoothed down and peened to the point where the porcelain enamel coating later applied will not only present a smooth and finished surface but will be tenaciously bonded to the metal. Thorough cleaning of these surfaces is effected in the blasting zone a by a plurality of abrasive throwing wheels W1, W2, W3, W4 and W5, which are so arranged that the abrasive streams pro` jected therefrom effectively attack the interior o surfaces p1, p2, p3, p4, p5 and p, and the top edge surface p12, and the exterior side wall surfaces p and p9. Mechanism is provided for guiding and presenting these surfaces to the full force of the abrasive blasts projected into blasting zone a. This mechanism includes parts which are fixed to each of the hangers and parts which are independently supported.

In the other blasting zone b a plurality of abrasive throwing wheels W6, W7, W8, W9 and W10 are provided which are so arranged as to project their streams of abrasive against all exterior surfaces as well as the interior surfaces of the workpieces as they travel therethrough. This is effected by the provision. of mechanism F for rotating the workpieces suspended by the hangers during their travel through the blasting zone b so as to finally clean, polish and peen the interior surfaces p1, p2, P3, P4, p5 and p6, the top edge p12 and exterior side wall surfaces p8 and 'p9 previously subjected to the abrasive blast in zone a, and in addition t thoroughly clean, polish and peen the exterior end wall surfaces p10 and p11 and to clean the exterior bottom wail surface p1 sufficiently to remove encrusted sand and scale.

In order that the workpieces p may be arranged as close together asv possible and thereby utilize the vprojected abrasive streams to the maximum in cleaning the workpieces p, the,` hangers and the workplaces suspended therefrom are positioned relatively close together. It isobvious that the workpieces may be suspended in closer relationship if all alternate workpleces moving through blasting zone b are rotated in one direction and all intermediate workpieces moving through blasting zone b are rotated in the opposite direction. This invention, therefore, further comprehends improved mechanism for rotating all the alternate hangers B while moving through blasting zone b in one direction and for rotating all the intermediate hangers B moving through blasting zone b in the opposite direction. l

Any desired number of abrasive throwing wheels may be provided as may be necessary or desirabletoeffectively clean the surfaces of the workpieces p under treatment at thedesired production speeds. While I have illustrated in Figs. 1, 2 and 3 five abrasive throwing wheels for projecting abrasive into the one treating zone a and iivev wheels for projecting abrasive into the other treating zone`b, it will be appreciated that this invention is in no wise limited to the use of only such number of abrasive throwing wheels but any desired number thereof may be provided. The abrasive throwing wheels preferably used are control cage and impeller type wheels, such as disclosed in Peik Pat. No. 1,953,566 having certain refinements in design as illustrated in Unger Pat. 2,162,139. r

Each wheel comprises generally a pair of side wall forming discs 20 and 2i having channelshaped abrasive throwing blades 22 mounted therebetween, which extend inwardly short of the axis of rotation of the wheel to provide a central space. A tubular control cage 23 extends into the central space of the wheel and is normally stationary during operation of the wheel but is so mounted that it may be adjusted to place the discharge outlet in the cage in any desired clockdial position to regulate the direction of fire of the abrasive stream projected therefrom. The wheel is equipped with a vaned impeller 24 positioned within the control cage 23 and fixed to the rear side wall disc 2| of the wheel to rotate with the blades 22 thereof. Abrasive is supplied to the interior of the impeller by means of a feed spout .25 having a funnel formation 26 at the upper end thereof.

Each wheel W may be positioned entirely within the blastingr section 2 of the cabinet and has a hub 2'i secured to the rear side wall disc 2i thereof. The wheel shaft 28 fixed to the hub 21 is preferably positioned on the outside of the cabinet and is rotatably mounted in suitable spaced bearings 30 which may be secured to the adjacent side wall of the cabinet. The wheel shaft 28 is driven by a motor 3i having a drive pulley 32 over which V-belts 32 are trainedfthe V-belts 32' also being trained around the pulley 33 secured to the end of the wheel shaft 28.

The front side wall t and rear side wall 5 of the cabinet may both be recessed in the manner illustrated in Fig. l so as to provide an offset side wall portion and 5' respectively upony which the motors 3| and bearings 3D are mounted, andl an end wall portion and 5 respectively having an opening therein through which a portion of the hub 27 of the wheel projects. In this arrangement the driving motors 3|, V-belts 32', wheel shafting 28 and shaft bearings 30 are fully protected from ilying abrasive, while the abrasive throwing wheels are free to operate within the blasting section 2 of the cabinet.

It will also be noted, by referring more particularly to Fig. 1, that the rear side wall 5 of the blasting section 2 of the cabinet is spaced a substantial distance from the blasting position of the wheels mounted on the front wall 4, and front side wall 4 is spaced a substantial dist-Once from the blasting position of the wheels mounted on the rear side wall 5. In this construction of the cabinet the cabinet side walls 4 and 5 of the blasting section 2 of the cabinet are spaced sufliciently far apart so that any abrasive which may fail to strike the workpieces p advancing through the blasting zones has lost its abrading force before reaching the opposite side wall.

Both the alternate and intermediate work-supporting carriers B and B4', as illustrated more particularly in Figs. 2, 3, 14 'and 16 arev generally similar in construction, each comprising a pair of rollers 31 which roll on the flanges 36 of the I-beam shaped track C. The rollers 31 are secured to the arms 39 of the vU-shaped yoke 38, each arm carrying a stub shaft 40 on which the rollers 31 are journalled. Each yoke 38 is provided with a downwardly extending leg 4| which terminates in a cup-shaped receiver 42. A tubular sleeve 43 has the upper end thereof projecting into the cup 42 and is iirmly secured to the cylindrical wall of the cup. A spindle 44 is rotatably mounted within the sleeve 43 on a thrust bearing comprising a bearing part 45 fixed to the upper end of the sleeve 43 and a bearing part 46 iixed to the upper end of the spindle 44, the bearing parts 45 and 45 having a raceway therebetween for ball bearings 41. The spindle 44 may be provided with-a attened head 48 which rests on the bearing part 46.

