US2154878A

US2154878A - Apparatus for abrasively treating metallic objects

Info

Publication number: US2154878A
Application number: US85645A
Authority: US
Inventors: David C Turnbull
Original assignee: American Foundry Equipment Co
Current assignee: American Foundry Equipment Co
Priority date: 1936-06-17
Filing date: 1936-06-17
Publication date: 1939-04-18
Anticipated expiration: 1956-04-18

Description

April 18, 1939.

D. C. TURNBULL APPARATUS FOR ABRASIVELY TREATING METALLIC OBJECTS l4 Sheets-Sheet 1 Original Filed June 17, 1936 m&

INVENTOR 0/4 1/10 6. TUE/v50. BY

ATTORNEY Ap 18, 1939- D. c. TURNBULL 2,154,878

I APPARATUS FOR ABRASIVELY TREATING METALLIC OBJECTS Original Filed June 17, 1956 14 Sheets-Sheet 2 INVENTOR 0/: W0 6. TUBA/BULL.

ATTIORNEY April 18, 1939. D. c. TURNBULL 2,154,878

APPARATUS FOR ABRASIVELY TREATING METALLIC OBJECTS Original Filed June 17, 1936 14 Sheets-Sheet 3 INVENTOR 0A Wu C. Tl/R/VEl/LL aw Wm ATTO R N EY April 1939. I D. c. TURNBULL 8 APPARATUS FOR A-BRASIVELY TREATING METALLIC OBJECTS Original Filed June 17, 1936 14 Sheets-Sheet 4 INVENTOR. DAVID C. Tu/r/vauu.

. YWWM ATTORN EY April 1 8 .1939. D. c. TURNBULL APPARATUS FOR ABRASIVELY TREATING METALLIC OBJECTS Original Filed June-l7, 1936 14 Sheets-Sheet 5 INVENTCR DAV/p C. TURNBl/LL.

ATTORNEY April 18, 1939. D. c. TURNBULL 2,154,878

APPARATUS FOR ABRASIVELY TREATING METALLIC OBJECTS Original Filed June 17, 1936 14 Sheets-Sheet 6 INVENTOR Dav/a C. 7Z/fiW8l/LL ATTORNEY April 1939- D. c. TU-RNBUILL 2,154,878

APPARATUS FOR ABRASIVELY TREATING METALLIC OBJECTS Original Fi'led- June 1 .7, 1936 1L4 Sheets-Sheet 7 INVENTOR v Oar/0 C. Tun/V6011 dad/4110M? ATTORNEY April 1939- D. c. TURNBULL APPARATUS FOR ABRASIVELY TREATING METALLIC OBJECTS Original Filed June 17, 1936 14 Sheets-Sheet 8 INVENTORI 0A W0 C. 7Z/KP/VBULL. BY Wax ax;

ATTORNEY April 18, 1939- D. c. TURNBULL 2,154,878

APPARATUS FOR ABRASIVELY TREATING METALLIC OBJECTS Original Filed June' 17, 1936 14 Sheets-Sheet 9 INVENTOR BY W4 M ATTORNEY 0A Wu C. Tf/RNBULL.

April 1939- D. c. TURNBULL Y 2,154,878

APPARATUS FOR ABRASIVELY TREATING METALLIC OBJECTS Original Filed June 17, 1936 14 Sheets-Sheet l0 WI m MW INVENTOR DAVID C. TURNBl/LL. D

ATTORNEY April 18, 1939.

D. c. TURNBULL 2,154,878

APPARATUS FOR ABRASIVELY TREATING METALLIC OBJECTS l4 Sheets-Sheet 11 Original Filed June 1'7, 1936 MEI I will i 20/ l Mn? m mil "'{I MIH MW WIN j; v away/0 Efi IPZ BULL. JM M ATTCDRNEY April 1939- D. c. TU RNBULL 2,154,873:

APPARATUS PQR ABRASIVEL-Y TREATING MET'ALLLGY OBJECTS Q riginal Filed; June- ];7,. I936 14 Sheets45lmeetv l2 INVENTOR DAV/D C. TURNBULL.

ATTORNEY April 18, 1939- D. c. TURNBULL 2,154,878

APPARATUS FOR ABRASIVELY TREATING METALLIC OBJECTS Original Filed June 17, 1936 14 Sheets-Sheet l3 INVENTOR BY 'T ATTORNEY 0/! Wu C. Tunwauu.

April 18, 1939. D. c. TURNBULL 2,154,378

APPARATUS FOR ABRASIVELY TREATING METALLIC OBJECTS Original Filed June 17, 1936 14 Sheets-Sheet l4 /Y a INVENTOR 0/? W0 C. TURNBl/LL. BY //J ww ATTORNEY Patented Apr. 18, 1939 UNITED STATES APPARATUS FOR ABRASIVELY TREATING METALLIC OBJECTS David-C. Turnbull, Mishawaka, Ind., assignor to The American Foundry Equipment Company, Mishawaka, Ind., a corporation of Delaware Application June 1'7, 1936, Serial No. 85,645 Renewed November 19, 1938 18 Claims.

This invention relates to apparatus for abrasively treating metallic objects.

In cleaning, polishing, hardening or treating metallic castings and forgings or otherwise modifying the surface characteristics thereof, it is generally desirable to expose all or predetermined portions of the surfaces of the articles uniformly to the action of the stream of abrasive or treating material. Where the articles to be treated are relatively small and rugged they can be exposed conveniently for treatment in a tumbling mill. However, tumbling is not suitable in many instances as, for example, where the articles are large and heavy, or are delicate and brittle, or have substantial projections, or where they have relatively deep cavities or openings. Furthermore, it is often desirable to expose the articles tobe treated to the abrasive stream in a predetermined manner in order to insure 20 complete treatment of certain portions or all of the surface of each article, which cannot be properly effected in tumbling mills as heretofore constructed.

Where relatively large quantities of articles are to be treated, it is also desirable to pass them in succession through the abrasive stream in a more or less continuous feeding operation to eliminate the necessity for shutting down the apparatus, as is necessary in batch operations. Preferably, the operation should be adapted to be carried out partially or completely by automatic apparatus.

According to the present invention, the article to be treated is supported on a suitable conveyor mechanism which imparts to the article a generally screw-like movement, comprising a-rotational or turning movement and a forward or linear movement through the stream of treating particles projected by suitable abrasive-throwing 40 apparatus. The treating stream is projected in a fan-like formation whereby the several portions of the stream strike the article at varying angles along its path of movement, thereby effectively and uniformly treating the various sur-' axis and associated with control means for bring ing the cradle members successively into articlesupporting position and thereafter imparting a turning movement to the article while thus supported. The cradle members are also actuated to advance the articles forwardlythrough the abrasive stream simultaneously with the turning movement. A loading mechanism is provided for depositing the articles to be treated gently on the conveyor in predetermined position. Un- 1 loading or discharge mechanism is provided for receiving the treated articles from the conveyor and removing them therefrom.

One or more abrasive throwing wheels are provided, comprising a plurality of spaced radially arranged blades extending substantially from the periphery of the wheel inwardly short of the axis of rotation to define a central opening. An impeller rotatable with the throwing blades is positioned within the central opening and a normally stationary control member having a discharge outlet therein surrounds the impeller. The discharge outlet in the control member may comprise a series of openings dimensioned to provide substantially even distribution of the abrasive over the work surface.

The present invention provides apparatus by which castings, forgings, or other articles can be quickly and, effectively cleaned, polished, hardened or otherwise treated with a maximum of efficiency and with the assurance that predetermined-surface portions or all of the surfaces, including the surfaces of projections and cavities, are fully and uniformly treated. The apparatus is suitable for continuous and semi-automatic or fully automatic operation.

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

Although thenovel features which are believed to be characteristic of this invention will be particularly pointed out in the claims appended hereto, the inventionitself, as to its objects andadvantages, and the manner in which it may be carried out, may be better understood by referring to the following description taken in connection withthe accompanying drawings forming a part thereof, in which:

Fig. 1 is a side elevational view showing one form of apparatus suitable forcarrying out th present invention;

Fig. 2 is a rear end elevational view of the apparatus shown in Fig. 1;

.Fig. 3 is an enlarged fragmentary side elevain Fig. 1, certain parts of the structure being broken away to expose the interior;

Fig. 4 is an enlarged fragmentary view partly in cross-section, of the driving head at the charging end of the apparatus (right-hand end, as viewed in Fig. 1) and adjacent portions of the structure;

Fig. 5 is an enlarged transverse cross-sectional view taken along line 5-5 of Fig. 4 and showing one control cam for controlling the rocking of the cradle elements;