Both the alternate and intermediate hangers B and B' are each provided with a work-supporting spindle 53 which is connected to the carriage spindle 44. The spindle 44 is secured to a heavy collar member 41 which is provided with a bearing collar 48 secured to the upper end thereof and which is positioned adjacent a bearing collar 49 secured to the lower end of the sleeve 43, thus permitting the heavy collar member 41' and( spindle 44 to freely rotate within the sleeve 43. The upper end of the work-supporting spindle 53 is removably secured within a socket 52 of collar member 41 by means of a suitable key 5|. The spindles 53 are of sufilcient length to extend through a slot 55 in the top wall i1 of the cabinet, the slot 55 being directly below the track C. The lower end of each hanger spindle 53 is provided with a. hook element 56 to which the workpiece p may be conveniently attached. Each of the work-supporting spindles 53 and the workpiece which it supports may be rotated from the thrust bearing contained within the stationary sleeve 43 of the hanger carriage.

All the hangers B and B' are connected together by means of a continuous conveyor chain 68 which is positioned directly beneath the track C. The conveyor chain 60 may be in the form of a heavy link'chain comprising paired links 6| connected to intermediate links 62 by heavy studs 63. The leg portion 4| of each hanger bracket 38 is provided with a reduced neck portion 64 which extends through aligned apertures in the paired links 6| so that the paired links 6| seat between an'enlarged collar portion 85 and an enlarged head portion 88 provided on eachleg 4|. Thus connected. the work-supporting hangers B and B can be arranged in uniform spaced relationship with the rollers 31 thereof free to roll on the ilanges 38 of the track C.

The work-supporting hangers are causedto travel along the track C by driving mechanism D which engages the conveyor chain 88, and comprises a conveyor driving motor 81 mounted on the top wall |1 of-the cabinet and having a driving connection with a speed reducer 88. The drive shaft 69 of the speed reducer 68 carries a sprocket 10 which carries a drive chain 1|.`

Drive chain 1| is trained around a sprocket 12 xed to a stub shaft 18 rotatably mounted in a bearing collar 14 xed to the top wall |1 oi' the cabinet. Stub shaft 13 carries a large sprocket wheel 15 which meshes with the conveyor chain 60. Driving motor 61 thus operates to continuously advance the workpieces p suspended from hangers B and B through the blasting zones a and b within the cabinet.

In order that the interior surfaces and certain exterior surfaces of the workpiece p which require thorough cleaning be adequately blast treated in blasting zone a, mechanism is provided for guiding the workpieces through the iirst stage a' of blasting zone a while held in one position as shown in Fig. 1, and through the second stage a" of blasting zone a while held in a somewhat different position. This mechanism comprises a device associated with all of the hangers B and B', as illustrated more particularly in Figs. 1, 2, 14, 15 and 16, which includes three equally spaced guide rollers 8|, 82 and 83, each supported upon an arm iixed to the heavy collar member 41 which serves as a hub therefor. Each of the rollers 8|, 82 and 83 is rotatably mounted upon a bearing stud 84 fixed to the end of each arm 80. The arms 80 rotate with their associated hanger spindle 44 and Work-supporting spindle 53.

A guide track 85 oi' considerable length extends along the path of travel of the work-supporting hangers and guides them while passing through the first stage a' of the first blasting zone a. The guide track 85 may comprise an angle-shaped member having a vertical guide wall 86 along which two of the guide rollers associated with each hanger may roll. The guide track 85 may be supported on the top wall I1 of the cabinet or it may be suitably suspended from the ceiling of the plant in which the cabinetis installed so that its supports do not interfere with the normal advance travel of the hanger. It will be noted that a part 81 of guide track 85 projects some distance beyond the front entrance wall I2 of the entrance vestibule and its leading end is provided with a cam wall 88 to permit unobstructed engagement of two of the guide rollers with the vertical guide wall 88 of the guide track 85.

The hanger hook 58 from which the workpiece p is suspended is so constructed as to firmly grip the workpiece and prevent the workpiece from swinging or rotating on the hanger hook 56. When a suspended workpiece p is ready to enter the cabinet, a workman guides the workpiece -so that two of the hanger guide rollers 8| and 82 roll into contact with the vertical guide wall 86 of the track 85. 'I'he workpieces p are then advanced through the entrance vestibule and through stage a of blasting zone a While held in the position illustrated in Fig. l. During advance movement of the suspended workpieces p along the guide track 85, the workpieces do not rock or rotate but have a continuous advancing movement only as they are subjected to the abrasive blasts from the abrasive throwing..

Wheels W1, W, and W3.

When the workpiece has reached the'end of its travel along guide rail 85 and when it has completely or partially passed through the abrasive stream projected by the abrasive throwing whee1 W3, guide roller 83 passes onto a switch track 90 which may be in the form of an angle bar and which has a vertical guide wall 9|. The vertical guide wall 9| has a curved end portion 92 to permit free and unobstructed rolling movement of the guide roller 83 in contact with the vertical wall 9|. The work-supporting hanger continues its advance along switch track 9|, which may be suitably suspended from the ceiling of the plant,l until the other two' guide rollers 82 and 8| have cleared the guide track 85, as indicated more particularly in Fig 1.

When this occurs, guide roller 83 moves into contact with the cam portion 93 of a second guide rail 94 which may have an angular cross-section and which may be suspended from the ceiling of the plant in which the cabinet is installed. 'I'he second guide rail 94 has a vertical guide wall 95 which joins cam guide wall 93. Cam guide wall 93 engages the outer periphery of guide roller 83 and leads it into contact with the inside face of guide wall 95. Since the hanger is continuously advanced by the conveyor chain 6U driven by motor 6l, the work-supporting spindle 53 and its suspended workpiece p is rotated, as roller 83 moves over cam guide wall 93, in an arc of from 60 to 90 and this operation swings guide roller 82 into contact with the inside face 'of guide wall 95 of the second guide rail 94. When thus rotated, the workpieces p will assume the position illustrated inFig. l and they are advanced in this position as they travel through the blasting streams projected from the abrasive throwing wheels W4 and W5 in the second stage a" of the first blasting zone a.

By referring more particularly to Fig. 2 and Figs. 4 to 8, inclusive, it will be noted that the workpieces p asthus guided and directed will directly present all of their interior surfaces and certain of their exterior surfaces to the Iblasting streams projected by the wheels positioned along the rst blasting zone a. As shown in Figs. 2 and 4, for example, the abrasive throwing wheel W1, rotating counterclockwise, will project its stream so as to clean the lower portions of exterior side wall surface p3, interior side wall surface p3, interior bottom Wall surface p1, interior end wall surface p4, adjacent corner surfaces p6 and the lower half of the edge surfaces p12.