Fig. 6 is an enlarged fragmentary view, partly in cross-section, of the driving head at the discharge end of the apparatus (left-hand end, as viewed in Fig. 1) and portions of the adjacent structure;

Fig. 7 is an enlarged transverse cross-sectional view taken along line of Fig. 6 and showing the other control cam;

Fig. 8 is an enlarged transverse cross-sectional view through the article-conveying apparatus, this view being taken along line 8-8 of Fig. 3;

Fig. 9 is an enlarged cross-sectional view of the article-conveyor as it appears alongline 9-9 of Fig. 3;

Fig. 10 is a view similar to Fig. 9 illustrating another position of the article on the conveyor;

Fig. 11 is another view similar to Fig. 9 illustrating still another position of the article on the conveyor;

Fig. 12 is an enlarged transverse cross-sectional view taken along line I 2l2 of Fig. 3 and illustrating the structure at the discharge end of the apparatus; V

Fig. 13 is an elevational view of a throwing wheel suitable for use in the apparatus shown in Fig. 1, portions of the structure being broken away to expose the interior;

Fig. 14 is a cross-sectional view taken along line "-44 of Fig. 13;

Fig. 15 is a fragmentary cross-sectional view taken along line l5'l5 of Fig. 13;

Fig. 16 is a perspective view of one of the throwing blades of the wheel shown in Fig. 13;

Fig. 17 is a perspective view of the control member of the wheel shown in Fig. 13; and

Fig. 18 is a diagrammatic view of the wheel of Fig. 13 in position over a work piece and illustrating the direction oi. flight of the abrasive thrown from the wheel.

In the following description and in the claims, various details will be identified by specific names for convenience, but they are intended to be as generic in their application as the art will permit. Like reference characters denote like parts in the several figures of the drawings.

In the drawings accompanying and forming part of this specification, certain specific disclosure of the invention is made for purposes of explanation, but it will be understood that the details may be modified in various respects without departure from the broad aspect of the invention.

The invention may be carried out with any one of a number of types of abrasive projecting devices but I prefer to use an abrasive projector of the centrifugal throwing wheel type provided gether by studs 4 having reduced end portions 5 entering openings 6 in the side plates and secured as by plug welding. The side plate 2 preferably is secured as by bolts 1 to a hub member 8 which is suitably mounted on a shaft 9.

Throwing blades III are disposed between and carried by the

side plates

2 and 3 and extend substantially radially thereof from the periphery to points inwardly short of the center. Each throwing blade I0 may be formed with side flanges ll adapted to seat in grooves I2 in the

side plates

2 and 3 and is secured by a screw l3 extending through the side plate 3 and entering a recess I4 which may be formed in the blade I0.

Disposed in the generally circular space defined by the ends of the throwing blades i0 is an impeller i 5, which may include spaced parallel side plates i6 and I1 and a plurality of radially extending blades l8. The impeller I5 is suitably secured, as by a bolt [9, to a center plate 20 which preferably is supported in the side plate 2, as by screws 2|.

Surrounding the impeller l5 and disposed within the space between the ends of the blades i0 is a control member preferably of generally cylindrical form. The control member 25 has a trough-like extension 26 projecting through an opening 22 in the side plate 3 and is partially closed at the other end by an inwardly turned flange 21. Preferably, the control member 25 is suitably mounted in fixed position as by a member 28 disposed outside of the wheel and is adjustable about its axis for a purpose which will hereinafter appear. 1 The control member 25 is provided with a discharge aperture, desirably in the form of a series of spaced openings, such as openings 0 0 O and 0 extending longitudinally of the control mem-t her a distance approximately equal to the length of the impeller blades [8, and aligned therewith.

-A circular gasket 29 may be provided to prevent abrasive from working in between the side plate 3 and the blades and may be of suitable wearresisting material, and a projecting ring 30 may be provided for protecting the front face of the wheel. Asuitable feeding means, such as a feed pipe 3|, is provided for supplying abrasive to the impeller l5 through opening 23 therein.

The wheel is operated by rotating the shaft 9 which effects rotation of the impeller I5 and the

side plates

2 and 3 carrying the throwing blades l0. Abrasive is fed to the impeller i5 through the feed pipe 3i and the impeller i5 hurls the abrasive through the discharge openings 0 0 O and O and the abrasive is deposited on the throwing blades II) as they pass the several openings. The abrasive is carried along the leading surface of each throwing blade ill by centrifugal force and is projected from the throwing blades l0 adjacent the periphery by combined centrifugal and rotary force, along a path a until it impinges against the surface of the work piece 10. The abrasive is thrownfrom the blades I0 and spreads out fanwise to form a stream which is approximately equal to the width of the throwing blades so that the composite portions of the stream impinge against the work piece w at different angles. Thus, when a substantially flat work piece is positioned adjacent the wheel in a manner similar to that shown in Fig. 18, a substantially elongated rectangular impingement pattern of substantially uniform density is produced.

Although a single discharge opening may be provided in the control member 25, preferably a plurality of openingssuch as the openings 0", O and O are provided, and the openings may be of successively increasing length in the direction of rotation of the wheel. Thus, the abrasive is projected from the wheel in a series of adjacent streams a a a and a corresponding to the openings 0 O, O and 0 respectively.

A fixed relationship exists between the clockdial position of the discharge openings 0 O O and O of the control member 25 and the point of .discharge of the abrasive from the throwing blades I0. By adjusting the position of the discharge openings 0 O 0 andO, the direction of the abrasive thrown by the wheel may be regulated and controlled. The provision of a plurality of openings which increase progressively in area in the direction of rotation of the wheel results in a substantially uniform density of abrasive in any transverse cross-section of the abrasive stream and thus the substantially uniform impingement of the work piece is produced.

Referring now to Fig. l, the apparatus comprises a base support 49 mounting a housing 50 which is divided by partition members and 52 into a loading chamber 53, a treating chamber 54 and an unloading chamber 55. A conveyor 56 extends substantially throughout the housing and suitably shaped

openings

51 and 58 are provided in partitions 5I and 52 for accommodating the conveyor 56.

Mounted on the top Wall of the housing 50 is a plurality of abrasive projectors B and C which, by way of example, may be of the type hereinbefore described. The projector B is mounted adjacent an opening 60 in the top Wall of the housing and may extend partially therethrough so as to project an abrasive stream 1) into the treating chamber 54. The projector B is mounted on a shaft 6| (Figs. 2 and 9) journalled in bearings 62 and carrying a pulley 63. A belt 66 is trained over the pulley 63 and also over a pulley 65 connected to the drive shaft of a motor 64 for driving the projector B. The projector B may be enclosed in a suitable housing 68 which may be hinged at 69 to the housing 50 and latched in position by a latch I0.

A second projector C (Fig. 3) may be provided for throwing an abrasive stream 0 and may be constructed similar to the projector B and driven in a similar manner. However, preferably the projector C is mounted to rotate in a reverse direction with respect to the projector B so that the abrasive stream 0 is directed oppositely to the abrasive stream b.

The projectors B and C (Fig. 1) are supplied with an abrasive material, such as shot, steel grit, or the like, from a hopper 15 from which extends a conduit 16 feeding a. hopper 11. Branch conduits I8 extending from the hopper ll lead to the projectors B and C respectively. Each conduit I8 supplies a feed-pipe 19 supported on a bracket 80, which conducts the abrasive into the wheel. A control valve BI is provided in each conduit I8 for controlling the supply of abrasive material.

Disposed below the housing 50 (Figs. 1 and 2) is a hopper 85 which may be disposed in a suitable pit 86. The hopper 85 is adapted to collect abrasive which has been projected into the chamber 54. The abrasive is withdrawn from the hopper 85 by a screw conveyor 81 communicating with a second conveyor 68 which conveys the abrasive to an elevator 89. A motor 90 is connected by a chain drive 9| to the conveyor 88 and the latter is connected by a chain drive 92 to the conveyor 61. A motor 93 may be'provided for driving the elevator to elevate the abrasive from the pit 86 to the cleaner 15 from whence it flows by gravity through the conduit 16 to the hopper I1 and is again thrown by the projectors.