As the workpieces continuously advance, the abrasive throwing wheel W2 rotating clockwise as illustrated in Figs. 2 and 5 will blast clean the upper portions of exterior side wall surface p8, interior side wall surface p3, interior bottom wall surface p1, interior end wall surface p5, adjacent corner surfaces p6 and the upper parts of the edge portions p12. As the workpieces continue their advances, the abrasive throwing wheel W3 rotating clockwise as illustrated in Figs. 2 and 6 will blast clean the center portions of exterior side wall surface p8, interior side wall surface p3, interior bottom wall surface p1, adjacent corner surfaces p6 and the center parts of the edge portions p12.

As the workpieces p continue their advance,

it will be noted that they are rotated through an angle of from 60 to 90 which is effected by the spur track 90, and cam wall 93 and guide wall 95 of the second guide track 04 over which guide rollers 83 and 82 roll. The workpieces pwill then travel through the blast stream projected from abrasive throwing wheel W4, rotating counterclockwise as illustrated in Figs. 2 and 7, which operates to clean the lower portion of interior side wall surface p3, interior bottom wall surface p1, interior end wall surface p4, adjacent corner surfaces p8, the lower vportion of edge parts p12, and the lower portion of exterior side wall surface p9- As the workpieces continue their adv/ance, the abrasive stream fired by the abrasive throwing wheel W5 rotating clockwise as illustrated in Figs.

l2 and 8 operates to blast clean the upper portion of interior side wall surface p2, interior bottom wall surface p1, interior end wall surface p5, the upper portion of the edge parts p12' and, finally, the upper portion of the exterior side Wall surface p9.

It will thus be noted that during the continuous passage of the workpieces through blasting zone a, the entire exterior side wall surfaces p3 and p9, the entire interior end wall surfaces p4 and p5, the entire interior side Wall surfaces p2 and p3, all interior corner portions p, and all exterior edge portions p12 have been directly exposed to the full force of the abrasive streams projected from the abrasive throwing wheels W1, W2, W3, W4 and W5. These surfaces have by this treatment been all substantially thoroughly blast cleaned during their passage through blasting Zone a. The hangers and their suspended workpieces then pass out of the blasting zone a, moveearound the main chain driving sprocket 15, and into the second blasting zone b.

In the second blasting zone b the workpieces are rotated a number of times through a complete 360 rotation during their continuance travel through the second blasting zone b. Improved mechanism is provided for uniformly rotating all the workpiece-supporting spindles, all alternate work-supporting hangers B having their spindles 53 rotated in one direction and the spindles 53 of all intermediate work-supporting hangers B being rotated in the opposite direction. Highly effective and efficient mechanism F is provided for effecting this rotation.

My improved spinner mechanism includes a sprocket member |00 attached to each spindle 53 of the alternate work-supporting hamers B. Each sprocket member |00 has a collar portion |03 which is xedly secured to the hanger spindle 53 by a suitable key or set screw |03, shown in Figs. 14 and 15. Sprocket member |00 has a sprocket wheel IUI formed integral therewith and an Vintegral spacing disc |02 positioned above the sprocket wheel 40|. The spindles 53 of each intermediate hanger B also carries a sprocket member |00 similar to the alternate sprocket members |00 except that the sprocket wheel |0|' of the intermediate sprocket member |00' is arranged above its associated spacing disc |02. As heretofore brought out, each hanger spindle 53 rotates in the bearing positioned within the fixed sleeve 43 of the hanger. The alternate sprocket members |00 provide means for rotating the spindles 53 of alternate hangers B in one direction while the sprocket members |00' provide means for rotating the spindles 53 of the intermediate hangers B in the opposite direction.

All of the spindle driving sprocket members andl |00' are rotated during their passage throughE the blasting zone b by a continuously driven notor which drives reduction gearing ||0. A drive chain |01 is trained around a sprocket |08 attached to the shaft |09 of the reduction gearing ||0, as illustrated more particularly in Fig. 1. The drive chain |01 is also trained around sprocket ||3 fixed to a stub shaft ||4 adjacent the path of travel of the worksupporting hangers when movingthrough the blasting zone b. The stub shaft |4 rotates in a bearing collar ||5 suitably secured to the top wal1 |1 of the cabinet. Stub shaft ||4 has fixed thereto a gear ||5 which meshes with a gear ||1 fixed to an adjacent stub shaft ||8 rotatably mounted in a bearing collar ||9 supported on the top wall I1 of the cabinet. Stub shaft ||8 has a sprocket |20 xed thereto and carries one end of a continuous spinner chain |2| designed to mesh with the sprocket |0| of sprocket members |00 attached to the spindles 53 of alternate work-supporting hangers B. The other end of the continuous spinner chain |2| is trained around a sprocket |22 fixed to a hub |23 which rotates on a stationary stub shaft |24 fixed to a socket |25 supported upon the top wall l1 of the cabinet.

The intermediate sprocket members |00 attached to the spindles 53 of intermediate worksupporting hangers B are rotated by a spinner chain |2| positioned directly above the spinner chain |2|. One end of the continuous spinner chain |2| is trained around a sprocket |21 fixed to the driven stub shaft |24. The other end of the continuous spinner chain |2|' is supported upon a sprocket |28 fixed to a hub |29 which freely rotates on the fixed stub shaft |24.

With the driving arrangement as above provided, it will be appreciated that spinner drive chai-n |2| travels in one direction, as indicated in Fig. 3, to rotate the alternate sprocket members |00 xed to alternate spindles 53 in one direction, while spinner chain I2 travels in the opposite direction to rotate the intermediate sprocket members |20 and associated intermediate hanger spindles 53 in the opposite direction, thus permitting the work-supporting hangers B and B' to be arranged so that a minimum of space or clearance is provided between the workpieces p suspended therefrom.

To insure positive driving engagement between spinner chain |2| and sprocket members 00 and positive driving engagement between spinner chain |2|' and intermediate sprocket members |00' during passage of the workpieces through blasting zone b. I have provided chain backing means which is simple in construction and highly efficient. As illustrated more particularly in Figs. 1, 3 and 16, a pair of chain backing pedestals |30 are provided which rest upon the top wall |1 of the cabinet, and are positioned between the inner and outer runs of the spinner chains |2| and |2|'. Each backing pedestal |30 comprises a stub shaft 3| whose lower end is fixed to a base |32 rigidly supported on the top wall |1 of theA cabinet. A heavy chain-contact disc |33 is provided with a hub portion |34 which is free to idle on stub shaft |3| and is positioned between the inner and outer runs of spinner chain 2| with its periphery positioned to bulge the inner sprocket-engaging run of the chain |2|.l A second contact disc |33' having a hub portion |34 is free to idle on the upper end of -fixed stub shaft |3| and is positioned between the inner and outer runs of spinner chain |2|' and arranged to bulge the inner sprocket-engaging run of the chain |2|'. The contact discs |33 and |33 may be removably mounted on the stub shaft |3| by means of a collar |35 removably secured to the upper end of stub shaft |3| by a removable key or set screw |38. A

To reduce friction and permit the spinner chains |2| and |2|' to smoothly roll over or with the peripheries of the respective contact discs |33 and |33', the spinner chains |2| and 2|' are provided with roller sleeves |31 which are free to roll on the pins |38 which connect the paired outer links |39 to the paired inner links |40 of the chain. 'I'he chain roller sleeves |31 roll over or with the peripheriespf the respective free rotating contact discs |33 and |33' substantially without friction and serve to bulge the inner runs of the chains |2| and |2 so that they positively engage spinner sprockets |0| and |0| respectively.

It will also be noted that the chain-engaging peripheries of the contact discs |33 and |33 bulge the driving run of the spinner chains |2| and |2|' to the point where the spinner sprockets |0| and |0| will not interfere with the rotative movement of the chain-supporting sprockets |20, |22, |21 and |28. The spinner sprockets |0| and |0|' will engage the driving run of the spinner chains |2| and |2| respectively at a point somewhere between the idling sprockets |22 and |28 and the adjacent pedestal |30, and the spinner. sprockets |0| and 0| will disengage themselves from the driving run of the spinner chains |2| and |2|' respectively somewhere between the other pedestal |30 and the driving sprockets |20 and 21. Thus the spinner sprockets |0| and |0| freely move into and out of engagement with the spinner driving chain |0| and |0|' to rotate all of the worksupporting spindles 53 during their advance through the blasting zone b.

To further insure positive driving engagement between the spinner chains |2| and |2|' with the alternate and intermediate spindle sprocket members 0| and |0|' during advance of their suspended workpieces in through blasting zone b, the hanger spindles 53 are retained in non-swaying position and so held that their respective spinner sprockets |0| and |0| are in positive driving contact with the respective spinner chains |2| and |2|. This is ,effected by the spacing disc |02 on each of the spindle sprocket members |0| and |0|" whose peripheries are arranged to roll over a series of closely spaced rollers |4|. It will be noted that the backing discs |02 of both the alternate sprocket members |0| and intermediate sprocket members |0I travel in substantially the same horizontal plane and along a substantially straight line, so that the closely spaced contact rollers |4| may also be mounted along a straight horizontal line. Each contact roller |4| is free to rotate on a pin |42 fixed at each end to the horizontal legs |43 of a pairof spaced angle bars |44.

The angle bars |44 may be secured to a plurality of spaced brackets |45 having their foot portions |46 secured to the top wall 1 of the cabinet, as illustrated more particularly in Figs. l and 15. The spaced angle bars |44, having the closely spaced contact rollers |4| rotatably mounted therebetween, may extend the full distance between the ends of the spinner chains so that each hanger spindle 53 is prevented from swinging on the track C as it advances through the blasting zone b.

Means are also provided for supporting relatively long inner and outer runs of the spinner chains |2| and |2|'. As shown more particularly in Figs. 1 and 17, a pair of spaced brackets |41' to support the i'nner runs and a pair of spaced brackets 01' to support the outer runs of spinner chains |2| and |2|' are provided which are positioned between chain pedestals |30 and rest upon the top wall |`l of the cabinet. j The brackets |61 and |41' may be cast in one piece and are each provided with a vertical wall |48 adjacent the respective inner and outer runs of the spinner chains |2| and |2|. Each pair of bracketsA Ml and |01 support la pair of angle bars |49, the vertical leg |50 of which is secured to the wall |08 of the paired brackets with the other leg |5| projecting horizontally therefrom. The vertical leg |50 of each angle bar M9 is provided with a bar-shaped track |5| along which the chain rollers |31 are adapted to roll. It will be noted that each of the chain pins |38 is provided with a U-shaped yoke |53 at the lower end thereof on which a roller |50 is rotatably mounted. The chain rollers |54 are arranged to roll on the horizontally extended leg |5| of the angle bar |69. The upper angle bar |49 is arranged to support and guide the spinner chain |2| while the lower angle bar M9 is arranged to support and guide the other spinner chain |2I.

It will thus be noted that the chain-guiding bars |49 provide a firm support ,for the relatively long inner and outer runs of the spinner chains |2| and |2| so as to insure positive driving engagement with the spindle sprockets |00 and |00'. friction along the angle bars IES by reason of the rollers |50 and |31 provided on the spinner chains. It will also be noted that the backing discs |33 and |33 bulge the inner runs ef the spinner chains- |2| and |2|', so that the spinner sprockets |00 and |00 will not interfere with the rotating movement of the chain-supporting sprockets |20, |22, |21 and |28, but will engage the inner runs of the respective spinner chains |2| and |2| somewhere between thevsprockets |22 and |28 and the adjacent pedestal |30 and will disengage themselves from the inner runs of the spinner chains |2| and IZI somewhere between the other pedestal |30 and sprockets |20 and |21. Thus the alternate spindle sprockets |00 freely move into and out of engagement with their spinner driving chain |2| to rotate all of the alternate hangers B during their advance along the blasting zone b of the cabinet, while intermediate spindle sprockets |00 freely move into and out of engagement with their spinner driving chain |2I' during advance movement of the intermediate oppositgly rotating hangers B during their advance movement along the blasting zone b.

As the workpieces suspended on the respective alternate and intermediate hangers B and B' advance through the blasting zone b in the direction of the arrow, as shown in Figs. l, 3 and 9, they first move into and through the blasting stream projected by abrasive throwing wheel W6 rotating clockwise, as indicated in Figs. 3 and 8. The abrasive throwing wheel Ws is positioned slightly above the path of travel of the workpieces p and its control cage is so adjusted as to project its The chains advance substantially without abrasive stream onto the exterior end wall surface p11 of the workpiece as the workpiece@ rotates. Substantially al1 of the abrasive stream red by the abrasive throwing wheel W is projected against only the exterior end wall surface p11, which advances and rotates directly in the path of the abrasive blast, and thus any desired cleaning effect may be attained. For example, exterior end wall surface p11 may be thoroughly cleaned, polished and peened for receiving the porcelain enamel coating, by feeding a. relatively large volume of abrasive through the wheel but if the exterior end wall surface p11 requiresonly superflcial cleaning to remove the encrusted sand and scale, such cleaning can be effected by feeding a lesser volume of abrasive to the wheel W5.