Referring'to Fig. 8, the housing 50 is provided with a loading opening I00 for permitting access to the loading chamber 53. Mounted in position to enter the opening I00 is a loading frame IOI comprising a plurality of frame members I02 having at their lower ends sector plates I03 formed with arcuate edges I20 adapted to rock on a shelf HI and with upright edges I04 adapted, when in one position, to lie against a vertical wall of the housing 50. Extending between the sector plates I03 is a shaft I05 carrying rollers I06 adapted to ride along the curved edges I01 of a plurality of spaced guide plates I08 mounted on a bracket I09 within the housing 50. i

The frame members I02 carry at their upper ends plates IIO connected by shafts III and H2, which extend beyond the plates H0 and carry side plates I I3. The shaft I I4 is supported by the outer plates H3 and serves as a handle for the loading frame IN. A rack H5 is carried by the upper ends of the frame members I02 and comprises a plurality of spaced bars II6 having adjacent inner end lugs III. Webs I I8 extend from the frame members I02 and support the bars I I6. The lower shaft II2 extends beyond the outer plates H3 and is adapted to strike against stop brackets I I9 secured within the housing.

For the purposes of illustration, the work pieces or articles treated are represented by cylinder blocks M; however, it will be understood that the invention is not limited to the treatment of such articles but is adapted to treat any one of a large number of articles of various shapes and sizes; furthermore, articles of various shapes and sizes can be treated successively in the same apparatus.

The article to be cleaned, such as a block M, is deposited on the rack H5 and the frame IN is tilted inwardly through the opening I00. The frame IOI swings about a moving pivot provided by the arcuate edge I20 of the sections I03 rolling on the shelf I2I and the rollers I06 travelling along the guiding edge I01 until the shaft II2 strikes against the stops I9, in which position the block M is in position to be picked up by the conveyor 56 in a manner which will hereinafter be described.

Referring now to Figs. 1 and 3, the conveyor 56 comprises driving heads I99, 200 mounted beyond the ends of the housing 50 and a plurality of spaced, and generally parallel, elongated cradles 20I extending between and carried by the driving heads I99 and 200.

Each cradle 20I (see Figs. 3 and 8) preferably comprises a shaft i90 carrying a plurality of longitudinally spaced forks I89, each including an arm I9I and arm I92 arranged substantially at right angles and secured to the shaft as by bolts I95 extending through an angle plate I96.

The driving heads I99, 200 are substantially identical in construction, hence only one of these will be described in detail. Referring to Fig. 1,

' the driving head 200 is rotatably mounted on a stub shaft I98 supported in

frames

202 and 203 mounted on the support 49. Each frame 203 (see Figs. 4 and 6) may comprise an angle 204 secured as by rivets to a bracket 205 and a plu rality of frame plates 206 connected by a bolt v cured to a flange 2I4 of a bearing sleeve 2I5 to which is secured a driving sprocket 2I6. A bolt 2" may extend through the plate 2I I, flange 2, and driving sprocket 2 l6 for securing these members together. The bearing sleeve 2 I5 is mounted on the bearing member 208 and a bushing 2I9 is interposed therebetween and thrust washers 220 may be interposed between the ends of the bearing sleeve 2I5 and the bearing

members

208 and 206, respectively.

The cylindrical shell 2I2 may be provided with one or more openings 22I, closed by a removable cover plate 222, and the end plate 2 may have one or more openings closed by removable cover plates 224, thereby permitting access to the interior of the driving head 200 after it has been assembled.

The end plate 2I0 is provided with a central opening 230 in which is seated a main bearing 23| having a recess which carries a roller bearing 234. Packing 235, a sealing ring 236 and a sealing ring 231 may be provided for sealing the hear-- ing 23I. The bearing 23I may be secured to a plate 238 which, in turn, is secured to a cover plate 239 adapted to close an opening 240 in the end of the housing wall 24I. Closure rings 242 and 243 may extend over the marginal portion of the plate 239 further to seal the opening 240.,

Each cradle shaft I90 extends through an opening 246 in the end plate 2 I 0 and is journalled therein by a self-aligning bearing 241. The bearing 241 includes a pair of bearing plates 248 secured to th end plate 2I0 and defining a hearing seat 249 having bowed side walls. A hearing sleeve 250 having bulged side wall portions is seated in the bearing seat 249 and a bushing 252 is received in the sleeve. An end ring 254 and cover plate 255 are provided and a cover sleeve 256 is telescoped over the inner end of the bearing sleeve 250.

Slidable in the bushing 252 is a sleeve portion 251 of a driving member 258 which receives a reduced end 259 of the shaft I90. The reduced end 259 is connected to the driving member 258 by a key 260.