Ls the workpieces continue their rotational advance through blasting zone b they move into, through and out of the blasting stream projected by abrasive throwing wheel W", as illustrated in Figs. 1, 3 and 10. Abrasive throwing wheel W'I rotating clockwise is so positioned and its control cage so adjusted that it projects its polishing and peening abrasive stream against the upper portion of interior side wall surfaces p3 and p3, interior bottom wall surface p1, interior end wall surface p5, adjacent corner surfaces p6, adjacent edge surfaces p12, and the upper portion of exterior side wall surfaces p8 and p9, all of which surfaces have been previously abraded while pass- ,ing through the blasting zone a. Abrasive throwing wheel W7 also superficially cleans the upper portion of the exterior bottom wallsurface p".

During the further continued rotational advance of the workpieces through blasting zone b, the center portion thereof enters and passes through the blasting stream projected by abrasive throwing wheel W8 rotating clockwise, as indicated in Figs. 3 and 11. The abrasive throwing wheel W8 is so positioned and its control cage so adjusted as Yto finally polish and peen the previously abraded center portion of the interior side wall surfaces p2 and p3, interior bottom wall surface p1, adjacent corner surfaces p6, adjacent edge surfaces p12, and exterior side wall surfaces p3 and p9, and to superfcially abrade the center portion of the exterior bottom wall surface p".

During further continued rotational advance of the workpieces in blasting zone b, the workpieces enter and lpass. through the abrasive blasting stream projected by abrasive throwing wheel W9 rotating counterclockwise, as indicated in Figs. 3 and 12. The abrasive throwing wheel W9 is so positioned and its control cage so adjusted as to fire its polishing and peening abrasive stream against the lower portion of previously abraded interior side wall surfaces p2 and p3, interior bottom wall surface p1, interior end wall surface p4, adjacent corner surfaces p6, adjacent edge surfaces p12 and the lower portion of exterior side wall surfaces p9 and p9. Abrasive throwing wheel W9 also supercially cleans the lower portion of the exterior bottom wall surface p".

The workpieces continue their rotational advance through the blasting stream projected by the abrasive throwing wheel W10 rotating counterclockwse, as indicated in Figs. 3 and 13, which is positioned below the path of travel of the workpieces p and has its control cage so adjusted as to clean the exterior end wall surface p1 of the workpiece. By controlling the volume of the abrasive feed to the abrasive throwing wheel W1,.

fl projected by abrasive throwing wheel W10, or exterior end wall surface p10 may be only superficially cleaned by reducing the volume of abrasive feed to the wheel W10.

T he workpiece-supporting hangers then move out of engagement with the spinner chains |2| and |2|' and move through the exit vestibule 3 and onto that section of the track which leads to the unloading zone d or to other zones in the plant where other operations may be performed on the workpieces while still suspended from the hang- GIS.

It will now be appreciated that during the passage of the workpieces through the blasting zone b where they are rotated during their advance, abrasive throwing wheel W and abrasive throwing wheel W may be supplied with a relatively large volume of abrasive to thoroughly clean, polish and peen the exterior end wall surfaces p11 and p10 of the advancing workpieces, or they may be supplied with a lesser volume of abrasive to only superficlally clean the exterior end wall surfaces p11 and p10 respectively. Thus by regulating the volume of abrasive feed to the wheels W0 and W10, any desired degree of cleaning of the exterior end wall surfaces p11 and p10 may be effected.

It will further be noted that abrasive throwing wheels W", W0 and W0 operate to polish and peen the previously abraded interior side wall surfaces p2 and p3, interior end wall surfaces p0 and p4, interior bottom wallsurface p1, adjacent corner surfaces p0, adjacent edge surfaces p10, and also to polish and peen the previously abraded exterior side wall surfaces p0 and p0 during advance of the workpieces through the streams projected by abrasive throwing wheels W", W0 and W0. These surfaces can thus be placed in excellent condition to tenaciously retain porcelain enamel or other coating, which can be smoothly applied to give the surfaces a fine finish. The encrusted sand and scale is also removed from the exterior bottom wall surface p" during passage of each workpiece through the blasting streams projected by the abrasive throwing wheels W1, W0 and W0.

It will be further appreciated that the abrasive fed to the abrasive throwing wheels W1, W2, W3, W4 and W5 in the first blasting zone a may be of such character as to effect maximum cleaning of the surfaces abraded in this blasting zone, and for this purpose cracked steel grit or other sharp cutting abrasive may be selected in accordance with the character of the cleaning required. These wheels may readily be supplied with the selected character of abrasive by a separate abrasive-cycling system. The abrasive throwing wheels W", W0 and W0, which are to polish and peen the surfaces which are to receive porcelain enamel or other finish coating, may be supplied with another type of abrasive through a separate abrasive-cycling system, which abrasive may comprise round steel shot of selected sizes or such other abrasive material best designed to give these surfaces the desired surface finish. If exterior end wall surfaces p11 and p10 are to be only superflcially cleaned the wheels W0 and W10 may be connected to the same abrasive-cycling system which supplies abrasive to the abrasive throwing wheels positioned 1n the rst blasting zone a, or they may be supplied from the same abrasive-cycling system and with the same character of abrasive as is supplied to abrasive throwing wheels W7, W0 and W0, or a special character of abrasive may be supplied to abrasive throwing wheels W and W10 by a separate abrasive-cycling system. It will thus be appreciated that the abrasive throwing wheels may be supplied with any character of abrasive desired, fed to the wheels in any desired volume, and thrown at any desired velocity, and that any desired number of abrasive throwing wheels may be employed dependent upon the shape of the workpieces, the character of the surfaces, and the character of the surface nish and production speeds desired.

The entrance opening I3 of the entrance ves-l tibule I and theexit opening I6 of the exit vestibule are each closed by a pair of d rs which may be made of either exible rubbe or steel. Each of the hangers is provided with a coneshaper member |54 which is flxed to the rotatable spindle 53 of each of the hangers B and B'. Each cone-shaped shield |54 is of such diameter and so arranged that the peripheral portion |55 thereof will engage the paired doors during advance movement of the hangers to swingl the doors open so that the workpieces p need not strike the doors.

The cone-shaped shields |54 have their reduced ends |56 arranged to extend into the slot 55 in the top wall |1 of the cabinet, as illustrated more particularly in Fig. 16, so as to partially close the slot and prevent abrasive from escaping from the cabinet and damaging the mechanism mounted on the top wall of the cabinet. To further prevent the escape of abrasive through the slot 55 in the top wall of the cabinet, a pair of downwardly inclined baille plates |51 are provided whose upper ends are secured to the framing I9 which extends along an'd on each side of the slot 55. A flexible rubber baille |53 is secured to each ofthe downwardly inclined baille plates |51 as by means of a clamping plate |53 and bolt |60. A downwardly inclined end portion |6| of each flexible baille |58 is free to ilex around the hanger spindles 53 as they move therebetween. v

Abrasive sealing means is also provided above the path of travel of the cone-shapedshields |54, as illustrated more particularly in Fig. 16. This further sealing means comprises a pair of lower flexible rubber flaps |64 and a pair of upper ilexible rubber flaps |65. Each of the lower ilaps |64 rests on a bar |66 seated on the top wall I1 of the cabinet closely adjacent to the slot 55. A lJ-shaped spacing member |61 has the lower leg |68 thereof resting on one of the bars |65 with the lower flaps |64 clamped therebetween. The upper flaps |65 rest on the upper leg |69 of the U-shaped member |61 and is held in place by a clamping bar or member |10 held in place by screws |1|.

By this novel sealing arrangement a triple seal is provided along the path of travel of the spinner spindles 53 which positively prevents any escape of abrasive from within the cabinet through the slot 55 inhthe top wall of the cabinet. 'I'he flexible flaps |58 provide an initial seal within the cabinet. The cone-shaped shields |54 fixed to each of the spinner spindles 53 provide a further and secondary seal. Finally the paired fiexible flaps |64 and |65 provide a tertiary seal which absolutely prevents any dust or other particles that may have escaped through the flexible baille |58 and the cone-shaped shields |54 from escaping into'the atmosphere.

My improved blasting' apparatus permits convenient loading of the workpieces p on the alternate hangers B and intermediate hangers B' dur- 2,844,476 Alng their travel along the loading zone c. The

hangers B and B' with their suspended workpieces closely adjacent one another are guided so that the guide rollers 82 and 8| associated with each work-supporting hanger moves into contact with the vertical guide wall 86 of guide rail 85 prior to their entrance into the entrance vestibule I. The workpieces continue their advance into stage a' of the blasting zone a while held in the position indicated in Figs.' l and 2, in which position the* blasting wheels W1, W11 and W3 effectively clean the exterior side wall surface p3, interior side wall surface p3, interior bottom wall surface p1. interior end wall surfaces p5, adjacent interior corner surfaces p6 and adjacent edge surfaces p12.

During further continued advance of the workpieces into stage a" of blasting zone a, the spur trapk 90 and cam track portion 93 operate to swing the suspended workpieces through an arc of' from 60 to 90 until the guide rollers 82 and 83 associated with each hanger move into contact with the vertical guide wall 95 of thesecond guide rail 94. When thus positioned the workpieces present interior side wall surface p2, interior bottorn wall surface p1, interior end wall surface p4, adjacent interior corner surfaces p5, adjacent edge surfaces p12, and the exterior side wall surface p9 to the abrasive streams projected by abrasive throwing wheels W4 and W5, which operate to clean and thoroughly remove encrusted sand and scale from these surfaces.

The workpiece-supporting hangers then move around the large conveyor chain advancing sprocket'l and into the second blasting zone b where spinner chain |2| engages spinner sprockets lill of the alternate work-supporting hangers B and spinner chain I2 I engages spinner sprockets IUI' of the intermediate work-supporting hangers B to rotate the workpieces through several complete revolutions during their passage through the blasting zone b. During their passage through blasting zone b abrasive throwing wheel W6 operates to clean the exterior end wall surface p1?il to the desired degree, abrasive throwing wheels W", WB and W9 operate to peen and polish the previously blasted interior side wall surfaces p2 and p3, interior bottom wall surface p1, interior end walls surfaces p4 and p5, interior corner surfaces p, and exterior edge surfaces p12, and in additional supercially abrade and clean the ex-y terior bottom wall surface p7. During continued rotational advance through the blasting zone b. abrasive throwing wheel W cleans exterior end wail surface p10 to the desired degree.

It will be noted that the workpieces p traveling through blasting zone b travel in the opposite direction from but parallel to and only a short distance from the path of travel of the workpieces advancing through blasting zone a. Thus any abrasive projected by abrasive throwing wheels W1, W2, W3, W4 and,W5 in the first blasting zone which fails to strike the closely positioned workpieces p in the first blasting zone a will substantially all strike the workpieces immediately to the rear passing through the second blasting zone b. In the same manner any abrasive projected by the abrasive throwing wheels W, W", W8, W9 and W10, which fails to strike the workpieces passing through the second blasting zone b will substantially al1 strike the workpieces immediately to the rear thereof passing through blasting zone a.

relatively close together, substantially all of the abrasive fired from all the wheels is employed to perform useful abrading action with resulting high cleaning efficiency.

The spinner-rotating mechanism is so constructed and arranged as to effectively engage the spinner sprockets Illlfand I 80' substantially without shock or strain to the parts. The hangers B and B are prevented from undesirable swinging movement during their travel through the blasting zone a by the guide tracks 85 and 94 and cooperating spur track 98, and are prevented from undesirable swinging movement in blasting zone b by contact disc |02, contact rollers |4I, contact discs |33 and |33 and guide rails |50 and |50.

y The conveyor-advancing mechanism is so arranged and constructed that the workpieces may be completely advanced through blasting zones a and b in the blast section 2 of the cabinet Without delay or stoppage of continuous production. Since the spinner speed reducer is completely independent of the hanger-advancing speed reducer 68, each may be adjustedto the desired operating speed independently of the other.

In event the hollow metal ware or articles to be cleaned do not require final polishing or finishing in the blasting zone b, it will be appreciated that the centrifugal blasting wheels W8, W", W8, W9 and W10, as shown in Fig. 1, may be eliminated from the apparatus or not operated. The metal ware passing through the silenced zone b would still be impinged during their rotative movement by some stray or rebounding abrasive from blasting zone a thrown by the abrasive throwing wheels W1, W2, W3, W-1 and W5.