The cover plate 239- is formed with an opening 262 to accommodate the reduced shaft end 259 and the sleeve portion 251 of the driving member 258. The shaft I90. has a shoulder 263, and a collar 264 and a ring 265 are interposed in abutting relation between the shoulder 263 and the end of the sleeve portion 251. carries asleeve 266 which telescopes about the cover sleeve 256 and slides within a flanged cover sleeve 261 carried by the plate 239 upstanding about the opening 262,

Each of the shafts I90 is supported in a manner similar to that just described and each opening 240 is sealed in a similar manner. Each shaft I90 is slidable longitudinally in its bearing sleeve 252 and carries with it the driving member 258, the collar 264 and ring' -265 and the sealing sleeve 266. Thus, considerable longitudinal movement of the shaft I90 is possible and the sealing arrangement effectively prevents any abrasive from The ring 265 passing through the opening 240 in the housing wall 24I.

Integral with and extending laterally from the outer end of the driving member 258 are control crank arms 210 and 21I. The crank arm 21I is provided at its end with a stud bolt 214 which is prevented from rotating by a key 21.5 and is secured by a nut 216. Rotatably carried by the bolt 214 and retained by a head 211 thereof is a guide roller 219. A similar guide roller 218 is carried in a similar manner by the arm 210.

Mounted in position to cooperate with the guide rollers 218 and 219 of the crank arms is a control cam 28I fixedly secured to the bearing block 208. The control cam 28I comprises a circular plate 282 and a cylindrical rim 283 secured together and serving as a supporting frame. The plate 282 is seated against a shoulder 284 in the bearing block 208 and is secured to a flange 285 by suitable means, such as bolts 281. 7

Referring now to Fig. 7, the plate 28I carries a plurality of flange members which cooperate .with the rim member 283 in defining a plurality of cam track portions. Flange members 300 and 30I provide a track 302 and flange member 303 defines with flange member 30I a track 304. Flange member 305 defines with

members

306 and 308 tracks 301 and 309 respectively. Flange members 3I0 and 3H define a cam track 3I2. Elongated flange members 3I3 and 3I4 define an elongated track 3I5. If desired, for convenience of manufacture the flange members 3I3 and 3I4 may be constituted by a plurality of members.

It will be seen that as the shafts I90 are rotated about their common axis and travel along the circular path indicated by the broken line 22, the roller 218 of each crank 213 is guided by the tracks 302, 309 and 3I2 along a path indicated by the broken line at. During this movement the roller 219 is guided by cam tracks 304, 301 and 3I5 along a path indicated by the broken line g. It will be seen that each crank is at all times positively actuated by the various cam track portions in such a manner as to rock the shaft I90 through an angle of somewhat more than 90 in the course of one trip around the path 11. Obviously this angle may be varied considerably by suitable formation of the cam tracks.

An inclined cam plate defining a riser cam 322 is secured to the frame plate 282 and has one end 323 terminating in the cam track 3I5 and the other end 324 terminating adjacent the end of the cam track 3I5. The plate 322 is formed with an upwardly inclined rise from the end 323 toward the end 324. Thus when each roller 219 is guided along the track 3I5 the head 211 rides onto the riser cam 322 and, as the head advances along the riser cam 322, the shaft I90 is urged longitudinally (to the right, as viewed in Figs. 3 and 4).

Referring now to Fig. 4, the driving head I99 at the charging end of the apparatus is constructed and supported in a manner similar to the driving head 200. Disposed in the driving head I99 at the charging end of the apparatus is a control cam 280 constructed and fixedly supported in a manner 28I.

Referring now to Fig. 5, the cam 280 includes a. plate 282 and rim 283 and a plurality of flange members secured to the plate 282. Flange memgenerally similar to the cam bers 400 and 40I define a track 402 and flange members 40I and 403 define a track 404.

Flange members

405 and 406 define a track 401 and

flange members

405 and 408 define a track 409.

Flange members and4lI define a track 2. A flange member 4I3 including a plurality of members and flange member 4I4 also including a plurality of members, define an elongated track 4I5. A riser cam 422 is disposed with one end 423 projecting into the track 401 and the other end 424 projecting into the track 5, and is formed with an upwardly inclined rise from the leading end 423 to the departing end 424. This cam operates to urge each shaft I90 to the left (as viewed in Figs. 3 and 6.)

It will be seen that the cam tracks of the cams 280 and 28I are complementary and that the cams act similarly upon the crank arms 210, 21I at the two ends of the shafts, thereby positively controlling the rocking of the shafts I90 as they are carried about their common axis. During the movement of each shaft through its uppermost position, it is simultaneously moved toward the discharge end of theapparatus and during another portion of its travel along the path 11, it is moved toward the charging end.