It will be also appreciated that the articles may be first conducted into the blasting zone b, as.

shown in Fig. 18, by driving the conveyor chain in the direction of the arrow there shown. In such event the rotating articles rst pass through blasting zone b and are impinged by the abrasive blast from the successive abrasive throwing wheels W10, W9, W8, W'I and W6. A vestibule 200 is positioned adjacent the end wall 6 of the cabinet, as shown in Fig. 18, wherein a workman may be stationed to guide the workpieces in their movement into the blasting zone a and to place the guide rollers 8| and 82 into contact with the track 86. The apparatus shown in Eig. 18 may be provided with blasting wheels W5, W4, W3, W2 and W1, as shown in Fig. 1, so as to clean such surfaces of the workpieces as require thorough cleaning, as above described. In event it is unnecessary to treat the workpieces with theabrasive throwing wheels W5, W4, W3, W2 and W1 in the arrangement illustrated in Fig. 18, these wheels may be silenced or eliminated from the Thus, by spacing the work-supporting hangers B apparatus as illustrated in Fig. 18. In event the blasting zone a is not employed, the workpieces may be so arranged, as shown in Fig. 18, that their interior surfaces face the centrifugal blasting wheels W", W", W8, W9 and W10 so as to be impinged by stray or rebounding abrasive fired by these wheels.

It will therefore be appreciated that this invention comprehends the employment of two blasting zones a. and b, with the workpieces moving first through either blasting zone a or blasting zone b and also comprehends an apparatus wherein only blasting zone a or blasting zone b is employed, as the cleaning problem may require.

While certain novel features of the invention have been disclosed and are pointed out in the annexed claims, it will be understood that various omissions, substitutions and changes may be made by those skilled in the art without departing from the spirit of the invention.

What is claimed is: 1. In blast cleaning apparatus, a track, a cary riage suspended from, and movable along, said track, a work-supporting spindle rotatably supported by said carriage, an odd number of equally spaced radially extending guide arms fixed to said spindle, a guide roller rotatably mounted on each of said arms, a substantially straight guide track extending along one side of the path of advance of said carriage adapted to provide a guide for a pair of adjoining rollers and preventing lateral movement of said spindle, a substantially straight guide track extending beyond and along the other side of the pathof advance of said carriage adapted to provide a guide for another pair of adjoining rollers, and a stationary member positioned between the adjacent ends of said guide tracks for engaging the roller on one of said guide arms to rotate said spindle through a predetermined arc of less than 360.

2. In blast cleaning apparatus, a track, a worksupporting carriage suspended from, and movable along, said track, a work-supporting spindle rotatably supported from said carriage, an odd l number of equally spaced radially extending guide arms fixed to said spindle, a guide roller rotatably mounted on each of said arms adjacent the outer end thereof, a substantially straight guide track extending along one side of the path of advance of said spindle adapted to provide a guide for two of said rollers during the advance of said spindle for a predetermined distance and to prevent lateral movement of said spindle, a substantially straight guide track extending along the other side of the path of advance of said spindle and beyond said first guide track adapted to provide a guide for two of said rollers when said spindle .has been rotated through a predetermined arc, and a stationary member positioned between the adjacent ends of said guide tracks for engaging the roller on one of said guide arms to rotate said spindle and the workpiece supported thereon through said predetermined arc.

3. In blast cleaning apparatus, a track, a worksupporting carriage movable along said track, a work-supporting spindle rotatably supported from said carriage, three equally spaced radially d extending guide arms fixed to said spindle, a guide roller rotatably mounted on each of said arms adjacent the outer end thereof, a guide track extending along one side of the path of advance of said carriage adapted to provide a guide for two of said rollers during the advance of said spindle for a predetermined distance, a guide track extending along the other side of the path of advance of said spindle and beyond said ilrst guide track adapted to provide a guide for two of said rollers when said spindle has been rotated through an arc of 60 to 90, and means positioned between the adjacent ends of said guide tracks for rotating said spindle and the workpiece supported thereon through said arc.

4. In blast cleaning apparatus, a track, a worksupporting carriage movable along said track, a work-supporting spindle rotatably suspended from said carriage, means for advancing said carriage and work-supporting spindle along a predetermined blasting zone, three equally spaced radially extending guide arms fixed to said spindle, a guide roller rotatably mounted on each of said arms adjacent the outer end thereof, a guide track extending along one side of the path of advance of said spindle adapted to provide a guide for two of said rollers during the advance of said spindle for a predetermined distance along said blasting zone, a guide track extending along the other side o! the path of advance of said spindle and beyond said rst guide track adapted to provide a guide for two of said rollers wheh said spindle has been rotated through a predetermined arc, and a spur track positioned between the adjacent ends of said guide tracks for engaging one of said rollers and automatically rotating said spindle through said predetermined arc during the advance of said carriage from said first to said second guide track.

5. In blast cleaning apparatus, a track, a worksupporting carrige movable along said track, a tubular sleeve fixed to said carriage, a thrust bearing positioned Within said sleeve, a worksupporting spindle rotatably supported in said thrust bearing, means i'or advancing said carriage and work-supporting spindle along a pre'- determined blasting zone, an odd number of equally spaced radially extending guide arms nxea to said spidle, a guide roller rotatably mounted on each of said arms adjacent the outer end thereof, a guide track extending along one side of the path of advance of said carriage adapted to provide a guide for two of said rollers during the advance of said carriage for a predetermined distance along said blasting zone, a guide track extending along the other side of the path of advance of said carriage and beyond said rst guide track adapted to provide a guide for two of said rollers when said spindle has been rotated through a predetermined arc, and a switch track positioned between the adjacent ends of said guide track for engaging one of said rollers and automatically rotating said spindle through said predetermined arc during the advance of said carriage from said first to said second guide track.

6. In blast cleaning apparatus, a plurality of work-supporting carriers, means for transporting said carriers along a predetermined path, ,a

' work-supporting spindle rotatably suspended from each of said carriers, three equally spaced radially extending guide arms ilxed to each of said spindles, a guide roller rotatably mounted on each of said arms, a relatively straight guide member extending along one side of the path of advance of said spindles providing a guide for two of said rollers during advance of said -splndles a predetermined distance, a relatively straight guide member ext-ending along the other side of thepath of advance of said spindles and beyond said first guide member adapted to provide a guide for two of said rollers when said spindles have been rotated through a predetermined arc, and means, positioned between the adjacent ends of said guide member for rotating said spindles through said predetermined arc during advance thereof from said ilrst to said 1 second guide member.

dles a predetermined distance, a relatively straight guide. track extending along the other side of the path of advance of said spindles and beyond said iirst guide track adapted to provide a guide for two oi said rollers when said spindles have been rotated through a predetermined arc, a spur track positioned between the adjacent ends of said guide tracks for engaging one of said rollers oi each spindle and rotating said spindles through said predetermined arc during advance thereof from said iirst to said second guide track, ax 'i means beyond said guide tracks for rotating alternate spindles in one direction and intermediate spindles in the opposite direction during their continued advance.