Referring now to Figs. 3 and 12, the apparatus is provided with suitable discharge apparatus for receiving the blocks M from the conveyor and removing them from the housing after they have been treated. The portion 450 of each shaft I90 which projects into the discharge chamber 55 is formed cylindrically and a hollow cylindrical drum 45I surrounds and is supported by the cylindrical portions 450. The drum 45I is formed with a flared or bell-mounted end 452 adapted to bear against a bracket 454 to position the drum 45I and to shield the adjacent mechanism.

The end of the drum 45I which is adjacent the cradle members may be suitably drawn out or otherwise formed to provide a plurality of tapered extensions 453 extending between each pair of adjacent shafts I90 to assist the block M in riding onto the drum 45I as the block is discharged from the conveyor, and to connect the drum 45I to the shaft I90 for actuation thereby. Secured to the end wall of the housing 50 is a deflector 460 which prevents the block M from falling off the drum 45I in the wrong direction.

Formed in the housing wall adjacent the discharge drum 45I is a discharge opening 465. A discharge chute 466 extends through the opening 465 and is suitably shaped to receive the block M from the drum 45I and permit it to slide out through the discharge opening 465 and deposit it onto a suitable cushion 469 formed of suitable cushioning material, such as sponge rubber. The discharge opening 465 may be closed by one or more flexible curtains 461 suspended from a bracket 468. w

The conveyor 56 is driven from a suitable source of power such as an electric motor 410 (Figs. land 2) which drives a speed reducer 412 which in turn actuates' a chain 413 operatively connected to a drive shaft 414 journaled in bearings 415 and 416. The shaft 414 actuates a chain 411 at each end of the apparatus, and each chain 411 is trained over the corresponding driving sprocket 2I6. When the motor 410 is energized it rotates the shaft 414 which in turn effects rotation simultaneously of thedriving sprockets 2I6 at the ends of the apparatus and the corresponding driving heads I99 and 200.

Operation The operation of the apparatus is as follows: A block M to be treated is deposited on the rack H5 and the loading frame IN is pushed into the loading chamber 53 until the shaft II2 strikes the I tion.

of the control cams 280 and 28I, as previously described, and hence the cradle 20I carrying the block M turns the block as it moves from left to right (as viewed in Fig. 8). Preferably, the block M is turned about an axis extending generally in the direction of forward movement of the article and approximately passing throug or near the block.

As the cradle I carrying the block M is rotated further in a clockwise direction, it is rocked to a position wherein the arms I92 are approximately horizontal and the arms I9I of the next succeeding cradle 20I are also approximately horizontal and approximately at the same level. Upon further rotation of the conveyor, the arms I9I of the succeeding cradle 20I engage the block M and lift it from the arms I92 of the first cradle 20I. It will be noted that as each cradle 20I moves into a position to receive the block M, the arms I9I are displaced longitudinally from the arms I92 of the cradle which carries the block and thus can engage the block M prior to disengagement of the arms I92 of the preceding cradle.

The cradle 20I which receives the block M continues to rotate about the common axis of the cradles 20I and simultaneously to rock about the axis of its shaft I90. The cradle 20I turns the block M in a counter-clockwise direction (as viewed in Figs. 8 to 11) and simultaneously carries the block in a clockwise direction. Thus, the net effect is a rotary movement of the block within a limited space and the movement approximates a rotation of the block about an axis passing through the block and parallel to the direction of forward movement.

During the portion of the movement of the cradle 20I wherein it carries the block M the riser cam 422 (Fig. 5) is effective to slide the shaft I90 longitudinally toward the discharge end (lefthand end, as viewed in Fig. 3) and thereby advances the block M. Thus the block M is engaged by certain forks of each cradle 20I in a position in advance of the position in which it was received by the preceding cradle. This results in a forward movement of the block M along the conveyor 56, simultaneously with the turning movement.

As the block M is advanced by the conveyor 56, it enters the abrasive stream 1) and the particles impinge against the block from an angle determined by the shapes of the streams. In the present example, the abrasive at the entering end approaches from a substantially vertical direc- As the block is advanced through the stream 1) it is turned about and the various portions of the surface successively enter and pass through the stream laterally. If the block is relatively narrow and the stream is relatively wide it will remain substantially in the stream during its entire travel. However, generally the stream will be somewhat narrower than the block and hence the various portions ofthe block pass into and out of the stream a plurality of times.

The block is further advanced in the stream and passes through portions of the stream having varying angles of impingement, the range of which may vary throughout a considerable angle, which may considerably exceed 90. Thus both front and rear wall surfaces as well as projections and cavities are struck by the particles. Preferably, the abrasive streams b and c are arranged oppositely so that the total angle approaches 180.

When the block M is advanced to the end of the conveyor 56, it is moved onto the dischargedrum 5| and is deposited thereby onto the dis-- charge chute 466 and slides out of the housing andonto the cushion 459. The deflector 460 prevents the block M from dropping off the drum on the opposite side from the discharge chute 466.

From the foregoing, it will be seen that the present invention provides apparatus for conveniently and satisfactorily cleaning, polishing, hardening, or otherwise modifying the surface characteristics of numerous types of castings, forgings, or other metallic objects. This apparatus is admirably adapted for the treatment of articles which enlarge and heavy or which have are subjected to impingement by abrasive projected from varying angles.

' Each article can be fully treated on all sides in the course of a single trip through the apparatus and the operation is a continuous one, thus maximum eillciency can be realized. The apparatus is adapted for automatic and production line operation, suitable apparatus being provided for supplying articles to the present apparatus and conveying them therefrom. The apparatus is positive and reliable in operation and requires little attention on the part of an operator.

The apparatus is capable of being constructed in various sizes and can be designed to operate upon relatively large and heavy articles.- The apparatus is easy to operate and can be readily disassembled for the purpose of repairing or replacing parts. substantially all of the wearing parts, with the exception ofthe cradles, are completely and effectively screened from the.destructive action of the flying abrasive and hence are not subject to rapid wearing. The arm portions of the cradles may be easily replaced when worn and, if desired, the cradle shafts may be made in sections to facilitate removal of the squared portions when they become worn out.

It is to. be understood that where the expression "abrasive or abrasive particles is used herein, it is not limited to a material consisting of particles which are inherently abrasive. The material may consist of any one of a number of materials of various characteristics as, for example, hard steel shot, cracked steel grits, quartz sand, or other material suitable for cleaning, polishing, hardening, or otherwise treating the surfaces of the work piece. The particles may have various sizes and characteristics depending upon the result desired and may range from relatively large to relatively small particles and from relatively smooth particles, such as steel balls, to exceedingly sharp and abrasive particles, such as clean, sharp sand.

Various characteristics may be imparted to the surface of the work piece by employing various abrasive materials. For example, where it is desired to harden the surface of the article treated, a material consisting of hard, smooth and sizeable particles, such as hard, round and smooth steel shot, may be employed. The smooth shot does not scratch or cut the surface of the work piece but exerts a peening or working action thereon and greatly increases the surface hardness.

Where it is desired to impart a stippled or roughened surface characteristic, relatively small, sharp particles, such as cracked steel grits or sharp, clean quartz sand, maybe employed, and this material cuts pits or depressions in the surface of the work piece to provide the desired 1 roughened surface.

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. Apparatus for abrasively treating metal articles including, means for projecting a stream of abrasive particles, and conveyor means for transporting an article to be treated through said stream, said conveyor means including a plurality of cradle members, means mounting said cradle members for rotation about a common axis, means for actuating said cradle members to suecessively engage said article, means actuating one or more of said cradle members to advance said article in a generally horizontal direction through the stream, and means actuating one or more of said cradle elements to turn said article in the stream.

2. Apparatus for abrasively treating metal articles including, means for projecting a stream of abrasive particles, and conveyor means for transporting an article to be treated through said stream, said conveyor means including a pair of end frames, a plurality of cradle elements extending between and carried by said end frames, means for rotating said end frames to move said cradle elements about a common axis, and cam means adjacent said end frames for individually rocking certain of said cradle elements and for oscillating certain of said cradle elements longi-, tudinally.

3. Apparatus for abrasively treating metal articles including, meansfor projecting a stream of treatingparticles, and conveyor means for transporting an article to be treated in a generally horizontal direction through said stream and turning said article in the stream, said conveyor means including a plurality of cradle elements each having a plurality of; laterally extending 'ment to receive and remove said article from the last-named cradle element during rotation thereof.

4. Apparatus for abrasively treating metalarticles including, means for projecting a stream of abrasive particles, and conveyor means for