8. In blast cleaning apparatus, a cabinet having a rst and a second blasting zone, centrifugal abrasive projectors for projecting streams oi!y abrasive into each o1' said blasting zones. a plurality of work-supporting carriers, means for transporting said carriers along a predetermined path through said blasting zones, a work-supporting spindle rotatably suspended from each of said carriers, cooperating means including a plurality of guide rollers mounted on arms on each of said spindles, two straight stationary guide members engaging two of said guide rollers to retain said spindles against rotation during a predetermined advance movement thereof along one stage of said first blasting zone, a stationary member aWranged between the end of one and the beginning of the other straight guide member and in the path of one oi said rollers to engage said roller and rotate said spindle through a predetermined arc oi' 60 to 90 whereafter said spindles are retained against further rotation during their advance along the second stage oi said first blasting zone by engagement of rollers by the second guide member, and means for rotating alternate spindles in one direction and intermediate spindles in the opposite direction during their advance along said second blasting zone.

9. In blast cleaning apparatus, a cabinet having two blasting zones, a plurality of work-supporting carriers, means for transporting said carriers along a predetermined path through said blasting zones, a iirst series of centrifugal abrasive projectors arranged to project a plurality oi abrasive streams into said first blasting zone whereby to blast the surfaces of the workpieces requiring thorough cleaning and a second series of centrifugal abrasive projectors arranged to blast all surfaces of said workplaces in said second blasting zone, a work-supporting spindle rotatably suspended from each of said carriers, means operative to retain said spindles against rotation during a predetermined advance movement thereof along said first blasting zone, to thereafter rotate said spindles through a predetermined arc of less than 360 while in said first blasting zone and thereafter to retain said spindles against further rotation during their further advance movement along said first blasting zone, said operative means including a plurality of arms secured to each of said spindles and a guide roller rotatably mounted on each of said arms, two substantially straight tracks arranged in series along the path of said spindles to provide a guide for any pair of rollers on two adjacent arms, and a stationary member arranged between the end of one and the beginning of the other track for engaging one of said rollers to impart a rotation to said spindle, and means for rotating alternate spindles in one direction and intermediate spindles in the opposite direc- Y tion during advance movement of the spindles along said second blasting zone.

10. In blast cleaning apparatus, a cabinet having two blasting zones, abrasive projectors for projecting streams of abrasive into each of said blasting zones, a plurality of work-supporting carriers, means for transporting said carriers along a predetermined path through said blasting zones, a work-supporting spindle rotatably suspended from each of said carriers, means operative to retain said spindles againstl rotation during a predetermined advance movement there'- of along said first blasting zone, to thereafter rotate said spindles through a predetermined arc of lessthan 360 while in said rst blasting zone and thereafter to retain said spindles against further rotation during their further advance movement along said first blasting zone, said operative means including a plurality of arms secured to each of said spindles and a guide roller rotatably mounted on each oi' said arms, two substantially straight tracks arranged in series along the path of said spindles to provide a guide for any pairofrollers on two adjacent arms, and a stationary member arranged between the end oi' one and the beginning of the other track for engaging one of said rollers to impart a rotation to said spindle, a spinner sprocket fixed to each said spindles, and means for rotating the sprockets of alternate spindles in one direction and the sprockets of intermediate spindles in the opposite direction during advance movement of the spindles along said second blasting zone.

11. In blast cleaning apparatus, a plurality of work-supporting carriers, means for transporting said carriers along a predetermined path Athrough a blasting zone, a work-supporting spindie rotatably suspended from each of said carriers, a spinner sprocket fixed to each of said spindles, a continuous drive chain having an outer run and an inner run in driving engagement with the sprockets of alternate spindles, a continuous drive chain having an outer run and an inner run in driving engagement with the sprockets of intermediate spindles, means for driving one of said chains in one direction and the other chain 4in the opposite direction to rotate alternate spindles in one direction and intermediate spindles in the opposite direction, and means including freely rotating contact discs arranged between the inner arid outer runs of said drive chains and having their peripheries positioned to bulge the inner sprocket engaging runs of said chains to facilitate engagement between said spinner sprockets and said chains.

12. In blast cleaning apparatus, a plurality of work-supporting carriers, means for transporting said carriers along a predetermined path through a blasting zone, a work-supporting spindle rotatably suspended from each of said carriers, a spinner sprocket fixed to each of said spindles, a continuous drive chain having an outer run and an inner run in driving engagement with the sprocketsof alternate spindles, a continuous drive chain having an outer run and an inner run in driving engagement with the sprockets of intermediate spindles, means for driving one of said spinner chains in one direction and the other said spinner chain in the opposite direction to rotate alternate spindles in one direction and intermediate spindles in the opposite direction, and a pair of chain backing members positioned between the ends and between the runs oi' said drive chains, each o! said chain backing members including a pair of freely rotating contact discs arranged between the inner and outer runs o! said drive chains and having their peripheries positioned to bulge the sprocket engaging runs of said spinner chains to facilitate engagement and disengagement of said spinner sprockets with their respective drive chains.

13. In .'blast cleaning apparatus, a plurality of work-supporting carriers, means for transporting said carriers along a predetermined path through a blast cleaning zone, a work-supporting spindle rotatably suspended from each of said carriers, a sprocket xed to each oi said spindles, a drive chain for rotating the sprockets of alternate spindles in one direction, a drive chain for rotating the sprockets of intermediate spindles in the opposite direction, a contact disc eccentrically xed to each of said spindles adjacent said sprocket, a guide member positioned along the path of travel of said contact discs opposite to the sprocket engaging runs of said drive chains, and a plurality of rollers rotatably supported by said guide member against which the peripheries of said contact discs may roll during advance movement of said spindles to retain said spindle astiene -sprocket fixed to each of said spindles, a drive chain for rotating the sprockets of alternate spindles in one direction, a drive chain for rotating the sprockets of intermediate spindles in the opposite direction, a contact disc eccentrically xed to each oi said spindles adjacent said sprocket, a guide member positioned along the path of travel of said contact discs opposite to the sprocket engaging runs of said drive chains, a plurality of rollers rotatably supported by said guide member against which the peripheries of said contact discs may roll during advance movement of said spindles to retain said spindle sprockets in driving engagement with the sprocket engaging runs oi.' said drive chains, and means including guide bars extending along the runs of said drive chains to guide and support said chains.

DAVID c. TURNBULL.

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